优化支持0.5集

internal/handler/emby_show_episodes_season_test.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
 
 	"github.com/gin-gonic/gin"
@@ -309,3 +310,63 @@ func TestEmbyShowEpisodesPagingAdvances(t *testing.T) {
 		t.Fatalf("page 3 = %#v, want an empty page so clients stop paging", third)
 	}
 }
+
+// 半集（S01E11.5）在 Emby 侧必须和第 11 集并列返回：一旦被折成一个条目，
+// TotalRecordCount 就会比 Items 多一条，按总数翻页的客户端会一直重发同一页
+// （这就是「第一季分集加载不出来」的根因）。Emby 的 IndexNumber 只能是整数，
+// 所以集号仍占 11，小数通过条目名体现。
+func TestEmbyShowEpisodesKeepsHalfEpisodeVisible(t *testing.T) {
+	router, secret, seriesID := embySeriesRouter(t, []model.Media{
+		{
+			Base:       model.Base{ID: "e11"},
+			Title:      "三月的狮子",
+			Path:       "D:\\media\\tv\\三月的狮子\\三月的狮子 - S01E11.mkv",
+			SeasonNum:  1,
+			EpisodeNum: 11,
+			Container:  "mkv",
+		},
+		{
+			Base:            model.Base{ID: "e11half"},
+			Title:           "三月的狮子",
+			Path:            "D:\\media\\tv\\三月的狮子\\三月的狮子 - S01E11.5.mkv",
+			SeasonNum:       1,
+			EpisodeNum:      11,
+			EpisodeFraction: 0.5,
+			Container:       "mkv",
+		},
+		{
+			Base:       model.Base{ID: "e12"},
+			Title:      "三月的狮子",
+			Path:       "D:\\media\\tv\\三月的狮子\\三月的狮子 - S01E12.mkv",
+			SeasonNum:  1,
+			EpisodeNum: 12,
+			Container:  "mkv",
+		},
+	})
+
+	items, total := fetchEpisodeItems(t, router, secret, "/Shows/"+seriesID+"/Episodes?Season=1")
+	if total != 3 || len(items) != 3 {
+		t.Fatalf("TotalRecordCount = %d, items = %d, want 3/3", total, len(items))
+	}
+	wantOrder := []string{"e11", "e11half", "e12"}
+	for i, want := range wantOrder {
+		id, _ := items[i]["Id"].(string)
+		if id != want {
+			t.Fatalf("items[%d] = %q, want %q (order %#v)", i, id, want, items)
+		}
+	}
+	for _, item := range items {
+		sources, _ := item["MediaSources"].([]any)
+		if len(sources) != 1 {
+			t.Fatalf("item %v folded %d sources, want 1", item["Id"], len(sources))
+		}
+	}
+
+	halfName, _ := items[1]["Name"].(string)
+	if !strings.HasPrefix(halfName, "第 11.5 集") {
+		t.Fatalf("half episode name = %q, want prefix 第 11.5 集", halfName)
+	}
+	if idx, _ := items[1]["IndexNumber"].(float64); int(idx) != 11 {
+		t.Fatalf("half episode IndexNumber = %v, want 11 (Emby only supports integers)", items[1]["IndexNumber"])
+	}
+}

internal/model/library_media.go

@@ -26,38 +26,39 @@ type LibraryRoot struct {
 // Media 是单个可播放项。剧集链接到 SeriesID；电影 SeriesID == ""。
 type Media struct {
 	Base
-	LibraryID     string  `gorm:"index;size:36;index:idx_media_library_release,priority:1" json:"library_id"`
-	LibraryRootID string  `gorm:"index;size:36" json:"library_root_id,omitempty"`
-	SeriesID      string  `gorm:"index;size:128" json:"series_id,omitempty"`
-	Title         string  `gorm:"size:255;not null" json:"title"`
-	OriginalName  string  `gorm:"size:255" json:"original_name,omitempty"`
-	EpisodeTitle  string  `gorm:"size:255" json:"episode_title,omitempty"`
-	Path          string  `gorm:"uniqueIndex;size:1024;not null" json:"path"`
-	RelativePath  string  `gorm:"size:1024" json:"relative_path,omitempty"`
-	SizeBytes     int64   `json:"size_bytes"`
-	DurationSec   int     `json:"duration_sec"`
-	Width         int     `json:"width"`
-	Height        int     `json:"height"`
-	VideoCodec    string  `gorm:"size:32" json:"video_codec,omitempty"`
-	AudioCodec    string  `gorm:"size:32" json:"audio_codec,omitempty"`
-	Container     string  `gorm:"size:128" json:"container,omitempty"`
-	PosterURL     string  `gorm:"size:1024" json:"poster_url,omitempty"`
-	BackdropURL   string  `gorm:"size:1024" json:"backdrop_url,omitempty"`
-	Overview      string  `gorm:"type:text" json:"overview,omitempty"`
-	Rating        float32 `json:"rating"`
-	Year          int     `json:"year"`
-	ReleaseDate   string  `gorm:"size:10;index:idx_media_library_release,priority:2" json:"release_date,omitempty"`
-	SeasonNum     int     `json:"season_num"`
-	EpisodeNum    int     `json:"episode_num"`
-	ScrapeStatus  string  `gorm:"size:16;default:pending" json:"scrape_status"`
-	TMDbID        int     `json:"tmdb_id"`
-	BangumiID     int     `json:"bangumi_id"`
-	DoubanID      string  `gorm:"column:douban_id;size:32" json:"douban_id,omitempty"`
-	TheTVDBID     string  `gorm:"column:thetvdb_id;size:64" json:"thetvdb_id,omitempty"`
-	Languages     string  `gorm:"size:64"  json:"languages,omitempty"` // 逗号分隔的 ISO 639-1 代码，如 "zh,en"
-	Countries     string  `gorm:"size:128" json:"countries,omitempty"` // 逗号分隔的 ISO 3166-1，如 "CN,US"
-	Genres        string  `gorm:"type:text" json:"genres,omitempty"`   // 逗号分隔的类型名，如 "Action,Animation"
-	NSFW          bool    `gorm:"default:false" json:"nsfw"`
+	LibraryID       string  `gorm:"index;size:36;index:idx_media_library_release,priority:1" json:"library_id"`
+	LibraryRootID   string  `gorm:"index;size:36" json:"library_root_id,omitempty"`
+	SeriesID        string  `gorm:"index;size:128" json:"series_id,omitempty"`
+	Title           string  `gorm:"size:255;not null" json:"title"`
+	OriginalName    string  `gorm:"size:255" json:"original_name,omitempty"`
+	EpisodeTitle    string  `gorm:"size:255" json:"episode_title,omitempty"`
+	Path            string  `gorm:"uniqueIndex;size:1024;not null" json:"path"`
+	RelativePath    string  `gorm:"size:1024" json:"relative_path,omitempty"`
+	SizeBytes       int64   `json:"size_bytes"`
+	DurationSec     int     `json:"duration_sec"`
+	Width           int     `json:"width"`
+	Height          int     `json:"height"`
+	VideoCodec      string  `gorm:"size:32" json:"video_codec,omitempty"`
+	AudioCodec      string  `gorm:"size:32" json:"audio_codec,omitempty"`
+	Container       string  `gorm:"size:128" json:"container,omitempty"`
+	PosterURL       string  `gorm:"size:1024" json:"poster_url,omitempty"`
+	BackdropURL     string  `gorm:"size:1024" json:"backdrop_url,omitempty"`
+	Overview        string  `gorm:"type:text" json:"overview,omitempty"`
+	Rating          float32 `json:"rating"`
+	Year            int     `json:"year"`
+	ReleaseDate     string  `gorm:"size:10;index:idx_media_library_release,priority:2" json:"release_date,omitempty"`
+	SeasonNum       int     `json:"season_num"`
+	EpisodeNum      int     `json:"episode_num"`
+	EpisodeFraction float64 `gorm:"default:0" json:"episode_fraction,omitempty"` // 集号小数部分（S01E11.5 → 0.5）；Emby 的 IndexNumber 只能是整数，小数单独存放
+	ScrapeStatus    string  `gorm:"size:16;default:pending" json:"scrape_status"`
+	TMDbID          int     `json:"tmdb_id"`
+	BangumiID       int     `json:"bangumi_id"`
+	DoubanID        string  `gorm:"column:douban_id;size:32" json:"douban_id,omitempty"`
+	TheTVDBID       string  `gorm:"column:thetvdb_id;size:64" json:"thetvdb_id,omitempty"`
+	Languages       string  `gorm:"size:64"  json:"languages,omitempty"` // 逗号分隔的 ISO 639-1 代码，如 "zh,en"
+	Countries       string  `gorm:"size:128" json:"countries,omitempty"` // 逗号分隔的 ISO 3166-1，如 "CN,US"
+	Genres          string  `gorm:"type:text" json:"genres,omitempty"`   // 逗号分隔的类型名，如 "Action,Animation"
+	NSFW            bool    `gorm:"default:false" json:"nsfw"`
 
 	// STRMURL is the indirection target for .strm files: when present the
 	// stream handler redirects to it instead of opening the local file.

internal/repository/media_repository_upsert.go

@@ -332,6 +332,11 @@ func addMediaPlacementUpdates(updates map[string]any, existing, incoming model.M
 	if episodeChanged {
 		updates["episode_num"] = incoming.EpisodeNum
 	}
+	// 半集的小数部分独立于整数集号比较：S01E11.5 重命名/新增/删除时都要落库，
+	// 否则「11」与「11.5」会被当成同一集折叠。
+	if existing.EpisodeFraction != incoming.EpisodeFraction {
+		updates["episode_fraction"] = incoming.EpisodeFraction
+	}
 	if strings.TrimSpace(existing.ScrapeStatus) == "no_match" && incoming.ScrapeStatus != "matched" && (seasonChanged || episodeChanged) {
 		updates["scrape_status"] = "pending"
 	}

internal/service/emby_items_detail.go

@@ -682,9 +682,21 @@ func (e *EmbyService) itemPayload(ctx context.Context, m *model.Media, fav bool,
 		seasonID = e.seasonIDForMedia(ctx, m)
 		parentID = seasonID
 		episodeTitle := strings.TrimSpace(m.EpisodeTitle)
-		if episodeTitle != "" {
+		// 半集（S01E11.5）在 Emby 协议里只能占用整数 IndexNumber 11，标题里
+		// 不再带上小数就会和真正的第 11 集完全分不清，所以显式补上集号。
+		halfLabel := ""
+		if m.EpisodeFraction > 0 && m.EpisodeNum > 0 {
+			halfLabel = fmt.Sprintf("第 %s 集", FormatEpisodeNumber(m.EpisodeNum, m.EpisodeFraction))
+		}
+		switch {
+		case episodeTitle != "":
 			name = episodeTitle
-		} else if m.EpisodeNum > 0 {
+			if halfLabel != "" && !strings.HasPrefix(episodeTitle, halfLabel) {
+				name = halfLabel + " · " + episodeTitle
+			}
+		case halfLabel != "":
+			name = halfLabel
+		case m.EpisodeNum > 0:
 			name = fmt.Sprintf("第 %d 集", m.EpisodeNum)
 		}
 	}

internal/service/emby_items_list.go

@@ -153,6 +153,9 @@ func (e *EmbyService) episodeItems(ctx context.Context, rows []model.Media, p It
 		if rows[i].EpisodeNum != rows[j].EpisodeNum {
 			return rows[i].EpisodeNum < rows[j].EpisodeNum
 		}
+		if rows[i].EpisodeFraction != rows[j].EpisodeFraction {
+			return rows[i].EpisodeFraction < rows[j].EpisodeFraction
+		}
 		return rows[i].CreatedAt.Before(rows[j].CreatedAt)
 	})
 	// 先折叠同集的多个版本再统计总数与分页，与 payloadsForMedia 内部保持同一步骤。

internal/service/emby_media_sources.go

@@ -33,7 +33,7 @@ func (e *EmbyService) mediaVersionSiblings(ctx context.Context, m *model.Media)
 	}
 	q := e.repo.DB.WithContext(ctx).Model(&model.Media{}).
 		Where("library_id IN ?", libraryIDs).
-		Where("season_num = ? AND episode_num = ?", m.SeasonNum, m.EpisodeNum)
+		Where("season_num = ? AND episode_num = ? AND episode_fraction = ?", m.SeasonNum, m.EpisodeNum, m.EpisodeFraction)
 	if m.TMDbID > 0 {
 		q = q.Where("tm_db_id = ?", m.TMDbID)
 	} else if m.BangumiID > 0 {
@@ -110,11 +110,15 @@ func (e *EmbyService) mediaVersionKey(ctx context.Context, m *model.Media) strin
 	}
 	kind := mediaSpecialKind(m.Path)
 	season, episode := m.SeasonNum, m.EpisodeNum
+	fraction := m.EpisodeFraction
 	if kind != "" && kind != mediaSpecialTheatrical && episode <= 0 {
-		if parsedSeason, parsedEpisode := ParseEpisode(m.Path); parsedEpisode > 0 {
-			season, episode = parsedSeason, parsedEpisode
+		if parsedSeason, parsedEpisode, parsedFraction := ParseEpisodeParts(m.Path); parsedEpisode > 0 {
+			season, episode, fraction = parsedSeason, parsedEpisode, parsedFraction
 		}
 	}
+	// 集号后缀让 S01E11.5 与 S01E11 属于不同版本组；没有小数时后缀为空，
+	// 键与历史完全一致。
+	fractionSuffix := episodeFractionSuffix(fraction)
 	kindKey := ""
 	if kind != "" {
 		kindKey = "|kind:" + kind
@@ -126,10 +130,10 @@ func (e *EmbyService) mediaVersionKey(ctx context.Context, m *model.Media) strin
 		return libraryGroup + "|special-item:" + kind + "|id:" + m.ID
 	}
 	if m.TMDbID > 0 {
-		return fmt.Sprintf("%s|tmdb:%d|s:%d|e:%d%s", libraryGroup, m.TMDbID, season, episode, kindKey)
+		return fmt.Sprintf("%s|tmdb:%d|s:%d|e:%d%s%s", libraryGroup, m.TMDbID, season, episode, fractionSuffix, kindKey)
 	}
 	if m.BangumiID > 0 {
-		return fmt.Sprintf("%s|bangumi:%d|s:%d|e:%d%s", libraryGroup, m.BangumiID, season, episode, kindKey)
+		return fmt.Sprintf("%s|bangumi:%d|s:%d|e:%d%s%s", libraryGroup, m.BangumiID, season, episode, fractionSuffix, kindKey)
 	}
 	title := strings.ToLower(strings.TrimSpace(m.Title))
 	if title == "" {
@@ -138,7 +142,7 @@ func (e *EmbyService) mediaVersionKey(ctx context.Context, m *model.Media) strin
 	if title == "" {
 		return ""
 	}
-	return fmt.Sprintf("%s|title:%s|y:%d|s:%d|e:%d%s", libraryGroup, title, m.Year, season, episode, kindKey)
+	return fmt.Sprintf("%s|title:%s|y:%d|s:%d|e:%d%s%s", libraryGroup, title, m.Year, season, episode, fractionSuffix, kindKey)
 }
 
 func preferMediaVersion(candidate, current model.Media) bool {

internal/service/emby_series.go

@@ -55,7 +55,7 @@ func (e *EmbyService) findSeriesGroup(ctx context.Context, id, userID string) (e
 		// 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 = ''")
 	}
-	if err := q.Order("media.season_num asc, media.episode_num asc, media.created_at asc").Limit(embySeriesGroupingLimit).Find(&rows).Error; err != nil {
+	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) {
@@ -68,20 +68,20 @@ func (e *EmbyService) findSeriesGroup(ctx context.Context, id, userID string) (e
 		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{
+				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
@@ -108,7 +108,7 @@ func (e *EmbyService) findSeasonGroup(ctx context.Context, id, userID string) (e
 		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.created_at asc").
+		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 embySeasonGroup{}, false, err
@@ -167,7 +167,7 @@ func (e *EmbyService) seasonGroupForSeries(ctx context.Context, id, seriesID, us
 		Where("series_id = ? AND (season_num > 0 OR episode_num > 0)", seriesID)
 	rq = e.applyUserMediaVisibility(ctx, rq, userID)
 	if err := rq.
-		Order("media.season_num asc, media.episode_num asc, media.created_at asc").
+		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 embySeasonGroup{}, false, err
@@ -194,26 +194,26 @@ func (e *EmbyService) seriesGroupsFromMedia(ctx context.Context, rows []model.Me
 		seriesID := e.seriesIDForMedia(ctx, &row)
 		group, ok := byID[seriesID]
 		if !ok {
-				group = &embySeriesGroup{
-					ID:                 seriesID,
-					LibraryID:          row.LibraryID,
-					Name:               e.seriesNameForMedia(ctx, &row),
-					Year:               row.Year,
-					ReleaseDate:        row.ReleaseDate,
-					TMDbID:             row.TMDbID,
-					BangumiID:          row.BangumiID,
-					CreatedAt:          row.CreatedAt,
-					DateLastMediaAdded: row.CreatedAt,
-				}
-				byID[seriesID] = group
-				order = append(order, seriesID)
-			}
-			if row.CreatedAt.Before(group.CreatedAt) || group.CreatedAt.IsZero() {
-				group.CreatedAt = row.CreatedAt
-			}
-			if row.CreatedAt.After(group.DateLastMediaAdded) {
-				group.DateLastMediaAdded = row.CreatedAt
+			group = &embySeriesGroup{
+				ID:                 seriesID,
+				LibraryID:          row.LibraryID,
+				Name:               e.seriesNameForMedia(ctx, &row),
+				Year:               row.Year,
+				ReleaseDate:        row.ReleaseDate,
+				TMDbID:             row.TMDbID,
+				BangumiID:          row.BangumiID,
+				CreatedAt:          row.CreatedAt,
+				DateLastMediaAdded: row.CreatedAt,
 			}
+			byID[seriesID] = group
+			order = append(order, seriesID)
+		}
+		if row.CreatedAt.Before(group.CreatedAt) || group.CreatedAt.IsZero() {
+			group.CreatedAt = row.CreatedAt
+		}
+		if row.CreatedAt.After(group.DateLastMediaAdded) {
+			group.DateLastMediaAdded = row.CreatedAt
+		}
 		if strings.TrimSpace(row.ReleaseDate) != "" && mediaReleaseSortTime(row).After(embySeriesReleaseSortTime(*group)) {
 			group.ReleaseDate = row.ReleaseDate
 			if row.Year > 0 {
@@ -249,6 +249,9 @@ func (e *EmbyService) seriesGroupsFromMedia(ctx context.Context, rows []model.Me
 			if group.Episodes[i].EpisodeNum != group.Episodes[j].EpisodeNum {
 				return group.Episodes[i].EpisodeNum < group.Episodes[j].EpisodeNum
 			}
+			if group.Episodes[i].EpisodeFraction != group.Episodes[j].EpisodeFraction {
+				return group.Episodes[i].EpisodeFraction < group.Episodes[j].EpisodeFraction
+			}
 			return group.Episodes[i].CreatedAt.Before(group.Episodes[j].CreatedAt)
 		})
 		groups = append(groups, group)

internal/service/episode_parser.go

@@ -28,9 +28,13 @@ import (
 )
 
 var (
-	patSEnE       = regexp.MustCompile(`(?i)s(\d{1,2})e(\d{1,3})`)
-	patSEnERange  = regexp.MustCompile(`(?i)s(\d{1,2})e(\d{1,3})\s*[-~–—]\s*(?:s(\d{1,2}))?e?(\d{1,3})(?:[^0-9]|$)`)
-	patDanglingSE = regexp.MustCompile(`(?i)(?:^|[\s._-])s\d{1,2}e(?:[\s._-]|$)`)
+	patSEnE = regexp.MustCompile(`(?i)s(\d{1,2})e(\d{1,3})`)
+	// patSEnEFraction 捕获 S01E11.5 这类「半集」写法的小数位：只在 SxxEyy 后
+	// 紧跟一个点加一位数字时成立；解析时还要确认该数字后面不是另一个数字，
+	// 否则 S01E11.1080p 的分辨率会被误读成小数集号。
+	patSEnEFraction = regexp.MustCompile(`(?i)s(\d{1,2})e(\d{1,3})\.(\d)`)
+	patSEnERange    = regexp.MustCompile(`(?i)s(\d{1,2})e(\d{1,3})\s*[-~–—]\s*(?:s(\d{1,2}))?e?(\d{1,3})(?:[^0-9]|$)`)
+	patDanglingSE   = regexp.MustCompile(`(?i)(?:^|[\s._-])s\d{1,2}e(?:[\s._-]|$)`)
 	// patNxE 匹配 1x02 这类季集写法的捕获组，同时用于从标题里剔除季集残留
 	// （ReplaceAllString），因此本身不带边界守卫。解析时改用 patNxEGuarded，
 	// 避免 "1920x1080" 被从中间匹配出 "20x108" 而误判成 S20E108。
@@ -123,6 +127,62 @@ func ParseEpisode(path string) (season, episode int) {
 	return 0, 0
 }
 
+// ParseEpisodeParts 在 ParseEpisode 的基础上返回集号的小数部分：
+// S01E11.5 → (1, 11, 0.5)。小数部分用来把「半集」和同季的整集区分开
+// （折叠/身份键、排序、网页端显示集号都带上它），解析不出来时为 0。
+func ParseEpisodeParts(path string) (season, episode int, fraction float64) {
+	name := mediaSidecarBase(path)
+	if name == "" {
+		name = strings.TrimSuffix(filepath.Base(path), filepath.Ext(path))
+	}
+	if m := patSEnE.FindStringSubmatch(name); len(m) == 3 {
+		return mustAtoi(m[1]), mustAtoi(m[2]), episodeFractionFromName(name)
+	}
+	season, episode = ParseEpisode(path)
+	return season, episode, 0
+}
+
+// episodeFractionFromName 从 "S01E11.5" 这类名字里取出小数部分（0.5）。
+// 只在 SxxEyy 后紧跟「点 + 一位数字」、且该数字之后不是数字时才成立，
+// 否则 S01E11.1080p / S01E05.10bit 会被读成小数集号。
+func episodeFractionFromName(name string) float64 {
+	lower := strings.ToLower(name)
+	m := patSEnEFraction.FindStringSubmatchIndex(lower)
+	if len(m) != 8 {
+		return 0
+	}
+	digitsStart, digitsEnd := m[6], m[7]
+	if digitsStart < 0 || digitsEnd <= digitsStart {
+		return 0
+	}
+	if digitsEnd < len(lower) && lower[digitsEnd] >= '0' && lower[digitsEnd] <= '9' {
+		return 0
+	}
+	value, err := strconv.ParseFloat("0."+lower[digitsStart:digitsEnd], 64)
+	if err != nil || value <= 0 || value >= 1 {
+		return 0
+	}
+	return value
+}
+
+// episodeFractionSuffix 把小数部分渲染成身份/显示后缀：0.5 → ".5"，无小数 → ""。
+// 折叠键用它拼接，所以没有小数的集（绝大多数）产生的键与历史完全一致。
+func episodeFractionSuffix(fraction float64) string {
+	if fraction <= 0 || fraction >= 1 {
+		return ""
+	}
+	formatted := strconv.FormatFloat(fraction, 'f', -1, 64)
+	if !strings.HasPrefix(formatted, "0.") {
+		return ""
+	}
+	return formatted[1:]
+}
+
+// FormatEpisodeNumber 把整数集号与小数部分拼成显示集号：11 → "11"，11.5 → "11.5"。
+func FormatEpisodeNumber(episode int, fraction float64) string {
+	return strconv.Itoa(episode) + episodeFractionSuffix(fraction)
+}
+
 // resolutionEpisodeArtifact returns the bogus (season, episode) pair the legacy
 // `(\d{1,2})x(\d{1,3})` pattern would extract from a WxH pixel-dimension token
 // in path — e.g. 1920x1080 -> (20, 108), 3840x2160 -> (40, 216). Reports ok=false
@@ -215,6 +275,21 @@ func onlineEpisodeIdentityFromPath(path string) (season, episode int) {
 	return season, episode
 }
 
+// onlineEpisodeFractionFromPath 返回按在线身份规则得到的集号小数部分：
+// S01E11.5 → 0.5。只有在线身份未被重映射（SxxE00 特别篇那种改写）时才给出，
+// 避免把重映射后的特别篇又带上原季的小数。
+func onlineEpisodeFractionFromPath(path string) float64 {
+	season, episode, fraction := ParseEpisodeParts(path)
+	if fraction <= 0 || episode <= 0 {
+		return 0
+	}
+	onlineSeason, onlineEpisode := onlineEpisodeIdentityFromPath(path)
+	if onlineSeason != season || onlineEpisode != episode {
+		return 0
+	}
+	return fraction
+}
+
 type episodeRef struct {
 	Season  int
 	Episode int

internal/service/episode_parser_test.go

@@ -152,3 +152,60 @@ func TestDropResolutionArtifactEpisodeIdentity(t *testing.T) {
 		t.Fatalf("legitimate S20E108 identity was cleared: %+v", legit)
 	}
 }
+
+// S01E11.5 这类「半集」要保留小数部分，才能和真正的第 11 集区分开；
+// 同时不能把 S01E11.1080p / S01E05.10bit 这类分辨率、位深读成小数集号。
+func TestParseEpisodePartsReadsHalfEpisodes(t *testing.T) {
+	cases := []struct {
+		name         string
+		path         string
+		wantSeason   int
+		wantEpisode  int
+		wantFraction float64
+	}{
+		{"half episode in anime folder", `动漫/三月的狮子/3月的狮子 S01E11.5.mkv.strm`, 1, 11, 0.5},
+		{"half episode bare", `三月的狮子 S01E07.5.mkv`, 1, 7, 0.5},
+		{"plain episode has no fraction", `三月的狮子 S01E11.mkv`, 1, 11, 0},
+		{"resolution is not a fraction", `Show S01E11.1080p.WEB-DL.mkv`, 1, 11, 0},
+		{"bit depth is not a fraction", `Show S01E05.10bit.mkv`, 1, 5, 0},
+		{"special naming keeps integral episode", `三月的狮子 S00E11.mkv`, 0, 11, 0},
+		{"no episode marker", `movie.mkv`, 0, 0, 0},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			season, episode, fraction := ParseEpisodeParts(tc.path)
+			if season != tc.wantSeason || episode != tc.wantEpisode || fraction != tc.wantFraction {
+				t.Fatalf("ParseEpisodeParts(%q) = (%d, %d, %v), want (%d, %d, %v)",
+					tc.path, season, episode, fraction, tc.wantSeason, tc.wantEpisode, tc.wantFraction)
+			}
+			// ParseEpisode 必须保持原行为（只返回整数季集号）。
+			plainSeason, plainEpisode := ParseEpisode(tc.path)
+			if plainSeason != tc.wantSeason || plainEpisode != tc.wantEpisode {
+				t.Fatalf("ParseEpisode(%q) = (%d, %d), want (%d, %d)",
+					tc.path, plainSeason, plainEpisode, tc.wantSeason, tc.wantEpisode)
+			}
+		})
+	}
+}
+
+func TestOnlineEpisodeFractionFromPath(t *testing.T) {
+	if got := onlineEpisodeFractionFromPath(`动漫/三月的狮子/3月的狮子 S01E11.5.mkv.strm`); got != 0.5 {
+		t.Fatalf("half episode fraction = %v, want 0.5", got)
+	}
+	if got := onlineEpisodeFractionFromPath(`三月的狮子 S01E11.mkv`); got != 0 {
+		t.Fatalf("plain episode fraction = %v, want 0", got)
+	}
+	// S01E00 会被重映射成特别篇 S00E01，此时不能再带上原季的小数规则。
+	if got := onlineEpisodeFractionFromPath(`三月的狮子 S01E00.mkv`); got != 0 {
+		t.Fatalf("remapped special fraction = %v, want 0", got)
+	}
+}
+
+func TestFormatEpisodeNumber(t *testing.T) {
+	if got := FormatEpisodeNumber(11, 0.5); got != "11.5" {
+		t.Fatalf("FormatEpisodeNumber(11, 0.5) = %q, want 11.5", got)
+	}
+	if got := FormatEpisodeNumber(11, 0); got != "11" {
+		t.Fatalf("FormatEpisodeNumber(11, 0) = %q, want 11", got)
+	}
+}

internal/service/local_availability.go

@@ -53,7 +53,7 @@ func LookupLocalAvailability(ctx context.Context, repo *repository.Container, ti
 	var rows []model.Media
 	if err := repo.DB.WithContext(ctx).
 		Where("title LIKE ? OR original_name LIKE ? OR path LIKE ?", like, like, like).
-		Order("season_num asc, episode_num asc, created_at desc").
+		Order("season_num asc, episode_num asc, episode_fraction asc, created_at desc").
 		Limit(2000).
 		Find(&rows).Error; err != nil {
 		return out

internal/service/manual_scrape.go

@@ -82,10 +82,14 @@ func rebuildManualScrapeIdentity(media *model.Media, lib *model.Library, match *
 	switch mediaType {
 	case "tv", "anime", "variety":
 		media.SeasonNum, media.EpisodeNum = onlineEpisodeIdentityFromPath(media.Path)
+		// 半集（S01E11.5）的小数部分同样按路径重建，否则重新刮削会把 11.5
+		// 变回普通的第 11 集。
+		media.EpisodeFraction = onlineEpisodeFractionFromPath(media.Path)
 		media.EpisodeTitle = ""
 	case "movie", "adult":
 		media.SeasonNum = 0
 		media.EpisodeNum = 0
+		media.EpisodeFraction = 0
 		media.EpisodeTitle = ""
 	}
 }

internal/service/media_metadata.go

@@ -19,7 +19,10 @@ type MediaMetadataUpdate struct {
 	Rating       *float32 `json:"rating"`
 	SeasonNum    *int     `json:"season_num"`
 	EpisodeNum   *int     `json:"episode_num"`
-	TMDbID       *int     `json:"tmdb_id"`
+	// EpisodeFraction 是集号的小数部分（11.5 的 0.5）。单独提供是为了让编辑
+	// 「集」时不会把半集写成整数集号，也不会把整集写成小数。
+	EpisodeFraction *float64 `json:"episode_fraction"`
+	TMDbID          *int     `json:"tmdb_id"`
 	BangumiID    *int     `json:"bangumi_id"`
 	DoubanID     *string  `json:"douban_id"`
 	TheTVDBID    *string  `json:"thetvdb_id"`
@@ -77,6 +80,9 @@ func (s *MediaService) UpdateMetadata(ctx context.Context, id string, req MediaM
 	if req.EpisodeNum != nil {
 		updates["episode_num"] = clampNonNegativeInt(*req.EpisodeNum)
 	}
+	if req.EpisodeFraction != nil {
+		updates["episode_fraction"] = clampEpisodeFraction(*req.EpisodeFraction)
+	}
 	if req.TMDbID != nil {
 		updates["tm_db_id"] = clampNonNegativeInt(*req.TMDbID)
 	}
@@ -141,6 +147,15 @@ func clampNonNegativeInt(value int) int {
 	return value
 }
 
+// clampEpisodeFraction 把集号小数部分夹到 [0,1)：小于 0 或大于等于 1 都视为
+// 「没有小数」，避免把非法值写进库。
+func clampEpisodeFraction(value float64) float64 {
+	if value <= 0 || value >= 1 {
+		return 0
+	}
+	return value
+}
+
 func clampRating(value float32) float32 {
 	if value < 0 {
 		return 0

internal/service/media_series.go

@@ -287,7 +287,7 @@ func (s *MediaService) ListLibrarySeriesEpisodes(ctx context.Context, libraryID,
 	return out, nil
 }
 
-// sortEpisodesForDisplay 与历史行为一致：季/集号升序，再按入库时间兜底。
+// sortEpisodesForDisplay 与历史行为一致：季/集号升序（含半集的小数部分），再按入库时间兜底。
 func sortEpisodesForDisplay(out []model.Media) {
 	sort.SliceStable(out, func(i, j int) bool {
 		if out[i].SeasonNum != out[j].SeasonNum {
@@ -296,6 +296,9 @@ func sortEpisodesForDisplay(out []model.Media) {
 		if out[i].EpisodeNum != out[j].EpisodeNum {
 			return out[i].EpisodeNum < out[j].EpisodeNum
 		}
+		if out[i].EpisodeFraction != out[j].EpisodeFraction {
+			return out[i].EpisodeFraction < out[j].EpisodeFraction
+		}
 		return out[i].CreatedAt.Before(out[j].CreatedAt)
 	})
 }
@@ -403,6 +406,9 @@ func (s *MediaService) ListMediaEpisodes(ctx context.Context, mediaID string, vi
 		if out[i].EpisodeNum != out[j].EpisodeNum {
 			return out[i].EpisodeNum < out[j].EpisodeNum
 		}
+		if out[i].EpisodeFraction != out[j].EpisodeFraction {
+			return out[i].EpisodeFraction < out[j].EpisodeFraction
+		}
 		if out[i].Path != out[j].Path {
 			return out[i].Path < out[j].Path
 		}

internal/service/media_versions.go

@@ -134,6 +134,9 @@ func GroupEpisodeVersionsForDisplay(items []model.Media) []MediaItem {
 		if grouped[i].EpisodeNum != grouped[j].EpisodeNum {
 			return grouped[i].EpisodeNum < grouped[j].EpisodeNum
 		}
+		if grouped[i].EpisodeFraction != grouped[j].EpisodeFraction {
+			return grouped[i].EpisodeFraction < grouped[j].EpisodeFraction
+		}
 		return grouped[i].CreatedAt.Before(grouped[j].CreatedAt)
 	})
 	return grouped
@@ -192,7 +195,7 @@ func adultVouchedGroupKey(m model.Media, vouched map[string]bool) string {
 	return fmt.Sprintf("adult:%s:%s", libKey, code)
 }
 
-func mediaVersionGroupKey(m model.Media) string {	// 远程 Emby 挂载条目保持独立，不与其它远程条目或本地条目折叠合并。
+func mediaVersionGroupKey(m model.Media) string { // 远程 Emby 挂载条目保持独立，不与其它远程条目或本地条目折叠合并。
 	if IsEmbyRemoteID(m.ID) {
 		return fmt.Sprintf("embyremote:%s", m.ID)
 	}
@@ -200,11 +203,15 @@ func mediaVersionGroupKey(m model.Media) string {	// 远程 Emby 挂载条目保
 	libKey := mediaVersionLibraryKey(m)
 	specialKind := mediaSpecialKind(m.Path)
 	season, episode := m.SeasonNum, m.EpisodeNum
+	fraction := m.EpisodeFraction
 	if specialKind != "" && specialKind != mediaSpecialTheatrical && episode <= 0 {
-		if parsedSeason, parsedEpisode := ParseEpisode(m.Path); parsedEpisode > 0 {
-			season, episode = parsedSeason, parsedEpisode
+		if parsedSeason, parsedEpisode, parsedFraction := ParseEpisodeParts(m.Path); parsedEpisode > 0 {
+			season, episode, fraction = parsedSeason, parsedEpisode, parsedFraction
 		}
 	}
+	// 集号后缀：S01E11.5 记成 "11.5"，没有小数的集后缀为空，
+	// 因此绝大多数条目的版本身份键与历史完全一致。
+	episodeTag := fmt.Sprintf("%d:%d%s", season, episode, episodeFractionSuffix(fraction))
 
 	if season > 0 || episode > 0 {
 		kind := specialKind
@@ -213,13 +220,13 @@ func mediaVersionGroupKey(m model.Media) string {	// 远程 Emby 挂载条目保
 		}
 		switch {
 		case m.TMDbID > 0:
-			return fmt.Sprintf("episode:%s:tmdb:%d:%d:%d", kind, m.TMDbID, season, episode)
+			return fmt.Sprintf("episode:%s:tmdb:%d:%s", kind, m.TMDbID, episodeTag)
 		case m.BangumiID > 0:
-			return fmt.Sprintf("episode:%s:bangumi:%d:%d:%d", kind, m.BangumiID, season, episode)
+			return fmt.Sprintf("episode:%s:bangumi:%d:%s", kind, m.BangumiID, episodeTag)
 		case strings.TrimSpace(m.DoubanID) != "":
-			return fmt.Sprintf("episode:%s:douban:%s:%d:%d", kind, strings.ToLower(strings.TrimSpace(m.DoubanID)), season, episode)
+			return fmt.Sprintf("episode:%s:douban:%s:%s", kind, strings.ToLower(strings.TrimSpace(m.DoubanID)), episodeTag)
 		case strings.TrimSpace(m.TheTVDBID) != "":
-			return fmt.Sprintf("episode:%s:thetvdb:%s:%d:%d", kind, strings.ToLower(strings.TrimSpace(m.TheTVDBID)), season, episode)
+			return fmt.Sprintf("episode:%s:thetvdb:%s:%s", kind, strings.ToLower(strings.TrimSpace(m.TheTVDBID)), episodeTag)
 		}
 		title := firstNonEmpty(m.OriginalName, m.Title)
 		if title == "" {
@@ -234,7 +241,7 @@ func mediaVersionGroupKey(m model.Media) string {	// 远程 Emby 挂载条目保
 			kind,
 			libKey,
 			title,
-			fmt.Sprintf("%d:%d", season, episode),
+			episodeTag,
 		}, "|")
 	}
 

internal/service/media_versions_test.go

@@ -737,3 +737,53 @@ func TestMediaAdultGroupCodeRequiresNSFW(t *testing.T) {
 		})
 	}
 }
+
+// S01E11 与 S01E11.5 必须折叠成两条不同记录（既不合并，也不丢集），
+// 且 11.5 排在 11 之后、12 之前。这是「第一季分集加载不出来」那次的根因：
+// 两条同季同集的记录被折成一条，计数与返回条目对不上。
+func TestGroupEpisodeVersionsForDisplayKeepsHalfEpisodeSeparate(t *testing.T) {
+	rows := []model.Media{
+		{Base: model.Base{ID: "ep12"}, LibraryID: "anime", Title: "三月的狮子", SeasonNum: 1, EpisodeNum: 12, TMDbID: 65336, Path: "/anime/三月的狮子/3月的狮子 S01E12.mkv"},
+		{Base: model.Base{ID: "ep11"}, LibraryID: "anime", Title: "三月的狮子", SeasonNum: 1, EpisodeNum: 11, TMDbID: 65336, Path: "/anime/三月的狮子/3月的狮子 S01E11.mkv"},
+		{Base: model.Base{ID: "ep11half"}, LibraryID: "anime", Title: "三月的狮子", SeasonNum: 1, EpisodeNum: 11, EpisodeFraction: 0.5, TMDbID: 65336, Path: "/anime/三月的狮子/3月的狮子 S01E11.5.mkv"},
+	}
+
+	grouped := GroupEpisodeVersionsForDisplay(rows)
+	if len(grouped) != 3 {
+		t.Fatalf("grouped len = %d, want 3 (11 / 11.5 / 12): %#v", len(grouped), grouped)
+	}
+	wantOrder := []string{"ep11", "ep11half", "ep12"}
+	for i, want := range wantOrder {
+		if grouped[i].ID != want {
+			t.Fatalf("grouped[%d] = %q, want %q (order %#v)", i, grouped[i].ID, want, grouped)
+		}
+	}
+	for _, item := range grouped {
+		if len(item.Versions) != 0 {
+			t.Fatalf("half episode must not fold with the integral one: %#v", grouped)
+		}
+	}
+}
+
+// 版本身份键必须区分 11 与 11.5，同时保持没有小数时的历史键不变。
+func TestMediaVersionGroupKeyDistinguishesHalfEpisode(t *testing.T) {
+	base := model.Media{LibraryID: "anime", Title: "三月的狮子", SeasonNum: 1, EpisodeNum: 11}
+	plain := base
+	half := base
+	half.EpisodeFraction = 0.5
+
+	plainKey := mediaVersionGroupKey(plain)
+	halfKey := mediaVersionGroupKey(half)
+	if plainKey == "" || halfKey == "" {
+		t.Fatalf("version keys must not be empty: %q %q", plainKey, halfKey)
+	}
+	if plainKey == halfKey {
+		t.Fatalf("11 and 11.5 must have different version keys, both = %q", plainKey)
+	}
+	if !strings.HasSuffix(halfKey, "1:11.5") {
+		t.Fatalf("half episode key = %q, want suffix 1:11.5", halfKey)
+	}
+	if !strings.HasSuffix(plainKey, "1:11") {
+		t.Fatalf("plain episode key = %q, want suffix 1:11", plainKey)
+	}
+}

internal/service/nfo.go

@@ -142,7 +142,9 @@ func WriteMediaNFO(m *model.Media) (string, error) {
 	if m.SeasonNum > 0 || m.EpisodeNum > 0 {
 		title := strings.TrimSpace(m.EpisodeTitle)
 		if title == "" && m.EpisodeNum > 0 {
-			title = fmt.Sprintf("第 %d 集", m.EpisodeNum)
+			// 兜底标题也要带上小数：S01E11.5 导出成「第 11.5 集」，
+			// 否则回写 NFO 后重新入库会把半集写成普通的第 11 集。
+			title = fmt.Sprintf("第 %s 集", FormatEpisodeNumber(m.EpisodeNum, m.EpisodeFraction))
 		}
 		if title == "" {
 			title = strings.TrimSpace(m.Title)

internal/service/scanner.go

@@ -170,9 +170,12 @@ type existingLocalMedia struct {
 	TheTVDBID     string
 	SeasonNum     int
 	EpisodeNum    int
-	Genres        string
-	Countries     string
-	Languages     string
-	NSFW          bool
-	ScrapeStatus  string
+	// EpisodeFraction 是集号的小数部分（S01E11.5 → 0.5）；变化同样要触发刷新，
+	// 否则已有行上的「半集」标记不会被写回。
+	EpisodeFraction float64
+	Genres          string
+	Countries       string
+	Languages       string
+	NSFW            bool
+	ScrapeStatus    string
 }

internal/service/scanner_existing_media.go

@@ -33,7 +33,7 @@ func (s *ScannerService) existingLocalMediaSnapshotForRoot(ctx context.Context,
 		query = query.Where("(library_root_id = ? OR library_root_id = '' OR library_root_id IS NULL)", rootID)
 	}
 	rows, err := query.
-		Select("path", "library_root_id", "relative_path", "title", "original_name", "episode_title", "size_bytes", "duration_sec", "width", "height", "video_codec", "audio_codec", "container", "strm_url", "file_id", "poster_url", "backdrop_url", "overview", "year", "release_date", "rating", "tm_db_id", "bangumi_id", "douban_id", "thetvdb_id", "season_num", "episode_num", "genres", "countries", "languages", "nsfw", "scrape_status").
+		Select("path", "library_root_id", "relative_path", "title", "original_name", "episode_title", "size_bytes", "duration_sec", "width", "height", "video_codec", "audio_codec", "container", "strm_url", "file_id", "poster_url", "backdrop_url", "overview", "year", "release_date", "rating", "tm_db_id", "bangumi_id", "douban_id", "thetvdb_id", "season_num", "episode_num", "episode_fraction", "genres", "countries", "languages", "nsfw", "scrape_status").
 		Rows()
 	if err != nil {
 		return nil, err
@@ -74,6 +74,7 @@ func (s *ScannerService) existingLocalMediaSnapshotForRoot(ctx context.Context,
 			&row.TheTVDBID,
 			&row.SeasonNum,
 			&row.EpisodeNum,
+			&row.EpisodeFraction,
 			&row.Genres,
 			&row.Countries,
 			&row.Languages,

internal/service/scanner_local_ingest.go

@@ -23,18 +23,19 @@ func (s *ScannerService) ingestFile(ctx context.Context, lib *model.Library, roo
 		return
 	}
 
-	parsedSeason, parsedEpisode := ParseEpisode(path)
+	parsedSeason, parsedEpisode, parsedFraction := ParseEpisodeParts(path)
 	localMeta := s.readLocalScanMetadata(lib, root, path, parsedSeason, parsedEpisode)
 	media := s.buildLocalScanMedia(localScanMediaInput{
-		lib:           lib,
-		root:          root,
-		path:          path,
-		ext:           ext,
-		fileID:        fileID,
-		size:          size,
-		parsedSeason:  parsedSeason,
-		parsedEpisode: parsedEpisode,
-		localMeta:     localMeta,
+		lib:            lib,
+		root:           root,
+		path:           path,
+		ext:            ext,
+		fileID:         fileID,
+		size:           size,
+		parsedSeason:   parsedSeason,
+		parsedEpisode:  parsedEpisode,
+		parsedFraction: parsedFraction,
+		localMeta:      localMeta,
 	})
 	isNewMedia, skipUnchanged := s.localMediaScanState(localMediaScanStateInput{
 		ctx:           ctx,
@@ -169,15 +170,16 @@ func localMediaProbeDataMissing(existing existingLocalMedia) bool {
 }
 
 type localScanMediaInput struct {
-	lib           *model.Library
-	root          *model.LibraryRoot
-	path          string
-	ext           string
-	fileID        string
-	size          int64
-	parsedSeason  int
-	parsedEpisode int
-	localMeta     *LocalMetadata
+	lib            *model.Library
+	root           *model.LibraryRoot
+	path           string
+	ext            string
+	fileID         string
+	size           int64
+	parsedSeason   int
+	parsedEpisode  int
+	parsedFraction float64
+	localMeta      *LocalMetadata
 }
 
 func (s *ScannerService) buildLocalScanMedia(in localScanMediaInput) *model.Media {
@@ -191,17 +193,18 @@ func (s *ScannerService) buildLocalScanMedia(in localScanMediaInput) *model.Medi
 	title, year = preferISOParentScrapeIdentity(in.path, in.lib.Path, title, year)
 
 	media := &model.Media{
-		LibraryID:     in.lib.ID,
-		LibraryRootID: libraryRootID(in.root),
-		RelativePath:  localRelativePath(in.path, in.root),
-		Title:         title,
-		Year:          year,
-		Path:          in.path,
-		SizeBytes:     in.size,
-		Container:     strings.TrimPrefix(in.ext, "."),
-		FileID:        in.fileID,
-		SeasonNum:     in.parsedSeason,
-		EpisodeNum:    in.parsedEpisode,
+		LibraryID:       in.lib.ID,
+		LibraryRootID:   libraryRootID(in.root),
+		RelativePath:    localRelativePath(in.path, in.root),
+		Title:           title,
+		Year:            year,
+		Path:            in.path,
+		SizeBytes:       in.size,
+		Container:       strings.TrimPrefix(in.ext, "."),
+		FileID:          in.fileID,
+		SeasonNum:       in.parsedSeason,
+		EpisodeNum:      in.parsedEpisode,
+		EpisodeFraction: in.parsedFraction,
 	}
 	if in.ext == ".strm" {
 		media.Container = "strm"

internal/service/scanner_metadata_refresh.go

@@ -17,6 +17,9 @@ type scanDerivedMetadata struct {
 	TheTVDBID    string
 	SeasonNum    int
 	EpisodeNum   int
+	// EpisodeFraction 是集号的小数部分（S01E11.5 → 0.5）：它变化时同样要刷新，
+	// 否则已有行上的半集标记永远写不进去。
+	EpisodeFraction float64
 }
 
 func localMetadataNeedsRefresh(existing existingLocalMedia, local *LocalMetadata) bool {
@@ -97,16 +100,17 @@ func localDerivedMetadataNeedsRefresh(existing existingLocalMedia, incoming *mod
 		return true
 	}
 	return scanDerivedMetadataNeedsRefresh(scanDerivedMetadata{
-		Title:        existing.Title,
-		ScrapeStatus: existing.ScrapeStatus,
-		Year:         existing.Year,
-		ReleaseDate:  existing.ReleaseDate,
-		TMDbID:       existing.TMDbID,
-		BangumiID:    existing.BangumiID,
-		DoubanID:     existing.DoubanID,
-		TheTVDBID:    existing.TheTVDBID,
-		SeasonNum:    existing.SeasonNum,
-		EpisodeNum:   existing.EpisodeNum,
+		Title:           existing.Title,
+		ScrapeStatus:    existing.ScrapeStatus,
+		Year:            existing.Year,
+		ReleaseDate:     existing.ReleaseDate,
+		TMDbID:          existing.TMDbID,
+		BangumiID:       existing.BangumiID,
+		DoubanID:        existing.DoubanID,
+		TheTVDBID:       existing.TheTVDBID,
+		SeasonNum:       existing.SeasonNum,
+		EpisodeNum:      existing.EpisodeNum,
+		EpisodeFraction: existing.EpisodeFraction,
 	}, incoming)
 }
 
@@ -128,6 +132,9 @@ func scanDerivedMetadataNeedsRefresh(existing scanDerivedMetadata, incoming *mod
 	if incoming.EpisodeNum > 0 && existing.EpisodeNum != incoming.EpisodeNum {
 		return true
 	}
+	if (incoming.SeasonNum > 0 || incoming.EpisodeNum > 0) && existing.EpisodeFraction != incoming.EpisodeFraction {
+		return true
+	}
 	if incoming.TMDbID > 0 && existing.TMDbID != incoming.TMDbID {
 		return true
 	}

web/src/api/library.ts

@@ -83,6 +83,8 @@ export interface MediaMetadataUpdate {
   rating?: number
   season_num?: number
   episode_num?: number
+  /** 集号的小数部分（11.5 的 0.5）；与 episode_num 一起构成显示集号。 */
+  episode_fraction?: number
   tmdb_id?: number
   bangumi_id?: number
   douban_id?: string

web/src/components/MetadataEditDialog.tsx

@@ -4,6 +4,7 @@ import toast from 'react-hot-toast'
 
 import { mediaAPI, type MediaMetadataUpdate } from '../api/library'
 import type { Media } from '../types'
+import { formatEpisodeNumber } from '../utils/episodeNumber'
 
 interface MetadataEditDialogProps {
   open: boolean
@@ -58,7 +59,7 @@ export function MetadataEditDialog({
       release_date: media.release_date || '',
       rating: media.rating > 0 ? String(media.rating) : '',
       season_num: media.season_num > 0 || media.episode_num > 0 ? String(media.season_num || 0) : '',
-      episode_num: media.episode_num > 0 ? String(media.episode_num) : '',
+      episode_num: media.episode_num > 0 ? formatEpisodeNumber(media) : '',
       tmdb_id: media.tmdb_id > 0 ? String(media.tmdb_id) : '',
       bangumi_id: media.bangumi_id > 0 ? String(media.bangumi_id) : '',
       douban_id: media.douban_id || '',
@@ -105,7 +106,11 @@ export function MetadataEditDialog({
     if (!isSeries) {
       payload.original_name = form.original_name
       payload.season_num = Math.trunc(toNumber(form.season_num))
-      payload.episode_num = Math.trunc(toNumber(form.episode_num))
+      // 「集」输入框接受 11.5 这种半集写法：整数部分进 episode_num，
+      // 小数部分单独进 episode_fraction，避免保存后变成整集或残留小数。
+      const episodeValue = toNumber(form.episode_num)
+      payload.episode_num = Math.trunc(episodeValue)
+      payload.episode_fraction = Number((episodeValue - Math.trunc(episodeValue)).toFixed(3))
     }
     return payload
   }

web/src/components/PlayerMobileTheaterInfo.tsx

@@ -3,6 +3,7 @@ import type { ReactNode } from 'react'
 import { ChevronDown, Layers, ListVideo } from 'lucide-react'
 
 import type { Media } from '../types'
+import { formatEpisodeLabel, formatEpisodeNumber } from '../utils/episodeNumber'
 import { mediaVersionLabel, mediaVersionMatches } from '../utils/mediaVersion'
 
 // PlayerMobileTheaterInfo — 竖屏剧场模式下视频下方的可滚动内容区。
@@ -38,15 +39,17 @@ type PlayerMobileTheaterInfoProps = {
 }
 
 function episodeShortLabel(ep: Media): string {
-  if (ep.episode_num > 0) return `${ep.episode_num}`
+  const number = formatEpisodeNumber(ep)
+  if (number) return number
   const title = ep.episode_title?.trim() || ep.title?.trim() || ''
   return title ? title.slice(0, 4) : '·'
 }
 
 function episodeFullLabel(ep: Media): string {
-  if (ep.episode_num > 0) {
+  const label = formatEpisodeLabel(ep)
+  if (label) {
     const title = ep.episode_title?.trim()
-    return title && title !== ep.title?.trim() ? `第 ${ep.episode_num} 集 · ${title}` : `第 ${ep.episode_num} 集`
+    return title && title !== ep.title?.trim() ? `${label} · ${title}` : label
   }
   return ep.episode_title?.trim() || ep.title?.trim() || '未命名'
 }

web/src/components/PlayerPlaylistPanel.tsx

@@ -2,6 +2,7 @@ import { useEffect, useMemo, useRef, useState } from 'react'
 import { Check, Cloud, Film, Layers, Play, Search, X } from 'lucide-react'
 
 import type { Media } from '../types'
+import { formatEpisodeLabel, formatEpisodeNumber, episodeNumberValue } from '../utils/episodeNumber'
 import { seasonLabel, seasonSortOrder, seriesTitleFromPath } from '../utils/groupSeries'
 import {
   isStrmMedia,
@@ -72,7 +73,7 @@ export function PlayerPlaylistPanel({
       seasonsMap.get(s)!.push(ep)
     }
     for (const [, list] of seasonsMap) {
-      list.sort((a, b) => (a.episode_num || 0) - (b.episode_num || 0))
+      list.sort((a, b) => episodeNumberValue(a) - episodeNumberValue(b))
     }
     return Array.from(seasonsMap.entries())
       .sort(([a], [b]) => seasonSortOrder(a) - seasonSortOrder(b))
@@ -118,7 +119,7 @@ export function PlayerPlaylistPanel({
     ? listToDisplay.filter((ep) => {
         const query = filterText.trim().toLowerCase()
         const title = (ep.episode_title || ep.title || '').toLowerCase()
-        const epNum = String(ep.episode_num)
+        const epNum = formatEpisodeNumber(ep)
         return title.includes(query) || epNum === query || `e${epNum}`.includes(query) || `第${epNum}集`.includes(query)
       })
     : listToDisplay
@@ -293,7 +294,7 @@ export function PlayerPlaylistPanel({
                 const durationText =
                   ep.duration_sec > 0 ? `${Math.round(ep.duration_sec / 60)} 分钟` : ''
                 const cellTitle = [
-                  ep.episode_num > 0 ? `第 ${ep.episode_num} 集` : '',
+                  formatEpisodeLabel(ep),
                   displayTitle,
                   durationText,
                   versions.length > 0 ? `${versions.length} 个版本` : '',
@@ -316,7 +317,7 @@ export function PlayerPlaylistPanel({
                       {isPlaying ? (
                         <Play size={12} className="fill-current" />
                       ) : ep.episode_num > 0 ? (
-                        ep.episode_num
+                        formatEpisodeNumber(ep)
                       ) : (
                         <Film size={13} className="text-white/45" />
                       )}
@@ -429,7 +430,8 @@ function getEpisodeTitle(ep: Media, siblings: Media[]): string {
     return mediaTitle
   }
 
-  return ep.episode_num > 0 ? `第 ${ep.episode_num} 集` : mediaTitle || title || '未命名'
+  const episodeLabel = formatEpisodeLabel(ep)
+  return episodeLabel || mediaTitle || title || '未命名'
 }
 
 function looksLikeSeriesTitle(ep: Media, title: string, siblings: Media[]): boolean {

web/src/pages/HomePageSections.tsx

@@ -28,6 +28,7 @@ import type { SeriesCard } from '../utils/groupSeries'
 import { seriesCardLink } from '../utils/groupSeries'
 import { isRemoteEmbyID } from '../utils/remoteEmby'
 import { getLibraryArtworks } from './librariesPageModel'
+import { formatEpisodeNumber } from '../utils/episodeNumber'
 
 const TYPE_ICONS: Record<string, ReactNode> = {
   movie: <Film size={18} />,
@@ -773,7 +774,7 @@ function ContinueCard({ media, progress }: { media: Media; progress: number }) {
           {media.year > 0 && <span>{media.year}</span>}
           {media.season_num !== undefined && media.episode_num !== undefined && (
             <span>
-              S{media.season_num}E{media.episode_num}
+              S{media.season_num}E{formatEpisodeNumber(media)}
             </span>
           )}
         </div>

web/src/pages/LibrarySeriesDetailHeader.tsx

@@ -7,6 +7,7 @@ import { ExternalPlayerButton } from '../components/ExternalPlayerButton'
 import { MediaFavouriteButton } from '../components/MediaFavouriteButton'
 import type { Media } from '../types'
 import { isTheatricalFeature, seriesTitle, type SeriesCard } from '../utils/groupSeries'
+import { episodeNumberValue } from '../utils/episodeNumber'
 
 type LibrarySeriesDetailHeaderProps = {
   series: SeriesCard
@@ -152,7 +153,7 @@ function firstPlayableEpisode(episodes: Media[]): Media | null {
   const sorted = [...episodes]
   sorted.sort((a, b) =>
     (a.season_num || 0) - (b.season_num || 0)
-    || (a.episode_num || 0) - (b.episode_num || 0),
+    || episodeNumberValue(a) - episodeNumberValue(b),
   )
   return sorted[0] ?? null
 }

web/src/pages/LibrarySeriesEpisodes.tsx

@@ -11,6 +11,7 @@ import {
   THEATRICAL_SEASON,
 } from '../utils/groupSeries'
 import { formatSize } from './libraryPageModel'
+import { formatEpisodeLabel, formatEpisodeNumber } from '../utils/episodeNumber'
 
 type SeasonGroup = {
   season: number
@@ -95,14 +96,14 @@ export function LibrarySeriesEpisodes({
                         referrerPolicy="no-referrer"
                       />
                     ) : (
-                      <span className="text-brand-600 font-bold text-sm">{ep.episode_num || '—'}</span>
+                      <span className="text-brand-600 font-bold text-sm">{formatEpisodeNumber(ep) || '—'}</span>
                     )}
                     <div className="absolute inset-0 flex items-center justify-center bg-black/25 opacity-0 transition-opacity duration-200 group-hover:opacity-100">
                       <Play size={15} className="fill-white text-white drop-shadow-sm" />
                     </div>
                     {ep.episode_num > 0 && (
                       <span className="absolute bottom-0 right-0 rounded-tl bg-black/75 px-1 py-0.5 text-[9px] font-bold leading-none text-white backdrop-blur-[2px]">
-                        {ep.episode_num}
+                        {formatEpisodeNumber(ep)}
                       </span>
                     )}
                   </div>
@@ -153,15 +154,18 @@ function episodeDisplayTitle(ep: Media, siblings: Media[]): string {
     }
   }
 
-  if (ep.episode_num > 0) {
+  const episodeLabel = formatEpisodeLabel(ep)
+  if (episodeLabel) {
     if (!mainTitle) {
-      return `第 ${ep.episode_num} 集`
+      return episodeLabel
     }
-    const prefixRegex = new RegExp(`^(第\\s*0*${ep.episode_num}\\s*集|ep?\\.?\\s*0*${ep.episode_num}\\b)`, 'i')
+    // 标题里已经以「第 11 集 / 第 11.5 集 / ep 11」开头时直接用它，避免重复前缀。
+    const episodeNumber = formatEpisodeNumber(ep).replace(/[.*+?^${}()|[\]\\]/g, '\\$&')
+    const prefixRegex = new RegExp(`^(第\\s*0*${episodeNumber}\\s*集|ep?\\.?\\s*0*${episodeNumber}\\b)`, 'i')
     if (prefixRegex.test(mainTitle)) {
       return mainTitle
     }
-    return `第 ${ep.episode_num} 集 · ${mainTitle}`
+    return `${episodeLabel} · ${mainTitle}`
   }
 
   return mainTitle || '未命名'

web/src/pages/PlayerPage.tsx

@@ -19,6 +19,7 @@ import { profileAPI } from '../api/profile'
 import { useAuthStore } from '../stores/auth'
 import type { Media, PlaybackInfo, PlaybackQuality, PlaybackSegment, PlaybackSegmentKind } from '../types'
 import { getSeriesKey, seriesTitleFromPath } from '../utils/groupSeries'
+import { formatEpisodeLabel } from '../utils/episodeNumber'
 import { mediaVersionMatches, mediaVersionsOf } from '../utils/mediaVersion'
 import { DEFAULT_PLAYBACK_RATE, normalizePlaybackRate } from '../utils/playbackRate'
 import { resolveActiveSkip, skippedNoticeText, toSkipSegments, type SkipPrompt } from '../utils/skipSegments'
@@ -2347,7 +2348,8 @@ function formatEpisodeDisplay(ep: Media, siblings: Media[]): string {
     return mediaTitle
   }
 
-  return ep.episode_num > 0 ? `第 ${ep.episode_num} 集` : mediaTitle || title || '未命名'
+  const episodeLabel = formatEpisodeLabel(ep)
+  return episodeLabel || mediaTitle || title || '未命名'
 }
 
 function findPlaybackQualityById(info: PlaybackInfo | null, id: string): PlaybackQuality | undefined {

web/src/pages/useLibrarySeriesSelection.ts

@@ -10,6 +10,7 @@ import {
   type SeriesCard,
 } from '../utils/groupSeries'
 import { resolveSeriesCardByKey } from '../utils/seriesCardResolve'
+import { episodeNumberValue } from '../utils/episodeNumber'
 
 type SeasonEpisodes = {
   season: number
@@ -72,7 +73,7 @@ export function useLibrarySeriesSelection({
       seasons.get(s)!.push(ep)
     }
     for (const [, list] of seasons) {
-      list.sort((a, b) => (a.episode_num || 0) - (b.episode_num || 0))
+      list.sort((a, b) => episodeNumberValue(a) - episodeNumberValue(b))
     }
     return Array.from(seasons.entries())
       .sort(([a], [b]) => seasonSortOrder(a) - seasonSortOrder(b))

web/src/pages/useMediaDetailPageState.ts

@@ -9,6 +9,7 @@ import { confirmActionResult } from '../components/confirmAction'
 import { useEpisodeArtworkPreference } from '../hooks/useEpisodeArtworkPreference'
 import type { Media } from '../types'
 import { seasonSortOrder } from '../utils/groupSeries'
+import { episodeNumberValue } from '../utils/episodeNumber'
 import { mediaLibraryBackTarget } from './MediaDetailPageModel'
 
 type MediaDetailLocationState = { from?: string } | null
@@ -81,7 +82,7 @@ export function useMediaDetailPageState({ id, navigate }: MediaDetailPageStatePa
       seasons.get(s)!.push(ep)
     }
     for (const [, list] of seasons) {
-      list.sort((a, b) => (a.episode_num || 0) - (b.episode_num || 0))
+      list.sort((a, b) => episodeNumberValue(a) - episodeNumberValue(b))
     }
     return Array.from(seasons.entries())
       .sort(([a], [b]) => seasonSortOrder(a) - seasonSortOrder(b))

web/src/types/media.ts

@@ -28,6 +28,8 @@ export interface Media {
   release_date?: string
   season_num: number
   episode_num: number
+  /** 集号的小数部分（S01E11.5 → 0.5）；没有小数时缺省。 */
+  episode_fraction?: number
   scrape_status: string
   tmdb_id: number
   bangumi_id: number

web/src/utils/episodeNumber.ts

@@ -0,0 +1,36 @@
+import type { Media } from '../types'
+
+type EpisodeNumberSource = Pick<Media, 'episode_num' | 'episode_fraction'> | null | undefined
+
+/**
+ * 含小数的集号：S01E11.5 → 11.5。没有小数（绝大多数集）时就是 episode_num。
+ *
+ * 后端把整数集号和它的小数部分分开存（Emby 协议的 IndexNumber 只能是整数），
+ * 网页端所有「显示集号 / 按集排序」的地方都应该用这个函数，而不是直接读
+ * episode_num，否则 11 与 11.5 会显示、排序成同一集。
+ */
+export function episodeNumberValue(media: EpisodeNumberSource): number {
+  const base = media?.episode_num ?? 0
+  const fraction = media?.episode_fraction ?? 0
+  if (!(fraction > 0 && fraction < 1)) return base
+  return base + fraction
+}
+
+/** 显示用集号文本：11 → "11"，11.5 → "11.5"；没有集号时返回空串。 */
+export function formatEpisodeNumber(media: EpisodeNumberSource): string {
+  const value = episodeNumberValue(media)
+  return value > 0 ? String(value) : ''
+}
+
+/** "第 11 集" / "第 11.5 集"；没有集号时返回空串。 */
+export function formatEpisodeLabel(media: EpisodeNumberSource): string {
+  const value = formatEpisodeNumber(media)
+  return value ? `第 ${value} 集` : ''
+}
+
+/** 按 (季, 集, 小数部分) 升序比较，供剧集列表排序复用。 */
+export function compareEpisodeOrder(a: Media, b: Media): number {
+  const seasonDiff = (a.season_num ?? 0) - (b.season_num ?? 0)
+  if (seasonDiff !== 0) return seasonDiff
+  return episodeNumberValue(a) - episodeNumberValue(b)
+}