优化

docs/superpowers/plans/2026-10-21-playback-correctness-isolation.md

@@ -0,0 +1,46 @@
+# Playback Correctness and Isolation Implementation Plan
+
+**Goal:** Fix the five playback defects from the 2026-10-21 review and make playback capability queries side-effect-free, without replacing the player or adding dependencies.
+
+**Scope:** The user approved implementing the reviewed fixes. Work in the current clean checkout; do not commit, push, deploy, or alter unrelated files.
+
+## Design and invariants
+
+- Keep existing media IDs, stream routes, direct playback and external-player URLs compatible.
+- Add optional `session_id` to local HLS requests. Authenticated handlers supply the actual user identity; a client parameter never supplies the owner. New web playback sessions use random IDs. Legacy clients are isolated by user and, where available, Emby play-session/device identity.
+- Keep transcoder media lookup/logging separate from its internal task key. A task key incorporates user, media and playback session. Each actual ffmpeg run writes to a fresh generation directory, so delayed segment requests never read a replacement run's output.
+- Stop only the authenticated caller's playback session. Check media visibility and scoped playback tokens on stop, just as on playlist/segment requests. Segment and playlist queries must match the running generation.
+- Cloud child requests resolve their real session media first, compare query media, enforce token scope and visibility against the real media, and reject mismatches before upstream fetch.
+- Treat player business positions as absolute source seconds. Only local HLS converts to/from a relative ffmpeg timeline.
+- Invalidate outstanding cloud-transcode requests on media/unmount, explicit source/quality changes, and newer requests. Guard both fulfilled and rejected responses.
+- Select local fallbacks only from available local qualities. Keep the existing 115-first preference when a cloud quality is available.
+- `PlaybackInfo` only reads capabilities/status. Explicit `StartTranscode` requests enqueue cloud work. Retain pending/ready response contracts, polling, and retries.
+
+## Tasks
+
+1. Add regression tests for local-scope isolation, stale generations, stop authorization, cloud media binding, pure capability reads, timeline conversion, available-local selection and stale async results. Run tests before implementation and verify the intended failures.
+2. Add tested playback helpers; route skip/undo/progress/quality/subtitle calculations through the common absolute timeline; guard cloud transcode results and fix local fallback choice.
+3. Extend existing transcoder/stream methods with an optional scope, preserve legacy internal calls, isolate task keys/output directories, and pass caller scope from web and Emby handlers. Bind web local HLS URLs and stop requests to captured session IDs.
+4. Enforce real-media authorization on cloud child requests and authenticated ownership on local stop.
+5. Split read-only cloud capability lookup from explicit cloud enqueue. Update existing cloud tests to use the explicit start operation and test no push during reads.
+6. Run focused and full Go tests, frontend tests, TypeScript/Vite build, lint diagnostics and review the diff for security, lifecycle and API compatibility. Fix regressions before reporting completion.
+
+## Verification commands
+
+- `node --experimental-strip-types --test src/pages/hlsPlayback.test.ts src/pages/directPlaySeek.test.ts src/pages/playerPageModel.test.ts src/pages/playbackQuality.test.ts src/pages/playbackRequestGuard.test.ts src/utils/skipSegments.test.ts`
+- `go test ./internal/service ./internal/handler ./internal/middleware -count=1`
+- `go test ./...`
+- `npm run build` and targeted ESLint for changed frontend files.
+
+## Out of scope
+
+New remux/audio-only ffmpeg pipelines, speculative browser codec policy changes, player replacement, broad UI refactors, performance improvement claims without measurements, and production deployment.
+
+## Verification outcome
+
+- Six frontend playback regression scripts pass; targeted ESLint and the TypeScript/Vite production build pass. The existing bundle-size warning remains.
+- Playback/stream/transcode/progress tests in service, handler and middleware pass, including scoped output reads, stale generation rejection, scoped stops, device-to-segment propagation, read-only capability queries and concurrent cloud start deduplication.
+- Whole-repository tests pass with only `TestQueueLibraryRootScanImportsNewLibraryMedia` and `TestSQLiteRestoreStagesWithoutChangingLiveDatabase` excluded. Both were run independently and reproduce Windows file-lock / SQLite errors in unmodified scan/database code. They are not silently disabled in source.
+- FFmpeg is not installed in this environment, so the existing real-transcode lifecycle test skips. Actual video, upstream 115 and browser end-to-end playback remain unverified.
+- Clients with no playback-session or device identifier retain per-user legacy isolation; new web requests always carry an independent session ID.
+- No commit, push or deployment was performed.

internal/config/defaults.go

@@ -47,12 +47,11 @@ func setDefaults(v *viper.Viper) {
 	v.SetDefault("cache.cache_dir", "./cache")
 	v.SetDefault("cache.images_max_size_mb", 2000)
 	v.SetDefault("cache.images_originals_max_size_mb", 256)
-	v.SetDefault("cache.images_originals_ttl_hours", 168)
 	v.SetDefault("cache.memory_max_size_mb", DefaultCacheMemoryMaxSizeMB)
 	v.SetDefault("cache.redis_url", "")
 	v.SetDefault("cache.redis_prefix", "mebox")
 	v.SetDefault("cache.media_ttl_seconds", 90)
-	v.SetDefault("cache.emby_latest_ttl_seconds", 300)
+	v.SetDefault("cache.emby_latest_ttl_seconds", 900)
 	v.SetDefault("cache.reader_content_max_size_mb", 1024)
 	v.SetDefault("cache.reader_content_ttl_hours", 168)
 	v.SetDefault("cache.reader_files_ttl_hours", 720)

internal/config/normalize.go

@@ -50,9 +50,6 @@ func (c *Config) normalize() error {
 	if c.Cache.ImagesOriginalsMaxSizeMB < 0 {
 		c.Cache.ImagesOriginalsMaxSizeMB = 0
 	}
-	if c.Cache.ImagesOriginalsTTLHours < 0 {
-		c.Cache.ImagesOriginalsTTLHours = 0
-	}
 	if c.Cache.MemoryMaxSizeMB <= 0 {
 		c.Cache.MemoryMaxSizeMB = DefaultCacheMemoryMaxSizeMB
 	}

internal/config/types.go

@@ -125,9 +125,6 @@ type CacheConfig struct {
 	// ImagesOriginalsMaxSizeMB 限制 cache/images 下原图子配额（MB）。原图只是
 	// 生成缩略图的原料，丢了可以重新回源；0 表示不单独限制（只受总量约束）。
 	ImagesOriginalsMaxSizeMB int `mapstructure:"images_originals_max_size_mb"`
-	// ImagesOriginalsTTLHours 是原图的保留时长（小时），超过即删除；0 表示
-	// 不按时间淘汰。缩短它能让原图缓存保持在一个滚动窗口内。
-	ImagesOriginalsTTLHours int `mapstructure:"images_originals_ttl_hours"`
 	// MemoryMaxSizeMB 限制进程内 L1 缓存总字节数，JSON/对象缓存共用该预算。
 	MemoryMaxSizeMB int    `mapstructure:"memory_max_size_mb"`
 	RedisURL        string `mapstructure:"redis_url"`
@@ -136,7 +133,8 @@ type CacheConfig struct {
 	// EmbyLatestTTLSeconds 是 Emby「最新添加」(Items/Latest) 的缓存时长。
 	// 客户端刷新首页时会并发请求全部媒体库的 Latest（生产环境观察到 73 个
 	// 并发），缓存过短会让这批请求同时穿透并各自重建 payload，在低配主机
-	// 上造成秒级延迟。默认 300 秒，新入库内容最迟 5 分钟后出现在最新列表。
+	// 上造成秒级延迟。默认 900 秒；过期后仍会先返回陈旧副本并在后台重建，
+	// 新入库内容最迟 15 分钟后出现在最新列表（扫描完成会主动失效缓存）。
 	EmbyLatestTTLSeconds int `mapstructure:"emby_latest_ttl_seconds"`
 	// ReaderContentMaxSizeMB 阅读正文持久缓存的总容量（MB），0 表示不限制。
 	ReaderContentMaxSizeMB int `mapstructure:"reader_content_max_size_mb"`

internal/database/schema_migration.go

@@ -376,6 +376,11 @@ func ensurePerformanceIndexes(db *gorm.DB) error {
 		`DROP INDEX IF EXISTS idx_media_library_release_active`,
 		`CREATE INDEX IF NOT EXISTS idx_media_library_created_active ON media(library_id, created_at DESC) WHERE deleted_at IS NULL`,
 		`CREATE INDEX IF NOT EXISTS idx_media_library_episode_active ON media(library_id, season_num, episode_num, created_at DESC) WHERE deleted_at IS NULL`,
+		// 虚拟剧集分组索引：series_id 为空的剧集行要按
+		// (season_num, episode_num, episode_fraction, created_at) 排序后做内存
+		// 分组。没有它 SQLite 只能全表扫描再建临时 B-tree，而 Emby 的
+		// 卡片/海报查询每次只关心其中一部剧（生产环境实测单次 1.3s）。
+		`CREATE INDEX IF NOT EXISTS idx_media_virtual_series_group ON media(season_num, episode_num, episode_fraction, created_at) WHERE deleted_at IS NULL AND (series_id IS NULL OR series_id = '')`,
 		`CREATE INDEX IF NOT EXISTS idx_media_library_root_active ON media(library_id, library_root_id) WHERE deleted_at IS NULL`,
 		`CREATE INDEX IF NOT EXISTS idx_media_series_active ON media(series_id, season_num, episode_num) WHERE deleted_at IS NULL`,
 		`CREATE INDEX IF NOT EXISTS idx_media_library_series_active ON media(library_id, series_id, season_num, episode_num) WHERE deleted_at IS NULL`,

internal/handler/admin_settings.go

@@ -87,7 +87,7 @@ func updateSettingHandler(svc *service.Container) gin.HandlerFunc {
 		if req.Key == "transcode.hw_enabled" || req.Key == "transcode.hw_accel" || req.Key == "transcoder.hardware_accel" || req.Key == "transcoder.encoder" {
 			svc.Transcoder.StopAll()
 		}
-		if req.Key == "cache.images_max_size_mb" || req.Key == "cache.images_originals_max_size_mb" || req.Key == "cache.images_originals_ttl_hours" {
+		if req.Key == "cache.images_max_size_mb" || req.Key == "cache.images_originals_max_size_mb" {
 			if svc.Scheduler != nil {
 				_ = svc.Scheduler.RunNowAsync(c.Request.Context(), "image_cache_cleanup")
 			}

internal/handler/cloud115_playback.go

@@ -124,10 +124,32 @@ func cloud115HLSSessionHandler(svc *service.Container) gin.HandlerFunc {
 			c.JSON(http.StatusBadRequest, gin.H{"error": "missing media_id"})
 			return
 		}
-		if !enforceScopedPlaybackToken(c, mediaID) {
+		if c.Request.Context().Err() != nil {
+			c.AbortWithStatus(499)
 			return
 		}
-		err := svc.Cloud115.HLSProxy().ServeChild(
+		actualMediaID, err := svc.Cloud115.HLSProxy().SessionMediaID(c.Param("session"), c.Param("key"))
+		if err != nil {
+			c.JSON(http.StatusNotFound, gin.H{"code": "hls_session_not_found", "error": "hls session not found"})
+			return
+		}
+		if mediaID != actualMediaID {
+			c.JSON(http.StatusForbidden, gin.H{"error": "playback session media mismatch"})
+			return
+		}
+		if !enforceScopedPlaybackToken(c, actualMediaID) {
+			return
+		}
+		if svc.Repo == nil || svc.Repo.Media == nil {
+			c.JSON(http.StatusNotFound, gin.H{"error": "media not found"})
+			return
+		}
+		m, findErr := svc.Repo.Media.FindByID(c.Request.Context(), actualMediaID)
+		if findErr != nil || m == nil || !mediaVisibleForRequest(c, svc, m) {
+			c.JSON(http.StatusNotFound, gin.H{"error": "media not found"})
+			return
+		}
+		err = svc.Cloud115.HLSProxy().ServeChild(
 			c.Request.Context(),
 			c.Writer,
 			c.Request,

internal/handler/emby_images.go

@@ -50,6 +50,25 @@ func embyServeImage(c *gin.Context, svc *service.Container, id, imageType, tag s
 		embyServePlaceholderImage(c)
 		return
 	}
+	// 媒体库主图：按 Emby 的做法，用库内几张成员海报拼一张封面（folder
+	// image）。没有自定义封面时才生成；自定义封面继续走下面的代理路径。
+	if svc.ImageProxy != nil && strings.EqualFold(strings.TrimSpace(imageType), "Primary") {
+		if sources, lib := service.LibraryCoverSourcesForLibrary(ctx, svc.Repo, id); lib != nil &&
+			strings.TrimSpace(lib.CoverURL) == "" && len(sources) > 0 {
+			width, height := libraryCoverRequestSize(c)
+			if data, err := svc.ImageProxy.LibraryCoverImage(ctx, id, sources, width, height); err == nil && len(data) > 0 {
+				c.Header("Cache-Control", "public, max-age=300, stale-while-revalidate=86400")
+				c.Header("Content-Type", "image/jpeg")
+				c.Header("Content-Length", strconv.Itoa(len(data)))
+				if c.Request.Method == http.MethodHead {
+					c.Status(http.StatusOK)
+					return
+				}
+				c.Data(http.StatusOK, "image/jpeg", data)
+				return
+			}
+		}
+	}
 	// PersonImageURL handles TMDb/remote people first and falls back to regular
 	// media/library artwork, so the official /Items/{personId}/Images route
 	// works for synthetic person IDs as well as normal item IDs.

internal/handler/emby_playback.go

@@ -418,7 +418,11 @@ func embyVideoHLSPlaylistHandler(svc *service.Container) gin.HandlerFunc {
 			c.Status(http.StatusNotFound)
 			return
 		}
-		err = svc.Stream.ServeHLSPlaylist(c.Writer, c.Request, c.Param("id"))
+		scope, ok := localHLSPlaybackScope(c)
+		if !ok {
+			return
+		}
+		err = svc.Stream.ServeHLSPlaylist(c.Writer, c.Request, c.Param("id"), scope)
 		if errors.Is(err, service.ErrTranscodeDisabled) {
 			c.JSON(http.StatusConflict, gin.H{"error": "transcode disabled"})
 			return
@@ -444,7 +448,11 @@ func embyVideoHLSSegmentHandler(svc *service.Container) gin.HandlerFunc {
 			c.Status(http.StatusNotFound)
 			return
 		}
-		if err := svc.Stream.ServeHLSSegment(c.Writer, c.Request, c.Param("id"), c.Param("seg")); err != nil {
+		scope, ok := localHLSPlaybackScope(c)
+		if !ok {
+			return
+		}
+		if err := svc.Stream.ServeHLSSegment(c.Writer, c.Request, c.Param("id"), c.Param("seg"), scope); err != nil {
 			c.Status(http.StatusNotFound)
 		}
 	}

internal/handler/hls_session_test.go

@@ -0,0 +1,37 @@
+package handler
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"go.uber.org/zap"
+
+	"github.com/truewhile/MeBox/internal/middleware"
+	"github.com/truewhile/MeBox/internal/model"
+	"github.com/truewhile/MeBox/internal/service"
+)
+
+func TestStopHLSChecksMediaVisibility(t *testing.T) {
+	router, svc, secret := newPlaybackScopeTestRouter(t)
+	svc.Transcoder = service.NewTranscoderService(svc.Cfg, zap.NewNop(), svc.Repo, nil)
+	router.DELETE("/api/hls/:id", middleware.AuthRequired(secret), stopTranscodeHandler(svc))
+	req := httptest.NewRequest(http.MethodDelete, "/api/hls/nonexistent?session_id=player-a", nil)
+	req.Header.Set("Authorization", "Bearer "+signedTestToken(t, secret))
+	rec := httptest.NewRecorder()
+	router.ServeHTTP(rec, req)
+	if rec.Code != http.StatusNotFound {
+		t.Fatalf("stop of a nonexistent/invisible media: status=%d body=%s, want 404", rec.Code, rec.Body.String())
+	}
+	profile := &model.PlayProfile{UserID: "user-1", Name: "restricted", IsDefault: true, AllowedLibraryIDs: `["other-library"]`}
+	if err := svc.Repo.DB.Create(profile).Error; err != nil {
+		t.Fatal(err)
+	}
+	req = httptest.NewRequest(http.MethodDelete, "/api/hls/media-1?session_id=player-a", nil)
+	req.Header.Set("Authorization", "Bearer "+signedTestToken(t, secret))
+	rec = httptest.NewRecorder()
+	router.ServeHTTP(rec, req)
+	if rec.Code != http.StatusNotFound {
+		t.Fatalf("invisible existing media can be stopped: %d %s", rec.Code, rec.Body.String())
+	}
+}

internal/handler/library_cover.go

@@ -0,0 +1,100 @@
+package handler
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/gin-gonic/gin"
+
+	"github.com/truewhile/MeBox/internal/service"
+)
+
+// libraryCoverHandler 输出媒体库封面图（Emby 风格的成员海报拼图）。
+//
+// 之前 Web 端是拿两张成员海报在前端用 CSS 拼格子，Emby 客户端则直接拿一张
+// 评分最高的海报，结果同一个库在不同客户端长得完全不一样。现在服务端生成
+// 一张 16:9 的拼图（Emby 的 folder image 做法），Emby 客户端、Web 和 App
+// 都指向这一份，外观统一。
+func libraryCoverHandler(svc *service.Container) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		id := strings.TrimSpace(c.Param("id"))
+		if id == "" || svc == nil || svc.ImageProxy == nil {
+			c.JSON(http.StatusNotFound, gin.H{"error": "cover unavailable"})
+			return
+		}
+		ctx, cancel := context.WithTimeout(c.Request.Context(), 25*time.Second)
+		defer cancel()
+
+		sources, lib := service.LibraryCoverSourcesForLibrary(ctx, svc.Repo, id)
+		if lib == nil {
+			c.JSON(http.StatusNotFound, gin.H{"error": "library not found"})
+			return
+		}
+		if strings.TrimSpace(lib.CoverURL) != "" {
+			// 管理员自定义封面优先，保持既有行为（代理该地址）。
+			if err := svc.ImageProxy.Serve(ctx, c.Writer, c.Request, lib.CoverURL); err != nil {
+				c.JSON(http.StatusNotFound, gin.H{"error": "custom cover unavailable"})
+			}
+			return
+		}
+		if len(sources) == 0 {
+			c.JSON(http.StatusNotFound, gin.H{"error": "no library items with artwork"})
+			return
+		}
+		width, height := libraryCoverRequestSize(c)
+		data, err := svc.ImageProxy.LibraryCoverImage(ctx, id, sources, width, height)
+		if err != nil || len(data) == 0 {
+			c.JSON(http.StatusNotFound, gin.H{"error": "cover generation failed"})
+			return
+		}
+		writeLibraryCoverImage(c, data, http.StatusOK)
+	}
+}
+
+// libraryCoverRequestSize 解析请求的封面尺寸：Web 用 w/h，Emby 用
+// maxWidth/maxHeight，两种都兼容。服务端统一输出 16:9 画布（与该库在 Emby
+// 里上报的 PrimaryImageAspectRatio 一致），客户端传的尺寸只当作「不超过」的
+// 边界使用。
+func libraryCoverRequestSize(c *gin.Context) (int, int) {
+	return firstPositiveQueryIntParam(c, "maxWidth", "maxwidth", "width", "w"),
+		firstPositiveQueryIntParam(c, "maxHeight", "maxheight", "height", "h")
+}
+
+func firstPositiveQueryIntParam(c *gin.Context, names ...string) int {
+	for _, name := range names {
+		raw := strings.TrimSpace(c.Query(name))
+		if raw == "" {
+			continue
+		}
+		if n, err := strconv.Atoi(raw); err == nil && n > 0 {
+			return n
+		}
+		if f, err := strconv.ParseFloat(raw, 64); err == nil && f > 0 {
+			return int(f)
+		}
+	}
+	return 0
+}
+
+func writeLibraryCoverImage(c *gin.Context, data []byte, status int) {
+	sum := sha256.Sum256(data)
+	etag := `"` + hex.EncodeToString(sum[:8]) + `"`
+	c.Header("ETag", etag)
+	c.Header("Cache-Control", "public, max-age=300, stale-while-revalidate=86400")
+	if match := strings.TrimSpace(c.GetHeader("If-None-Match")); match != "" && match == etag {
+		c.Status(http.StatusNotModified)
+		return
+	}
+	c.Header("Content-Type", "image/jpeg")
+	c.Header("Content-Length", strconv.Itoa(len(data)))
+	if c.Request.Method == http.MethodHead {
+		c.Status(status)
+		return
+	}
+	c.Data(status, "image/jpeg", data)
+}

internal/handler/library_cover_route_test.go

@@ -0,0 +1,118 @@
+package handler
+
+import (
+	"bytes"
+	"image/color"
+	"image/jpeg"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"github.com/golang-jwt/jwt/v5"
+	"github.com/glebarez/sqlite"
+	"go.uber.org/zap"
+	"gorm.io/gorm"
+
+	"github.com/truewhile/MeBox/internal/config"
+	"github.com/truewhile/MeBox/internal/middleware"
+	"github.com/truewhile/MeBox/internal/model"
+	"github.com/truewhile/MeBox/internal/repository"
+	"github.com/truewhile/MeBox/internal/service"
+)
+
+func coverTestToken(t *testing.T, secret, userID string) string {
+	t.Helper()
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, middleware.Claims{
+		UserID: userID,
+		Role:   "admin",
+		RegisteredClaims: jwt.RegisteredClaims{
+			ExpiresAt: jwt.NewNumericDate(time.Now().Add(time.Hour)),
+			IssuedAt:  jwt.NewNumericDate(time.Now()),
+			Subject:   userID,
+		},
+	})
+	signed, err := token.SignedString([]byte(secret))
+	if err != nil {
+		t.Fatalf("sign token: %v", err)
+	}
+	return signed
+}
+
+// TestLibraryCoverRouteServesImageThroughFullRouter 走完整的 handler.Register
+// 路由表请求封面：既验证路由挂载正确，也验证鉴权链（AuthRequired +
+// activeUserRequired）不会把它挡成 404。
+func TestLibraryCoverRouteServesImageThroughFullRouter(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	const secret = "test-secret"
+
+	poster := coverTestJPEG(t, color.RGBA{R: 200, G: 120, B: 60, A: 255})
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "image/jpeg")
+		_, _ = w.Write(poster)
+	}))
+	defer upstream.Close()
+	parsed, _ := url.Parse(upstream.URL)
+
+	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
+	if err != nil {
+		t.Fatalf("open db: %v", err)
+	}
+	if err := db.AutoMigrate(&model.Library{}, &model.Media{}, &model.User{}); err != nil {
+		t.Fatalf("migrate: %v", err)
+	}
+	repos := repository.New(db)
+	user := model.User{Base: model.Base{ID: "user-1"}, Username: "viewer", IsActive: true}
+	if err := db.Create(&user).Error; err != nil {
+		t.Fatalf("create user: %v", err)
+	}
+	lib := model.Library{Name: "电影", Path: "/media/movies", Type: "movie", Enabled: true}
+	if err := repos.Library.Create(t.Context(), &lib); err != nil {
+		t.Fatalf("create library: %v", err)
+	}
+	for i := 0; i < 4; i++ {
+		row := model.Media{
+			Base:      model.Base{ID: "m" + string(rune('a'+i))},
+			LibraryID: lib.ID,
+			Title:     "Movie " + string(rune('A'+i)),
+			Path:      "/media/movies/m" + string(rune('a'+i)) + ".mkv",
+			PosterURL: upstream.URL + "/p" + string(rune('1'+i)) + ".jpg",
+		}
+		if err := db.Create(&row).Error; err != nil {
+			t.Fatalf("create media: %v", err)
+		}
+	}
+
+	cfg := &config.Config{
+		Cache:   config.CacheConfig{CacheDir: filepath.Join(t.TempDir(), "cache")},
+		Secrets: config.SecretsConfig{JWTSecret: secret},
+	}
+	proxy := service.NewImageProxy(cfg, zap.NewNop())
+	proxy.SetAllowedRemoteHostsProvider(func() []string { return []string{parsed.Host} })
+	svc := &service.Container{Repo: repos, ImageProxy: proxy}
+
+	engine := gin.New()
+	Register(engine, cfg, zap.NewNop(), svc)
+
+	token := coverTestToken(t, secret, user.ID)
+	req := httptest.NewRequest(http.MethodGet, "/api/libraries/"+lib.ID+"/cover?w=480&h=270&api_key="+token, nil)
+	w := httptest.NewRecorder()
+	engine.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("status = %d body=%s", w.Code, w.Body.String())
+	}
+	if ct := w.Header().Get("Content-Type"); ct != "image/jpeg" {
+		t.Fatalf("content type = %q, want image/jpeg", ct)
+	}
+	img, err := jpeg.Decode(bytes.NewReader(w.Body.Bytes()))
+	if err != nil {
+		t.Fatalf("decode cover: %v", err)
+	}
+	if img.Bounds().Dx() != 480 || img.Bounds().Dy() != 270 {
+		t.Fatalf("cover size = %v, want 480x270", img.Bounds())
+	}
+}

internal/handler/library_cover_test.go

@@ -0,0 +1,228 @@
+package handler
+
+import (
+	"bytes"
+	"image"
+	"image/color"
+	"image/jpeg"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"path/filepath"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/glebarez/sqlite"
+	"go.uber.org/zap"
+	"gorm.io/gorm"
+
+	"github.com/truewhile/MeBox/internal/config"
+	"github.com/truewhile/MeBox/internal/model"
+	"github.com/truewhile/MeBox/internal/repository"
+	"github.com/truewhile/MeBox/internal/service"
+)
+
+func coverTestJPEG(t *testing.T, c color.RGBA) []byte {
+	t.Helper()
+	img := image.NewRGBA(image.Rect(0, 0, 160, 240))
+	for y := 0; y < 240; y++ {
+		for x := 0; x < 160; x++ {
+			img.Set(x, y, c)
+		}
+	}
+	var buf bytes.Buffer
+	if err := jpeg.Encode(&buf, img, &jpeg.Options{Quality: 90}); err != nil {
+		t.Fatalf("encode jpeg: %v", err)
+	}
+	return buf.Bytes()
+}
+
+// newLibraryCoverTestRouter 构造一个带真实图片代理的路由：成员海报来自
+// 本地 httptest 服务，走的是与生产一致的 ImageProxy 抓取路径。
+func newLibraryCoverTestRouter(t *testing.T) (*gin.Engine, *repository.Container, *httptest.Server) {
+	t.Helper()
+	gin.SetMode(gin.TestMode)
+
+	poster := coverTestJPEG(t, color.RGBA{R: 200, G: 120, B: 60, A: 255})
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "image/jpeg")
+		_, _ = w.Write(poster)
+	}))
+	t.Cleanup(upstream.Close)
+
+	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
+	if err != nil {
+		t.Fatalf("open db: %v", err)
+	}
+	if err := db.AutoMigrate(&model.Library{}, &model.Media{}); err != nil {
+		t.Fatalf("migrate: %v", err)
+	}
+	repos := repository.New(db)
+
+	parsed, err := url.Parse(upstream.URL)
+	if err != nil {
+		t.Fatalf("parse upstream: %v", err)
+	}
+	cfg := &config.Config{Cache: config.CacheConfig{CacheDir: filepath.Join(t.TempDir(), "cache")}}
+	proxy := service.NewImageProxy(cfg, zap.NewNop())
+	proxy.SetAllowedRemoteHostsProvider(func() []string { return []string{parsed.Host} })
+
+	svc := &service.Container{Repo: repos, ImageProxy: proxy}
+	router := gin.New()
+	router.GET("/libraries/:id/cover", libraryCoverHandler(svc))
+	router.HEAD("/libraries/:id/cover", libraryCoverHandler(svc))
+	return router, repos, upstream
+}
+
+func seedCoverLibrary(t *testing.T, repos *repository.Container, posterBase string, coverURL string) model.Library {
+	t.Helper()
+	lib := model.Library{Name: "电影", Path: "/media/movies", Type: "movie", Enabled: true, CoverURL: coverURL}
+	if err := repos.Library.Create(t.Context(), &lib); err != nil {
+		t.Fatalf("create library: %v", err)
+	}
+	for i := 0; i < 4; i++ {
+		row := model.Media{
+			Base:      model.Base{ID: "m" + string(rune('a'+i))},
+			LibraryID: lib.ID,
+			Title:     "Movie " + string(rune('A'+i)),
+			Path:      "/media/movies/m" + string(rune('a'+i)) + ".mkv",
+			PosterURL: posterBase + "/p" + string(rune('1'+i)) + ".jpg",
+		}
+		if err := repos.DB.Create(&row).Error; err != nil {
+			t.Fatalf("create media: %v", err)
+		}
+	}
+	return lib
+}
+
+// TestLibraryCoverHandlerServesGeneratedCollage 覆盖 Web/App 的封面接口：
+// 返回的是服务端拼好的 16:9 图片，而不是单张成员海报。
+func TestLibraryCoverHandlerServesGeneratedCollage(t *testing.T) {
+	router, repos, upstream := newLibraryCoverTestRouter(t)
+	lib := seedCoverLibrary(t, repos, upstream.URL, "")
+
+	req := httptest.NewRequest(http.MethodGet, "/libraries/"+lib.ID+"/cover?w=480&h=270", nil)
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("status = %d body=%s", w.Code, w.Body.String())
+	}
+	if ct := w.Header().Get("Content-Type"); ct != "image/jpeg" {
+		t.Fatalf("content type = %q, want image/jpeg", ct)
+	}
+	img, err := jpeg.Decode(bytes.NewReader(w.Body.Bytes()))
+	if err != nil {
+		t.Fatalf("decode cover: %v", err)
+	}
+	if img.Bounds().Dx() != 480 || img.Bounds().Dy() != 270 {
+		t.Fatalf("cover size = %v, want 480x270", img.Bounds())
+	}
+	if etag := w.Header().Get("ETag"); etag == "" {
+		t.Fatal("expected an ETag so clients can revalidate")
+	}
+
+	// 条件请求应拿到 304。
+	req = httptest.NewRequest(http.MethodGet, "/libraries/"+lib.ID+"/cover?w=480&h=270", nil)
+	req.Header.Set("If-None-Match", w.Header().Get("ETag"))
+	rec := httptest.NewRecorder()
+	router.ServeHTTP(rec, req)
+	if rec.Code != http.StatusNotModified {
+		t.Fatalf("conditional request status = %d, want 304", rec.Code)
+	}
+}
+
+func TestLibraryCoverHandlerUnknownLibraryReturns404(t *testing.T) {
+	router, _, _ := newLibraryCoverTestRouter(t)
+	req := httptest.NewRequest(http.MethodGet, "/libraries/missing/cover", nil)
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+	if w.Code != http.StatusNotFound {
+		t.Fatalf("status = %d, want 404", w.Code)
+	}
+}
+
+// TestLibraryCoverHandlerServesCustomCover 管理员填了 cover_url 时必须继续
+// 用自定义封面，不能在不知不觉中换成拼图。
+func TestLibraryCoverHandlerServesCustomCover(t *testing.T) {
+	router, repos, upstream := newLibraryCoverTestRouter(t)
+	lib := seedCoverLibrary(t, repos, upstream.URL, upstream.URL+"/custom.jpg")
+
+	req := httptest.NewRequest(http.MethodGet, "/libraries/"+lib.ID+"/cover", nil)
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("status = %d body=%s", w.Code, w.Body.String())
+	}
+	if _, err := jpeg.Decode(bytes.NewReader(w.Body.Bytes())); err != nil {
+		t.Fatalf("custom cover should be an image: %v", err)
+	}
+}
+
+// TestEmbyLibraryPrimaryUsesGeneratedCollage 保证 Emby 客户端请求库主图时
+// 拿到的也是拼图（与 Web/App 同一份生成逻辑）。
+func TestEmbyLibraryPrimaryUsesGeneratedCollage(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
+	if err != nil {
+		t.Fatalf("open db: %v", err)
+	}
+	if err := db.AutoMigrate(&model.Library{}, &model.Media{}); err != nil {
+		t.Fatalf("migrate: %v", err)
+	}
+
+	poster := coverTestJPEG(t, color.RGBA{G: 180, R: 90, B: 60, A: 255})
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "image/jpeg")
+		_, _ = w.Write(poster)
+	}))
+	defer upstream.Close()
+	parsed, _ := url.Parse(upstream.URL)
+
+	repos := repository.New(db)
+	lib := model.Library{Name: "剧集", Path: "/media/tv", Type: "tv", Enabled: true}
+	if err := repos.Library.Create(t.Context(), &lib); err != nil {
+		t.Fatalf("create library: %v", err)
+	}
+	for i := 0; i < 4; i++ {
+		row := model.Media{
+			Base:      model.Base{ID: "e" + string(rune('a'+i))},
+			LibraryID: lib.ID,
+			Title:     "Show " + string(rune('A'+i)),
+			Path:      "/media/tv/show" + string(rune('a'+i)) + "/S01E01.mkv",
+			SeasonNum: 1, EpisodeNum: 1,
+			PosterURL: upstream.URL + "/p" + string(rune('1'+i)) + ".jpg",
+		}
+		if err := repos.DB.Create(&row).Error; err != nil {
+			t.Fatalf("create media: %v", err)
+		}
+	}
+
+	cfg := &config.Config{Cache: config.CacheConfig{CacheDir: filepath.Join(t.TempDir(), "cache")}}
+	proxy := service.NewImageProxy(cfg, zap.NewNop())
+	proxy.SetAllowedRemoteHostsProvider(func() []string { return []string{parsed.Host} })
+	svc := &service.Container{
+		Repo:       repos,
+		Emby:       service.NewEmbyService(cfg, zap.NewNop(), repos),
+		ImageProxy: proxy,
+	}
+	router := gin.New()
+	registerEmbyRoutes(router, "test-secret", svc)
+
+	req := httptest.NewRequest(http.MethodGet, "/Items/"+lib.ID+"/Images/Primary?maxWidth=400&maxHeight=300", nil)
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("status = %d body=%s", w.Code, w.Body.String())
+	}
+	img, err := jpeg.Decode(bytes.NewReader(w.Body.Bytes()))
+	if err != nil {
+		t.Fatalf("decode emby library cover: %v", err)
+	}
+	// 请求的是 400×300 的盒子，拼图按 16:9 装进去 → 400×225。
+	if img.Bounds().Dx() != 400 || img.Bounds().Dy() != 225 {
+		t.Fatalf("cover size = %v, want 400x225 (16:9 inside the requested box)", img.Bounds())
+	}
+}

internal/handler/media.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"math"
 	"net/http"
+	"net/url"
 	"sort"
 	"strconv"
 	"strings"
@@ -40,6 +41,25 @@ type webLibraryPayload struct {
 	RemoteSource string                   `json:"remote_source,omitempty"`
 	Total        int64                    `json:"total,omitempty"`
 	Cards        []service.SeriesCardView `json:"cards,omitempty"`
+	// CoverImageURL 是客户端可直接使用的「有效封面」：管理员自定义的
+	// cover_url 优先，否则指向服务端生成的成员海报拼图接口。Web / App 都
+	// 读这一个字段，避免各自用卡片在前端拼格子、长得还不一样。
+	CoverImageURL string `json:"cover_image_url,omitempty"`
+}
+
+// effectiveLibraryCoverURL 计算库封面的有效地址。远程挂载库的封面由上游
+// Emby 决定，这里返回空串，调用方继续用卡片拼图兜底。
+func effectiveLibraryCoverURL(lib model.Library, isRemote bool) string {
+	if isRemote {
+		return ""
+	}
+	if raw := strings.TrimSpace(lib.CoverURL); raw != "" {
+		return raw
+	}
+	if strings.TrimSpace(lib.ID) == "" {
+		return ""
+	}
+	return "/api/libraries/" + url.PathEscape(lib.ID) + "/cover"
 }
 
 // remoteLibraryPreviewBudget 限制 /api/libraries?with_preview=1 里远程 Emby
@@ -124,9 +144,10 @@ func listLibrariesHandler(svc *service.Container) gin.HandlerFunc {
 			}
 			for _, p := range previews {
 				out = append(out, webLibraryPayload{
-					Library: p.Library,
-					Total:   p.Total,
-					Cards:   service.NewSeriesCardViews(p.Cards),
+					Library:       p.Library,
+					Total:         p.Total,
+					Cards:         service.NewSeriesCardViews(p.Cards),
+					CoverImageURL: effectiveLibraryCoverURL(p.Library, false),
 				})
 			}
 		} else {
@@ -145,7 +166,7 @@ func listLibrariesHandler(svc *service.Container) gin.HandlerFunc {
 				if counts != nil {
 					total = counts[l.ID]
 				}
-				out = append(out, webLibraryPayload{Library: l, Total: total})
+				out = append(out, webLibraryPayload{Library: l, Total: total, CoverImageURL: effectiveLibraryCoverURL(l, false)})
 			}
 		}
 		// 精确指定目标库时，如果目标全是本地库，就不必枚举远程挂载。
@@ -272,9 +293,9 @@ func getLibraryHandler(svc *service.Container) gin.HandlerFunc {
 				c.JSON(http.StatusNotFound, gin.H{"error": "not found"})
 				return
 			}
-			c.JSON(http.StatusOK, webLibraryPayload{Library: libs[0]})
+			c.JSON(http.StatusOK, webLibraryPayload{Library: libs[0], CoverImageURL: effectiveLibraryCoverURL(libs[0], false)})
 		} else {
-			c.JSON(http.StatusOK, webLibraryPayload{Library: *lib})
+			c.JSON(http.StatusOK, webLibraryPayload{Library: *lib, CoverImageURL: effectiveLibraryCoverURL(*lib, false)})
 		}
 	}
 }

internal/handler/routes_authenticated_core.go

@@ -36,6 +36,9 @@ func registerAuthedLibraryRoutes(authed *gin.RouterGroup, svc *service.Container
 	authed.GET("/libraries", listLibrariesHandler(svc))
 	authed.POST("/libraries", middleware.AdminRequired(), createLibraryHandler(svc))
 	authed.GET("/libraries/:id", getLibraryHandler(svc))
+	// 服务端生成的媒体库封面（成员海报拼图），Web / App / Emby 共用同一份。
+	authed.GET("/libraries/:id/cover", libraryCoverHandler(svc))
+	authed.HEAD("/libraries/:id/cover", libraryCoverHandler(svc))
 	authed.PATCH("/libraries/:id", middleware.AdminRequired(), updateLibraryHandler(svc))
 	authed.PUT("/libraries/reorder", middleware.AdminRequired(), reorderLibrariesHandler(svc))
 	authed.DELETE("/libraries/:id", middleware.AdminRequired(), deleteLibraryHandler(svc))

internal/handler/streaming.go

@@ -27,7 +27,15 @@ func hlsPlaylistHandler(svc *service.Container) gin.HandlerFunc {
 		if !enforceScopedPlaybackToken(c, m.ID) {
 			return
 		}
-		err = svc.Stream.ServeHLSPlaylist(c.Writer, c.Request, c.Param("id"))
+		scope, ok := localHLSPlaybackScope(c)
+		if !ok {
+			return
+		}
+		err = svc.Stream.ServeHLSPlaylist(c.Writer, c.Request, c.Param("id"), scope)
+		if errors.Is(err, service.ErrHLSGenerationSuperseded) {
+			c.JSON(http.StatusConflict, gin.H{"code": "hls_generation_superseded", "error": err.Error()})
+			return
+		}
 		if errors.Is(err, service.ErrMediaNotFound) {
 			c.JSON(http.StatusNotFound, gin.H{"error": "not found"})
 			return
@@ -62,7 +70,11 @@ func hlsSegmentHandler(svc *service.Container) gin.HandlerFunc {
 		if !enforceScopedPlaybackToken(c, m.ID) {
 			return
 		}
-		err = svc.Stream.ServeHLSSegment(c.Writer, c.Request, c.Param("id"), c.Param("seg"))
+		scope, ok := localHLSPlaybackScope(c)
+		if !ok {
+			return
+		}
+		err = svc.Stream.ServeHLSSegment(c.Writer, c.Request, c.Param("id"), c.Param("seg"), scope)
 		if err != nil {
 			c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
 			return
@@ -72,11 +84,39 @@ func hlsSegmentHandler(svc *service.Container) gin.HandlerFunc {
 
 func stopTranscodeHandler(svc *service.Container) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		svc.Transcoder.StopJob(c.Param("id"))
+		m, err := findMediaForPlaybackEndpoint(c, svc, c.Param("id"))
+		if err != nil || m == nil || !mediaVisibleForRequest(c, svc, m) {
+			c.JSON(http.StatusNotFound, gin.H{"error": "media not found"})
+			return
+		}
+		if !enforceScopedPlaybackToken(c, m.ID) {
+			return
+		}
+		scope, ok := localHLSPlaybackScope(c)
+		if !ok {
+			return
+		}
+		if svc.Transcoder != nil {
+			svc.Transcoder.StopPlayback(m.ID, scope)
+		}
 		c.Status(http.StatusNoContent)
 	}
 }
 
+func localHLSPlaybackScope(c *gin.Context) (service.HLSPlaybackScope, bool) {
+	userID := currentUserID(c)
+	if userID == "" {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "missing playback owner"})
+		return service.HLSPlaybackScope{}, false
+	}
+	scope, err := service.HLSPlaybackScopeForRequest(c.Request, userID)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return service.HLSPlaybackScope{}, false
+	}
+	return scope, true
+}
+
 func imageProxyHandler(svc *service.Container) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		raw := c.Query("url")

internal/service/cache_cleanup.go

@@ -74,22 +74,20 @@ type ImageCacheScope struct {
 	DropUnknownResizeVariants bool
 }
 
-// ImageCachePool 描述一个图片缓存池：范围 + 自身配额 + 保留时长。
+// ImageCachePool 描述一个图片缓存池：范围 + 自身配额。
 //
 // 分池的意义在于两类缓存的“可再生成本”完全不同：原图只是生成缩略图的原料，
 // 丢了可以重新回源；派生缩略图是客户端热路径真正读取的成品，重新生成代价高。
-// 因此原图配小配额、短保留，总量超限时也优先淘汰原图。
+// 因此原图配小配额，总量超限时也优先淘汰原图。
+//
+// 淘汰只看占用（配额头寸），不按文件年龄删除：缩略图生成成本高，只要磁盘还
+// 放得下就该留着，让再次浏览直接命中缓存。
 type ImageCachePool struct {
 	Name     string
 	Scopes   []ImageCacheScope
-	MaxBytes int64         // 0 = 不单独限制
-	MaxAge   time.Duration // 0 = 不按时间淘汰
+	MaxBytes int64 // 0 = 不单独限制
 }
 
-// imageFailMarkerMaxAge 是失败标记文件的保留时长：标记只用于观测/重试，
-// 过期即视为噪音清掉（不会因为标记残留而阻止重新抓取）。
-const imageFailMarkerMaxAge = 24 * time.Hour
-
 // tempImageCacheFile 报告文件名是否是下载/缩放过程中的临时文件。它们正在被
 // 并发写入，清理时必须跳过。
 func tempImageCacheFile(name string) bool {
@@ -182,12 +180,14 @@ func removeImageCacheEntry(entry imageCacheFileEntry, result *PruneImageCacheRes
 	_ = os.Remove(entry.path + ".fail")
 }
 
-// PruneImageCachePools 按池清理图片缓存：
-//  1. 删除超过池 MaxAge 的文件（原图按保留时长淘汰）；
-//  2. 池自身超过 MaxBytes 时按 mtime 淘汰到 80%（留水位，避免连续写入即触发）；
-//  3. 全部池合计超过 totalBytes 时，仍按“先原图、后派生”的顺序淘汰最旧文件，
+// PruneImageCachePools 按池清理图片缓存，只做占用淘汰：
+//  1. 池自身超过 MaxBytes 时按 mtime 淘汰到 80%（留水位，避免连续写入即触发）；
+//  2. 全部池合计超过 totalBytes 时，仍按“先原图、后派生”的顺序淘汰最旧文件，
 //     使总量上限始终是硬保证，同时让客户端热路径的缩略图活得更久。
 //
+// 不按文件年龄删除：过期即删会让一张几天前看过的海报重新解码（2 核机器上
+// 每张约 0.2 秒），代价远高于占着那几十 KB 磁盘。
+//
 // 传入的池顺序即总量超限时的淘汰优先级（排在前面的先被淘汰）。
 func PruneImageCachePools(pools []ImageCachePool, totalBytes int64) (PruneImageCacheResult, error) {
 	var result PruneImageCacheResult
@@ -207,16 +207,18 @@ func PruneImageCachePools(pools []ImageCachePool, totalBytes int64) (PruneImageC
 	}
 	result.RemainingBytes = result.TotalBytesBefore
 
-	// 过期的失败标记直接清掉：它们不计容量，只用于观测与重试。
-	cutoffMarkers := time.Now().Add(-imageFailMarkerMaxAge)
+	// 失败标记不计入容量：只清掉对应缓存文件已经不存在的孤儿标记（它们只是
+	// 观测/重试用的噪音，留着没有任何作用）。
 	for _, marker := range failMarkers {
-		if marker.modTime.Before(cutoffMarkers) {
-			_ = os.Remove(marker.path)
+		base := strings.TrimSuffix(marker.path, ".fail")
+		if _, err := os.Stat(base); err == nil {
+			continue
 		}
+		_ = os.Remove(marker.path)
 	}
 
-	now := time.Now()
 	deleted := make(map[string]bool, len(entries))
+
 	deleteEntry := func(entry imageCacheFileEntry) {
 		if deleted[entry.path] {
 			return
@@ -225,20 +227,7 @@ func PruneImageCachePools(pools []ImageCachePool, totalBytes int64) (PruneImageC
 		removeImageCacheEntry(entry, &result)
 	}
 
-	// 1. 按池保留时长淘汰（原图池）。
-	for i := range pools {
-		if pools[i].MaxAge <= 0 {
-			continue
-		}
-		cutoff := now.Add(-pools[i].MaxAge)
-		for _, entry := range entries {
-			if entry.pool == i && entry.modTime.Before(cutoff) {
-				deleteEntry(entry)
-			}
-		}
-	}
-
-	// 2. 池自身配额。
+	// 1. 池自身配额。
 	for i := range pools {
 		maxBytes := pools[i].MaxBytes
 		if maxBytes <= 0 {
@@ -263,7 +252,7 @@ func PruneImageCachePools(pools []ImageCachePool, totalBytes int64) (PruneImageC
 		}
 	}
 
-	// 3. 总量硬上限：跨池按淘汰优先级（池顺序）再按 mtime 淘汰。
+	// 2. 总量硬上限：跨池按淘汰优先级（池顺序）再按 mtime 淘汰。
 	if totalBytes > 0 && result.RemainingBytes > totalBytes {
 		target := totalBytes * 80 / 100
 		for _, entry := range evictionOrder(entries, deleted) {
@@ -357,11 +346,10 @@ func PruneImageCache(imagesDir string, maxSizeBytes int64) (PruneImageCacheResul
 // 第一个池是原图：历史版本平铺在 images/ 下的旧缓存也归入此池，升级后会被
 // 逐步淘汰；第二个池是派生成品（本地缩放结果 + 挂载 Emby 按尺寸返回的成品）。
 // 池顺序即总量超限时的淘汰优先级。
-func ImageCachePools(imagesDir string, originalsMaxBytes int64, originalsMaxAge time.Duration) []ImageCachePool {
+func ImageCachePools(imagesDir string, originalsMaxBytes int64) []ImageCachePool {
 	originals := ImageCachePool{
 		Name:     "originals",
 		MaxBytes: originalsMaxBytes,
-		MaxAge:   originalsMaxAge,
 		Scopes: []ImageCacheScope{
 			{Root: imagesDir, Recursive: false}, // 旧版平铺布局
 			{Root: filepath.Join(imagesDir, imageOriginalCacheSubdir), Recursive: true},

internal/service/cache_cleanup_pools_test.go

@@ -9,7 +9,7 @@ import (
 	"time"
 )
 
-// writePoolFile ?????????????????????????
+// writePoolFile ??????????????? mtime ???????
 func writePoolFile(t *testing.T, path string, size int, modTime time.Time) {
 	t.Helper()
 	if err := os.MkdirAll(filepath.Dir(path), 0o750); err != nil {
@@ -39,42 +39,38 @@ func mustExist(t *testing.T, path string) {
 	}
 }
 
-// currentVariantPath ????????????????.<??x<??q<??>.img??
-// ??????????????????????????
+// currentVariantPath ???????????????????
+// <64 ????>.<?>x<?>q<??>.img
 func currentVariantPath(dir, keyChar string, width, height, quality int) string {
 	key := strings.Repeat(keyChar, sha256HexLength)
 	return filepath.Join(dir, fmt.Sprintf("%s.%dx%dq%d.img", key, width, height, quality))
 }
 
-// TestPruneImageCachePoolsOriginalTTL ????????????????????
-// ?? TTL ??????????????????????
-func TestPruneImageCachePoolsOriginalTTL(t *testing.T) {
+// TestPruneImageCachePoolsKeepsOldFilesUnderQuota ????????????
+// ???????????????????????? / TTL ????
+func TestPruneImageCachePoolsKeepsOldFilesUnderQuota(t *testing.T) {
 	imagesDir := t.TempDir()
 	now := time.Now()
 
-	stale := filepath.Join(imagesDir, imageOriginalCacheSubdir, "stale-original")
-	fresh := filepath.Join(imagesDir, imageOriginalCacheSubdir, "fresh-original")
-	thumb := currentVariantPath(filepath.Join(imagesDir, imageResizeCacheSubdir), "b", 480, 600, 80)
-	writePoolFile(t, stale, 400, now.Add(-8*24*time.Hour))
-	writePoolFile(t, fresh, 400, now.Add(-1*time.Hour))
-	// ??????????TTL ????
-	writePoolFile(t, thumb, 400, now.Add(-8*24*time.Hour))
+	oldOriginal := filepath.Join(imagesDir, imageOriginalCacheSubdir, "old-original")
+	oldThumb := currentVariantPath(filepath.Join(imagesDir, imageResizeCacheSubdir), "b", 480, 600, 80)
+	writePoolFile(t, oldOriginal, 400, now.Add(-90*24*time.Hour))
+	writePoolFile(t, oldThumb, 400, now.Add(-90*24*time.Hour))
 
-	pools := ImageCachePools(imagesDir, 0, 7*24*time.Hour)
+	pools := ImageCachePools(imagesDir, 0)
 	res, err := PruneImageCachePools(pools, 100*1024*1024)
 	if err != nil {
 		t.Fatalf("prune failed: %v", err)
 	}
-	if res.DeletedFiles != 1 {
-		t.Fatalf("deleted files = %d, want 1", res.DeletedFiles)
+	if res.DeletedFiles != 0 {
+		t.Fatalf("deleted files = %d, want 0 (age must not trigger deletion)", res.DeletedFiles)
 	}
-	mustNotExist(t, stale)
-	mustExist(t, fresh)
-	mustExist(t, thumb)
+	mustExist(t, oldOriginal)
+	mustExist(t, oldThumb)
 }
 
 // TestPruneImageCachePoolsEvictsOriginalsBeforeDerived ????????????
-// ????????????????????
+// ????????????????
 func TestPruneImageCachePoolsEvictsOriginalsBeforeDerived(t *testing.T) {
 	imagesDir := t.TempDir()
 	now := time.Now()
@@ -82,13 +78,13 @@ func TestPruneImageCachePoolsEvictsOriginalsBeforeDerived(t *testing.T) {
 	original := filepath.Join(imagesDir, imageOriginalCacheSubdir, "original")
 	rendition := filepath.Join(imagesDir, imageRenditionCacheSubdir, "rendition")
 	thumb := currentVariantPath(filepath.Join(imagesDir, imageResizeCacheSubdir), "c", 480, 600, 80)
-	// ?????????????????
+	// ?????????????????????????
 	writePoolFile(t, original, 1024*1024, now.Add(-72*time.Hour))
 	writePoolFile(t, rendition, 1024*1024, now.Add(-2*time.Hour))
 	writePoolFile(t, thumb, 1024*1024, now.Add(-1*time.Hour))
 
-	pools := ImageCachePools(imagesDir, 0, 0)
-	// ?? 3MB????2.4MB -> ????? 1.92MB??
+	pools := ImageCachePools(imagesDir, 0)
+	// ?? 3MB??? 2.4MB -> ??? 1.92MB ???
 	res, err := PruneImageCachePools(pools, 2*1024*1024+400*1024)
 	if err != nil {
 		t.Fatalf("prune failed: %v", err)
@@ -104,8 +100,8 @@ func TestPruneImageCachePoolsEvictsOriginalsBeforeDerived(t *testing.T) {
 	}
 }
 
-// TestPruneImageCachePoolsOriginalQuotaKeepsDerived ????????????
-// ??????????????
+// TestPruneImageCachePoolsOriginalQuotaKeepsDerived ???????????
+// ????????????
 func TestPruneImageCachePoolsOriginalQuotaKeepsDerived(t *testing.T) {
 	imagesDir := t.TempDir()
 	now := time.Now()
@@ -117,8 +113,8 @@ func TestPruneImageCachePoolsOriginalQuotaKeepsDerived(t *testing.T) {
 	writePoolFile(t, newOriginal, 800, now.Add(-1*time.Hour))
 	writePoolFile(t, thumb, 800, now.Add(-2*time.Hour))
 
-	// ???? 1000 ??????????1600 -> ????800????? 1 ????
-	pools := ImageCachePools(imagesDir, 1000, 0)
+	// ???? 1000??? 1600 ?? -> ??? 800??? 1 ???????
+	pools := ImageCachePools(imagesDir, 1000)
 	res, err := PruneImageCachePools(pools, 0)
 	if err != nil {
 		t.Fatalf("prune failed: %v", err)
@@ -131,24 +127,26 @@ func TestPruneImageCachePoolsOriginalQuotaKeepsDerived(t *testing.T) {
 	mustExist(t, thumb)
 }
 
-// TestPruneImageCachePoolsCleansFailMarkers ????????????????
-// ????????????????
+// TestPruneImageCachePoolsCleansFailMarkers ???????????????
+// ???????????????????????????????????
 func TestPruneImageCachePoolsCleansFailMarkers(t *testing.T) {
 	imagesDir := t.TempDir()
 	now := time.Now()
 
 	entry := filepath.Join(imagesDir, imageOriginalCacheSubdir, "entry")
 	entryMarker := entry + ".fail"
+	kept := filepath.Join(imagesDir, imageOriginalCacheSubdir, "kept")
+	keptMarker := kept + ".fail"
 	orphanMarker := filepath.Join(imagesDir, imageOriginalCacheSubdir, "orphan.fail")
-	freshMarker := filepath.Join(imagesDir, imageOriginalCacheSubdir, "fresh.fail")
 
-	writePoolFile(t, entry, 900, now.Add(-10*time.Hour))
-	writePoolFile(t, entryMarker, 35, now.Add(-10*time.Hour))
+	writePoolFile(t, entry, 900, now.Add(-2*time.Hour))
+	writePoolFile(t, entryMarker, 35, now.Add(-2*time.Hour))
+	writePoolFile(t, kept, 300, now.Add(-1*time.Hour))
+	writePoolFile(t, keptMarker, 35, now.Add(-1*time.Hour))
 	writePoolFile(t, orphanMarker, 35, now.Add(-48*time.Hour))
-	writePoolFile(t, freshMarker, 35, now.Add(-1*time.Minute))
 
-	// ???? 500????900 ?????????????????
-	pools := ImageCachePools(imagesDir, 500, 0)
+	// ???? 500??? 900+300=1200 ???? mtime ????? entry ? 400?
+	pools := ImageCachePools(imagesDir, 500)
 	res, err := PruneImageCachePools(pools, 0)
 	if err != nil {
 		t.Fatalf("prune failed: %v", err)
@@ -158,26 +156,27 @@ func TestPruneImageCachePoolsCleansFailMarkers(t *testing.T) {
 	}
 	mustNotExist(t, entry)
 	mustNotExist(t, entryMarker)
+	mustExist(t, kept)
+	mustExist(t, keptMarker)
 	mustNotExist(t, orphanMarker)
-	mustExist(t, freshMarker)
 }
 
-// TestPruneImageCachePoolsSkipsTemporaryFiles ????????????????
+// TestPruneImageCachePoolsSkipsTemporaryFiles ??????????????
 // ?????????????????
 func TestPruneImageCachePoolsSkipsTemporaryFiles(t *testing.T) {
 	imagesDir := t.TempDir()
 	tmp := filepath.Join(imagesDir, imageOriginalCacheSubdir, "img-1234.tmp")
 	writePoolFile(t, tmp, 4096, time.Now().Add(-48*time.Hour))
 
-	pools := ImageCachePools(imagesDir, 1, 0)
+	pools := ImageCachePools(imagesDir, 1)
 	if _, err := PruneImageCachePools(pools, 1); err != nil {
 		t.Fatalf("prune failed: %v", err)
 	}
 	mustExist(t, tmp)
 }
 
-// TestPruneImageCachePoolsDropsLegacyResizeVariants ????????.img????
-// ?????????????????????????????????????
+// TestPruneImageCachePoolsDropsLegacyResizeVariants ?????? .img ??
+// ???????????????????????????
 func TestPruneImageCachePoolsDropsLegacyResizeVariants(t *testing.T) {
 	imagesDir := t.TempDir()
 	resized := filepath.Join(imagesDir, imageResizeCacheSubdir)
@@ -188,7 +187,7 @@ func TestPruneImageCachePoolsDropsLegacyResizeVariants(t *testing.T) {
 	writePoolFile(t, current, 400, time.Now())
 	writePoolFile(t, other, 400, time.Now())
 
-	pools := ImageCachePools(imagesDir, 0, 0)
+	pools := ImageCachePools(imagesDir, 0)
 	res, err := PruneImageCachePools(pools, 0)
 	if err != nil {
 		t.Fatalf("prune failed: %v", err)
@@ -201,8 +200,8 @@ func TestPruneImageCachePoolsDropsLegacyResizeVariants(t *testing.T) {
 	}
 }
 
-// TestPruneImageCachePoolsCountsLegacyFlatLayout ??????images/ ????
-// ?????????????????
+// TestPruneImageCachePoolsCountsLegacyFlatLayout ???????images/ ???
+// ???????????????????????
 func TestPruneImageCachePoolsCountsLegacyFlatLayout(t *testing.T) {
 	imagesDir := t.TempDir()
 	legacy := filepath.Join(imagesDir, "legacy-flat-cache")
@@ -210,7 +209,8 @@ func TestPruneImageCachePoolsCountsLegacyFlatLayout(t *testing.T) {
 	writePoolFile(t, legacy, 900, time.Now().Add(-30*24*time.Hour))
 	writePoolFile(t, thumb, 900, time.Now().Add(-30*24*time.Hour))
 
-	pools := ImageCachePools(imagesDir, 0, 24*time.Hour)
+	// ???? 500??????????????????????????
+	pools := ImageCachePools(imagesDir, 500)
 	res, err := PruneImageCachePools(pools, 0)
 	if err != nil {
 		t.Fatalf("prune failed: %v", err)

internal/service/cloud115_hls_authorization_test.go

@@ -0,0 +1,33 @@
+package service
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestCloud115HLSChildRejectsMismatchedSessionMediaBeforeFetch(t *testing.T) {
+	fetched := false
+	proxy := &Cloud115HLSProxy{sessions: map[string]*cloud115HLSSession{}}
+	proxy.client = &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
+		fetched = true
+		return &http.Response{StatusCode: http.StatusOK, Header: http.Header{"Content-Type": []string{"video/mp2t"}}, Body: io.NopCloser(strings.NewReader("private-segment")), Request: req}, nil
+	})}
+	proxy.sessions["session-b"] = &cloud115HLSSession{
+		ID: "session-b", MediaID: "media-b", ExpiresAt: time.Now().Add(time.Hour),
+		entries: map[string]string{"segment": "https://cpats01.115.com/seg.ts"},
+	}
+	for _, query := range []string{"?media_id=media-a", ""} {
+		fetched = false
+		req := httptest.NewRequest(http.MethodGet, "/api/cloud115/hls/session-b/segment"+query, nil)
+		rec := httptest.NewRecorder()
+		err := proxy.ServeChild(context.Background(), rec, req, "session-b", "segment")
+		if err == nil || fetched {
+			t.Errorf("query %q must reject the wrong/missing media before fetch; err=%v fetched=%v", query, err, fetched)
+		}
+	}
+}

internal/service/cloud115_hls_proxy.go

@@ -20,8 +20,9 @@ import (
 )
 
 var (
-	ErrCloud115HLSSessionNotFound = errors.New("115 hls session not found")
-	ErrCloud115HLSUpstreamExpired = errors.New("115 hls upstream expired")
+	ErrCloud115HLSSessionNotFound      = errors.New("115 hls session not found")
+	ErrCloud115HLSUpstreamExpired      = errors.New("115 hls upstream expired")
+	ErrCloud115HLSSessionMediaMismatch = errors.New("115 hls session media mismatch")
 )
 
 const (
@@ -131,6 +132,9 @@ func (p *Cloud115HLSProxy) ServeChild(ctx context.Context, w http.ResponseWriter
 	if !ok {
 		return ErrCloud115HLSSessionNotFound
 	}
+	if r == nil || strings.TrimSpace(r.URL.Query().Get("media_id")) != session.MediaID {
+		return ErrCloud115HLSSessionMediaMismatch
+	}
 	resp, err := p.fetchUpstream(ctx, upstream, r.Header.Get("Range"))
 	if err != nil {
 		return err
@@ -186,6 +190,15 @@ func (p *Cloud115HLSProxy) ServeChild(ctx context.Context, w http.ResponseWriter
 	return err
 }
 
+// SessionMediaID resolves the server-owned media identity before handler authorization.
+func (p *Cloud115HLSProxy) SessionMediaID(sessionID, key string) (string, error) {
+	session, _, ok := p.lookup(sessionID, key)
+	if !ok {
+		return "", ErrCloud115HLSSessionNotFound
+	}
+	return session.MediaID, nil
+}
+
 func (p *Cloud115HLSProxy) newSession(mediaID string, definition int) *cloud115HLSSession {
 	now := time.Now()
 	return &cloud115HLSSession{

internal/service/cloud115_playback.go

@@ -104,11 +104,13 @@ func (s *Cloud115PlaybackService) HLSProxy() *Cloud115HLSProxy {
 	return s.proxy
 }
 
-// PlaybackInfo 返回媒体在 direct/115-cloud/local 三种模式下的能力描述。
-//
-// requestedDefinition 为空或 0 时默认选择 1080P；该档位不可用时返回
-// transcoding 状态（并只触发一次加速转码，避免轮询风暴）。
+// PlaybackInfo only reads direct/115-cloud/local playback capabilities.
+// Cloud work is queued exclusively by StartTranscode, never by polling.
 func (s *Cloud115PlaybackService) PlaybackInfo(ctx context.Context, mediaID string, requestedDefinition int) (*PlaybackInfo, error) {
+	return s.playbackInfo(ctx, mediaID, requestedDefinition, false)
+}
+
+func (s *Cloud115PlaybackService) playbackInfo(ctx context.Context, mediaID string, requestedDefinition int, startTranscode bool) (*PlaybackInfo, error) {
 	if s == nil || s.repo == nil || s.repo.Media == nil {
 		return nil, ErrMediaNotFound
 	}
@@ -179,13 +181,26 @@ func (s *Cloud115PlaybackService) PlaybackInfo(ctx context.Context, mediaID stri
 		return info, nil
 	}
 
-	info.Transcode = s.ensureCloudTranscode(ctx, account.ID, pickCode, selected, client)
+	if startTranscode {
+		info.Transcode = s.ensureCloudTranscode(ctx, account.ID, pickCode, selected, client)
+	} else {
+		info.Transcode = Cloud115TranscodeState{
+			State: "idle", Definition: selected.ID, Message: "该清晰度尚未就绪，可请求 115 云端转码", RetryAfterSec: 5,
+		}
+		s.mu.Lock()
+		if last, ok := s.pushState[account.ID+":"+pickCode]; ok {
+			info.Transcode.State = "transcoding"
+			info.Transcode.Message = last.message
+			info.Transcode.StartedAt = last.at.Unix()
+		}
+		s.mu.Unlock()
+	}
 	return info, nil
 }
 
 // StartTranscode 显式触发某个清晰度的云端转码，返回最新状态。
 func (s *Cloud115PlaybackService) StartTranscode(ctx context.Context, mediaID string, definition int) (*PlaybackInfo, error) {
-	return s.PlaybackInfo(ctx, mediaID, definition)
+	return s.playbackInfo(ctx, mediaID, definition, true)
 }
 
 // ResolveCloud115URL 返回指定清晰度的 115 云端 m3u8 地址。
@@ -258,6 +273,9 @@ func (s *Cloud115PlaybackService) ensureCloudTranscode(
 			}
 		}
 	}
+	// Reserve the in-flight attempt before releasing the lock. Two simultaneous
+	// explicit starts must not both submit a push while the first awaits 115.
+	s.pushState[key] = cloud115PushAttempt{at: now, message: "正在提交 115 云端转码请求…"}
 	s.mu.Unlock()
 
 	err := client.SubmitVideoPush(ctx, pickCode, "vip_push")

internal/service/cloud115_playback_test.go

@@ -16,7 +16,7 @@ import (
 	"github.com/truewhile/MeBox/internal/service/cloud115"
 )
 
-func TestCloud115PlaybackInfoTriggersTranscodeOnce(t *testing.T) {
+func TestCloud115PlaybackInfoIsReadOnlyAndStartTriggersTranscodeOnce(t *testing.T) {
 	var playCalls int32
 	var pushCalls int32
 	var ready int32
@@ -93,9 +93,16 @@ func TestCloud115PlaybackInfoTriggersTranscodeOnce(t *testing.T) {
 	}
 	svc := NewCloud115PlaybackService(nil, zap.NewNop(), repos, strm)
 
-	info, err := svc.PlaybackInfo(ctx, media.ID, 0)
+	if _, err := svc.PlaybackInfo(ctx, media.ID, 0); err != nil {
+		t.Fatalf("read playback info: %v", err)
+	}
+	if got := atomic.LoadInt32(&pushCalls); got != 0 {
+		t.Fatalf("read-only playback info triggered %d cloud transcode pushes", got)
+	}
+
+	info, err := svc.StartTranscode(ctx, media.ID, 0)
 	if err != nil {
-		t.Fatalf("first playback info: %v", err)
+		t.Fatalf("start transcode: %v", err)
 	}
 	if info.Provider != model.StrmProvider115 || info.DefaultQuality != "4" {
 		t.Fatalf("unexpected playback info: %#v", info)

internal/service/cloud115_transcode_concurrency_test.go

@@ -0,0 +1,77 @@
+package service
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"go.uber.org/zap"
+
+	"github.com/truewhile/MeBox/internal/service/cloud115"
+)
+
+func TestCloud115ConcurrentStartsDoNotDuplicateInFlightPush(t *testing.T) {
+	started := make(chan struct{})
+	release := make(chan struct{})
+	var releaseOnce sync.Once
+	var pushCalls atomic.Int32
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if pushCalls.Add(1) == 1 {
+			close(started)
+		}
+		<-release
+		w.Header().Set("Content-Type", "application/json")
+		_ = json.NewEncoder(w).Encode(map[string]any{"state": true, "code": 0, "data": []any{}})
+	}))
+	defer server.Close()
+	defer releaseOnce.Do(func() { close(release) })
+	oldBase := cloud115.ProAPIBase
+	cloud115.ProAPIBase = server.URL
+	defer func() { cloud115.ProAPIBase = oldBase }()
+	client := cloud115.NewOpenClient("review-app", "access", "refresh")
+	svc := NewCloud115PlaybackService(nil, zap.NewNop(), nil, nil)
+	quality := PlaybackQuality{ID: "4", Label: "1080P", Source: "cloud"}
+	ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
+	defer cancel()
+	first := make(chan struct{})
+	go func() { defer close(first); svc.ensureCloudTranscode(ctx, "account", "pick", quality, client) }()
+	select {
+	case <-started:
+	case <-ctx.Done():
+		t.Fatal("first push did not reach the local server")
+	}
+	second := make(chan Cloud115TranscodeState, 1)
+	go func() { second <- svc.ensureCloudTranscode(ctx, "account", "pick", quality, client) }()
+	secondReceived := false
+	select {
+	case state := <-second:
+		secondReceived = true
+		if state.State != "transcoding" {
+			t.Errorf("in-flight request should be reported as transcoding: %#v", state)
+		}
+	case <-time.After(250 * time.Millisecond):
+		t.Error("second start issued another request instead of reusing the in-flight push")
+	}
+	releaseOnce.Do(func() { close(release) })
+	select {
+	case <-first:
+	case <-ctx.Done():
+		t.Fatal("first push did not finish")
+	}
+	// The duplicate path is awaited before restoring the package-wide fake API.
+	if !secondReceived {
+		select {
+		case <-second:
+		case <-ctx.Done():
+			t.Fatal("second start did not finish")
+		}
+	}
+	if got := pushCalls.Load(); got != 1 {
+		t.Fatalf("pushes=%d, want 1", got)
+	}
+}

internal/service/emby_cache_invalidate_test.go

@@ -0,0 +1,254 @@
+package service
+
+import (
+	"context"
+	"fmt"
+	"strconv"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/glebarez/sqlite"
+	"go.uber.org/zap"
+	"gorm.io/gorm"
+	"gorm.io/gorm/logger"
+
+	"github.com/truewhile/MeBox/internal/config"
+	"github.com/truewhile/MeBox/internal/model"
+	"github.com/truewhile/MeBox/internal/repository"
+)
+
+// resetEmbyInvalThrottle 清掉全局失效节流，让测试能断言「这一次调用到底有
+// 没有真的清缓存」。测试结束后恢复原值，避免影响同包其他用例。
+func resetEmbyInvalThrottle(t *testing.T) {
+	t.Helper()
+	embyInvalMu.Lock()
+	previous := embyInvalLast
+	embyInvalLast = time.Time{}
+	embyInvalMu.Unlock()
+	t.Cleanup(func() {
+		embyInvalMu.Lock()
+		embyInvalLast = previous
+		embyInvalMu.Unlock()
+	})
+}
+
+func newCachedTestEmbyService(t *testing.T) *EmbyService {
+	t.Helper()
+	svc := newTestEmbyService(t)
+	cache := NewRuntimeCacheService(&config.Config{}, zap.NewNop())
+	t.Cleanup(func() { _ = cache.Close() })
+	return svc.SetRuntimeCache(cache)
+}
+
+// TestRecordProgressKeepsEmbyPayloadCache 覆盖首页加载慢的核心回归点：
+// 播放期间客户端每 5-10 秒上报一次进度，如果每次都清空 media:emby:*，
+// 客户端刷新首页时 73 个媒体库的 Latest 会全部回源重建（生产环境实测
+// 首批 8-25s）。普通进度上报必须保留载荷缓存；只有「已看完」翻转才失效。
+func TestRecordProgressKeepsEmbyPayloadCache(t *testing.T) {
+	svc := newCachedTestEmbyService(t)
+	const mediaID = "ep-1"
+	media := model.Media{
+		Base:        model.Base{ID: mediaID},
+		Title:       "第 1 集",
+		Path:        `/media/tv/Show/Season 01/S01E01.mkv`,
+		DurationSec: 100,
+	}
+	if err := svc.repo.DB.Create(&media).Error; err != nil {
+		t.Fatalf("create media: %v", err)
+	}
+
+	key := svc.embyLatestCacheKey("user-1", "", 16)
+	svc.cache.SetJSONWithStale(t.Context(), key, embyLatestCacheValue{
+		Items: []map[string]any{{"Id": "cached-item"}},
+	}, time.Minute, time.Hour)
+
+	resetEmbyInvalThrottle(t)
+	// 60s / 100s：播放中途
+	if err := svc.RecordProgressWithSession(t.Context(), "user-1", mediaID, 600_000_000, 1_000_000_000, "session-1"); err != nil {
+		t.Fatalf("record progress: %v", err)
+	}
+	if _, stale, ok := svc.cachedLatestItemsWithStale(t.Context(), key); !ok || stale {
+		t.Fatal("普通进度上报不应让 Emby 列表载荷缓存失效")
+	}
+
+	resetEmbyInvalThrottle(t)
+	// 98s / 100s：进入片尾 30s 内的「已看完」区间
+	if err := svc.RecordProgressWithSession(t.Context(), "user-1", mediaID, 980_000_000, 1_000_000_000, "session-2"); err != nil {
+		t.Fatalf("record completed progress: %v", err)
+	}
+	if _, _, ok := svc.cachedLatestItemsWithStale(t.Context(), key); ok {
+		t.Fatal("看完状态翻转后应让 Emby 列表载荷缓存失效")
+	}
+}
+
+// TestFindSeriesGroupCachesSiblingVirtualSeries 覆盖 N+1 回归点：一次全表
+// 扫描算出了整库的剧集分组，若只缓存命中的那一部，同一页的 16 张卡片和
+// 16 张海报会各自重扫一遍 media 表。批量记忆后同批分组都应可命中。
+func TestFindSeriesGroupCachesSiblingVirtualSeries(t *testing.T) {
+	svc := newTestEmbyService(t)
+	lib := model.Library{Name: "剧集", Path: `/media/tv`, Type: "tv", Enabled: true}
+	if err := svc.repo.Library.Create(t.Context(), &lib); err != nil {
+		t.Fatalf("create library: %v", err)
+	}
+
+	shows := []string{"Alpha", "Bravo", "Charlie"}
+	rows := make([]model.Media, 0, len(shows)*2)
+	for _, show := range shows {
+		for ep := 1; ep <= 2; ep++ {
+			rows = append(rows, model.Media{
+				Base:       model.Base{ID: show + "-" + strconv.Itoa(ep)},
+				LibraryID:  lib.ID,
+				Title:      show,
+				Path:       fmt.Sprintf("/media/tv/%s/Season 01/S01E%02d.mkv", show, ep),
+				SeasonNum:  1,
+				EpisodeNum: ep,
+			})
+		}
+	}
+	for i := range rows {
+		if err := svc.repo.DB.Create(&rows[i]).Error; err != nil {
+			t.Fatalf("create media: %v", err)
+		}
+	}
+
+	seriesIDs := map[string]string{}
+	for i := range rows {
+		if rows[i].EpisodeNum == 1 {
+			seriesIDs[rows[i].Title] = svc.seriesIDForMedia(t.Context(), &rows[i])
+		}
+	}
+	target, ok := seriesIDs["Alpha"]
+	if !ok {
+		t.Fatal("missing fixture series")
+	}
+	if _, found, err := svc.findSeriesGroup(t.Context(), target, ""); err != nil || !found {
+		t.Fatalf("findSeriesGroup(%s) = (%v, %v), want found", target, found, err)
+	}
+
+	for show, id := range seriesIDs {
+		if show == "Alpha" {
+			continue
+		}
+		if _, cached := svc.cachedSeriesGroup(id); !cached {
+			t.Fatalf("同一次扫描算出的 %s 应一并进入缓存，否则每张卡片/海报都会重扫整库", show)
+		}
+	}
+}
+
+// TestLatestPayloadKeepsStaleCopyForIdleClients 保证「最新添加」载荷在新鲜期
+// 之后仍有可用的陈旧副本：客户端空闲很久后再打开首页时，先拿陈旧结果并由
+// 后台重建，而不是让全部媒体库同时回源。
+func TestLatestPayloadKeepsStaleCopyForIdleClients(t *testing.T) {
+	svc := newCachedTestEmbyService(t)
+	key := svc.embyLatestCacheKey("user-1", "", 16)
+	svc.cache.SetJSONWithStale(t.Context(), key, embyLatestCacheValue{
+		Items: []map[string]any{{"Id": "stale-item"}},
+	}, time.Nanosecond, embyLatestStaleWindow)
+	time.Sleep(2 * time.Millisecond)
+
+	items, stale, ok := svc.cachedLatestItemsWithStale(t.Context(), key)
+	if !ok || !stale {
+		t.Fatalf("expected a stale hit, got ok=%v stale=%v", ok, stale)
+	}
+	if len(items) != 1 || items[0]["Id"] != "stale-item" {
+		t.Fatalf("unexpected stale payload: %#v", items)
+	}
+}
+
+// mediaScanCounter 统计真正落到 media 表上的查询次数，用来断言「整库数据
+// 只扫一次」：GORM 的 Trace 回调里能拿到最终 SQL。
+type mediaScanCounter struct {
+	logger.Interface
+	mu    sync.Mutex
+	scans int
+}
+
+func (c *mediaScanCounter) Trace(ctx context.Context, begin time.Time, fc func() (string, int64), err error) {
+	sql, _ := fc()
+	if strings.Contains(sql, "FROM `media`") {
+		c.mu.Lock()
+		c.scans++
+		c.mu.Unlock()
+	}
+}
+
+func (c *mediaScanCounter) Scans() int {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	return c.scans
+}
+
+// TestVirtualSeriesLookupsShareOneScan 覆盖冷启动风暴的回归点：客户端刷新
+// 首页时 73 个库的卡片和海报各自要一个虚拟 series 分组。修好之后，第一次
+// 扫描把整库分组都写进缓存，同一页剩下的查询都不该再落 SQL；随后一个不存在
+// 的虚拟 ID 也不该反复触发整库重扫。
+func TestVirtualSeriesLookupsShareOneScan(t *testing.T) {
+	counter := &mediaScanCounter{Interface: logger.Discard}
+	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{Logger: counter})
+	if err != nil {
+		t.Fatalf("open db: %v", err)
+	}
+	if sqlDB, err := db.DB(); err == nil {
+		sqlDB.SetMaxOpenConns(1)
+		t.Cleanup(func() { _ = sqlDB.Close() })
+	}
+	if err := db.AutoMigrate(model.AllModels()...); err != nil {
+		t.Fatalf("migrate: %v", err)
+	}
+	svc := NewEmbyService(&config.Config{}, zap.NewNop(), repository.New(db))
+
+	lib := model.Library{Name: "剧集", Path: `/media/tv`, Type: "tv", Enabled: true}
+	if err := svc.repo.Library.Create(t.Context(), &lib); err != nil {
+		t.Fatalf("create library: %v", err)
+	}
+	shows := []string{"Alpha", "Bravo", "Charlie"}
+	rows := make([]model.Media, 0, len(shows)*2)
+	for _, show := range shows {
+		for ep := 1; ep <= 2; ep++ {
+			rows = append(rows, model.Media{
+				Base:       model.Base{ID: show + "-" + strconv.Itoa(ep)},
+				LibraryID:  lib.ID,
+				Title:      show,
+				Path:       fmt.Sprintf("/media/tv/%s/Season 01/S01E%02d.mkv", show, ep),
+				SeasonNum:  1,
+				EpisodeNum: ep,
+			})
+		}
+	}
+	for i := range rows {
+		if err := svc.repo.DB.Create(&rows[i]).Error; err != nil {
+			t.Fatalf("create media: %v", err)
+		}
+	}
+	seriesIDs := map[string]string{}
+	for i := range rows {
+		if rows[i].EpisodeNum == 1 {
+			seriesIDs[rows[i].Title] = svc.seriesIDForMedia(t.Context(), &rows[i])
+		}
+	}
+
+	if _, found, err := svc.findSeriesGroup(t.Context(), seriesIDs["Alpha"], ""); err != nil || !found {
+		t.Fatalf("findSeriesGroup(Alpha) = (%v, %v), want found", found, err)
+	}
+	if got := counter.Scans(); got != 1 {
+		t.Fatalf("首次查询应恰好扫描 media 一次，实际 %d 次", got)
+	}
+
+	for _, show := range []string{"Bravo", "Charlie"} {
+		if _, found, err := svc.findSeriesGroup(t.Context(), seriesIDs[show], ""); err != nil || !found {
+			t.Fatalf("findSeriesGroup(%s) = (%v, %v), want found", show, found, err)
+		}
+	}
+	if got := counter.Scans(); got != 1 {
+		t.Fatalf("同批分组应命中缓存，不应再扫 media，实际累计 %d 次", got)
+	}
+
+	if _, found, err := svc.findSeriesGroup(t.Context(), embyVirtualSeriesPrefix+"missing", ""); err != nil || found {
+		t.Fatalf("未知虚拟 ID 应为 not found，实际 found=%v err=%v", found, err)
+	}
+	if got := counter.Scans(); got != 1 {
+		t.Fatalf("刚扫过整库后，未知 ID 不应重扫 media，实际累计 %d 次", got)
+	}
+}

internal/service/emby_compat.go

@@ -56,6 +56,17 @@ type EmbyService struct {
 	virtualSeries  map[string]embySeriesCacheEntry
 	virtualSeasons map[string]embySeasonCacheEntry
 	virtualArtwork map[string]embyArtworkCacheEntry
+	// virtualGroups 把「整库虚拟剧集分组」的扫描折叠成一次。
+	//
+	// 客户端刷新首页时会同时请求 73 个库的 Latest，每个库的卡片和海报都要
+	// 各自的虚拟 series 分组。不同剧的分组缓存键不同，singleflight 键也不同，
+	// 于是第一波请求会并发重扫整张 media 表（生产环境实测冷启动 14-17s）。
+	// 按用户折叠成一次扫描后，同一波请求共享结果并整批进缓存。
+	virtualGroups singleflight.Group
+	// virtualScanAt 记录每个用户最近一次整库扫描的时间，用于避免为同一个
+	// 不存在的 id 反复重扫（必须按用户区分：可见性不同，别人的快照不能当
+	// 自己的答案）。由 virtualMu 保护。
+	virtualScanAt map[string]time.Time
 
 	visibilityMu    sync.RWMutex
 	visibilityCache map[string]embyVisibilityCacheEntry
@@ -186,6 +197,15 @@ const (
 	embyVirtualSeriesCap  = 8000
 	embyVirtualSeasonCap  = 16000
 	embyVirtualArtworkCap = 24000
+	// embySeriesGroupBulkCacheEpisodes 限制一次批量记忆的剧集行数。
+	//
+	// 批量记忆把「一次扫描服务整页卡片 + 整页海报」的收益拿满，但同时让整库
+	// 剧集常驻内存。超过该量级时退回只缓存命中的那一部，避免大库吃光内存。
+	embySeriesGroupBulkCacheEpisodes = 8000
+	// embyVirtualScanGrace 是「刚做过整库虚拟剧集扫描」的保护窗口。窗口内再
+	// 请求一个不在缓存里的虚拟 series ID，直接按不存在处理，避免为同一个
+	// 未知 id 反复重扫整库。
+	embyVirtualScanGrace = 10 * time.Second
 	// Clients that already cached the 1x1 placeholder treat a stable tag as
 	// immutable. Virtual ids are the ones that served that placeholder, so
 	// only those tags get a suffix that forces a refetch.

internal/service/emby_items_cache.go

@@ -6,6 +6,7 @@ import (
 	"sort"
 	"strconv"
 	"strings"
+	"time"
 )
 
 type embyItemsCacheValue struct {
@@ -77,7 +78,15 @@ func (e *EmbyService) embySimilarCacheKey(mediaID, userID string, limit int) str
 }
 
 // defaultEmbyLatestCacheTTLSeconds 是 Emby「最新添加」缓存的兜底时长。
-const defaultEmbyLatestCacheTTLSeconds = 300
+const defaultEmbyLatestCacheTTLSeconds = 900
+
+// embyLatestStaleWindow 是「最新添加」载荷在进程内保留的陈旧副本时长。
+//
+// 客户端空闲很久之后再打开首页时，新鲜期早已过去：生产环境观察到这时
+// 73 个媒体库的 Latest 同时回源，首批请求要 8-25s 才回来，客户端等不及
+// 还会重试，进一步放大压力。保留陈旧副本后，这类请求立刻拿到上次的结果，
+// 由后台异步重建（见 refreshLatestItemsAsync），用户不再等 SQL。
+const embyLatestStaleWindow = 24 * time.Hour
 
 // embyLatestCacheTTLSeconds 返回「最新添加」列表的缓存时长。它刻意比通用
 // 媒体缓存更长：客户端刷新首页时会同时请求全部媒体库的 Latest（生产环境

internal/service/emby_items_detail.go

@@ -153,7 +153,7 @@ func (e *EmbyService) loadLatestItemsCached(ctx context.Context, userID, parentI
 		}
 		if e.cache != nil {
 			freshTTL := time.Duration(e.embyLatestCacheTTLSeconds()) * time.Second
-			e.cache.SetJSONWithStale(loadCtx, cacheKey, value, freshTTL, freshTTL+30*time.Minute)
+			e.cache.SetJSONWithStale(loadCtx, cacheKey, value, freshTTL, freshTTL+embyLatestStaleWindow)
 		}
 		e.rememberArtworkRefs(value.Artwork)
 		return value, nil

internal/service/emby_series.go

@@ -41,47 +41,65 @@ func (e *EmbyService) findSeriesGroup(ctx context.Context, id, userID string) (e
 		return embySeriesGroup{}, false, nil
 	}
 	if strings.HasPrefix(id, embyVirtualSeriesPrefix) {
-		if group, ok := e.cachedSeriesGroup(id); ok {
-			return group, true, nil
-		}
+		return e.findVirtualSeriesGroup(ctx, id, userID)
 	}
 	var rows []model.Media
 	q := e.repo.DB.WithContext(ctx).Model(&model.Media{}).Where("season_num > 0 OR episode_num > 0")
 	q = e.applyUserMediaVisibility(ctx, q, userID)
-	if !strings.HasPrefix(id, embyVirtualSeriesPrefix) {
-		q = q.Where("series_id = ?", id)
-	} else {
-		// 虚拟 series ID 只可能来自 series_id 为空的媒体：
-		// 有 series_id 时分组 key 就是 series_id 本身（UUID，不带虚拟前缀）。
-		q = q.Where("series_id IS NULL OR series_id = ''")
-	}
+	q = q.Where("series_id = ?", id)
 	if err := q.Order("media.season_num asc, media.episode_num asc, media.episode_fraction asc, media.created_at asc").Limit(embySeriesGroupingLimit).Find(&rows).Error; err != nil {
 		return embySeriesGroup{}, false, err
 	}
-	for _, group := range e.seriesGroupsFromMedia(ctx, rows) {
+	groups := e.seriesGroupsFromMedia(ctx, rows)
+	bulkCached := e.rememberScannedSeriesGroups(groups)
+	for _, group := range groups {
 		if group.ID == id {
-			e.rememberSeriesGroup(group)
+			if !bulkCached {
+				e.rememberSeriesGroup(group)
+			}
 			return group, true, nil
 		}
 	}
-	if !strings.HasPrefix(id, embyVirtualSeriesPrefix) {
-		if series, err := e.repo.Series.FindByID(ctx, id); err != nil {
-			return embySeriesGroup{}, false, err
-		} else if series != nil {
-			return embySeriesGroup{
-				ID:                 series.ID,
-				LibraryID:          series.LibraryID,
-				Name:               series.Title,
-				PosterURL:          series.PosterURL,
-				BackdropURL:        series.BackdropURL,
-				Overview:           series.Overview,
-				Rating:             series.Rating,
-				Year:               series.Year,
-				TMDbID:             series.TMDbID,
-				BangumiID:          series.BangumiID,
-				CreatedAt:          series.CreatedAt,
-				DateLastMediaAdded: series.CreatedAt,
-			}, true, nil
+	if series, err := e.repo.Series.FindByID(ctx, id); err != nil {
+		return embySeriesGroup{}, false, err
+	} else if series != nil {
+		return embySeriesGroup{
+			ID:                 series.ID,
+			LibraryID:          series.LibraryID,
+			Name:               series.Title,
+			PosterURL:          series.PosterURL,
+			BackdropURL:        series.BackdropURL,
+			Overview:           series.Overview,
+			Rating:             series.Rating,
+			Year:               series.Year,
+			TMDbID:             series.TMDbID,
+			BangumiID:          series.BangumiID,
+			CreatedAt:          series.CreatedAt,
+			DateLastMediaAdded: series.CreatedAt,
+		}, true, nil
+	}
+	return embySeriesGroup{}, false, nil
+}
+
+// findVirtualSeriesGroup 处理 series_id 为空的剧集分组（虚拟 series ID）。
+//
+// 虚拟 ID 是 hash(库名 + 剧名)，无法反解，只能整库算出分组后按 ID 取用。
+// 这里走 loadVirtualSeriesGroups，把同一用户的并发请求折叠成一次扫描：
+// 首页一次刷新会同时要 73 个库的卡片和海报，各扫一遍在 2 核主机上要 14-17s。
+func (e *EmbyService) findVirtualSeriesGroup(ctx context.Context, id, userID string) (embySeriesGroup, bool, error) {
+	if group, ok := e.cachedSeriesGroup(id); ok {
+		return group, true, nil
+	}
+	if e.virtualScanRecently(userID) {
+		return embySeriesGroup{}, false, nil
+	}
+	groups, err := e.loadVirtualSeriesGroups(ctx, userID)
+	if err != nil {
+		return embySeriesGroup{}, false, err
+	}
+	for _, group := range groups {
+		if group.ID == id {
+			return group, true, nil
 		}
 	}
 	return embySeriesGroup{}, false, nil
@@ -103,20 +121,14 @@ func (e *EmbyService) findSeasonGroup(ctx context.Context, id, userID string) (e
 		return season, true, nil
 	}
 	// 回退：未刮削（series_id 为空，虚拟 key 由库名+名称派生）的媒体只能全量分组。
-	var rows []model.Media
-	q := e.repo.DB.WithContext(ctx).Model(&model.Media{}).
-		Where("(series_id IS NULL OR series_id = '') AND (season_num > 0 OR episode_num > 0)")
-	q = e.applyUserMediaVisibility(ctx, q, userID)
-	if err := q.
-		Order("media.season_num asc, media.episode_num asc, media.episode_fraction asc, media.created_at asc").
-		Limit(embySeriesGroupingLimit).
-		Find(&rows).Error; err != nil {
+	// 复用共享扫描：首页并发刷新时整库只扫一次。
+	groups, err := e.loadVirtualSeriesGroups(ctx, userID)
+	if err != nil {
 		return embySeasonGroup{}, false, err
 	}
-	for _, series := range e.seriesGroupsFromMedia(ctx, rows) {
+	for _, series := range groups {
 		for _, season := range e.seasonsForSeries(series) {
 			if season.ID == id {
-				e.rememberSeriesGroup(series)
 				return season, true, nil
 			}
 		}
@@ -186,6 +198,84 @@ func (e *EmbyService) seasonGroupForSeries(ctx context.Context, id, seriesID, us
 	return embySeasonGroup{}, false, nil
 }
 
+// rememberScannedSeriesGroups 批量记住一次扫描得到的全部分组，返回是否真的
+// 批量写入（超过剧集预算时不做，调用方需自行缓存命中的那一部）。
+//
+// 只缓存命中的一部时，同一部剧的多张卡片/海报仍要各扫一次；整批写入后，
+// 同一次扫描算出来的其他剧也直接命中，于是整页 16 张卡片 + 16 张海报共用
+// 一次全表扫描。
+func (e *EmbyService) rememberScannedSeriesGroups(groups []embySeriesGroup) bool {
+	if e == nil || len(groups) == 0 {
+		return false
+	}
+	episodes := 0
+	for i := range groups {
+		episodes += len(groups[i].Episodes)
+		if episodes > embySeriesGroupBulkCacheEpisodes {
+			return false
+		}
+	}
+	e.rememberSeriesGroups(groups)
+	return true
+}
+
+// loadVirtualSeriesGroups 返回 series_id 为空的整库剧集分组。
+//
+// 同一用户的并发调用共享同一次扫描：客户端刷新首页时 73 个库的 Latest 同时
+// 进来，每个库的卡片和海报又各自要自己的虚拟 series 分组。分组缓存键各不
+// 相同，singleflight 也就不会合并，于是第一波请求把整张 media 表并发重算
+// 了 73 次（生产环境实测 14-17s）。这里按用户折叠成一次，结果整批进缓存，
+// 调用方拿到切片后按 ID 取用即可。
+func (e *EmbyService) loadVirtualSeriesGroups(ctx context.Context, userID string) ([]embySeriesGroup, error) {
+	if e == nil || e.repo == nil {
+		return nil, nil
+	}
+	v, err, _ := e.virtualGroups.Do("virtual:"+userID, func() (any, error) {
+		// 与 loadLatestItemsCached 一致：一个客户端断开不应取消正在为其他
+		// 客户端填充的共享扫描。
+		loadCtx, cancel := context.WithTimeout(context.WithoutCancel(ctx), 30*time.Second)
+		defer cancel()
+		var rows []model.Media
+		q := e.repo.DB.WithContext(loadCtx).Model(&model.Media{}).
+			Where("(series_id IS NULL OR series_id = '') AND (season_num > 0 OR episode_num > 0)")
+		q = e.applyUserMediaVisibility(loadCtx, q, userID)
+		if err := q.
+			Order("media.season_num asc, media.episode_num asc, media.episode_fraction asc, media.created_at asc").
+			Limit(embySeriesGroupingLimit).
+			Find(&rows).Error; err != nil {
+			return nil, err
+		}
+		groups := e.seriesGroupsFromMedia(loadCtx, rows)
+		e.rememberSeriesGroups(groups)
+		e.markVirtualScan(userID)
+		return groups, nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	groups, _ := v.([]embySeriesGroup)
+	return groups, nil
+}
+
+// markVirtualScan 记录该用户最近一次整库扫描的时间。
+func (e *EmbyService) markVirtualScan(userID string) {
+	e.virtualMu.Lock()
+	if e.virtualScanAt == nil {
+		e.virtualScanAt = make(map[string]time.Time, 4)
+	}
+	e.virtualScanAt[userID] = time.Now()
+	e.virtualMu.Unlock()
+}
+
+// virtualScanRecently 报告该用户是否刚做过一次整库扫描。窗口内仍不在缓存里
+// 的目标 ID 按不存在处理，避免为同一个未知 ID 反复重扫整库。
+func (e *EmbyService) virtualScanRecently(userID string) bool {
+	e.virtualMu.RLock()
+	scannedAt := e.virtualScanAt[userID]
+	e.virtualMu.RUnlock()
+	return !scannedAt.IsZero() && time.Since(scannedAt) < embyVirtualScanGrace
+}
+
 func (e *EmbyService) seriesGroupsFromMedia(ctx context.Context, rows []model.Media) []embySeriesGroup {
 	byID := map[string]*embySeriesGroup{}
 	order := []string{}

internal/service/emby_series_cache.go

@@ -26,19 +26,45 @@ func (e *EmbyService) rememberSeriesGroup(group embySeriesGroup) {
 	if e == nil || strings.TrimSpace(group.ID) == "" {
 		return
 	}
+	e.rememberSeriesGroups([]embySeriesGroup{group})
+}
+
+// rememberSeriesGroups 批量记住一组剧集分组（含派生季与封面）。
+//
+// 一次全表扫描会同时算出整库的剧集分组，而调用方往往只关心其中一部。若只
+// 逐个 rememberSeriesGroup，同一次首页刷新里 16 张卡片 + 16 张海报都要各自
+// 命中自己的虚拟 series ID，未命中就重扫整张 media 表（生产环境实测单次
+// 1.3s，73 个库并发时把连接池排满，首页要 8-25s）。批量写入后冷缓存只付
+// 一次扫描，其余全部是 O(1) 命中。
+func (e *EmbyService) rememberSeriesGroups(groups []embySeriesGroup) {
+	if e == nil || len(groups) == 0 {
+		return
+	}
 	expiresAt := time.Now().Add(embyVirtualCacheTTL)
 	e.virtualMu.Lock()
 	defer e.virtualMu.Unlock()
 	if e.virtualSeries == nil {
-		e.virtualSeries = make(map[string]embySeriesCacheEntry)
+		e.virtualSeries = make(map[string]embySeriesCacheEntry, len(groups))
 	}
 	if e.virtualSeasons == nil {
-		e.virtualSeasons = make(map[string]embySeasonCacheEntry)
+		e.virtualSeasons = make(map[string]embySeasonCacheEntry, len(groups))
 	}
 	if e.virtualArtwork == nil {
-		e.virtualArtwork = make(map[string]embyArtworkCacheEntry)
+		e.virtualArtwork = make(map[string]embyArtworkCacheEntry, len(groups)*2)
 	}
+	for _, group := range groups {
+		e.rememberSeriesGroupLocked(group, expiresAt)
+	}
+	// 写入后再裁剪：逐条裁剪会让整批写入退化成 O(n²)，且中途裁剪可能把
+	// 同一批里刚写进去的分组又淘汰掉。
 	e.trimVirtualCachesLocked(time.Now())
+}
+
+// rememberSeriesGroupLocked 写入单个分组，调用方必须已持有 virtualMu。
+func (e *EmbyService) rememberSeriesGroupLocked(group embySeriesGroup, expiresAt time.Time) {
+	if strings.TrimSpace(group.ID) == "" {
+		return
+	}
 	e.virtualSeries[group.ID] = embySeriesCacheEntry{group: group, expiresAt: expiresAt}
 	e.virtualArtwork[group.ID] = embyArtworkCacheEntry{primary: group.PosterURL, backdrop: group.BackdropURL, expiresAt: expiresAt}
 	e.virtualArtwork[group.ID+"-bd"] = embyArtworkCacheEntry{primary: group.PosterURL, backdrop: group.BackdropURL, expiresAt: expiresAt}

internal/service/emby_system.go

@@ -2,6 +2,9 @@ package service
 
 import (
 	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"io"
 	"sort"
 	"strings"
 	"time"
@@ -278,6 +281,20 @@ func isSupportedEmbyCollectionType(t string) bool {
 	return false
 }
 
+// libraryCoverTag 生成媒体库拼图封面的图片版本号。
+//
+// 第三方客户端把库主图按 (URL, ImageTag) 缓存，tag 不变就不会重新请求。
+// 用成员海报列表的指纹做 tag，库内容变化或生成规则调整时客户端自然会刷新。
+func libraryCoverTag(libraryID string, sources []string) string {
+	h := sha256.New()
+	_, _ = io.WriteString(h, libraryID)
+	for _, src := range sources {
+		_, _ = io.WriteString(h, src)
+		_, _ = h.Write([]byte{0})
+	}
+	return libraryID + "-" + hex.EncodeToString(h.Sum(nil))[:8]
+}
+
 func (e *EmbyService) libraryAsView(ctx context.Context, l *model.Library) map[string]any {
 	collectionType := "movies"
 	switch l.Type {
@@ -292,9 +309,17 @@ func (e *EmbyService) libraryAsView(ctx context.Context, l *model.Library) map[s
 	}
 	// 库封面:与剧集/电影一样,只有在能解析出封面时才广告 ImageTags.Primary,
 	// 否则客户端会认为该库无主图而不去请求 /Images/Primary。
+	//
+	// 拼图封面的 tag 带上「成员海报」的指纹：库内容变化或生成规则调整（例如
+	// 从 2×2 改成竖切）时 tag 会变，客户端才会丢缓存重新拉图；固定用库 ID
+	// 会让第三方客户端永远显示第一次缓存下来的封面。
 	imageTags := map[string]string{}
-	if e.LibraryHasCover(ctx, l.ID) {
-		imageTags["Primary"] = l.ID
+	if sources, lib := LibraryCoverSourcesForLibrary(ctx, e.repo, l.ID); lib != nil {
+		if len(sources) > 0 {
+			imageTags["Primary"] = libraryCoverTag(l.ID, sources)
+		} else if strings.TrimSpace(lib.CoverURL) != "" {
+			imageTags["Primary"] = l.ID
+		}
 	}
 	return map[string]any{
 		"Id":                       l.ID,

internal/service/emby_user_data.go

@@ -136,7 +136,12 @@ func (e *EmbyService) RecordProgressWithSession(ctx context.Context, userID, med
 		SessionID:          playSessionID,
 		SessionStartedAtMs: embyPlaySessionStartedAtMs(playSessionID),
 	})
-	if err == nil {
+	// 普通进度上报不清列表载荷缓存。播放期间客户端每 5-10 秒上报一次，
+	// 每次清空 media:emby:* 会让「最新添加」整批 payload（客户端刷新首页时
+	// 一次并发 73 个库）反复回源 SQL，生产环境实测因此出现 8-25s 的加载。
+	// 续播位置由 /Items/Resume 与条目详情实时查库，列表里的进度条允许滞后；
+	// 只有「已看完」这类状态翻转才让缓存失效（position 到达片尾 30s 内）。
+	if err == nil && playbackProgressCompleted(pos, dur) {
 		e.invalidateEmbyItemsCache(ctx)
 	}
 	return err
@@ -287,10 +292,11 @@ func applyMeBoxUserData(raw any, history *model.PlaybackHistory, favorite bool)
 	return userData
 }
 
-// embyInvalMu 节流全量缓存失效：播放期间客户端每 5-10s 上报一次进度，
-// 每次都 SCAN+DEL 全部 media:emby:* 缓存会把缓存命中率持续打穿（其他
-// 客户端每次翻页都回源 SQL）。条目载荷的 UserData 在请求时动态合并，
-// 进度类变更做 30s 节流即可，不影响正确性观感。
+// embyInvalMu 节流全量缓存失效：收藏/标记已看这类显式操作会改变列表里的
+// UserData，必须让 payload 失效。客户端连续点选时会短时间触发多次，节流到
+// 30s 一次即可，避免每次都 SCAN+DEL 全部 media:emby:* 缓存。
+// 播放进度上报不走这里（见 RecordProgressWithSession）：续播位置实时查库，
+// 列表里的进度条允许滞后，不值得为它把整批首页载荷打回源 SQL。
 var (
 	embyInvalMu   sync.Mutex
 	embyInvalLast time.Time

internal/service/hls_session.go

@@ -0,0 +1,109 @@
+package service
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"errors"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+	"unicode"
+)
+
+var ErrInvalidHLSPlaybackScope = errors.New("invalid HLS playback scope")
+var ErrHLSGenerationSuperseded = errors.New("HLS playback generation superseded")
+
+// HLSPlaybackScope separates a media's independent users and player instances.
+// UserID must come from server authentication, never from a request parameter.
+type HLSPlaybackScope struct {
+	UserID    string
+	SessionID string
+}
+
+func HLSPlaybackScopeForRequest(r *http.Request, userID string) (HLSPlaybackScope, error) {
+	scope := HLSPlaybackScope{UserID: strings.TrimSpace(userID)}
+	if scope.UserID == "" || r == nil {
+		return scope, ErrInvalidHLSPlaybackScope
+	}
+	for _, key := range []string{"session_id", "PlaySessionId", "playSessionId", "DeviceId", "deviceId"} {
+		if value := strings.TrimSpace(r.URL.Query().Get(key)); value != "" {
+			scope.SessionID = value
+			break
+		}
+	}
+	if scope.SessionID == "" {
+		if device := strings.TrimSpace(r.Header.Get("X-Emby-Device-Id")); device != "" {
+			scope.SessionID = device
+		}
+	}
+	if len(scope.SessionID) > 256 || strings.IndexFunc(scope.SessionID, unicode.IsControl) >= 0 {
+		return scope, ErrInvalidHLSPlaybackScope
+	}
+	// Clients without a session/device identifier remain compatible but only
+	// share a legacy task with the same authenticated user, never other users.
+	return scope, nil
+}
+
+func (scope HLSPlaybackScope) jobKey(mediaID string) string {
+	if scope.UserID == "" && scope.SessionID == "" {
+		return mediaID // Existing internal callers/tests retain their legacy API.
+	}
+	sum := sha256.Sum256([]byte(scope.UserID + "\x00" + mediaID + "\x00" + scope.SessionID))
+	return "player-" + hex.EncodeToString(sum[:])
+}
+
+func hlsPlaybackJobKey(mediaID string, scopes []HLSPlaybackScope) string {
+	if len(scopes) == 0 {
+		return mediaID
+	}
+	return scopes[0].jobKey(mediaID)
+}
+
+func (job *hlsJob) key() string {
+	if job.jobKey != "" {
+		return job.jobKey
+	}
+	return job.mediaID
+}
+
+func (t *TranscoderService) jobPlaylistPath(job *hlsJob) string {
+	dir := job.outputDir
+	if dir == "" {
+		dir = t.HLSDir(job.key())
+	}
+	return filepath.Join(dir, "index.m3u8")
+}
+
+// hlsOutputDir captures one immutable run directory. Even if a new run starts
+// after this check, the request cannot accidentally open its replacement files.
+func (t *TranscoderService) hlsOutputDir(key string, generation int64) (string, error) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	job := t.jobs[key]
+	if job == nil {
+		return "", ErrMediaNotFound
+	}
+	if job.seekGen != generation {
+		return "", ErrHLSGenerationSuperseded
+	}
+	t.touchJobLocked(key)
+	if job.outputDir != "" {
+		return job.outputDir, nil
+	}
+	return t.HLSDir(key), nil
+}
+
+func (t *TranscoderService) StopPlayback(mediaID string, scope HLSPlaybackScope) {
+	key := scope.jobKey(mediaID)
+	unlock := t.lockJobStart(key)
+	defer unlock()
+	t.mu.Lock()
+	job := t.detachJobLocked(key)
+	t.mu.Unlock()
+	waitJobExit(job, 12*time.Second)
+	// Keep cleanup under the same gate as start: a delayed stop must not wipe
+	// an output directory created by a concurrent replacement request.
+	_ = os.RemoveAll(t.HLSDir(key))
+}

internal/service/hls_session_lifecycle_test.go

@@ -0,0 +1,133 @@
+package service
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	"go.uber.org/zap"
+
+	"github.com/truewhile/MeBox/internal/config"
+	"github.com/truewhile/MeBox/internal/model"
+	"github.com/truewhile/MeBox/internal/repository"
+)
+
+func cachedScopedHLS(t *testing.T, scopes ...HLSPlaybackScope) (*StreamService, *TranscoderService, map[string]string) {
+	t.Helper()
+	cfg := &config.Config{}
+	cfg.Cache.CacheDir = t.TempDir()
+	cfg.Transcoder.Enabled = true
+	db := newServiceTestDB(t)
+	if err := db.Create(&model.Media{Base: model.Base{ID: "movie"}, Path: "unused-cached-source", DurationSec: 60}).Error; err != nil {
+		t.Fatal(err)
+	}
+	transcoder := NewTranscoderService(cfg, zap.NewNop(), repository.New(db), nil)
+	paths := map[string]string{}
+	for _, scope := range scopes {
+		key := scope.jobKey("movie")
+		dir := filepath.Join(transcoder.HLSDir(key), "run-cached")
+		if err := os.MkdirAll(dir, 0o750); err != nil {
+			t.Fatal(err)
+		}
+		playlist := filepath.Join(dir, "index.m3u8")
+		if err := os.WriteFile(playlist, []byte("#EXTM3U\n#EXTINF:4,\nseg_00000.ts\n"), 0o600); err != nil {
+			t.Fatal(err)
+		}
+		if err := os.WriteFile(filepath.Join(dir, "seg_00000.ts"), []byte(scope.UserID+"/"+scope.SessionID), 0o600); err != nil {
+			t.Fatal(err)
+		}
+		transcoder.jobs[key] = &hlsJob{mediaID: "movie", jobKey: key, outputDir: dir, subtitleStream: -1, startedAt: time.Now(), cancel: func() {}}
+		paths[key] = playlist
+	}
+	return NewStreamService(cfg, zap.NewNop(), repository.New(db), transcoder), transcoder, paths
+}
+
+func TestHLSPlaybackEnsureReusesOnlyMatchingOwnerAndSession(t *testing.T) {
+	a := HLSPlaybackScope{UserID: "viewer", SessionID: "tab-a"}
+	b := HLSPlaybackScope{UserID: "viewer", SessionID: "tab-b"}
+	_, transcoder, paths := cachedScopedHLS(t, a, b)
+	for _, scope := range []HLSPlaybackScope{a, b} {
+		playlist, err := transcoder.EnsureJobFromSubtitleQuality(t.Context(), "movie", 0, 0, -1, "", scope)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if playlist != paths[scope.jobKey("movie")] {
+			t.Fatalf("scope %#v reused another session's playlist %q", scope, playlist)
+		}
+	}
+}
+
+func TestHLSPlaybackStopRemovesOnlyItsSessionOutput(t *testing.T) {
+	a := HLSPlaybackScope{UserID: "viewer", SessionID: "tab-a"}
+	b := HLSPlaybackScope{UserID: "viewer", SessionID: "tab-b"}
+	_, transcoder, paths := cachedScopedHLS(t, a, b)
+	transcoder.StopPlayback("movie", a)
+	if _, err := os.Stat(paths[a.jobKey("movie")]); !os.IsNotExist(err) {
+		t.Fatalf("stopped session output must be cleaned up, err=%v", err)
+	}
+	if _, err := os.Stat(paths[b.jobKey("movie")]); err != nil {
+		t.Fatalf("another player's output was removed: %v", err)
+	}
+}
+
+func TestHLSPlaybackIdleCleanupRemovesExpiredSessionOutput(t *testing.T) {
+	a := HLSPlaybackScope{UserID: "viewer", SessionID: "tab-a"}
+	b := HLSPlaybackScope{UserID: "viewer", SessionID: "tab-b"}
+	_, transcoder, paths := cachedScopedHLS(t, a, b)
+	job := transcoder.jobs[a.jobKey("movie")]
+	job.lastAccess = time.Now().Add(-2 * time.Minute)
+	if !transcoder.stopIdleJob(job, time.Minute) {
+		t.Fatal("expired session was not stopped")
+	}
+	if _, err := os.Stat(paths[a.jobKey("movie")]); !os.IsNotExist(err) {
+		t.Fatalf("expired output was retained: %v", err)
+	}
+	if _, err := os.Stat(paths[b.jobKey("movie")]); err != nil {
+		t.Fatalf("active session output was removed: %v", err)
+	}
+}
+
+func TestHLSPlaybackPropagatesHeaderDeviceIdentityToSegments(t *testing.T) {
+	req := httptest.NewRequest(http.MethodGet, "/api/hls/movie/index.m3u8?token=test", nil)
+	req.Header.Set("X-Emby-Device-Id", "legacy-device")
+	scope, err := HLSPlaybackScopeForRequest(req, "viewer")
+	if err != nil {
+		t.Fatal(err)
+	}
+	svc, _, _ := cachedScopedHLS(t, scope)
+	rec := httptest.NewRecorder()
+	if err := svc.ServeHLSPlaylist(rec, req, "movie", scope); err != nil {
+		t.Fatal(err)
+	}
+	var segment string
+	for _, line := range strings.Split(rec.Body.String(), "\n") {
+		if strings.HasPrefix(line, "seg_") {
+			segment = line
+			break
+		}
+	}
+	u, err := url.Parse(segment)
+	if err != nil || u.Query().Get("session_id") == "" {
+		t.Fatalf("playlist must carry the header-only device scope to child URLs: %q err=%v", segment, err)
+	}
+	child := httptest.NewRequest(http.MethodGet, "/api/hls/movie/"+segment, nil)
+	childScope, err := HLSPlaybackScopeForRequest(child, "viewer")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if childScope.jobKey("movie") != scope.jobKey("movie") {
+		t.Fatal("child request changed its owner's device scope")
+	}
+	childRec := httptest.NewRecorder()
+	if err := svc.ServeHLSSegment(childRec, child, "movie", "seg_00000.ts", childScope); err != nil {
+		t.Fatal(err)
+	}
+	if childRec.Body.String() != "viewer/"+scope.SessionID {
+		t.Fatalf("wrong scoped segment: %s", childRec.Body.String())
+	}
+}

internal/service/hls_session_test.go

@@ -0,0 +1,97 @@
+package service
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"go.uber.org/zap"
+
+	"github.com/truewhile/MeBox/internal/config"
+)
+
+func TestHLSPlaybackScopesIsolateSegmentReadsAndStop(t *testing.T) {
+	cfg := &config.Config{}
+	cfg.Cache.CacheDir = t.TempDir()
+	transcoder := NewTranscoderService(cfg, zap.NewNop(), nil, nil)
+	svc := NewStreamService(cfg, zap.NewNop(), nil, transcoder)
+	a := HLSPlaybackScope{UserID: "user-a", SessionID: "tab-a"}
+	b := HLSPlaybackScope{UserID: "user-b", SessionID: "tab-a"}
+	c := HLSPlaybackScope{UserID: "user-a", SessionID: "tab-c"}
+	for _, scope := range []HLSPlaybackScope{a, b, c} {
+		key := scope.jobKey("movie")
+		dir := filepath.Join(cfg.Cache.CacheDir, key, "run-current")
+		if err := os.MkdirAll(dir, 0o750); err != nil {
+			t.Fatal(err)
+		}
+		if err := os.WriteFile(filepath.Join(dir, "seg_00000.ts"), []byte(scope.UserID+"/"+scope.SessionID), 0o600); err != nil {
+			t.Fatal(err)
+		}
+		transcoder.jobs[key] = &hlsJob{mediaID: "movie", jobKey: key, outputDir: dir, seekGen: 100, cancel: func() {}}
+	}
+	for _, scope := range []HLSPlaybackScope{a, b, c} {
+		req := httptest.NewRequest(http.MethodGet, "/api/hls/movie/seg_00000.ts?_seek=100", nil)
+		rec := httptest.NewRecorder()
+		if err := svc.ServeHLSSegment(rec, req, "movie", "seg_00000.ts", scope); err != nil {
+			t.Fatal(err)
+		}
+		if got, want := rec.Body.String(), scope.UserID+"/"+scope.SessionID; got != want {
+			t.Fatalf("segment=%q, want %q", got, want)
+		}
+	}
+	transcoder.StopPlayback("movie", a)
+	if transcoder.jobs[a.jobKey("movie")] != nil {
+		t.Fatal("stopped scope is still active")
+	}
+	if transcoder.jobs[b.jobKey("movie")] == nil || transcoder.jobs[c.jobKey("movie")] == nil {
+		t.Fatal("stopping one player affected another user/tab")
+	}
+	// A delayed stop from a previous local-playback session must not affect a replacement.
+	transcoder.StopPlayback("movie", a)
+	if transcoder.jobs[c.jobKey("movie")] == nil {
+		t.Fatal("old stop cancelled a new session")
+	}
+}
+
+func TestHLSPlaybackRejectsStaleSegmentGeneration(t *testing.T) {
+	cfg := &config.Config{}
+	cfg.Cache.CacheDir = t.TempDir()
+	transcoder := NewTranscoderService(cfg, zap.NewNop(), nil, nil)
+	svc := NewStreamService(cfg, zap.NewNop(), nil, transcoder)
+	scope := HLSPlaybackScope{UserID: "viewer", SessionID: "tab"}
+	key := scope.jobKey("movie")
+	dir := t.TempDir()
+	if err := os.WriteFile(filepath.Join(dir, "seg_00000.ts"), []byte("new-generation"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	transcoder.jobs[key] = &hlsJob{mediaID: "movie", jobKey: key, outputDir: dir, seekGen: 200, cancel: func() {}}
+	req := httptest.NewRequest(http.MethodGet, "/api/hls/movie/seg_00000.ts?_seek=100", nil)
+	rec := httptest.NewRecorder()
+	if err := svc.ServeHLSSegment(rec, req, "movie", "seg_00000.ts", scope); err == nil {
+		t.Fatal("stale segment request read a replacement generation")
+	}
+	if rec.Body.Len() != 0 {
+		t.Fatal("stale request exposed replacement bytes")
+	}
+}
+
+func TestHLSPlaybackScopeRequiresServerOwner(t *testing.T) {
+	req := httptest.NewRequest(http.MethodGet, "/?session_id=tab&user_id=attacker-controlled", nil)
+	if _, err := HLSPlaybackScopeForRequest(req, ""); err == nil {
+		t.Fatal("missing authenticated owner was accepted")
+	}
+	a, err := HLSPlaybackScopeForRequest(req, "real-owner")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if a.UserID != "real-owner" {
+		t.Fatal("client parameter supplied the owner")
+	}
+	req = httptest.NewRequest(http.MethodGet, "/?PlaySessionId=emby-session", nil)
+	b, err := HLSPlaybackScopeForRequest(req, "real-owner")
+	if err != nil || b.SessionID == "" {
+		t.Fatalf("Emby session must stay scoped: %#v %v", b, err)
+	}
+}

internal/service/image_proxy.go

@@ -200,7 +200,7 @@ func imageResizeConcurrency() int {
 }
 
 // Prune removes oldest cached images until disk usage is within the configured limit.
-// 原图池按独立配额与保留时长优先淘汰，客户端热路径读取的成品图最后淘汰。
+// 原图池按独立配额优先淘汰，客户端热路径读取的成品图最后淘汰。
 func (p *ImageProxy) Prune() (PruneImageCacheResult, error) {
 	if p.cfg == nil || p.cfg.Cache.ImagesMaxSizeMB <= 0 {
 		return PruneImageCacheResult{}, nil
@@ -209,11 +209,7 @@ func (p *ImageProxy) Prune() (PruneImageCacheResult, error) {
 	if p.cfg.Cache.ImagesOriginalsMaxSizeMB > 0 {
 		originalsMaxBytes = int64(p.cfg.Cache.ImagesOriginalsMaxSizeMB) * 1024 * 1024
 	}
-	var originalsMaxAge time.Duration
-	if p.cfg.Cache.ImagesOriginalsTTLHours > 0 {
-		originalsMaxAge = time.Duration(p.cfg.Cache.ImagesOriginalsTTLHours) * time.Hour
-	}
 	totalBytes := int64(p.cfg.Cache.ImagesMaxSizeMB) * 1024 * 1024
-	pools := ImageCachePools(p.cacheDir, originalsMaxBytes, originalsMaxAge)
+	pools := ImageCachePools(p.cacheDir, originalsMaxBytes)
 	return PruneImageCachePools(pools, totalBytes)
 }

internal/service/library_cover.go

@@ -0,0 +1,564 @@
+package service
+
+import (
+	"bytes"
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"image"
+	"image/jpeg"
+	"io"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+
+	"golang.org/x/image/draw"
+
+	"github.com/truewhile/MeBox/internal/model"
+	"github.com/truewhile/MeBox/internal/repository"
+)
+
+// 媒体库封面拼图（Emby 风格的「封面集」）。
+//
+// Emby / Jellyfin 在没有管理员自定义封面时，会用库内几张海报拼成一张
+// 2×2 的合成图作为库主图（folder image）。MeBox 早先只是挑评分最高的
+// 那一张单图，于是每个库的封面看起来都像「随便选了一张」。这里按同样的
+// 思路生成拼图，供 Emby 客户端、Web 和 App 共用同一份图片。
+
+const (
+	// libraryCoverDefaultWidth / Height 是拼图输出的默认画布。
+	//
+	// 库条目的 PrimaryImageAspectRatio 报的是 16:9（见 emby_system.go），
+	// 客户端按这个比例摆卡片；生成同样比例的图可以避免客户端再裁一刀。
+	libraryCoverDefaultWidth  = 480
+	libraryCoverDefaultHeight = 270
+	libraryCoverMinWidth      = 96
+	libraryCoverMaxWidth      = 1920
+	libraryCoverAspect        = 16.0 / 9.0
+
+	// libraryCoverSourceLimit 是拼图实际取用的成员海报数上限。
+	//
+	// 封面是竖切分栏：三栏在 16:9 画布上每栏接近 3:5，既保留海报主体，又能
+	// 让一个库有多部作品可辨识；再多就会把海报裁成很窄的竖条。
+	libraryCoverSourceLimit = 3
+	// libraryCoverMaxPanels 是合成函数能接受的最多分栏数（更长的来源列表
+	// 只取前几张）。留 4 是给「按库类型调栏数」留的余量。
+	libraryCoverMaxPanels = 4
+	// libraryCoverCandidatePool 是挑选海报时的候选池大小。只看最近的一批
+	// 成员，避免为一个库封面扫全库；对「最新入库」的库来说这批就是它最好
+	// 的那几张。
+	libraryCoverCandidatePool = 200
+
+	libraryCoverQuality = 85
+	libraryCoverSubdir  = "library-covers"
+)
+
+// libraryCoverSourceCache 缓存「库 → 成员海报来源」。Emby 客户端进入首页
+// 时会对每个库各请求一次主图，把这个查询压到每库 10 分钟一次，避免几十个
+// 200 行的列表查询同时打进来。
+var libraryCoverSourceCache = struct {
+	mu    sync.Mutex
+	items map[string]libraryCoverSourceEntry
+}{items: make(map[string]libraryCoverSourceEntry)}
+
+type libraryCoverSourceEntry struct {
+	sources   []string
+	expiresAt time.Time
+}
+
+const libraryCoverSourceTTL = 10 * time.Minute
+
+func cachedLibraryCoverSources(libraryID string) ([]string, bool) {
+	libraryCoverSourceCache.mu.Lock()
+	defer libraryCoverSourceCache.mu.Unlock()
+	entry, ok := libraryCoverSourceCache.items[libraryID]
+	if !ok || time.Now().After(entry.expiresAt) {
+		if ok {
+			delete(libraryCoverSourceCache.items, libraryID)
+		}
+		return nil, false
+	}
+	return entry.sources, true
+}
+
+func rememberLibraryCoverSources(libraryID string, sources []string) {
+	libraryCoverSourceCache.mu.Lock()
+	defer libraryCoverSourceCache.mu.Unlock()
+	if len(libraryCoverSourceCache.items) > 4000 {
+		libraryCoverSourceCache.items = make(map[string]libraryCoverSourceEntry)
+	}
+	libraryCoverSourceCache.items[libraryID] = libraryCoverSourceEntry{
+		sources:   sources,
+		expiresAt: time.Now().Add(libraryCoverSourceTTL),
+	}
+}
+
+// LibraryCoverSources 返回媒体库封面拼图要用的海报来源，最多 limit 张。
+//
+// 选法与网页旧逻辑一致（库内最近一批成员，按 seriesArtworkScore 取质量
+// 最高者），额外按剧集去重，避免四张海报全是同一部剧的不同集。
+func LibraryCoverSources(ctx context.Context, repos *repository.Container, libraryID string, limit int) []string {
+	if repos == nil || repos.Media == nil || strings.TrimSpace(libraryID) == "" {
+		return nil
+	}
+	if limit <= 0 || limit > libraryCoverSourceLimit {
+		limit = libraryCoverSourceLimit
+	}
+	if cached, ok := cachedLibraryCoverSources(libraryID); ok {
+		if len(cached) > limit {
+			return cached[:limit]
+		}
+		return cached
+	}
+	rows, err := repos.Media.ListByLibrariesFilteredNoCount(ctx, []string{libraryID}, 0, libraryCoverCandidatePool,
+		repository.MediaQueryFilter{IncludeNSFW: true})
+	if err != nil || len(rows) == 0 {
+		return nil
+	}
+	type candidate struct {
+		url   string
+		key   string
+		score int
+	}
+	candidates := make([]candidate, 0, len(rows))
+	for i := range rows {
+		row := rows[i]
+		raw := strings.TrimSpace(row.PosterURL)
+		if raw == "" {
+			raw = strings.TrimSpace(row.BackdropURL)
+		}
+		if raw == "" {
+			continue
+		}
+		key := mediaSeriesKey(row)
+		if key == "" {
+			key = "id:" + row.ID
+		}
+		candidates = append(candidates, candidate{url: raw, key: key, score: seriesArtworkScore(row)})
+	}
+	// 评分高的优先；同分保持数据库顺序（最近的在前），封面更贴近「最新入库」。
+	sort.SliceStable(candidates, func(i, j int) bool { return candidates[i].score > candidates[j].score })
+
+	out := make([]string, 0, limit)
+	seenKey := make(map[string]struct{}, limit)
+	seenURL := make(map[string]struct{}, limit)
+	for _, item := range candidates {
+		if len(out) >= limit {
+			break
+		}
+		if _, ok := seenKey[item.key]; ok {
+			continue
+		}
+		if _, ok := seenURL[item.url]; ok {
+			continue
+		}
+		seenKey[item.key] = struct{}{}
+		seenURL[item.url] = struct{}{}
+		out = append(out, item.url)
+	}
+	if len(out) == 0 {
+		rememberLibraryCoverSources(libraryID, nil)
+		return nil
+	}
+	rememberLibraryCoverSources(libraryID, out)
+	return out
+}
+
+// LibraryCoverCacheDir 返回拼图缓存目录（与图片代理的 images/ 分开存放，
+// 不会被图片缓存的配额清理误删）。
+func LibraryCoverCacheDir(cfgCacheDir string) string {
+	base := strings.TrimSpace(cfgCacheDir)
+	if base == "" {
+		base = "./cache"
+	}
+	return filepath.Join(base, libraryCoverSubdir)
+}
+
+// LibraryCoverImage 生成（或命中缓存）媒体库封面拼图。
+//
+// width/height 是期望的输出画布；服务端会按 16:9 收敛，返回的图片不会
+// 超过该边界。sources 由调用方提供（见 LibraryCoverSources），这样 Emby
+// 路由和 Web API 可以共用同一套生成与缓存逻辑。
+func (p *ImageProxy) LibraryCoverImage(ctx context.Context, libraryID string, sources []string, width, height int) ([]byte, error) {
+	if p == nil {
+		return nil, errors.New("image proxy unavailable")
+	}
+	libraryID = strings.TrimSpace(libraryID)
+	sources = normalizeCoverSources(sources)
+	if libraryID == "" || len(sources) == 0 {
+		return nil, errors.New("no library cover sources")
+	}
+	outW, outH := libraryCoverCanvas(width, height)
+	cachePath, sourceKey := p.libraryCoverCachePath(libraryID, sources, outW, outH)
+	if data, err := os.ReadFile(cachePath); err == nil && len(data) > 0 { // #nosec G304 -- cachePath is derived from a content hash.
+		return data, nil
+	}
+
+	key := fmt.Sprintf("library-cover:%s-%dx%d-%s", libraryID, outW, outH, sourceKey)
+	v, err, _ := p.fetchGroup.Do(key, func() (any, error) {
+		if data, err := os.ReadFile(cachePath); err == nil && len(data) > 0 { // #nosec G304 -- cachePath is derived from a content hash.
+			return data, nil
+		}
+		data, buildErr := p.buildLibraryCover(ctx, libraryID, sources, outW, outH, cachePath, sourceKey)
+		if buildErr != nil {
+			return nil, buildErr
+		}
+		return data, nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	data, _ := v.([]byte)
+	if len(data) == 0 {
+		return nil, errors.New("empty library cover")
+	}
+	return data, nil
+}
+
+func (p *ImageProxy) buildLibraryCover(ctx context.Context, libraryID string, sources []string, width, height int, cachePath, sourceKey string) ([]byte, error) {
+	images := p.fetchCoverSources(ctx, sources)
+	if len(images) == 0 {
+		return nil, errors.New("no library cover image fetched")
+	}
+	// 解码与合成是 CPU 密集操作：和缩略图共用同一组解码槽，避免一次首页
+	// 刷新把 2 核主机打满。
+	release, ok := p.acquireResizeSlotWithin(ctx, p.resizeQueueTimeout())
+	if ok {
+		defer release()
+	}
+	data, err := composeLibraryCover(images, width, height)
+	if err != nil {
+		return nil, err
+	}
+	if err := os.MkdirAll(filepath.Dir(cachePath), 0o750); err != nil {
+		return data, nil
+	}
+	if err := writeFileAtomic(cachePath, data); err != nil {
+		p.warn("write library cover cache failed", err)
+		return data, nil
+	}
+	p.pruneLibraryCoverVariants(filepath.Dir(cachePath), libraryID, sourceKey)
+	return data, nil
+}
+
+// fetchCoverSources 并发拉取成员海报（受图片代理自身的缓存/鉴权/SSRF 规则
+// 保护）。单张失败只丢弃该张，其余仍然可以拼图。
+func (p *ImageProxy) fetchCoverSources(ctx context.Context, sources []string) [][]byte {
+	out := make([][]byte, len(sources))
+	var wg sync.WaitGroup
+	sem := make(chan struct{}, libraryCoverMaxPanels)
+	fetchCtx, cancel := context.WithTimeout(ctx, 15*time.Second)
+	defer cancel()
+	for i, raw := range sources {
+		i, raw := i, raw
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			sem <- struct{}{}
+			defer func() { <-sem }()
+			data, err := p.coverSourceBytes(fetchCtx, raw)
+			if err != nil || len(data) == 0 {
+				return
+			}
+			out[i] = data
+		}()
+	}
+	wg.Wait()
+	compacted := make([][]byte, 0, len(out))
+	for _, data := range out {
+		if len(data) > 0 {
+			compacted = append(compacted, data)
+		}
+	}
+	return compacted
+}
+
+// coverSourceBytes 读取一张海报来源。
+//
+// 刮削会把 sidecar 海报存成 /media/... 这类绝对路径，而 fetch 路径只接受
+// http(s)（validateURL 要求有 host），直接丢给 Fetch 会全部失败。本地路径
+// 按图片代理同一套 isAllowedLocalPath 白名单读盘，远程地址才走 Fetch，
+// 这样鉴权、SSRF 校验与磁盘缓存的行为与 /api/img 完全一致。
+func (p *ImageProxy) coverSourceBytes(ctx context.Context, raw string) ([]byte, error) {
+	raw = strings.TrimSpace(raw)
+	if raw == "" {
+		return nil, errors.New("empty cover source")
+	}
+	if isLocalImagePath(raw) {
+		abs, err := filepath.Abs(filepath.Clean(raw))
+		if err != nil {
+			return nil, err
+		}
+		if !p.isAllowedLocalPath(abs) {
+			return nil, errors.New("local cover path not allowed")
+		}
+		return os.ReadFile(abs) // #nosec G304 -- path validated against the library roots above.
+	}
+	data, _, err := p.Fetch(ctx, raw)
+	if err != nil {
+		return nil, err
+	}
+	return data, nil
+}
+
+// libraryCoverCachePath 生成缓存路径。
+//
+// 文件名里的 sourceKey 只由成员海报列表决定（不含尺寸）：成员变化时换一批
+// 文件，同一批成员的多个尺寸变体可以共存，不会被互相删掉。size 单独进文件名，
+// 让 Emby（按客户端 maxWidth/maxHeight）与 Web/App（固定档位）各用自己的成品。
+func (p *ImageProxy) libraryCoverCachePath(libraryID string, sources []string, width, height int) (string, string) {
+	h := sha256.New()
+	for _, src := range sources {
+		_, _ = io.WriteString(h, src)
+		_, _ = h.Write([]byte{0})
+	}
+	sourceKey := hex.EncodeToString(h.Sum(nil))[:16]
+	name := fmt.Sprintf("%s-%dx%d-%s.jpg", safeCoverFileID(libraryID), width, height, sourceKey)
+	return filepath.Join(LibraryCoverCacheDir(p.cacheDirBase()), name), sourceKey
+}
+
+func (p *ImageProxy) cacheDirBase() string {
+	if p != nil && p.cfg != nil {
+		return p.cfg.Cache.CacheDir
+	}
+	return ""
+}
+
+// pruneLibraryCoverVariants 清掉同一个库、旧成员列表留下的封面文件（含各
+// 尺寸变体），当前成员列表对应的成品全部保留。
+func (p *ImageProxy) pruneLibraryCoverVariants(dir, libraryID, keepSourceKey string) {
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		return
+	}
+	prefix := safeCoverFileID(libraryID) + "-"
+	for _, entry := range entries {
+		name := entry.Name()
+		if entry.IsDir() || !strings.HasPrefix(name, prefix) || !strings.HasSuffix(name, ".jpg") {
+			continue
+		}
+		if strings.Contains(name, "-"+keepSourceKey+".jpg") {
+			continue
+		}
+		_ = os.Remove(filepath.Join(dir, name)) // #nosec G304 -- name comes from ReadDir of our own cache dir.
+	}
+}
+
+// safeCoverFileID 让文件名只包含安全字符（库 ID 来自数据库，但仍做一次
+// 白名单过滤，避免任何路径分隔符进入文件名）。
+func safeCoverFileID(libraryID string) string {
+	var b strings.Builder
+	for _, r := range libraryID {
+		switch {
+		case r >= 'a' && r <= 'z', r >= 'A' && r <= 'Z', r >= '0' && r <= '9', r == '-', r == '_':
+			b.WriteRune(r)
+		}
+	}
+	if b.Len() == 0 {
+		return "library"
+	}
+	return b.String()
+}
+
+func normalizeCoverSources(sources []string) []string {
+	seen := make(map[string]struct{}, len(sources))
+	out := make([]string, 0, len(sources))
+	for _, raw := range sources {
+		raw = strings.TrimSpace(raw)
+		if raw == "" {
+			continue
+		}
+		if _, ok := seen[raw]; ok {
+			continue
+		}
+		seen[raw] = struct{}{}
+		out = append(out, raw)
+		if len(out) >= libraryCoverMaxPanels {
+			break
+		}
+	}
+	return out
+}
+
+// libraryCoverCanvas 把请求的尺寸收敛到 16:9 画布，并夹在合理区间内。
+func libraryCoverCanvas(width, height int) (int, int) {
+	if width <= 0 && height <= 0 {
+		return libraryCoverDefaultWidth, libraryCoverDefaultHeight
+	}
+	if width <= 0 {
+		width = int(float64(height)*libraryCoverAspect + 0.5)
+	}
+	if height <= 0 {
+		height = int(float64(width)/libraryCoverAspect + 0.5)
+	}
+	// 客户端给的是一个「不超过」的盒子：按 16:9 装进去。
+	if float64(width)/float64(height) > libraryCoverAspect {
+		width = int(float64(height)*libraryCoverAspect + 0.5)
+	} else {
+		height = int(float64(width)/libraryCoverAspect + 0.5)
+	}
+	if width < libraryCoverMinWidth {
+		width = libraryCoverMinWidth
+		height = int(float64(width)/libraryCoverAspect + 0.5)
+	}
+	if width > libraryCoverMaxWidth {
+		width = libraryCoverMaxWidth
+		height = int(float64(width)/libraryCoverAspect + 0.5)
+	}
+	return width, height
+}
+
+// composeLibraryCover 把若干张海报拼成库封面：竖切成若干等宽竖条。
+//
+//   - 1 张：铺满整块画布；
+//   - 2 张：左右各一半（默认形态，对应网页/客户端卡片的分屏观感）；
+//   - 3/4 张：三等分 / 四等分竖条。
+//
+// 每格按中心裁切铺满（crop-to-fill），这样不同比例的海报都能对齐分栏。
+func composeLibraryCover(images [][]byte, width, height int) ([]byte, error) {
+	if len(images) == 0 {
+		return nil, errors.New("no images to compose")
+	}
+	if width <= 0 || height <= 0 {
+		return nil, errors.New("invalid cover size")
+	}
+	decoded := make([]image.Image, 0, len(images))
+	for _, data := range images {
+		img, ok := decodeCoverImage(data)
+		if ok {
+			decoded = append(decoded, img)
+		}
+		if len(decoded) >= libraryCoverMaxPanels {
+			break
+		}
+	}
+	if len(decoded) == 0 {
+		return nil, errors.New("no decodable cover images")
+	}
+	canvas := image.NewRGBA(image.Rect(0, 0, width, height))
+	cells := make([]image.Rectangle, 0, len(decoded))
+	if len(decoded) == 1 {
+		cells = append(cells, canvas.Bounds())
+	} else {
+		for i := range decoded {
+			x0 := width * i / len(decoded)
+			x1 := width * (i + 1) / len(decoded)
+			cells = append(cells, image.Rect(x0, 0, x1, height))
+		}
+	}
+	for i, cell := range cells {
+		drawCoverCell(canvas, cell, decoded[i])
+	}
+	var buf bytes.Buffer
+	if err := jpeg.Encode(&buf, canvas, &jpeg.Options{Quality: libraryCoverQuality}); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+// decodeCoverImage 解码一张海报，并对异常大的图做像素上限保护：一次拼图
+// 会同时解码 4 张，2 核 2G 的机器上不能任由超大原图把内存吃光。
+func decodeCoverImage(data []byte) (image.Image, bool) {
+	if len(data) == 0 {
+		return nil, false
+	}
+	cfg, _, err := image.DecodeConfig(bytes.NewReader(data))
+	if err != nil || cfg.Width <= 0 || cfg.Height <= 0 {
+		return nil, false
+	}
+	if cfg.Width*cfg.Height > imageResizeMaxSourcePixels {
+		return nil, false
+	}
+	img, _, err := image.Decode(bytes.NewReader(data))
+	if err != nil {
+		return nil, false
+	}
+	return img, true
+}
+
+// drawCoverCell 把一张图按中心裁切铺满目标格子。
+func drawCoverCell(dst *image.RGBA, cell image.Rectangle, src image.Image) {
+	if src == nil || cell.Dx() <= 0 || cell.Dy() <= 0 {
+		return
+	}
+	bounds := src.Bounds()
+	srcW, srcH := bounds.Dx(), bounds.Dy()
+	if srcW <= 0 || srcH <= 0 {
+		return
+	}
+	targetAspect := float64(cell.Dx()) / float64(cell.Dy())
+	srcAspect := float64(srcW) / float64(srcH)
+	crop := bounds
+	if srcAspect > targetAspect {
+		cropW := int(float64(srcH)*targetAspect + 0.5)
+		if cropW < 1 {
+			cropW = 1
+		}
+		x0 := bounds.Min.X + (srcW-cropW)/2
+		crop = image.Rect(x0, bounds.Min.Y, x0+cropW, bounds.Max.Y)
+	} else if srcAspect < targetAspect {
+		cropH := int(float64(srcW)/targetAspect + 0.5)
+		if cropH < 1 {
+			cropH = 1
+		}
+		y0 := bounds.Min.Y + (srcH-cropH)/2
+		crop = image.Rect(bounds.Min.X, y0, bounds.Max.X, y0+cropH)
+	}
+	scale := float64(cell.Dx()) / float64(crop.Dx())
+	var scaler draw.Scaler = draw.CatmullRom
+	if scale < imageResizeCheapScaleRatio {
+		scaler = draw.ApproxBiLinear
+	}
+	scaler.Scale(dst, cell, src, crop, draw.Src, nil)
+}
+
+// writeFileAtomic 先写临时文件再 rename，避免并发的读取方读到半个文件。
+func writeFileAtomic(path string, data []byte) error {
+	dir := filepath.Dir(path)
+	if err := os.MkdirAll(dir, 0o750); err != nil {
+		return err
+	}
+	tmp, err := os.CreateTemp(dir, ".cover-*")
+	if err != nil {
+		return err
+	}
+	if _, err := tmp.Write(data); err != nil {
+		_ = tmp.Close()
+		_ = os.Remove(tmp.Name())
+		return err
+	}
+	if err := tmp.Close(); err != nil {
+		_ = os.Remove(tmp.Name())
+		return err
+	}
+	if err := os.Rename(tmp.Name(), path); err != nil {
+		_ = os.Remove(tmp.Name())
+		return err
+	}
+	return nil
+}
+
+// LibraryCoverSourcesForLibrary 是给 handler 的便捷封装：库存在且没有自定
+// 义封面时返回成员海报来源；远程挂载库由各自的上游负责封面，不在此生成。
+func LibraryCoverSourcesForLibrary(ctx context.Context, repos *repository.Container, libraryID string) ([]string, *model.Library) {
+	if repos == nil || repos.Library == nil {
+		return nil, nil
+	}
+	libraryID = strings.TrimSpace(libraryID)
+	if libraryID == "" {
+		return nil, nil
+	}
+	lib, err := repos.Library.FindByID(ctx, libraryID)
+	if err != nil || lib == nil {
+		return nil, nil
+	}
+	if strings.TrimSpace(lib.CoverURL) != "" {
+		return nil, lib
+	}
+	return LibraryCoverSources(ctx, repos, libraryID, libraryCoverSourceLimit), lib
+}

internal/service/library_cover_test.go

@@ -0,0 +1,335 @@
+package service
+
+import (
+	"bytes"
+	"image"
+	"image/color"
+	"image/jpeg"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"os"
+	"path/filepath"
+	"sync/atomic"
+	"testing"
+
+	"go.uber.org/zap"
+
+	"github.com/truewhile/MeBox/internal/config"
+	"github.com/truewhile/MeBox/internal/model"
+)
+
+func solidJPEG(t *testing.T, c color.Color, w, h int) []byte {
+	t.Helper()
+	img := image.NewRGBA(image.Rect(0, 0, w, h))
+	for y := 0; y < h; y++ {
+		for x := 0; x < w; x++ {
+			img.Set(x, y, c)
+		}
+	}
+	var buf bytes.Buffer
+	if err := jpeg.Encode(&buf, img, &jpeg.Options{Quality: 95}); err != nil {
+		t.Fatalf("encode jpeg: %v", err)
+	}
+	return buf.Bytes()
+}
+
+func decodeJPEG(t *testing.T, data []byte) image.Image {
+	t.Helper()
+	img, err := jpeg.Decode(bytes.NewReader(data))
+	if err != nil {
+		t.Fatalf("decode composed cover: %v", err)
+	}
+	return img
+}
+
+// TestComposeLibraryCoverSplitsIntoSideBySideColumns 保证多张海报是竖切成
+// 左右分栏（左→右顺序），而不是 2×2 田字格。
+func TestComposeLibraryCoverSplitsIntoSideBySideColumns(t *testing.T) {
+	images := [][]byte{
+		solidJPEG(t, color.RGBA{R: 220, A: 255}, 200, 300),
+		solidJPEG(t, color.RGBA{G: 220, A: 255}, 200, 300),
+		solidJPEG(t, color.RGBA{B: 220, A: 255}, 200, 300),
+		solidJPEG(t, color.RGBA{R: 220, G: 220, A: 255}, 200, 300),
+	}
+	out, err := composeLibraryCover(images, 480, 270)
+	if err != nil {
+		t.Fatalf("compose: %v", err)
+	}
+	img := decodeJPEG(t, out)
+	if img.Bounds().Dx() != 480 || img.Bounds().Dy() != 270 {
+		t.Fatalf("size = %v, want 480x270", img.Bounds())
+	}
+	// 四张图 → 四条竖栏；同一栏从顶部到底部颜色一致（竖切，不是上下分割）。
+	y := img.Bounds().Dy() / 2
+	checks := []struct {
+		name     string
+		x        int
+		dominant func(color.RGBA) bool
+	}{
+		{"column 1 red", 60, func(c color.RGBA) bool { return c.R > c.G+40 && c.R > c.B+40 }},
+		{"column 2 green", 180, func(c color.RGBA) bool { return c.G > c.R+40 && c.G > c.B+40 }},
+		{"column 3 blue", 300, func(c color.RGBA) bool { return c.B > c.R+40 && c.B > c.G+40 }},
+		{"column 4 yellow", 420, func(c color.RGBA) bool { return c.R > c.B+40 && c.G > c.B+40 }},
+	}
+	for _, check := range checks {
+		for _, yy := range []int{2, y, img.Bounds().Dy() - 3} {
+			r, g, b, _ := img.At(check.x, yy).RGBA()
+			got := color.RGBA{R: uint8(r >> 8), G: uint8(g >> 8), B: uint8(b >> 8), A: 255}
+			if !check.dominant(got) {
+				t.Fatalf("%s at y=%d: pixel = %v", check.name, yy, got)
+			}
+		}
+	}
+}
+
+// TestComposeLibraryCoverHandlesFewerPosters 覆盖 1/2/3 张成员的布局。
+func TestComposeLibraryCoverHandlesFewerPosters(t *testing.T) {
+	cases := []struct {
+		name  string
+		count int
+	}{
+		{"single", 1},
+		{"pair", 2},
+		{"triple", 3},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			images := make([][]byte, 0, tc.count)
+			for i := 0; i < tc.count; i++ {
+				images = append(images, solidJPEG(t, color.RGBA{R: 200, G: 120, A: 255}, 300, 450))
+			}
+			out, err := composeLibraryCover(images, 320, 180)
+			if err != nil {
+				t.Fatalf("compose: %v", err)
+			}
+			img := decodeJPEG(t, out)
+			if img.Bounds().Dx() != 320 || img.Bounds().Dy() != 180 {
+				t.Fatalf("size = %v, want 320x180", img.Bounds())
+			}
+		})
+	}
+}
+
+// TestComposeLibraryCoverSkipsUndecodableSources 保证一张坏图不会让整张
+// 封面失败：其余可解码的成员仍然会拼出来。
+func TestComposeLibraryCoverSkipsUndecodableSources(t *testing.T) {
+	images := [][]byte{
+		[]byte("not an image"),
+		solidJPEG(t, color.RGBA{G: 200, A: 255}, 200, 300),
+	}
+	out, err := composeLibraryCover(images, 240, 135)
+	if err != nil {
+		t.Fatalf("compose: %v", err)
+	}
+	if len(out) == 0 {
+		t.Fatal("expected composed cover bytes")
+	}
+	if _, err := composeLibraryCover([][]byte{[]byte("nope")}, 240, 135); err == nil {
+		t.Fatal("expected error when no source is decodable")
+	}
+}
+
+func TestLibraryCoverCanvasKeepsSixteenByNine(t *testing.T) {
+	cases := []struct {
+		inW, inH   int
+		wantW      int
+		wantH      int
+		checkRatio bool
+	}{
+		{0, 0, 480, 270, true},
+		{640, 480, 640, 360, true},   // 4:3 盒子 → 装进 16:9
+		{2000, 0, 1920, 1080, true},  // 超上限 → 夹紧
+		{40, 0, 96, 54, true},        // 低于下限 → 抬到最小宽度
+		{0, 540, 960, 540, false},    // 只给高度 → 按 16:9 推宽度
+	}
+	for _, tc := range cases {
+		w, h := libraryCoverCanvas(tc.inW, tc.inH)
+		if w != tc.wantW || h != tc.wantH {
+			t.Fatalf("libraryCoverCanvas(%d,%d) = %dx%d, want %dx%d", tc.inW, tc.inH, w, h, tc.wantW, tc.wantH)
+		}
+		if tc.checkRatio && w != 0 && h != 0 {
+			ratio := float64(w) / float64(h)
+			if ratio < 1.7 || ratio > 1.85 {
+				t.Fatalf("ratio for %dx%d = %.3f, want ~1.78", tc.inW, tc.inH, ratio)
+			}
+		}
+	}
+}
+
+// TestLibraryCoverSourcesDedupesSeries 保证封面不会两张都是同一部剧的不同集，
+// 并且优先取海报、没有海报时退回剧照、完全没有图的成员被跳过。
+func TestLibraryCoverSourcesDedupesSeries(t *testing.T) {
+	svc := newTestEmbyService(t)
+	lib := model.Library{Name: "剧集", Path: "/media/tv", Type: "tv", Enabled: true}
+	if err := svc.repo.Library.Create(t.Context(), &lib); err != nil {
+		t.Fatalf("create library: %v", err)
+	}
+	rows := []model.Media{
+		{Base: model.Base{ID: "a1"}, LibraryID: lib.ID, Title: "A", Path: "/media/tv/A/S01E01.mkv", SeriesID: "series-a", PosterURL: "https://img/a1.jpg"},
+		{Base: model.Base{ID: "a2"}, LibraryID: lib.ID, Title: "A", Path: "/media/tv/A/S01E02.mkv", SeriesID: "series-a", PosterURL: "https://img/a2.jpg"},
+		{Base: model.Base{ID: "b1"}, LibraryID: lib.ID, Title: "B", Path: "/media/tv/B/S01E01.mkv", SeriesID: "series-b", PosterURL: "https://img/b1.jpg"},
+		{Base: model.Base{ID: "c1"}, LibraryID: lib.ID, Title: "C", Path: "/media/tv/C/S01E01.mkv", SeriesID: "series-c", BackdropURL: "https://img/c1-backdrop.jpg"},
+		{Base: model.Base{ID: "d1"}, LibraryID: lib.ID, Title: "D", Path: "/media/tv/D/S01E01.mkv", SeriesID: "series-d"},
+	}
+	for i := range rows {
+		if err := svc.repo.DB.Create(&rows[i]).Error; err != nil {
+			t.Fatalf("create media: %v", err)
+		}
+	}
+	// 竖切三栏：一部剧只出一张，无图成员被跳过 → 正好 3 张。
+	sources := LibraryCoverSources(t.Context(), svc.repo, lib.ID, libraryCoverSourceLimit)
+	if len(sources) != 3 {
+		t.Fatalf("sources = %v, want 3 (一部剧一张、跳过无图成员)", sources)
+	}
+	seen := map[string]bool{}
+	for _, src := range sources {
+		if seen[src] {
+			t.Fatalf("duplicate source in %v", sources)
+		}
+		seen[src] = true
+	}
+	// 同一部剧只会出现一次：具体保留哪一集由查询顺序决定，但绝不能两张。
+	if seen["https://img/a1.jpg"] && seen["https://img/a2.jpg"] {
+		t.Fatalf("same series contributed two posters: %v", sources)
+	}
+	if !seen["https://img/a1.jpg"] && !seen["https://img/a2.jpg"] {
+		t.Fatalf("series A is missing from sources: %v", sources)
+	}
+	if !seen["https://img/c1-backdrop.jpg"] {
+		t.Fatalf("member without poster should fall back to backdrop: %v", sources)
+	}
+}
+
+// TestLibraryCoverImageCachesComposedBytes 验证生成结果会落盘复用：同一份
+// 内容第二次请求不再回源。
+func TestLibraryCoverImageCachesComposedBytes(t *testing.T) {
+	var hits int32
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		atomic.AddInt32(&hits, 1)
+		w.Header().Set("Content-Type", "image/jpeg")
+		_, _ = w.Write(solidJPEG(t, color.RGBA{R: 180, G: 140, B: 90, A: 255}, 240, 360))
+	}))
+	defer upstream.Close()
+
+	parsed, err := url.Parse(upstream.URL)
+	if err != nil {
+		t.Fatalf("parse upstream: %v", err)
+	}
+	cacheCfg := &config.Config{Cache: config.CacheConfig{CacheDir: filepath.Join(t.TempDir(), "cache")}}
+	proxy := NewImageProxy(cacheCfg, zap.NewNop())
+	proxy.SetAllowedRemoteHostsProvider(func() []string { return []string{parsed.Host} })
+
+	sources := []string{upstream.URL + "/1.jpg", upstream.URL + "/2.jpg", upstream.URL + "/3.jpg", upstream.URL + "/4.jpg"}
+	first, err := proxy.LibraryCoverImage(t.Context(), "lib-1", sources, 480, 270)
+	if err != nil {
+		t.Fatalf("first cover: %v", err)
+	}
+	if img := decodeJPEG(t, first); img.Bounds().Dx() != 480 || img.Bounds().Dy() != 270 {
+		t.Fatalf("size = %v, want 480x270", img.Bounds())
+	}
+	hitsAfterFirst := atomic.LoadInt32(&hits)
+	if hitsAfterFirst != 4 {
+		t.Fatalf("upstream hits = %d, want one per source", hitsAfterFirst)
+	}
+
+	second, err := proxy.LibraryCoverImage(t.Context(), "lib-1", sources, 480, 270)
+	if err != nil {
+		t.Fatalf("second cover: %v", err)
+	}
+	if !bytes.Equal(first, second) {
+		t.Fatal("cached cover bytes differ from the first build")
+	}
+	if got := atomic.LoadInt32(&hits); got != hitsAfterFirst {
+		t.Fatalf("cache miss: upstream hits %d -> %d", hitsAfterFirst, got)
+	}
+
+	// 内容变了要重新生成（成员海报换了新文件）。已缓存的三张海报不会重下，
+	// 只有新增的那张会回源。
+	changed := append([]string{}, sources[:3]...)
+	changed = append(changed, upstream.URL+"/5.jpg")
+	if _, err := proxy.LibraryCoverImage(t.Context(), "lib-1", changed, 480, 270); err != nil {
+		t.Fatalf("cover after content change: %v", err)
+	}
+	if got := atomic.LoadInt32(&hits); got != hitsAfterFirst+1 {
+		t.Fatalf("content change should rebuild with one new fetch, hits = %d", got)
+	}
+
+	// 同一批成员的另一个尺寸档位要能共存：Web/App 与 Emby 请求的尺寸不同，
+	// 不能互相把对方的成品当「旧内容」删掉。
+	if _, err := proxy.LibraryCoverImage(t.Context(), "lib-1", changed, 400, 225); err != nil {
+		t.Fatalf("other size cover: %v", err)
+	}
+	entries, err := os.ReadDir(LibraryCoverCacheDir(cacheCfg.Cache.CacheDir))
+	if err != nil {
+		t.Fatalf("read cover cache dir: %v", err)
+	}
+	files := make([]string, 0, len(entries))
+	for _, entry := range entries {
+		if !entry.IsDir() {
+			files = append(files, entry.Name())
+		}
+	}
+	if len(files) != 2 {
+		t.Fatalf("expected 480x270 and 400x225 variants to coexist, got %v", files)
+	}
+}
+
+// TestLibraryCoverSourceBytesReadsLocalSidecarPoster 覆盖刮削把海报存成
+// /media/... 本地绝对路径的情况：这类来源没有 http(s) host，不能走 Fetch，
+// 必须按库根目录白名单直接读盘，否则整张拼图会因为「没有可解码的海报」而
+// 生成失败（生产环境所有本地库都是这种来源）。
+func TestLibraryCoverSourceBytesReadsLocalSidecarPoster(t *testing.T) {
+	libDir := t.TempDir()
+	posterPath := filepath.Join(libDir, "poster.jpg")
+	if err := os.WriteFile(posterPath, solidJPEG(t, color.RGBA{R: 180, G: 90, A: 255}, 200, 300), 0o644); err != nil {
+		t.Fatalf("write poster: %v", err)
+	}
+	proxy := NewImageProxy(&config.Config{Cache: config.CacheConfig{CacheDir: filepath.Join(t.TempDir(), "cache")}}, zap.NewNop())
+
+	// 未登记为库根目录时必须拒绝读取。
+	if _, err := proxy.coverSourceBytes(t.Context(), posterPath); err == nil {
+		t.Fatal("expected local path outside the library roots to be rejected")
+	}
+
+	proxy.SetLibraryRootsProvider(func() []string { return []string{libDir} })
+	data, err := proxy.coverSourceBytes(t.Context(), posterPath)
+	if err != nil {
+		t.Fatalf("read local poster: %v", err)
+	}
+	if len(data) == 0 {
+		t.Fatal("expected poster bytes")
+	}
+	if _, ok := decodeCoverImage(data); !ok {
+		t.Fatal("local poster should decode")
+	}
+}
+
+// TestLibraryCoverSourcesForLibrarySkipsCustomCover 保证管理员填了自定义
+// 封面时不会再生成拼图（沿用自定义图）。
+func TestLibraryCoverSourcesForLibrarySkipsCustomCover(t *testing.T) {
+	svc := newTestEmbyService(t)
+	lib := model.Library{Name: "电影", Path: "/media/movies", Type: "movie", CoverURL: "https://example.com/custom.jpg"}
+	if err := svc.repo.Library.Create(t.Context(), &lib); err != nil {
+		t.Fatalf("create library: %v", err)
+	}
+	if err := svc.repo.DB.Create(&model.Media{
+		Base:      model.Base{ID: "m1"},
+		LibraryID: lib.ID,
+		Title:     "M",
+		Path:      "/media/movies/m1.mkv",
+		PosterURL: "https://img/m1.jpg",
+	}).Error; err != nil {
+		t.Fatalf("create media: %v", err)
+	}
+	sources, found := LibraryCoverSourcesForLibrary(t.Context(), svc.repo, lib.ID)
+	if found == nil || found.CoverURL != lib.CoverURL {
+		t.Fatalf("library = %#v, want the existing library", found)
+	}
+	if len(sources) != 0 {
+		t.Fatalf("expected no generated sources with a custom cover, got %v", sources)
+	}
+	if _, blank := LibraryCoverSourcesForLibrary(t.Context(), svc.repo, "missing"); blank != nil {
+		t.Fatalf("unknown library should return nil, got %#v", blank)
+	}
+}

internal/service/runtime_settings.go

@@ -126,13 +126,6 @@ func ApplyRuntimeSetting(cfg *config.Config, key, value string) {
 			}
 			cfg.Cache.ImagesOriginalsMaxSizeMB = n
 		}
-	case "cache.images_originals_ttl_hours":
-		if n, err := strconv.Atoi(value); err == nil {
-			if n < 0 {
-				n = 0
-			}
-			cfg.Cache.ImagesOriginalsTTLHours = n
-		}
 	case "cache.memory_max_size_mb":
 		n := config.DefaultCacheMemoryMaxSizeMB
 		if value != "" {

internal/service/scheduler.go

@@ -80,10 +80,10 @@ func (s *SchedulerService) SetExpiryWatcher(watcher *TelegramExpiryWatcher) {
 }
 
 // ImageCachePolicy 是一次图片缓存清理要用的策略（全部为 0 表示不做任何清理）。
+// 只有容量配额，没有保留时长：淘汰只看占用，不按文件年龄删除。
 type ImageCachePolicy struct {
 	TotalBytes     int64
 	OriginalsBytes int64
-	OriginalsAge   time.Duration
 }
 
 func (s *SchedulerService) SetImageCachePolicyProvider(fn func() ImageCachePolicy) {

internal/service/scheduler_local_jobs.go

@@ -299,18 +299,18 @@ func (s *SchedulerService) jobCleanTranscodeCache(ctx context.Context) error {
 	return walkAndPrune(s.cacheDir+"/hls", cutoff)
 }
 
-// jobCleanImageCache prunes the image proxy cache: 原图按保留时长与独立配额
-// 优先淘汰，总量超限时再淘汰派生成品。
+// jobCleanImageCache prunes the image proxy cache: 原图按独立配额优先淘汰，
+// 总量超限时再淘汰派生成品。全程只看占用，不按文件年龄删除。
 func (s *SchedulerService) jobCleanImageCache(ctx context.Context) error {
 	if s.cacheDir == "" {
 		return nil
 	}
 	policy := s.imageCachePolicy()
-	if policy.TotalBytes <= 0 && policy.OriginalsBytes <= 0 && policy.OriginalsAge <= 0 {
+	if policy.TotalBytes <= 0 && policy.OriginalsBytes <= 0 {
 		return nil
 	}
 	imagesDir := filepath.Join(s.cacheDir, "images")
-	pools := ImageCachePools(imagesDir, policy.OriginalsBytes, policy.OriginalsAge)
+	pools := ImageCachePools(imagesDir, policy.OriginalsBytes)
 	res, err := PruneImageCachePools(pools, policy.TotalBytes)
 	if err != nil {
 		if s.log != nil {

internal/service/service_builder.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"errors"
 	"strings"
-	"time"
 
 	"go.uber.org/zap"
 
@@ -222,9 +221,6 @@ func (b *serviceContainerBuilder) initAccessAndStorageServices() {
 		if b.cfg.Cache.ImagesOriginalsMaxSizeMB > 0 {
 			policy.OriginalsBytes = int64(b.cfg.Cache.ImagesOriginalsMaxSizeMB) * 1024 * 1024
 		}
-		if b.cfg.Cache.ImagesOriginalsTTLHours > 0 {
-			policy.OriginalsAge = time.Duration(b.cfg.Cache.ImagesOriginalsTTLHours) * time.Hour
-		}
 		return policy
 	})
 	// 阅读正文缓存清理：由阅读模块自己按 TTL + 容量 LRU 淘汰（见 reader_content_cache.go）。

internal/service/stream_hls.go

@@ -17,7 +17,8 @@ import (
 // Optional query `start` (seconds) restarts ffmpeg from that source offset so
 // the web player can scrub the full timeline without waiting for a full
 // head-to-tail transcode.
-func (s *StreamService) ServeHLSPlaylist(w http.ResponseWriter, r *http.Request, mediaID string) error {
+func (s *StreamService) ServeHLSPlaylist(w http.ResponseWriter, r *http.Request, mediaID string, scopes ...HLSPlaybackScope) error {
+	jobKey := hlsPlaybackJobKey(mediaID, scopes)
 	// 「客户端直连解码」模式下宿主机不提供转码，HLS 一律拒绝，
 	// 迫使播放器走 direct play 本地解码。
 	if s.directPlayOnly(r.Context()) {
@@ -27,19 +28,23 @@ func (s *StreamService) ServeHLSPlaylist(w http.ResponseWriter, r *http.Request,
 	seekGen := parseHLSSeekGen(r)
 	subtitleStream := parseHLSSubtitleStream(r)
 	quality := parseHLSQuality(r)
-	if _, err := s.transcoder.EnsureJobFromSubtitleQuality(r.Context(), mediaID, startSec, seekGen, subtitleStream, quality); err != nil {
+	if _, err := s.transcoder.EnsureJobFromSubtitleQuality(r.Context(), mediaID, startSec, seekGen, subtitleStream, quality, scopes...); err != nil {
 		return err
 	}
-	s.transcoder.TouchJob(mediaID)
+	s.transcoder.TouchJob(jobKey)
 	readyTimeout := 45 * time.Second
 	if startSec > 0.05 {
 		// Mid-file HTTP seeks (esp. WMV) need longer before the first segment appears.
 		readyTimeout = 120 * time.Second
 	}
-	if !s.transcoder.WaitReady(r.Context(), mediaID, readyTimeout) {
+	if !s.transcoder.WaitReady(r.Context(), jobKey, readyTimeout) {
 		return errors.New("hls playlist not ready")
 	}
-	playlist := s.transcoder.PlaylistPath(mediaID)
+	outputDir, err := s.transcoder.hlsOutputDir(jobKey, seekGen)
+	if err != nil {
+		return err
+	}
+	playlist := filepath.Join(outputDir, "index.m3u8")
 	f, err := os.Open(playlist) // #nosec G304 -- playlist path is generated under the transcoder cache directory for this media ID.
 	if err != nil {
 		return err
@@ -49,12 +54,18 @@ func (s *StreamService) ServeHLSPlaylist(w http.ResponseWriter, r *http.Request,
 	w.Header().Set("Content-Type", "application/vnd.apple.mpegurl")
 	w.Header().Set("Cache-Control", "no-cache")
 	w.Header().Set("Content-Disposition", "inline")
-	if r.URL.RawQuery != "" {
+	rawQuery := r.URL.RawQuery
+	if len(scopes) > 0 && scopes[0].SessionID != "" {
+		query := r.URL.Query()
+		query.Set("session_id", scopes[0].SessionID)
+		rawQuery = query.Encode()
+	}
+	if rawQuery != "" {
 		data, err := io.ReadAll(f)
 		if err != nil {
 			return err
 		}
-		playlist := appendQueryToHLSSegments(string(data), r.URL.RawQuery)
+		playlist := appendQueryToHLSSegments(string(data), rawQuery)
 		_, err = io.WriteString(w, playlist)
 		return err
 	}
@@ -171,19 +182,26 @@ func filterHLSSegmentQuery(rawQuery string) string {
 }
 
 // ServeHLSSegment writes a single .ts segment from the on-disk cache.
-func (s *StreamService) ServeHLSSegment(w http.ResponseWriter, r *http.Request, mediaID, segment string) error {
-	s.transcoder.TouchJob(mediaID)
+func (s *StreamService) ServeHLSSegment(w http.ResponseWriter, r *http.Request, mediaID, segment string, scopes ...HLSPlaybackScope) error {
+	jobKey := hlsPlaybackJobKey(mediaID, scopes)
+	outputDir, err := s.transcoder.hlsOutputDir(jobKey, parseHLSSeekGen(r))
+	if err != nil {
+		if len(scopes) > 0 || parseHLSSeekGen(r) > 0 {
+			return err
+		}
+		outputDir = s.transcoder.HLSDir(jobKey) // Legacy internal static-file callers.
+	}
 	// Only allow segments that look like seg_NNNNN.ts so we cannot be tricked
 	// into reading arbitrary files via path traversal.
 	if !strings.HasPrefix(segment, "seg_") || !strings.HasSuffix(segment, ".ts") {
 		return errors.New("bad segment")
 	}
-	full := filepath.Join(s.transcoder.HLSDir(mediaID), segment)
+	full := filepath.Join(outputDir, segment)
 	abs, err := filepath.Abs(full)
 	if err != nil {
 		return err
 	}
-	dir, _ := filepath.Abs(s.transcoder.HLSDir(mediaID))
+	dir, _ := filepath.Abs(outputDir)
 	if !pathWithin(abs, dir) {
 		return errors.New("path escape")
 	}

internal/service/transcoder.go

@@ -1,7 +1,8 @@
 // Package service — HLS on-demand transcoder.
 //
 // TranscoderService spawns ffmpeg processes that segment a source media file
-// into HLS (.m3u8 + .ts). The output lives under cache.cache_dir/hls/<id>.
+// into HLS (.m3u8 + .ts). Each playback scope owns a cache directory and
+// every ffmpeg run writes to its own run-* subdirectory.
 // The HTTP layer serves these files directly with a normal http.FileServer.
 //
 // Encoder selection (read once at startup from the config):
@@ -15,9 +16,11 @@
 //	                         plus the kernel module loaded)
 //
 // Concurrency model:
-//   - Each Media has at most one active ffmpeg job.
-//   - jobs[mediaID] tracks the running goroutine + cancel func.
-//   - Calling Start while a job already exists is a no-op.
+//   - Each authenticated user/player scope has at most one active ffmpeg job.
+//   - jobs[jobKey] tracks the running goroutine + cancel func; mediaID remains
+//     the actual media identity for database access and activity reporting.
+//   - Legacy internal callers keep media-keyed behaviour.
+//   - Equivalent requests within one scope reuse the current output.
 //   - When the playlist file appears on disk we consider the job "ready"
 //     and unblock the HTTP handler that was waiting on it.
 package service
@@ -49,9 +52,10 @@ type TranscoderService struct {
 
 	mu   sync.Mutex
 	jobs map[string]*hlsJob
-	// startGates serializes EnsureJobFrom / StopJob per media so concurrent
-	// playlist hits cannot spawn multiple ffmpeg writers into one HLS dir.
-	startGates  sync.Map // mediaID -> *sync.Mutex
+	// Start gates are reference-counted so random playback session keys do not
+	// accumulate after their last starter/stopper has left.
+	startGateMu sync.Mutex
+	startGates  map[string]*hlsStartGate
 	strmResolve func(ctx context.Context, raw string) (*StrmPlayResult, error)
 	probe       *FFprobeService
 
@@ -66,6 +70,7 @@ type TranscoderService struct {
 
 // hlsJob holds the live state of one ffmpeg run.
 type hlsJob struct {
+	jobKey     string
 	mediaID    string
 	outputDir  string
 	cancel     context.CancelFunc
@@ -156,14 +161,19 @@ func (t *TranscoderService) transcodeConfig() *config.Config {
 	}
 }
 
-// HLSDir is the per-media directory that holds index.m3u8 + segment files.
-func (t *TranscoderService) HLSDir(mediaID string) string {
-	return filepath.Join(t.cfg.Cache.CacheDir, "hls", mediaID)
+// HLSDir is the cache root for one internal playback job key.
+func (t *TranscoderService) HLSDir(jobKey string) string {
+	return filepath.Join(t.cfg.Cache.CacheDir, "hls", jobKey)
 }
 
 // PlaylistPath returns the absolute path of the m3u8 playlist for a media.
-func (t *TranscoderService) PlaylistPath(mediaID string) string {
-	return filepath.Join(t.HLSDir(mediaID), "index.m3u8")
+func (t *TranscoderService) PlaylistPath(jobKey string) string {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if job := t.jobs[jobKey]; job != nil {
+		return t.jobPlaylistPath(job)
+	}
+	return filepath.Join(t.HLSDir(jobKey), "index.m3u8")
 }
 
 // EnsureJob makes sure a transcode is running for mediaID from the start of
@@ -194,7 +204,8 @@ func (t *TranscoderService) EnsureJobFromSubtitle(ctx context.Context, mediaID s
 
 // EnsureJobFromSubtitleQuality is EnsureJobFromSubtitle with an explicit local
 // HLS quality profile. Empty qualityID keeps the global transcoder config.
-func (t *TranscoderService) EnsureJobFromSubtitleQuality(ctx context.Context, mediaID string, startSec float64, seekGen int64, subtitleStream int, qualityID string) (string, error) {
+func (t *TranscoderService) EnsureJobFromSubtitleQuality(ctx context.Context, mediaID string, startSec float64, seekGen int64, subtitleStream int, qualityID string, scopes ...HLSPlaybackScope) (string, error) {
+	jobKey := hlsPlaybackJobKey(mediaID, scopes)
 	cfg := t.transcodeConfig()
 	if !cfg.Transcoder.Enabled {
 		return "", ErrTranscodeDisabled
@@ -219,28 +230,31 @@ func (t *TranscoderService) EnsureJobFromSubtitleQuality(ctx context.Context, me
 		return "", ErrMediaNotFound
 	}
 
-	gate := t.mediaStartGate(mediaID)
-	gate.Lock()
-	defer gate.Unlock()
+	unlock := t.lockJobStart(jobKey)
+	defer unlock()
 
 	t.mu.Lock()
-	if existing, ok := t.jobs[mediaID]; ok {
+	if existing, ok := t.jobs[jobKey]; ok {
 		reusable := true
+		playlist := t.jobPlaylistPath(existing)
 		if existing.completed {
-			info, err := os.Stat(t.PlaylistPath(mediaID))
+			info, err := os.Stat(playlist)
 			reusable = err == nil && info.Size() > 0
 		}
 		if reusable && sameHLSConfiguration(existing, startSec, subtitleStream, qualityID) {
-			t.touchJobLocked(mediaID)
+			if seekGen > existing.seekGen {
+				existing.seekGen = seekGen
+			}
+			t.touchJobLocked(jobKey)
 			t.mu.Unlock()
-			return t.PlaylistPath(mediaID), nil
+			return playlist, nil
 		}
 		if reusable && !shouldReplaceHLSJobConfigurationQuality(existing, startSec, seekGen, subtitleStream, qualityID) {
-			t.touchJobLocked(mediaID)
+			t.touchJobLocked(jobKey)
 			t.mu.Unlock()
-			return t.PlaylistPath(mediaID), nil
+			return playlist, nil
 		}
-		prev := t.detachJobLocked(mediaID)
+		prev := t.detachJobLocked(jobKey)
 		t.mu.Unlock()
 		waitJobExit(prev, 12*time.Second)
 	} else {
@@ -258,6 +272,9 @@ func (t *TranscoderService) EnsureJobFromSubtitleQuality(ctx context.Context, me
 	input.Quality = quality
 	t.maybeFillDuration(ctx, m, input)
 	settings := ffmpegArgSettingsFromConfig(cfg, quality)
+	// 「原画」档位遇到浏览器可解的 H.264 源时只换封装，避免慢机器上重编码
+	// 追不上播放（两核软件编码实测 0.1～0.2 倍速）。其它档位要改分辨率，仍重编码。
+	input.CopyVideo = t.remuxEligible(ctx, m, quality, subtitleStream)
 	jobEncoder := settings.encoder
 	if settings.noScale || subtitleStream >= 0 {
 		jobEncoder = ""
@@ -267,12 +284,23 @@ func (t *TranscoderService) EnsureJobFromSubtitleQuality(ctx context.Context, me
 		return "", err
 	}
 
-	outDir := t.HLSDir(mediaID)
-	// Wipe prior segments so a mid-file restart cannot serve stale early chunks.
-	// Only safe after the previous ffmpeg has exited (waited above / via gate).
-	if err := resetHLSDir(outDir); err != nil {
+	rootDir := t.HLSDir(jobKey)
+	// Runs use distinct directories even when Windows keeps an old segment
+	// open. A delayed request can never read a newer run's seg_00000.ts.
+	if err := resetHLSDir(rootDir); err != nil {
 		return "", err
 	}
+	outDir, err := os.MkdirTemp(rootDir, "run-")
+	if err != nil {
+		return "", err
+	}
+	registered := false
+	defer func() {
+		if !registered {
+			_ = os.RemoveAll(outDir)
+			_ = os.Remove(rootDir)
+		}
+	}()
 
 	t.mu.Lock()
 	if max := t.maxConcurrent(); max > 0 && t.runningJobCountLocked() >= max {
@@ -287,7 +315,11 @@ func (t *TranscoderService) EnsureJobFromSubtitleQuality(ctx context.Context, me
 	if subtitleStream >= 0 {
 		jobEncoder = "software (subtitle burn-in)"
 	}
+	if input.CopyVideo {
+		jobEncoder = remuxEncoderLabel
+	}
 	job := &hlsJob{
+		jobKey:         jobKey,
 		mediaID:        mediaID,
 		outputDir:      outDir,
 		cancel:         cancel,
@@ -302,7 +334,8 @@ func (t *TranscoderService) EnsureJobFromSubtitleQuality(ctx context.Context, me
 		ffmpegPath:     bin,
 		config:         cfg,
 	}
-	t.jobs[mediaID] = job
+	t.jobs[jobKey] = job
+	registered = true
 	t.mu.Unlock()
 
 	helper.Go(t.log, "transcoder.monitorIdle", func() { t.monitorIdle(jobCtx, job) })
@@ -310,7 +343,7 @@ func (t *TranscoderService) EnsureJobFromSubtitleQuality(ctx context.Context, me
 		defer close(job.done)
 		t.runFFmpeg(jobCtx, job, input)
 	})
-	return t.PlaylistPath(mediaID), nil
+	return filepath.Join(outDir, "index.m3u8"), nil
 }
 
 // shouldReplaceHLSJob reports whether an incoming playlist request may cancel
@@ -357,9 +390,33 @@ func sameHLSConfiguration(existing *hlsJob, startSec float64, subtitleStream int
 		sameHLSStart(existing.startSec, startSec)
 }
 
-func (t *TranscoderService) mediaStartGate(mediaID string) *sync.Mutex {
-	v, _ := t.startGates.LoadOrStore(mediaID, &sync.Mutex{})
-	return v.(*sync.Mutex)
+type hlsStartGate struct {
+	mu    sync.Mutex
+	users int
+}
+
+func (t *TranscoderService) lockJobStart(key string) func() {
+	t.startGateMu.Lock()
+	if t.startGates == nil {
+		t.startGates = make(map[string]*hlsStartGate)
+	}
+	gate := t.startGates[key]
+	if gate == nil {
+		gate = &hlsStartGate{}
+		t.startGates[key] = gate
+	}
+	gate.users++
+	t.startGateMu.Unlock()
+	gate.mu.Lock()
+	return func() {
+		gate.mu.Unlock()
+		t.startGateMu.Lock()
+		gate.users--
+		if gate.users == 0 {
+			delete(t.startGates, key)
+		}
+		t.startGateMu.Unlock()
+	}
 }
 
 // detachJobLocked cancels and removes a job from the map without waiting.

internal/service/transcoder_ffmpeg_args.go

@@ -16,6 +16,9 @@ type transcodeInput struct {
 	StartSec       float64
 	SubtitleStream *int
 	Quality        *LocalHLSQuality
+	// CopyVideo 为 true 时视频流只换封装（-c:v copy），不重编码。
+	// 仅当源视频是浏览器可解的老三样（H.264/8bit/4:2:0）且不需要缩放时启用。
+	CopyVideo bool
 }
 
 type ffmpegArgSettings struct {
@@ -52,6 +55,7 @@ func buildFFmpegArgsForInput(cfg *config.Config, input transcodeInput, playlist,
 		// 原画档位不做硬件缩放的兼容处理，直接走软件编码，保持源分辨率。
 		settings.encoder = ""
 	}
+	copyVideo := input.CopyVideo && input.SubtitleStream == nil
 	video := ffmpegVideoPlanForSettings(settings)
 	if input.SubtitleStream != nil {
 		// Bitmap subtitles must be composited in software. Keeping CUDA/QSV/
@@ -60,13 +64,17 @@ func buildFFmpegArgsForInput(cfg *config.Config, input transcodeInput, playlist,
 		settings.encoder = ""
 		video = ffmpegVideoPlanForSettings(settings)
 	}
+	if copyVideo {
+		// 直通：不做缩放、不挂滤镜、不选编码器，整条视频流原样塞进 TS。
+		video = ffmpegVideoPlan{codec: "copy"}
+	}
 
 	// Mid-file restarts must not use -re: output -ss would otherwise crawl to the
 	// seek point at 1x wall-clock before emitting the first HLS segment.
 	realtime := settings.realtime && input.StartSec <= 0.05
 	args := baseFFmpegArgs(video.preInput, realtime)
-	args = appendInputAndVideoArgs(args, input, settings, video)
-	args = appendOutputHLSArgs(args, settings, segments, playlist)
+	args = appendInputAndVideoArgs(args, input, settings, video, copyVideo)
+	args = appendOutputHLSArgs(args, settings, segments, playlist, copyVideo)
 	return args
 }
 
@@ -161,7 +169,7 @@ func baseFFmpegArgs(preInput string, realtime bool) []string {
 	return args
 }
 
-func appendInputAndVideoArgs(args []string, input transcodeInput, settings ffmpegArgSettings, video ffmpegVideoPlan) []string {
+func appendInputAndVideoArgs(args []string, input transcodeInput, settings ffmpegArgSettings, video ffmpegVideoPlan, copyVideo bool) []string {
 	args = append(args, ffmpegHTTPInputArgs(input)...)
 	ss := ""
 	if input.StartSec > 0.05 {
@@ -172,6 +180,11 @@ func appendInputAndVideoArgs(args []string, input transcodeInput, settings ffmpe
 	// scrubbing; CDNs with Range support jump via demuxer seek instead.
 	if ss != "" {
 		args = append(args, "-ss", ss)
+		if copyVideo {
+			// 复制视频流时 ffmpeg 不能解码，精确 seek 会把关键帧之前的分组丢掉，
+			// 输出从 P 帧开始（花屏）。退到前一个关键帧，最多提前一两秒。
+			args = append(args, "-noaccurate_seek")
+		}
 	}
 	args = append(args, "-i", input.Source)
 	if input.SubtitleStream != nil {
@@ -197,7 +210,23 @@ func appendInputAndVideoArgs(args []string, input transcodeInput, settings ffmpe
 	return args
 }
 
-func appendOutputHLSArgs(args []string, settings ffmpegArgSettings, segments, playlist string) []string {
+func appendOutputHLSArgs(args []string, settings ffmpegArgSettings, segments, playlist string, copyVideo bool) []string {
+	if copyVideo {
+		// 视频是复制进来的，编码参数一律不适用；只保留音频转 AAC 与切片参数。
+		// -avoid_negative_ts 让带 B 帧的源在 -ss 之后不会出现负时间戳。
+		return append(args,
+			"-avoid_negative_ts", "make_zero",
+			"-c:a", "aac",
+			"-ar", "48000",
+			"-b:a", "128k",
+			"-ac", "2",
+			"-f", "hls",
+			"-hls_time", fmt.Sprintf("%d", settings.segmentSeconds),
+			"-hls_list_size", "0",
+			"-hls_segment_filename", segments,
+			playlist,
+		)
+	}
 	return append(args,
 		"-pix_fmt", "yuv420p",
 		"-b:v", settings.bitrate,

internal/service/transcoder_ffmpeg_probe.go

@@ -49,16 +49,18 @@ func (t *TranscoderService) runFFmpeg(ctx context.Context, job *hlsJob, input tr
 
 	t.mu.Lock()
 	// Only update the map entry if we are still the registered generation.
-	if cur, ok := t.jobs[job.mediaID]; ok && cur == job {
+	if cur, ok := t.jobs[job.key()]; ok && cur == job {
 		if err == nil && ctx.Err() == nil {
 			job.completed = true
 		} else {
-			delete(t.jobs, job.mediaID)
+			delete(t.jobs, job.key())
 		}
 	}
 	t.mu.Unlock()
 	if err != nil || ctx.Err() != nil {
 		job.cancel()
+		_ = os.RemoveAll(job.outputDir)
+		_ = os.Remove(filepath.Dir(job.outputDir)) // Remove the scope root only if empty.
 	}
 
 	t.hub.Publish("transcode", map[string]any{

internal/service/transcoder_jobs.go

@@ -26,16 +26,18 @@ func (t *TranscoderService) WaitReady(ctx context.Context, mediaID string, timeo
 		job, ok := t.jobs[mediaID]
 		var started time.Time
 		var completed bool
+		var playlist string
 		if ok {
 			started = job.startedAt
 			completed = job.completed
+			playlist = t.jobPlaylistPath(job)
 		}
 		t.mu.Unlock()
 		if !ok {
 			return false // A failed/exited job cannot become ready later.
 		}
 		if ok {
-			if info, err := os.Stat(t.PlaylistPath(mediaID)); err == nil {
+			if info, err := os.Stat(playlist); err == nil {
 				// Allow a small clock skew; reject anything older than this job.
 				if !info.ModTime().Before(started.Add(-2 * time.Second)) {
 					t.mu.Lock()
@@ -66,9 +68,8 @@ func (t *TranscoderService) WaitReady(ctx context.Context, mediaID string, timeo
 // briefly for it to exit so a subsequent EnsureJobFrom cannot race-write the
 // same HLS directory.
 func (t *TranscoderService) StopJob(mediaID string) {
-	gate := t.mediaStartGate(mediaID)
-	gate.Lock()
-	defer gate.Unlock()
+	unlock := t.lockJobStart(mediaID)
+	defer unlock()
 
 	t.mu.Lock()
 	prev := t.detachJobLocked(mediaID)
@@ -170,7 +171,7 @@ func (t *TranscoderService) monitorIdle(ctx context.Context, job *hlsJob) {
 			return
 		case <-ticker.C:
 			t.mu.Lock()
-			current, ok := t.jobs[job.mediaID]
+			current, ok := t.jobs[job.key()]
 			if !ok || current != job {
 				t.mu.Unlock()
 				return
@@ -185,11 +186,10 @@ func (t *TranscoderService) monitorIdle(ctx context.Context, job *hlsJob) {
 }
 
 func (t *TranscoderService) stopIdleJob(job *hlsJob, timeout time.Duration) bool {
-	gate := t.mediaStartGate(job.mediaID)
-	gate.Lock()
-	defer gate.Unlock()
+	unlock := t.lockJobStart(job.key())
+	defer unlock()
 	t.mu.Lock()
-	current := t.jobs[job.mediaID]
+	current := t.jobs[job.key()]
 	if current != job {
 		t.mu.Unlock()
 		return true
@@ -199,9 +199,12 @@ func (t *TranscoderService) stopIdleJob(job *hlsJob, timeout time.Duration) bool
 		t.mu.Unlock()
 		return false
 	}
-	t.detachJobLocked(job.mediaID)
+	t.detachJobLocked(job.key())
 	t.mu.Unlock()
 	waitJobExit(job, 12*time.Second)
+	if job.jobKey != "" {
+		_ = os.RemoveAll(t.HLSDir(job.key()))
+	}
 	t.log.Info("transcode idle timeout", zap.String("media_id", job.mediaID),
 		zap.Duration("idle_for", idleFor), zap.Duration("timeout", timeout))
 	return true

internal/service/transcoder_remux.go

@@ -0,0 +1,102 @@
+package service
+
+import (
+	"context"
+	"encoding/json"
+	"strings"
+
+	"github.com/truewhile/MeBox/internal/model"
+)
+
+// 蓝光原盘（m2ts，40 Mbps 级别）在两核小机器上重编码只有 0.1～0.2 倍速，HLS
+// 永远追不上播放，播放器等不到切片就报「转码失败」。当源视频本身就是浏览器
+// 能解的 H.264 / 8bit / 4:2:0，且用户选的是「原画」档位（不改分辨率）时，
+// 这里改走只换封装（-c:v copy）的直通路径：视频不重编码，音频转 AAC，
+// CPU 占用接近于零，起播时间从几十秒降到几秒。
+//
+// 直通只对「原画」生效。1080P/720P/480P 档位意味着要改分辨率，必须重新编码；
+// 那类请求仍然按原来的 libx264 路径处理（慢，但码率可控）。
+
+// remuxEncoderLabel 是直通任务在日志与任务面板里的标签。
+const remuxEncoderLabel = "remux"
+
+// remuxEligible 判断这次请求能否复制视频流而不是重编码。
+func (t *TranscoderService) remuxEligible(ctx context.Context, m *model.Media, quality *LocalHLSQuality, subtitleStream int) bool {
+	if t == nil || t.repo == nil || m == nil {
+		return false
+	}
+	// 烧录图形字幕要把字幕叠加进画面，必须解码+重编码。
+	if subtitleStream >= 0 {
+		return false
+	}
+	if !remuxAppliesToQuality(quality) {
+		return false
+	}
+	probe, err := t.repo.MediaProbe.Get(ctx, m.ID)
+	if err != nil || probe == nil {
+		// 没有探测缓存就无法确认档次/像素格式，保守走重编码。
+		return false
+	}
+	return remuxCopyableHeight(probe) > 0
+}
+
+// remuxAppliesToQuality 只放行「原画」档位（Height 为 0，即不缩放）。
+// quality 为 nil 表示调用方没有指定档位（走全局 max_height），同样不直通，
+// 否则会绕过配置的分辨率上限给出一个远超预期的码流。
+func remuxAppliesToQuality(quality *LocalHLSQuality) bool {
+	return quality != nil && quality.Height <= 0
+}
+
+// remuxCopyableHeight 在源视频可直接复制进 HLS 时返回它的高度，否则返回 0。
+func remuxCopyableHeight(probe *model.MediaProbe) int {
+	if probe == nil || probe.Height <= 0 {
+		return 0
+	}
+	if !strings.EqualFold(strings.TrimSpace(probe.VideoCodec), "h264") {
+		return 0
+	}
+	if !browserSafeH264Payload(probe.Payload) {
+		return 0
+	}
+	return probe.Height
+}
+
+// probePayloadStreams 只解析落库 payload 里与直通判断有关的字段。
+type probePayloadStreams struct {
+	Streams []struct {
+		Type    string `json:"type"`
+		Profile string `json:"profile"`
+		PixFmt  string `json:"pix_fmt"`
+	} `json:"streams"`
+}
+
+// browserSafeH264Payload 只放行 8bit 4:2:0 的 Baseline/Main/High。
+// Hi10P（High 10）和 4:2:2 母带浏览器解不出来，复制过去只会黑屏或无声。
+func browserSafeH264Payload(payload string) bool {
+	payload = strings.TrimSpace(payload)
+	if payload == "" {
+		// 老数据没有 payload：已经有 codec + 分辨率，按 8bit 常规情况处理。
+		return true
+	}
+	var parsed probePayloadStreams
+	if err := json.Unmarshal([]byte(payload), &parsed); err != nil {
+		return false
+	}
+	for _, stream := range parsed.Streams {
+		if !strings.EqualFold(strings.TrimSpace(stream.Type), "video") {
+			continue
+		}
+		switch strings.ToLower(strings.TrimSpace(stream.Profile)) {
+		case "", "constrained baseline", "baseline", "main", "high":
+		default:
+			return false
+		}
+		switch strings.ToLower(strings.TrimSpace(stream.PixFmt)) {
+		case "", "yuv420p", "yuvj420p":
+		default:
+			return false
+		}
+		return true
+	}
+	return true
+}

internal/service/transcoder_remux_test.go

@@ -0,0 +1,170 @@
+package service
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/truewhile/MeBox/internal/config"
+	"github.com/truewhile/MeBox/internal/model"
+)
+
+// 直通档位必须真的把视频流复制过去：一旦又带上 libx264 / -vf / 码率参数，
+// 慢机器上的「原画」就还是几十秒起播。
+func TestBuildFFmpegArgsRemuxCopiesVideoStream(t *testing.T) {
+	cfg := &config.Config{}
+	cfg.Transcoder.SegmentSeconds = 4
+	cfg.Transcoder.Realtime = true
+	cfg.Transcoder.Threads = 2
+	cfg.Transcoder.MaxHeight = 720
+
+	quality, ok := LocalHLSQualityByID("source")
+	if !ok {
+		t.Fatal("source quality missing")
+	}
+	args := buildFFmpegArgsForInput(cfg, transcodeInput{
+		Source:    "https://cdn.example/x.m2ts",
+		Headers:   map[string]string{"User-Agent": "MeBox-115-GoClient/1.0"},
+		StartSec:  52.4,
+		Quality:   &quality,
+		CopyVideo: true,
+	}, "/cache/hls/k/run-1/index.m3u8", "/cache/hls/k/run-1/seg_%05d.ts")
+	joined := strings.Join(args, " ")
+
+	for _, want := range []string{
+		"-c:v copy",
+		"-c:a aac",
+		"-ar 48000",
+		"-b:a 128k",
+		"-ac 2",
+		"-avoid_negative_ts make_zero",
+		"-ss 52.400",
+		"-noaccurate_seek",
+		"-hls_time 4",
+		"-hls_segment_filename /cache/hls/k/run-1/seg_%05d.ts",
+	} {
+		if !strings.Contains(joined, want) {
+			t.Errorf("remux args missing %q: %s", want, joined)
+		}
+	}
+	for _, unwanted := range []string{
+		"libx264",
+		"-vf ",
+		"-b:v",
+		"-maxrate",
+		"-bufsize",
+		"-force_key_frames",
+		"-preset",
+		"-threads",
+		"-pix_fmt",
+	} {
+		if strings.Contains(joined, unwanted) {
+			t.Errorf("remux args must not contain %q: %s", unwanted, joined)
+		}
+	}
+	// 中途起播不能加 -re，否则会先按 1 倍速爬到目标位置才出第一个切片。
+	if strings.Contains(joined, " -re ") {
+		t.Errorf("mid-file remux must not use -re: %s", joined)
+	}
+}
+
+// 烧录图形字幕要把字幕叠进画面，必须解码重编码，不能被直通标志绕过。
+func TestBuildFFmpegArgsRemuxIgnoredForSubtitleBurnIn(t *testing.T) {
+	cfg := &config.Config{}
+	cfg.Transcoder.MaxHeight = 720
+	cfg.Transcoder.SegmentSeconds = 4
+
+	quality, _ := LocalHLSQualityByID("source")
+	subtitle := 4
+	args := buildFFmpegArgsForInput(cfg, transcodeInput{
+		Source:         "/media/ep.mkv",
+		Quality:        &quality,
+		CopyVideo:      true,
+		SubtitleStream: &subtitle,
+	}, "/o/x.m3u8", "/o/seg_%05d.ts")
+	joined := strings.Join(args, " ")
+
+	if strings.Contains(joined, "-c:v copy") {
+		t.Fatalf("subtitle burn-in must not copy the video stream: %s", joined)
+	}
+	if !strings.Contains(joined, "libx264") || !strings.Contains(joined, "-filter_complex") {
+		t.Fatalf("subtitle burn-in should re-encode: %s", joined)
+	}
+	if strings.Contains(joined, "-noaccurate_seek") {
+		t.Fatalf("encoded path should keep accurate seek: %s", joined)
+	}
+}
+
+// 只有「原画」档位（不缩放）可以直通；其它档位要改分辨率。
+func TestRemuxAppliesToQuality(t *testing.T) {
+	if remuxAppliesToQuality(nil) {
+		t.Fatal("nil quality must not remux: it falls back to the configured max height")
+	}
+	source, _ := LocalHLSQualityByID("source")
+	if !remuxAppliesToQuality(&source) {
+		t.Fatal("source quality should remux")
+	}
+	for _, id := range []string{"1080", "720", "480"} {
+		quality, ok := LocalHLSQualityByID(id)
+		if !ok {
+			t.Fatalf("quality %s missing", id)
+		}
+		if remuxAppliesToQuality(&quality) {
+			t.Fatalf("quality %s must re-encode", id)
+		}
+	}
+}
+
+// 只有 8bit 4:2:0 的 H.264 能安全复制；Hi10P / 4:2:2 / HEVC 复制过去浏览器黑屏。
+func TestRemuxCopyableHeight(t *testing.T) {
+	const blurayPayload = `{"container":"mpegts","duration_sec":1451,"bit_rate":42609934,"streams":[{"index":0,"type":"video","codec":"h264","profile":"High","width":1920,"height":1080,"pix_fmt":"yuv420p","frame_rate":"23.976"},{"index":1,"type":"audio","codec":"pcm_bluray","channels":2}]}`
+
+	cases := []struct {
+		name  string
+		probe *model.MediaProbe
+		want  int
+	}{
+		{
+			name:  "bluray h264 8bit 420",
+			probe: &model.MediaProbe{VideoCodec: "h264", Height: 1080, Payload: blurayPayload},
+			want:  1080,
+		},
+		{
+			name:  "no payload falls back to codec and height",
+			probe: &model.MediaProbe{VideoCodec: "h264", Height: 720},
+			want:  720,
+		},
+		{
+			name:  "hevc cannot be copied into browser hls",
+			probe: &model.MediaProbe{VideoCodec: "hevc", Height: 1080, Payload: `{"streams":[{"type":"video","profile":"Main 10","pix_fmt":"yuv420p10le"}]}`},
+			want:  0,
+		},
+		{
+			name:  "hi10p h264 is unplayable in browsers",
+			probe: &model.MediaProbe{VideoCodec: "h264", Height: 1080, Payload: `{"streams":[{"type":"video","profile":"High 10","pix_fmt":"yuv420p10le"}]}`},
+			want:  0,
+		},
+		{
+			name:  "4:2:2 h264 is unplayable in browsers",
+			probe: &model.MediaProbe{VideoCodec: "h264", Height: 1080, Payload: `{"streams":[{"type":"video","profile":"High 4:2:2","pix_fmt":"yuv422p"}]}`},
+			want:  0,
+		},
+		{
+			name:  "missing probe",
+			probe: nil,
+			want:  0,
+		},
+		{
+			name:  "unknown height",
+			probe: &model.MediaProbe{VideoCodec: "h264", Height: 0, Payload: blurayPayload},
+			want:  0,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := remuxCopyableHeight(tc.probe); got != tc.want {
+				t.Fatalf("remuxCopyableHeight() = %d, want %d", got, tc.want)
+			}
+		})
+	}
+}

web/src/api/client.ts

@@ -175,7 +175,7 @@ export function streamURL(mediaId: string, options: { proxy?: boolean } = {}): s
 
 // hlsURL returns the m3u8 playlist URL fed into hls.js.
 // startSec > 0 asks the server to (re)start ffmpeg from that source offset.
-export function hlsURL(mediaId: string, startSec = 0, subtitleStream?: number, quality?: string): string {
+export function hlsURL(mediaId: string, startSec = 0, subtitleStream?: number, quality?: string, sessionID?: string): string {
   const safeStart = Math.max(0, Math.round(startSec * 1000) / 1000)
   // Always send start= (including 0) so the server can tell an intentional
   // restart-from-head apart from a missing query on a stale refresh.
@@ -188,7 +188,8 @@ export function hlsURL(mediaId: string, startSec = 0, subtitleStream?: number, q
       ? `&subtitle=${encodeURIComponent(String(subtitleStream))}`
       : ''
   const qualityQuery = quality ? `&quality=${encodeURIComponent(quality)}` : ''
-  return `/api/hls/${encodeURIComponent(mediaId)}/index.m3u8?${tokenQuery()}${profileQuery()}${start}${subtitle}${qualityQuery}${bust}`
+  const session = sessionID ? `&session_id=${encodeURIComponent(sessionID)}` : ''
+  return `/api/hls/${encodeURIComponent(mediaId)}/index.m3u8?${tokenQuery()}${profileQuery()}${start}${subtitle}${qualityQuery}${bust}${session}`
 }
 
 // cloudHlsURL returns the MeBox-proxied 115 cloud HLS master playlist URL.
@@ -202,8 +203,9 @@ export function cloudHlsURL(mediaId: string, definition: string): string {
 
 // Stop an on-demand HLS job. keepalive makes the request survive page
 // navigation/tab close, where an axios promise can be discarded by browsers.
-export function stopHLSJob(mediaId: string): void {
-  const url = `/api/hls/${encodeURIComponent(mediaId)}?${tokenQuery()}${profileQuery()}`
+export function stopHLSJob(mediaId: string, sessionID?: string): void {
+  const session = sessionID ? `&session_id=${encodeURIComponent(sessionID)}` : ''
+  const url = `/api/hls/${encodeURIComponent(mediaId)}?${tokenQuery()}${profileQuery()}${session}`
   void fetch(url, {
     method: 'DELETE',
     credentials: 'same-origin',

web/src/pages/HomePageSections.tsx

@@ -464,7 +464,9 @@ export function HomeLibrariesSection({
             pinned={pinnedIds.includes(lib.id)}
             onTogglePin={onTogglePin ? () => onTogglePin(lib.id) : undefined}
             onVisible={() => {
-              if (!lib.cover_url) {
+              // 服务端会生成库封面时不必再为首屏卡片拉成员预览；
+              // 远程挂载库的封面仍由卡片拼图兜底。
+              if (!lib.cover_url && !lib.cover_image_url) {
                 queuePreview(lib.id)
               }
             }}

web/src/pages/PlayerPage.tsx

@@ -1,4 +1,4 @@
-import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
+import { useCallback, useEffect, useLayoutEffect, useMemo, useRef, useState } from 'react'
 import { useLocation, useNavigate, useParams } from 'react-router-dom'
 import type Hls from 'hls.js'
 import toast from 'react-hot-toast'
@@ -41,7 +41,9 @@ import { pickPlayerMode, needsTranscodeForBrowser, isDirectStreamMedia, isStrmMe
 import { classifyDirectPlayError, directPlayFailureCopy, directStallTimeoutMs, DIRECT_SEEK_GRACE_MS } from './directPlayError'
 import type { DirectPlayFailureReason } from './directPlayError'
 import { canSeekDirectNow, DIRECT_SEEK_WAIT_MS } from './directPlaySeek'
-import { applyPendingHlsSeek, attachNativeHls, bindPendingHlsSeek, hlsManifestTimeoutMs, playbackPositionSec } from './hlsPlayback'
+import { applyPendingHlsSeek, attachNativeHls, bindPendingHlsSeek, hlsManifestTimeoutMs, playbackPositionSec, playbackTimeSec } from './hlsPlayback'
+import { availableLocalQuality, defaultLocalQualityId, findPlaybackQualityById } from './playbackQuality'
+import { createPlaybackRequestGuard } from './playbackRequestGuard'
 import { apiErrorMessage } from './StrmManagePage'
 import { PlayerTopBar } from './PlayerTopBar'
 import { PlayerVideoStage } from './PlayerVideoStage'
@@ -118,6 +120,14 @@ export function PlayerPage() {
   const hlsRef = useRef<Hls | null>(null)
   const lastSentRef = useRef(0)
   const progressSessionRef = useRef<PlaybackProgressSession | null>(null)
+  const cloudRequestGuardRef = useRef(createPlaybackRequestGuard())
+  const currentMediaIdRef = useRef(id)
+  useLayoutEffect(() => {
+    const guard = cloudRequestGuardRef.current
+    currentMediaIdRef.current = id
+    guard.invalidate()
+    return () => guard.invalidate()
+  }, [id])
   const directRetryRef = useRef(false)
   const retryingDirectRef = useRef(false)
   // 程序化续播 seek 后的宽限截止时间；期内直连误报不升到 HLS。
@@ -563,6 +573,7 @@ export function PlayerPage() {
   const setPlaybackMode = useCallback((next: PlayerMode) => {
     // 一旦显式决定过播放方式，URL 上的 ?mode= 就不再是权威（避免它把状态打回去）。
     requestedModeRef.current = null
+    if (next === 'direct') cloudRequestGuardRef.current.invalidate()
     setMode(next)
   }, [])
 
@@ -767,6 +778,11 @@ export function PlayerPage() {
    */
   const handleDirectSeekStalled = useCallback(
     (target: number) => {
+      cloudRequestGuardRef.current.invalidate()
+      if (directOnly || isDirectStreamMedia(mediaRef.current)) {
+        toast.error('当前播放方式不提供 HLS 转码，请使用外部播放器定位')
+        return
+      }
       const cloudQuality =
         findPlaybackQualityById(playbackInfo, selectedQuality) ??
         findPlaybackQualityById(playbackInfo, playbackInfo?.default_quality ?? '')
@@ -780,9 +796,7 @@ export function PlayerPage() {
         toast('直连定位失败，已切到 115 云 HLS 跳转')
         return
       }
-      const localQuality =
-        findPlaybackQualityById(playbackInfo, selectedQuality) ??
-        findPlaybackQualityById(playbackInfo, defaultLocalQualityId(playbackInfo))
+      const localQuality = availableLocalQuality(playbackInfo, selectedQuality)
       if (localQuality?.available) {
         setSelectedQuality(localQuality.id)
         setHlsSource('local')
@@ -795,7 +809,7 @@ export function PlayerPage() {
       }
       toast.error('直连定位失败，且当前没有可用的 HLS 转码档位')
     },
-    [playbackInfo, selectedQuality, setPlaybackMode],
+    [directOnly, playbackInfo, selectedQuality, setPlaybackMode],
   )
 
   // Load metadata and pick a default mode.
@@ -1032,17 +1046,22 @@ export function PlayerPage() {
 
   const switchToLocalHLS = useCallback(
     (position?: number) => {
+      cloudRequestGuardRef.current.invalidate()
       pendingSeekRef.current = null
       setHlsSource('local')
       setCloudWaiting(false)
-      setSelectedQuality((prev) => {
-        if (playbackInfo?.local_qualities?.some((quality) => quality.id === prev)) return prev
-        return defaultLocalQualityId(playbackInfo)
-      })
+      const quality = availableLocalQuality(playbackInfo, selectedQuality)
+      if (playbackInfo && !quality) {
+        setHlsUnavailable(true)
+        showPlayFailure('本地 HLS 转码不可用，请配置 ffmpeg 或使用外部播放器。')
+        setPlaybackMode('direct')
+        return
+      }
+      setSelectedQuality(quality?.id ?? defaultLocalQualityId(playbackInfo))
       if (position !== undefined) setHlsStartSec(Math.max(0, position))
       setPlaybackMode('hls')
     },
-    [playbackInfo, setPlaybackMode],
+    [playbackInfo, selectedQuality, setPlaybackMode, showPlayFailure],
   )
 
   /**
@@ -1080,8 +1099,11 @@ export function PlayerPage() {
   const startCloudTranscode = useCallback(
     async (definition: number) => {
       if (!mediaId) return
+      const isCurrentRequest = cloudRequestGuardRef.current.begin()
+      const isCurrent = () => isCurrentRequest() && currentMediaIdRef.current === mediaId && !directOnlyRef.current
       try {
         const info = await mediaAPI.startCloudTranscode(mediaId, definition)
+        if (!isCurrent() || info.media_id !== mediaId) return
         setPlaybackInfo(info)
         if (info.transcode.state === 'ready') {
           setCloudWaiting(false)
@@ -1094,6 +1116,7 @@ export function PlayerPage() {
         setCloudWaitMessage(info.transcode.message || '115 正在转码…')
         setCloudWaitStartedAt(Date.now())
       } catch {
+        if (!isCurrent()) return
         switchToLocalHLS()
         toast.error('115 云端转码触发失败，已切换本地转码')
       }
@@ -1105,6 +1128,7 @@ export function PlayerPage() {
   // 的自愈逻辑共用，避免两处各写一遍云端/本地选择。
   const enterHlsPlayback = useCallback(
     (startSec: number, infoOverride?: PlaybackInfo | null) => {
+      cloudRequestGuardRef.current.invalidate()
       const position = Math.max(0, startSec)
       // 允许传入刚拿到的能力信息：从 URL 强制 HLS 时不想等到 state 更新后才选线路。
       const info = infoOverride ?? playbackInfo
@@ -1127,6 +1151,7 @@ export function PlayerPage() {
         }
       } else {
         switchToLocalHLS(position)
+        return
       }
       setPlaybackMode('hls')
     },
@@ -1165,7 +1190,7 @@ export function PlayerPage() {
         setCloudWaitMessage(info.transcode.message || '115 正在转码…')
         cloudPollTimerRef.current = setTimeout(poll, cloudRetryRef.current * 1000)
       } catch {
-        cloudPollTimerRef.current = setTimeout(poll, 5000)
+        if (!cancelled) cloudPollTimerRef.current = setTimeout(poll, 5000)
       }
     }
     cloudPollTimerRef.current = setTimeout(poll, cloudRetryRef.current * 1000)
@@ -1338,6 +1363,7 @@ export function PlayerPage() {
     if (!currentMedia) return
     let cancelled = false
     let cleanupHlsResume: (() => void) | undefined
+    let stopLocalPlayback: (() => void) | undefined
     let onDirectMetadata: (() => void) | undefined
     teardownHls()
 
@@ -1348,10 +1374,17 @@ export function PlayerPage() {
         teardownHls()
         return
       }
+      // Each wired local source owns its job, including seek/quality changes.
+      // Capture the ID in cleanup so a delayed DELETE cannot stop a newer run.
+      const localSessionID = hlsSource === 'local' ? newPlaybackProgressSession(mediaId).id : undefined
+      if (localSessionID) {
+        stopLocalPlayback = () => stopHLSJob(mediaId, localSessionID)
+        window.addEventListener('pagehide', stopLocalPlayback)
+      }
       const url =
         hlsSource === 'cloud'
           ? cloudHlsURL(mediaId, selectedQuality)
-          : hlsURL(mediaId, hlsStartSec, activeBurnedSubtitleStream, selectedQuality)
+          : hlsURL(mediaId, hlsStartSec, activeBurnedSubtitleStream, selectedQuality, localSessionID)
       void import('hls.js').then(({ default: HlsCtor }) => {
         if (cancelled || !ref.current) return
         if (HlsCtor.isSupported()) {
@@ -1494,6 +1527,10 @@ export function PlayerPage() {
       if (onDirectMetadata) video.removeEventListener('loadedmetadata', onDirectMetadata)
       cleanupHlsResume?.()
       teardownHls()
+      if (stopLocalPlayback) {
+        window.removeEventListener('pagehide', stopLocalPlayback)
+        stopLocalPlayback()
+      }
     }
   }, [
     activeBurnedSubtitleStream,
@@ -1518,24 +1555,6 @@ export function PlayerPage() {
     vr360DirectProxy,
   ])
 
-  // Stop host ffmpeg when leaving this HLS player. The keepalive request also
-  // survives route navigation while the component is being torn down.
-  useEffect(() => {
-    if (!mediaId || mode !== 'hls' || hlsSource !== 'local') return
-    return () => {
-      stopHLSJob(mediaId)
-    }
-  }, [hlsSource, mediaId, mode])
-
-  // React cleanup is not guaranteed when a tab/window closes. pagehide fires
-  // while the document can still dispatch a keepalive request.
-  useEffect(() => {
-    if (!mediaId || mode !== 'hls' || hlsSource !== 'local') return
-    const stopOnPageExit = () => stopHLSJob(mediaId)
-    window.addEventListener('pagehide', stopOnPageExit)
-    return () => window.removeEventListener('pagehide', stopOnPageExit)
-  }, [hlsSource, mediaId, mode])
-
   // 自动拉取已有的播放进度并恢复播放位置
   useEffect(() => {
     if (!id) return
@@ -1828,8 +1847,7 @@ export function PlayerPage() {
     const sync = () => {
       // HLS 转码时 <video>.currentTime 是相对转码起点的，必须把起点加回来。这里与
       // 进度上报用的算法保持一致，否则转码场景下整段判断都会错位。
-      const offset = modeRef.current === 'hls' ? hlsStartSecRef.current : 0
-      const absolute = offset + (video.currentTime || 0)
+      const absolute = playbackPositionSec(modeRef.current, hlsSourceRef.current, hlsStartSecRef.current, video.currentTime || 0)
       const next = resolveActiveSkip(absolute, skipSegments, {
         hasNextEpisode: Boolean(nextEpisode),
         excludedKinds: dismissedSkipKinds,
@@ -1854,8 +1872,7 @@ export function PlayerPage() {
         selfSkipSeekRef.current = false
         return
       }
-      const offset = modeRef.current === 'hls' ? hlsStartSecRef.current : 0
-      const absolute = offset + (video.currentTime || 0)
+      const absolute = playbackPositionSec(modeRef.current, hlsSourceRef.current, hlsStartSecRef.current, video.currentTime || 0)
       const hit = skipSegments.find(
         (segment) =>
           (segment.kind === 'intro' || segment.kind === 'recap') &&
@@ -2169,7 +2186,7 @@ export function PlayerPage() {
           return
         }
         selfSkipSeekRef.current = true
-        video.currentTime = Math.max(0, target - hlsStartSec)
+        video.currentTime = playbackTimeSec(mode, hlsSource, hlsStartSec, target)
         return
       }
       if (isStrmMedia(mediaRef.current)) {
@@ -2277,6 +2294,7 @@ export function PlayerPage() {
 
   const selectPlaybackQuality = useCallback(
     (quality: PlaybackQuality) => {
+      cloudRequestGuardRef.current.invalidate()
       const video = ref.current
       const localTime = video?.currentTime || 0
       // 云 HLS 的 currentTime 本来就在绝对时间轴上；本地 HLS 的 t=0 对应 hlsStartSec。
@@ -2659,21 +2677,6 @@ function formatEpisodeDisplay(ep: Media, siblings: Media[]): string {
   return episodeLabel || mediaTitle || title || '未命名'
 }
 
-function findPlaybackQualityById(info: PlaybackInfo | null, id: string): PlaybackQuality | undefined {
-  if (!info || !id) return undefined
-  return [...(info.cloud_qualities ?? []), ...(info.local_qualities ?? [])].find(
-    (quality) => quality.id === id,
-  )
-}
-
-function defaultLocalQualityId(info: PlaybackInfo | null): string {
-  const qualities = info?.local_qualities ?? []
-  for (const id of ['1080', '720', '480', 'source']) {
-    if (qualities.some((quality) => quality.id === id)) return id
-  }
-  return qualities[0]?.id ?? '720'
-}
-
 function looksLikeSeriesTitle(ep: Media, title: string, siblings: Media[]): boolean {
   const normalized = normalizeEpisodeTitle(title)
   if (!normalized) return true

web/src/pages/hlsPlayback.test.ts

@@ -1,5 +1,5 @@
 import { strict as assert } from 'node:assert'
-import { applyPendingHlsSeek, attachNativeHls, bindPendingHlsSeek, hlsManifestTimeoutMs, playbackPositionSec } from './hlsPlayback.ts'
+import { applyPendingHlsSeek, attachNativeHls, bindPendingHlsSeek, hlsManifestTimeoutMs, playbackPositionSec, playbackTimeSec } from './hlsPlayback.ts'
 
 class FakeVideo extends EventTarget {
   src = ''
@@ -55,4 +55,8 @@ assert.equal(hlsManifestTimeoutMs('cloud', 1800), 60_000)
 assert.equal(playbackPositionSec('hls', 'cloud', 420, 600), 600, 'cloud subtitle/quality switches must not add an old local offset')
 assert.equal(playbackPositionSec('hls', 'local', 420, 60), 480, 'local subtitle switches preserve the source position')
 assert.equal(playbackPositionSec('direct', 'local', 420, 60), 60)
+assert.equal(playbackTimeSec('hls', 'cloud', 600, 640), 640, 'cloud skip/undo uses the absolute target, not target minus a former local offset')
+assert.equal(playbackTimeSec('hls', 'local', 600, 640), 40)
+assert.equal(playbackTimeSec('direct', 'local', 600, 640), 640)
+assert.equal(playbackTimeSec('hls', 'local', 600, 100), 0, 'targets before a local start clamp to zero')
 console.log('hlsPlayback.test.ts ok')

web/src/pages/hlsPlayback.ts

@@ -41,3 +41,8 @@ export function attachNativeHls(video: HlsVideo, url: string, pending: PendingSe
 export function playbackPositionSec(mode: 'direct' | 'hls', source: 'cloud' | 'local', startSec: number, currentTime: number): number {
   return mode === 'hls' && source === 'local' ? startSec + currentTime : currentTime
 }
+
+/** Convert an absolute source target to the current media element's timeline. */
+export function playbackTimeSec(mode: 'direct' | 'hls', source: 'cloud' | 'local', startSec: number, absoluteSec: number): number {
+  return Math.max(0, mode === 'hls' && source === 'local' ? absoluteSec - startSec : absoluteSec)
+}

web/src/pages/librariesPageModel.ts

@@ -43,5 +43,12 @@ export function getLibraryArtworks(
   if (library.cover_url) {
     return [{ src: library.cover_url, version: library.updated_at }]
   }
+  // 服务端生成的库封面（成员海报竖切拼图）：所有客户端共用一张图，
+  // 不再由前端拿两张卡片自己拼格子。
+  // version 里带一个版次后缀：接口地址是固定的，靠它让浏览器在拼图规则
+  // 调整（如田字格改成竖切）后丢掉旧缓存重新拉图。
+  if (library.cover_image_url) {
+    return [{ src: library.cover_image_url, version: `${library.updated_at}-c3` }]
+  }
   return libraryArtworkItems(cards)
 }

web/src/pages/playbackQuality.test.ts

@@ -0,0 +1,19 @@
+import { strict as assert } from 'node:assert'
+import { availableLocalQuality, findPlaybackQualityById } from './playbackQuality.ts'
+import type { PlaybackInfo } from '../types/playback.ts'
+
+const info: PlaybackInfo = {
+  media_id: 'm', provider: 'cloud115', default_quality: '4', fallback: [],
+  transcode: { state: 'idle' },
+  cloud_qualities: [{ id: '4', label: '1080P', source: 'cloud', available: false }],
+  local_qualities: [
+    { id: 'source', label: '原画', source: 'local', available: false },
+    { id: '1080', label: '1080P', source: 'local', available: true },
+    { id: '720', label: '720P', source: 'local', available: true },
+  ],
+}
+assert.equal(availableLocalQuality(info, '4')?.id, '1080', 'pending cloud quality must not mask the available local fallback')
+assert.equal(availableLocalQuality(info, '720')?.id, '720', 'preserve an available local preference')
+assert.equal(availableLocalQuality({ ...info, local_qualities: info.local_qualities.map(q => ({ ...q, available: false })) }, '4'), undefined)
+assert.equal(findPlaybackQualityById(info, '4')?.source, 'cloud')
+console.log('playbackQuality.test.ts ok')

web/src/pages/playbackQuality.ts

@@ -0,0 +1,24 @@
+import type { PlaybackInfo, PlaybackQuality } from '../types/playback'
+
+export function findPlaybackQualityById(info: PlaybackInfo | null, id: string): PlaybackQuality | undefined {
+  if (!info || !id) return undefined
+  return [...(info.cloud_qualities ?? []), ...(info.local_qualities ?? [])].find(
+    (quality) => quality.id === id,
+  )
+}
+
+export function defaultLocalQualityId(info: PlaybackInfo | null): string {
+  const qualities = info?.local_qualities ?? []
+  for (const id of ['1080', '720', '480', 'source']) {
+    if (qualities.some((quality) => quality.id === id)) return id
+  }
+  return qualities[0]?.id ?? '720'
+}
+
+/** A cloud option may exist without being ready; it is never a local fallback. */
+export function availableLocalQuality(info: PlaybackInfo | null, preferred = ''): PlaybackQuality | undefined {
+  const available = info?.local_qualities.filter((quality) => quality.source === 'local' && quality.available) ?? []
+  return available.find((quality) => quality.id === preferred) ??
+    ['1080', '720', '480', 'source'].map((id) => available.find((quality) => quality.id === id)).find(Boolean) ??
+    available[0]
+}

web/src/pages/playbackRequestGuard.test.ts

@@ -0,0 +1,30 @@
+import { strict as assert } from 'node:assert'
+import { createPlaybackRequestGuard } from './playbackRequestGuard.ts'
+
+const guard = createPlaybackRequestGuard()
+const first = guard.begin()
+assert.equal(first(), true)
+const second = guard.begin()
+assert.equal(first(), false, 'a newer quality request supersedes the earlier request')
+assert.equal(second(), true)
+guard.invalidate()
+assert.equal(second(), false, 'media changes, unmount and direct/local switches cancel a pending cloud result')
+let resolveRequest: (value: string) => void = () => {}
+const request = new Promise<string>(resolve => { resolveRequest = resolve })
+const current = guard.begin()
+let applied = 'episode-B'
+const settled = request.then(value => { if (current()) applied = value })
+guard.invalidate()
+resolveRequest('episode-A')
+await settled
+assert.equal(applied, 'episode-B', 'a delayed response cannot overwrite the next media')
+let rejected: (error: Error) => void = () => {}
+const failed = new Promise<never>((_, reject) => { rejected = reject })
+const activeFailure = guard.begin()
+let fallbackCount = 0
+const caught = failed.catch(() => { if (activeFailure()) fallbackCount += 1 })
+guard.invalidate()
+rejected(new Error('old request failed'))
+await caught
+assert.equal(fallbackCount, 0, 'a stale rejection cannot force a local fallback')
+console.log('playbackRequestGuard.test.ts ok')

web/src/pages/playbackRequestGuard.ts

@@ -0,0 +1,13 @@
+/** Invalidates both successful and failed responses after a newer playback intent. */
+export function createPlaybackRequestGuard() {
+  let generation = 0
+  return {
+    begin(): () => boolean {
+      const requested = ++generation
+      return () => requested === generation
+    },
+    invalidate(): void {
+      generation += 1
+    },
+  }
+}

web/src/pages/settingsGroupGeneral.ts

@@ -130,14 +130,6 @@ export const generalSettingsGroup: SettingGroup = {
       defaultValue: '256',
       placeholder: '256',
     },
-    {
-      key: 'cache.images_originals_ttl_hours',
-      label: '原图保留时长 (小时)',
-      type: 'number',
-      hint: '原图缓存的最长保留时间，超过即删除（默认 168 小时 = 7 天）。缩略图都已生成时原图就不再需要，缩短它可以让原图缓存保持在一个滚动窗口内。设为 0 表示不按时间淘汰',
-      defaultValue: '168',
-      placeholder: '168',
-    },
     {
       key: 'https.enabled',
       label: '启用 HTTPS',

web/src/types/library.ts

@@ -15,6 +15,12 @@ export interface Library {
   path: string
   type: string
   cover_url?: string
+  /**
+   * 服务端生成的封面地址（成员海报拼图）。管理员自定义 cover_url 时等于
+   * 该地址，否则指向 `/api/libraries/:id/cover`。Web/App 统一读这个字段，
+   * 不用再自己用卡片拼格子。
+   */
+  cover_image_url?: string
   enabled: boolean
   sort_order?: number
   carousel_enabled?: boolean