优化转码逻辑

internal/service/service_builder.go

@@ -123,6 +123,7 @@ func (b *serviceContainerBuilder) initContentServices() {
 	b.c.Danmaku.SetStrmResolver(b.c.Strm.ResolvePlay)
 	// STRM 直连失败后的 HLS 转码：把 .strm 解析成 ffmpeg 可读取的本地路径或 HTTP 直链。
 	b.c.Transcoder.SetStrmPlayTargetResolver(b.c.Strm.ResolvePlayTarget)
+	b.c.Transcoder.SetProbe(b.c.FFprobe)
 	// 弹幕识别需要把远程 Emby 条目解析为 Media 元数据及可拉取前 16MB 的直链 URL。
 	if b.c.EmbyRemote != nil {
 		b.c.Danmaku.SetRemoteMediaResolver(func(ctx context.Context, encodedID string) (*model.Media, string, error) {

internal/service/stream_hls.go

@@ -6,19 +6,25 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
+	"strconv"
 	"strings"
 	"time"
 )
 
 // ServeHLSPlaylist makes sure a transcode is running and writes the m3u8.
 // We block (with a 30s timeout) until the playlist file shows up.
+//
+// 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 {
 	// 「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()) {
 		return ErrTranscodeDisabled
 	}
-	if _, err := s.transcoder.EnsureJob(r.Context(), mediaID); err != nil {
+	startSec := parseHLSStartSec(r)
+	if _, err := s.transcoder.EnsureJobFrom(r.Context(), mediaID, startSec); err != nil {
 		return err
 	}
 	s.transcoder.TouchJob(mediaID)
@@ -48,10 +54,31 @@ func (s *StreamService) ServeHLSPlaylist(w http.ResponseWriter, r *http.Request,
 	return nil
 }
 
+func parseHLSStartSec(r *http.Request) float64 {
+	if r == nil {
+		return 0
+	}
+	raw := strings.TrimSpace(r.URL.Query().Get("start"))
+	if raw == "" {
+		return 0
+	}
+	v, err := strconv.ParseFloat(raw, 64)
+	if err != nil || v < 0 {
+		return 0
+	}
+	return v
+}
+
 func appendQueryToHLSSegments(playlist, rawQuery string) string {
 	if strings.TrimSpace(rawQuery) == "" {
 		return playlist
 	}
+	// Segment fetches only need auth/profile tokens; drop start= so a seek
+	// restart does not keep forcing EnsureJobFrom on every .ts hit.
+	q := filterHLSSegmentQuery(rawQuery)
+	if q == "" {
+		return playlist
+	}
 	lines := strings.SplitAfter(playlist, "\n")
 	for i, line := range lines {
 		trimmed := strings.TrimSpace(line)
@@ -65,12 +92,31 @@ func appendQueryToHLSSegments(playlist, rawQuery string) string {
 			} else if strings.HasSuffix(line, "\n") {
 				lineEnding = "\n"
 			}
-			lines[i] = strings.TrimRight(line, "\r\n") + "?" + rawQuery + lineEnding
+			lines[i] = strings.TrimRight(line, "\r\n") + "?" + q + lineEnding
 		}
 	}
 	return strings.Join(lines, "")
 }
 
+func filterHLSSegmentQuery(rawQuery string) string {
+	parts := strings.Split(rawQuery, "&")
+	kept := make([]string, 0, len(parts))
+	for _, part := range parts {
+		if part == "" {
+			continue
+		}
+		key := part
+		if i := strings.IndexByte(part, '='); i >= 0 {
+			key = part[:i]
+		}
+		if strings.EqualFold(key, "start") {
+			continue
+		}
+		kept = append(kept, part)
+	}
+	return strings.Join(kept, "&")
+}
+
 // 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)

internal/service/transcoder.go

@@ -50,6 +50,7 @@ type TranscoderService struct {
 	mu          sync.Mutex
 	jobs        map[string]*hlsJob
 	strmResolve func(ctx context.Context, raw string) (*StrmPlayResult, error)
+	probe       *FFprobeService
 }
 
 // hlsJob holds the live state of one ffmpeg run.
@@ -61,6 +62,9 @@ type hlsJob struct {
 	lastAccess time.Time
 	playlistOK bool
 	encoder    string
+	// startSec is the source seek offset fed to ffmpeg (-ss). The HLS
+	// playlist itself always starts at t=0 for that session.
+	startSec float64
 }
 
 var (
@@ -92,13 +96,24 @@ func (t *TranscoderService) PlaylistPath(mediaID string) string {
 	return filepath.Join(t.HLSDir(mediaID), "index.m3u8")
 }
 
-// EnsureJob makes sure a transcode is running for mediaID. The function is
+// EnsureJob makes sure a transcode is running for mediaID from the start of
-// non-blocking: it returns the playlist path immediately. The caller is
+// the source. Prefer EnsureJobFrom when the player seeks into the middle.
-// expected to poll until WaitReady reports true.
 func (t *TranscoderService) EnsureJob(ctx context.Context, mediaID string) (string, error) {
+	return t.EnsureJobFrom(ctx, mediaID, 0)
+}
+
+// EnsureJobFrom starts (or reuses) an HLS job that seeks the source to
+// startSec before encoding. Reusing only happens when an active job already
+// matches that offset; otherwise the previous job is cancelled and the HLS
+// cache dir is wiped so the player can jump without waiting for a full
+// head-to-tail transcode.
+func (t *TranscoderService) EnsureJobFrom(ctx context.Context, mediaID string, startSec float64) (string, error) {
 	if !t.cfg.Transcoder.Enabled {
 		return "", ErrTranscodeDisabled
 	}
+	if startSec < 0 {
+		startSec = 0
+	}
 	m, err := t.repo.Media.FindByID(ctx, mediaID)
 	if err != nil {
 		return "", err
@@ -106,11 +121,16 @@ func (t *TranscoderService) EnsureJob(ctx context.Context, mediaID string) (stri
 	if m == nil {
 		return "", ErrMediaNotFound
 	}
+
 	t.mu.Lock()
-	if _, ok := t.jobs[mediaID]; ok {
+	if existing, ok := t.jobs[mediaID]; ok {
-		t.touchJobLocked(mediaID)
+		if sameHLSStart(existing.startSec, startSec) {
-		t.mu.Unlock()
+			t.touchJobLocked(mediaID)
-		return t.PlaylistPath(mediaID), nil
+			t.mu.Unlock()
+			return t.PlaylistPath(mediaID), nil
+		}
+		existing.cancel()
+		delete(t.jobs, mediaID)
 	}
 	t.mu.Unlock()
 
@@ -118,27 +138,34 @@ func (t *TranscoderService) EnsureJob(ctx context.Context, mediaID string) (stri
 	if err != nil {
 		return "", err
 	}
+	input.StartSec = startSec
+	t.maybeFillDuration(ctx, m, input)
 	if _, err := t.resolveFFmpegPath(); err != nil {
 		return "", err
 	}
 
+	outDir := t.HLSDir(mediaID)
+	// Wipe prior segments so a mid-file restart cannot serve stale early chunks.
+	_ = os.RemoveAll(outDir)
+	if err := os.MkdirAll(outDir, 0o750); err != nil {
+		return "", err
+	}
+
 	t.mu.Lock()
-	if _, ok := t.jobs[mediaID]; ok {
+	if existing, ok := t.jobs[mediaID]; ok {
-		t.touchJobLocked(mediaID)
+		if sameHLSStart(existing.startSec, startSec) {
-		t.mu.Unlock()
+			t.touchJobLocked(mediaID)
-		return t.PlaylistPath(mediaID), nil
+			t.mu.Unlock()
+			return t.PlaylistPath(mediaID), nil
+		}
+		existing.cancel()
+		delete(t.jobs, mediaID)
 	}
 	if max := t.maxConcurrent(); max > 0 && len(t.jobs) >= max {
 		t.mu.Unlock()
 		return "", ErrTranscodeBusy
 	}
 
-	outDir := t.HLSDir(mediaID)
-	if err := os.MkdirAll(outDir, 0o750); err != nil {
-		t.mu.Unlock()
-		return "", err
-	}
-
 	jobCtx, cancel := context.WithCancel(context.Background())
 	job := &hlsJob{
 		mediaID:    mediaID,
@@ -147,6 +174,7 @@ func (t *TranscoderService) EnsureJob(ctx context.Context, mediaID string) (stri
 		startedAt:  time.Now(),
 		lastAccess: time.Now(),
 		encoder:    t.effectiveEncoder(),
+		startSec:   startSec,
 	}
 	t.jobs[mediaID] = job
 	t.mu.Unlock()
@@ -156,6 +184,14 @@ func (t *TranscoderService) EnsureJob(ctx context.Context, mediaID string) (stri
 	return t.PlaylistPath(mediaID), nil
 }
 
+func sameHLSStart(a, b float64) bool {
+	const tol = 0.75
+	if a < b {
+		return b-a < tol
+	}
+	return a-b < tol
+}
+
 // SetStrmPlayTargetResolver wires STRM URL resolution so ffmpeg can transcode
 // remote .strm media (HTTP 直链 or local source path) after direct play fails.
 func (t *TranscoderService) SetStrmPlayTargetResolver(resolve func(ctx context.Context, raw string) (*StrmPlayResult, error)) {
@@ -165,6 +201,40 @@ func (t *TranscoderService) SetStrmPlayTargetResolver(resolve func(ctx context.C
 	t.strmResolve = resolve
 }
 
+// SetProbe wires ffprobe so STRM/HLS jobs can persist source duration when the
+// media row still has duration_sec=0 (common for .strm that was never probed).
+func (t *TranscoderService) SetProbe(probe *FFprobeService) {
+	if t == nil {
+		return
+	}
+	t.probe = probe
+}
+
+func (t *TranscoderService) maybeFillDuration(ctx context.Context, m *model.Media, input transcodeInput) {
+	if t == nil || t.probe == nil || m == nil || m.DurationSec > 0 || strings.TrimSpace(input.Source) == "" {
+		return
+	}
+	var (
+		res *ProbeResult
+		err error
+	)
+	if isHTTPSource(input.Source) {
+		res, err = t.probe.ProbeHTTP(ctx, input.Source, input.Headers)
+	} else {
+		res, err = t.probe.Probe(ctx, input.Source)
+	}
+	if err != nil || res == nil || res.DurationSec <= 0 {
+		return
+	}
+	m.DurationSec = res.DurationSec
+	if t.repo == nil || t.repo.DB == nil {
+		return
+	}
+	if err := t.repo.DB.WithContext(ctx).Model(&model.Media{}).Where("id = ?", m.ID).Update("duration_sec", res.DurationSec).Error; err != nil && t.log != nil {
+		t.log.Debug("persist probed duration failed", zap.String("media_id", m.ID), zap.Error(err))
+	}
+}
+
 func (t *TranscoderService) resolveTranscodeInput(ctx context.Context, m *model.Media) (transcodeInput, error) {
 	if m == nil {
 		return transcodeInput{}, ErrMediaNotFound

internal/service/transcoder_ffmpeg_args.go

@@ -11,8 +11,9 @@ import (
 )
 
 type transcodeInput struct {
-	Source  string
+	Source   string
-	Headers map[string]string
+	Headers  map[string]string
+	StartSec float64
 }
 
 type ffmpegArgSettings struct {
@@ -125,6 +126,11 @@ func baseFFmpegArgs(preInput string, realtime bool) []string {
 
 func appendInputAndVideoArgs(args []string, input transcodeInput, settings ffmpegArgSettings, video ffmpegVideoPlan) []string {
 	args = append(args, ffmpegHTTPInputArgs(input)...)
+	// Input seek (-ss before -i) lets mid-file HLS restarts jump without
+	// decoding everything before the click position.
+	if input.StartSec > 0.05 {
+		args = append(args, "-ss", strconv.FormatFloat(input.StartSec, 'f', 3, 64))
+	}
 	args = append(args, "-i", input.Source, "-map", "0:v:0?", "-map", "0:a:0?", "-vf", video.filter, "-c:v", video.codec)
 	if settings.threads > 0 && video.codec == "libx264" {
 		args = append(args, "-threads", strconv.Itoa(settings.threads))

internal/service/transcoder_ffmpeg_probe.go

@@ -40,6 +40,7 @@ func (t *TranscoderService) runFFmpeg(ctx context.Context, job *hlsJob, input tr
 		zap.String("media_id", job.mediaID),
 		zap.String("encoder", job.encoder),
 		zap.String("source", input.Source),
+		zap.Float64("start_sec", input.StartSec),
 	)
 	t.hub.Publish("transcode", map[string]any{
 		"media_id": job.mediaID,

internal/service/transcoder_test.go

@@ -193,3 +193,47 @@ func TestBuildFFmpegArgsHTTPInputReconnect(t *testing.T) {
 		t.Fatalf("http flags must come before -i, args=%v", args)
 	}
 }
+
+func TestBuildFFmpegArgsInputSeekBeforeDashI(t *testing.T) {
+	cfg := &config.Config{}
+	cfg.Transcoder.MaxHeight = 720
+	cfg.Transcoder.SegmentSeconds = 4
+	args := buildFFmpegArgsForInput(cfg, transcodeInput{
+		Source:   "/x.mkv",
+		StartSec: 125.5,
+	}, "/o/x.m3u8", "/o/seg_%05d.ts")
+	idxSS, idxI := -1, -1
+	for i, arg := range args {
+		if arg == "-ss" {
+			idxSS = i
+		}
+		if arg == "-i" && idxI < 0 {
+			idxI = i
+		}
+	}
+	if idxSS < 0 || idxI < 0 || idxSS > idxI {
+		t.Fatalf("expected -ss before -i, args=%v", args)
+	}
+	if args[idxSS+1] != "125.500" {
+		t.Fatalf("start = %q", args[idxSS+1])
+	}
+}
+
+func TestSameHLSStart(t *testing.T) {
+	if !sameHLSStart(10, 10.2) {
+		t.Fatal("expected close starts to match")
+	}
+	if sameHLSStart(10, 12) {
+		t.Fatal("expected distant starts to differ")
+	}
+}
+
+func TestFilterHLSSegmentQueryDropsStart(t *testing.T) {
+	got := filterHLSSegmentQuery("token=abc&start=120.5&profile_id=1")
+	if strings.Contains(got, "start=") {
+		t.Fatalf("start should be stripped, got %q", got)
+	}
+	if !strings.Contains(got, "token=abc") || !strings.Contains(got, "profile_id=1") {
+		t.Fatalf("auth/profile query should remain, got %q", got)
+	}
+}

web/src/api/client.ts

@@ -146,8 +146,10 @@ export function streamURL(mediaId: string): string {
 }
 
 // hlsURL returns the m3u8 playlist URL fed into hls.js.
-export function hlsURL(mediaId: string): string {
+// startSec > 0 asks the server to (re)start ffmpeg from that source offset.
-  return `/api/hls/${encodeURIComponent(mediaId)}/index.m3u8?${tokenQuery()}${profileQuery()}`
+export function hlsURL(mediaId: string, startSec = 0): string {
+  const start = startSec > 0.05 ? `&start=${encodeURIComponent(String(Math.floor(startSec * 1000) / 1000))}` : ''
+  return `/api/hls/${encodeURIComponent(mediaId)}/index.m3u8?${tokenQuery()}${profileQuery()}${start}`
 }
 
 // imageURL converts a remote poster URL into a same-origin proxy URL so it

web/src/components/PlayerControls.tsx

@@ -46,6 +46,12 @@ type PlayerControlsProps = {
   playlistOpen?: boolean
   hasPlaylist?: boolean
   onTogglePlaylist?: () => void
+  /** Media metadata duration (seconds). Used when HLS only knows transcoded length. */
+  knownDuration?: number
+  /** Absolute source offset of the current HLS session (seconds). */
+  streamOffset?: number
+  /** Absolute seek on the full timeline; return true when handled (e.g. HLS restart). */
+  onSeekAbsolute?: (seconds: number) => boolean
 }
 
 export function PlayerControls({
@@ -65,6 +71,9 @@ export function PlayerControls({
   playlistOpen = false,
   hasPlaylist = false,
   onTogglePlaylist,
+  knownDuration = 0,
+  streamOffset = 0,
+  onSeekAbsolute,
 }: PlayerControlsProps) {
   const video = () => videoRef.current
   const container = () =>
@@ -176,13 +185,14 @@ export function PlayerControls({
     }
     const syncTime = () => {
       if (!isScrubbingRef.current) {
-        setCurrentTime(el.currentTime)
+        setCurrentTime(streamOffset + el.currentTime)
       }
     }
     const syncMeta = () => {
-      setDuration(el.duration || 0)
+      const streamDur = Number.isFinite(el.duration) ? el.duration : 0
+      setDuration(Math.max(knownDuration || 0, streamOffset + streamDur))
       if (!isScrubbingRef.current) {
-        setCurrentTime(el.currentTime)
+        setCurrentTime(streamOffset + el.currentTime)
       }
     }
     const syncVolume = () => {
@@ -225,7 +235,14 @@ export function PlayerControls({
       if (hideTimerRef.current) clearTimeout(hideTimerRef.current)
     }
     // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [videoRef])
+  }, [videoRef, knownDuration, streamOffset])
+
+  // Keep the scrubber max in sync when metadata duration arrives after mount.
+  useEffect(() => {
+    const el = video()
+    const streamDur = el && Number.isFinite(el.duration) ? el.duration : 0
+    setDuration(Math.max(knownDuration || 0, streamOffset + streamDur))
+  }, [knownDuration, streamOffset])
 
   // 当悬停或菜单状态改变时，更新控制栏计时器
   useEffect(() => {
@@ -248,12 +265,23 @@ export function PlayerControls({
     else el.pause()
   }
 
+  const applyAbsoluteSeek = (absolute: number) => {
+    const el = video()
+    if (!el) return
+    if (onSeekAbsolute?.(absolute)) {
+      setCurrentTime(absolute)
+      return
+    }
+    const local = Math.max(0, absolute - streamOffset)
+    el.currentTime = local
+    setCurrentTime(streamOffset + local)
+  }
+
   const handleSeekChange = (v: number) => {
     setScrubValue(v)
     setCurrentTime(v)
-    const el = video()
+    if (!isScrubbing) {
-    if (el && !isScrubbing) {
+      applyAbsoluteSeek(v)
-      el.currentTime = v
     }
   }
 
@@ -264,11 +292,7 @@ export function PlayerControls({
   }
 
   const handleSeekEnd = (v: number) => {
-    const el = video()
+    applyAbsoluteSeek(v)
-    if (el) {
-      el.currentTime = v
-      setCurrentTime(v)
-    }
     setIsScrubbing(false)
     setScrubValue(null)
   }

web/src/pages/PlayerPage.tsx

@@ -72,6 +72,8 @@ export function PlayerPage() {
   const [directOnly, setDirectOnly] = useState(false)
   const [resumePosition, setResumePosition] = useState(0)
   const [initialSeekDone, setInitialSeekDone] = useState(false)
+  // HLS session source offset: playlist t=0 maps to this absolute second.
+  const [hlsStartSec, setHlsStartSec] = useState(0)
 
   // 弹幕控制：状态来自 /api/danmaku/config 初始值，用户在面板里实时调整。
   const [danmakuOpen, setDanmakuOpen] = useState(false)
@@ -187,6 +189,7 @@ export function PlayerPage() {
   useEffect(() => {
     setMedia(null)
     setLoadError('')
+    setHlsStartSec(0)
     setDanmakuEpisodeId(null)
     setDanmakuCandidates([])
     setDanmakuSearch(null)
@@ -245,12 +248,22 @@ export function PlayerPage() {
 
     const video = ref.current
     if (mode === 'hls') {
-      const url = hlsURL(media.id)
+      const url = hlsURL(media.id, hlsStartSec)
       void import('hls.js').then(({ default: HlsCtor }) => {
         if (HlsCtor.isSupported()) {
           const hls = new HlsCtor({ enableWorker: true, lowLatencyMode: false })
           hls.loadSource(url)
           hls.attachMedia(video)
+          hls.on(HlsCtor.Events.MANIFEST_PARSED, () => {
+            // .strm 入库时常缺 duration；转码启动时会补探测，这里刷新一次给进度条总时长。
+            if ((media.duration_sec || 0) > 0) return
+            mediaAPI
+              .get(media.id)
+              .then((fresh) => {
+                if ((fresh.duration_sec || 0) > 0) setMedia(fresh)
+              })
+              .catch(() => undefined)
+          })
           hls.on(HlsCtor.Events.ERROR, (_, data) => {
             if (data.fatal) {
               setHlsUnavailable(true)
@@ -283,8 +296,17 @@ export function PlayerPage() {
       }
       void video.play().catch(() => undefined)
     }
-    return () => teardownHls(media.id, mode === 'hls')
+    return () => teardownHls()
-  }, [hlsUnavailable, media, mode, params, setParams, teardownHls])
+  }, [hlsUnavailable, hlsStartSec, media, mode, params, setParams, teardownHls])
+
+  // Stop the host ffmpeg job only when leaving HLS for this media (not on mid-file seek restarts).
+  useEffect(() => {
+    if (!media || mode !== 'hls') return
+    const mediaId = media.id
+    return () => {
+      api.delete(`/hls/${encodeURIComponent(mediaId)}`).catch(() => undefined)
+    }
+  }, [media, mode])
 
   // 自动拉取已有的播放进度并恢复播放位置
   useEffect(() => {
@@ -302,8 +324,21 @@ export function PlayerPage() {
   }, [id])
 
   useEffect(() => {
+    if (!resumePosition || initialSeekDone) return
+    if (mode === 'hls') {
+      // Restart transcode near the resume point instead of seeking a short partial playlist.
+      if (Math.abs(hlsStartSec - resumePosition) > 2) {
+        setHlsStartSec(resumePosition)
+      }
+      setInitialSeekDone(true)
+      const m = Math.floor(resumePosition / 60)
+      const s = Math.floor(resumePosition % 60)
+      const timeStr = `${m.toString().padStart(2, '0')}:${s.toString().padStart(2, '0')}`
+      toast.success(`已恢复上次播放进度至 ${timeStr}`, { duration: 2500 })
+      return
+    }
     const video = ref.current
-    if (!video || !resumePosition || initialSeekDone) return
+    if (!video) return
     const applyResume = () => {
       if (resumePosition > 0 && Math.abs(video.currentTime - resumePosition) > 2) {
         video.currentTime = resumePosition
@@ -320,18 +355,22 @@ export function PlayerPage() {
       video.addEventListener('loadedmetadata', applyResume, { once: true })
       return () => video.removeEventListener('loadedmetadata', applyResume)
     }
-  }, [resumePosition, initialSeekDone])
+  }, [resumePosition, initialSeekDone, mode, hlsStartSec])
 
   // Persist resume position every 10 seconds while playing, and immediately upon pause/unmount.
   useEffect(() => {
     if (!media || !ref.current) return
     const video = ref.current
+    const absolutePositionMs = () =>
+      Math.floor(((mode === 'hls' ? hlsStartSec : 0) + video.currentTime) * 1000)
+    const absoluteDurationMs = () =>
+      Math.floor(Math.max(media.duration_sec || 0, (mode === 'hls' ? hlsStartSec : 0) + (video.duration || 0)) * 1000)
     const handler = () => {
       const now = Date.now()
       if (now - lastSentRef.current < 10_000) return
       lastSentRef.current = now
-      const positionMs = Math.floor(video.currentTime * 1000)
+      const positionMs = absolutePositionMs()
-      const durationMs = Math.floor((video.duration || 0) * 1000)
+      const durationMs = absoluteDurationMs()
       if (positionMs > 0) {
         playbackAPI.recordProgress(media.id, positionMs, durationMs).catch(() => undefined)
       }
@@ -341,13 +380,13 @@ export function PlayerPage() {
     return () => {
       video.removeEventListener('timeupdate', handler)
       video.removeEventListener('pause', handler)
-      const positionMs = Math.floor(video.currentTime * 1000)
+      const positionMs = absolutePositionMs()
-      const durationMs = Math.floor((video.duration || 0) * 1000)
+      const durationMs = absoluteDurationMs()
       if (positionMs > 0 && media) {
         playbackAPI.recordProgress(media.id, positionMs, durationMs).catch(() => undefined)
       }
     }
-  }, [media])
+  }, [media, mode, hlsStartSec])
 
   // 加载剧集/播放列表
   useEffect(() => {
@@ -521,11 +560,35 @@ export function PlayerPage() {
       return
     }
     const next = mode === 'hls' ? 'direct' : 'hls'
+    if (next === 'hls') {
+      setHlsStartSec(0)
+    }
     setMode(next)
     params.set('mode', next)
     setParams(params, { replace: true })
   }, [isDirectStream, mode, params, setParams])
 
+  const handleSeekAbsolute = useCallback(
+    (absoluteSec: number) => {
+      if (mode !== 'hls') return false
+      const video = ref.current
+      if (!video) return false
+      const target = Math.max(0, absoluteSec)
+      const local = target - hlsStartSec
+      const available = Number.isFinite(video.duration) ? video.duration : 0
+      // Stay inside the already-transcoded window of this HLS session.
+      if (local >= 0 && local <= Math.max(0, available - 0.5)) {
+        video.currentTime = local
+        return true
+      }
+      setPlayerError('')
+      toast('正在从该位置重新转码…', { duration: 2000 })
+      setHlsStartSec(target)
+      return true
+    },
+    [hlsStartSec, mode],
+  )
+
   // 用户切换字幕轨道：-1=关闭；记忆偏好，下次播放默认沿用。
   const selectSubtitle = useCallback((index: number) => {
     setSubtitleIndex(index)
@@ -614,6 +677,9 @@ export function PlayerPage() {
         playlistOpen={playlistOpen}
         hasPlaylist={playlistEpisodes.length > 0}
         onTogglePlaylist={togglePlaylistOpen}
+        knownDuration={media?.duration_sec || 0}
+        streamOffset={mode === 'hls' ? hlsStartSec : 0}
+        onSeekAbsolute={mode === 'hls' ? handleSeekAbsolute : undefined}
         playlistPanel={
           <PlayerPlaylistPanel
             open={playlistOpen}

web/src/pages/PlayerVideoStage.tsx

@@ -42,6 +42,9 @@ type PlayerVideoStageProps = {
   playlistOpen?: boolean
   hasPlaylist?: boolean
   onTogglePlaylist?: () => void
+  knownDuration?: number
+  streamOffset?: number
+  onSeekAbsolute?: (seconds: number) => boolean
 }
 
 export function PlayerVideoStage({
@@ -75,6 +78,9 @@ export function PlayerVideoStage({
   playlistOpen,
   hasPlaylist,
   onTogglePlaylist,
+  knownDuration,
+  streamOffset,
+  onSeekAbsolute,
 }: PlayerVideoStageProps) {
   const stageRef = useRef<HTMLDivElement>(null)
   const [videoRatio, setVideoRatio] = useState<number | null>(null)
@@ -319,6 +325,9 @@ export function PlayerVideoStage({
             playlistOpen={playlistOpen}
             hasPlaylist={hasPlaylist}
             onTogglePlaylist={onTogglePlaylist}
+            knownDuration={knownDuration}
+            streamOffset={streamOffset}
+            onSeekAbsolute={onSeekAbsolute}
           />
           {danmakuPanel}
           {playlistPanel}