merge: 合并转码配置与缩略图轴

docs/api-phase1.md

@@ -227,7 +227,8 @@ app.register.max-per-device-per-day
         "unlockCoin": 0,
         "likeCount": "45",
         "commentCount": "8",
-        "playUrl": "/files/episode/202610/xxx.mp4?e=1760000000&s=9f2c..."
+        "playUrl": "/files/episode/202610/xxx.mp4?e=1760000000&s=9f2c...",
+        "thumbnailsUrl": "/files/transcoded/88/thumbnails/thumbnails.vtt?e=1760000000&s=8a1d..."
       }
     ]
   }
@@ -244,6 +245,7 @@ app.register.max-per-device-per-day
 | `viewCount` | Long（JSON 字符串） | 取 `drama.view_count`，累计播放量，既有字段语义不变 |
 | `episodes[].likeCount` | Long（JSON 字符串） | 本集点赞数，取 `drama_episode.like_count` |
 | `episodes[].commentCount` | Long（JSON 字符串） | 本集未删除评论数，按 `episode_id` 统计 |
+| `episodes[].thumbnailsUrl` | String / null | 本集雪碧图 WebVTT 时间轴签名地址；没有 READY 产物时为 `null` |
 
 计数是只读快照：互动操作完成后客户端重新拉取详情即可刷新；`Long` 字段一律按字符串下发，
 客户端需要转成数字再展示（与 `viewCount` 相同）。
@@ -263,6 +265,7 @@ app.register.max-per-device-per-day
     "accessType": "FREE",
     "playUrl": "/files/episode/202610/xxx.mp4?e=1760000000&s=9f2c...",
     "qualities": ["AUTO"],
+    "thumbnailsUrl": "/files/transcoded/88/thumbnails/thumbnails.vtt?e=1760000000&s=8a1d...",
     "unlockCoin": 0,
     "previewSeconds": 0,
     "likeCount": "45",
@@ -277,6 +280,10 @@ app.register.max-per-device-per-day
 **判定顺序由服务端决定，客户端不得自行推断可否播放。** 签名默认 15 分钟有效；
 开启 `fruitshorts.media.signature-required` 后，`/files/episode/**` 没带有效签名会返回 403。
 
+`thumbnailsUrl` 指向 WebVTT：cue 链接为同目录相对雪碧图
+`sprite_XXX.jpg#xywh=x,y,w,h`。有 READY `media_thumbnail` 时返回签名地址，
+无产物时为 `null`；该字段不影响 `playUrl`、`qualities` 和 HLS/原文件回落。
+
 ### 1.5 观看记录与收藏（已实现）
 
 | 方法 | 路径 | 说明 |
@@ -597,6 +604,42 @@ GET /app/notices?pageIndex=1&pageSize=20
 **上传会话归属**：`uploadId` 相当于上传凭证，`chunk` / `complete` / 进度查询都校验会话发起人，
 别人拿到 `uploadId` 也塞不进分片（`{"code":403,"message":"无权操作该上传会话"}`）。
 
+**转码档位配置**
+
+| 方法 | 路径 | 权限点 | 说明 |
+| --- | --- | --- | --- |
+| GET | `/admin/media/transcode-profile` | `episode:upload` | 读取当前配置；缺省返回四档默认值 |
+| PUT | `/admin/media/transcode-profile` | `episode:upload` | 保存配置并记录操作日志 |
+
+配置保存在 `sys_config` 的 `media.transcode.profile`，JSON 结构：
+
+```json
+{
+  "enabled": true,
+  "segmentSeconds": 6,
+  "ladder": [
+    {
+      "quality": "360p",
+      "width": 640,
+      "height": 360,
+      "videoBitrateKbps": 400,
+      "audioBitrateKbps": 64,
+      "enabled": true
+    }
+  ],
+  "sprite": {
+    "enabled": true,
+    "intervalSeconds": 1,
+    "columns": 10,
+    "thumbWidth": 160
+  }
+}
+```
+
+`quality` 必须唯一且非空，宽高必须为大于 0 的偶数，音视频码率必须大于 0，
+至少启用一档；`segmentSeconds` 2–10、`intervalSeconds` 1–10、`columns` 5–20、
+`thumbWidth` 120–240。非法请求返回统一错误码 `400` 且不写库。
+
 ### 2.3 App 用户管理（已实现）
 
 | 方法 | 路径 | 权限点 | 说明 |

docs/plans/2026-10-22-media-transcode-profile-sprite.md

@@ -0,0 +1,53 @@
+# 转码档位配置、雪碧图与播放缩略图轴
+
+## 目标
+
+1. 后台可配置转码档位与雪碧图参数，worker 对之后的新任务在 30 秒内自动生效。
+2. 转码成功后生成雪碧图与 VTT，登记到 `media_thumbnail`。
+3. 播放接口与详情剧集返回 `thumbnailsUrl`，无产物时为 `null`。
+
+## 配置模型
+
+- `sys_config.config_key = media.transcode.profile`，值为 JSON。
+- 配置包含总开关、分片秒数、码率阶梯与雪碧图参数。
+- 缺省配置等价于现有 360p/480p/720p/1080p 四档。
+- 后台 GET 缺省或历史配置非法时返回 yml 等价默认值；PUT 非法时返回统一 400，且不写库。
+- worker 读取配置缓存 30 秒；缺省、解析失败或校验失败时回退 yml 默认阶梯。
+
+## 权限取舍
+
+现有权限点没有 `media:transcode`。本次两个接口复用最小可用的
+`episode:upload`，避免新增权限点导致已有角色需要补授权；不新增菜单或权限 SQL。
+
+## 数据与产物
+
+- 新增 `media_thumbnail`，按 `episode_id` 唯一，记录 VTT、雪碧图前缀、采样参数、
+  尺寸、帧数、时长、状态、错误与总大小。
+- 雪碧图目录固定在 `transcoded/{taskId}/thumbnails/`：
+  `thumbnails.vtt` + `sprite_001.jpg` 等多张图。
+- VTT cue 链接使用相对路径 `sprite_XXX.jpg#xywh=x,y,w,h`，同一 VTT 目录下可直接解析。
+- 缩略图失败只把 `media_thumbnail.status` 置 `FAILED` 并记录错误；主 HLS 仍成功。
+
+## 播放
+
+- `PlayRespVO` 和 `AppEpisodeVO` 增加 `thumbnailsUrl`。
+- 查询 `media_thumbnail` 仅读取 `READY` 产物；objectKey 经
+  `MediaStorageService.toPublicUrl` 后使用现有 `PlaybackSigner` 签名。
+- 详情剧集列表批量查询缩略图，禁止 N+1。
+- 不改变现有 HLS/原文件回落与 qualities 列表。
+
+## 测试
+
+- worker：配置解析、非法配置回退 yml、30 秒缓存、VTT 坐标、多雪碧图索引、
+  缩略图失败不阻断主转码。
+- admin：GET 默认值、PUT 非法不落库、PUT 成功落库。
+- playback：有 READY 缩略图返回签名 `thumbnailsUrl`，无产物返回 `null`。
+- 门禁：`mvn -pl fruitshorts-transcode-worker,fruitshorts-admin-api,fruitshorts-app-api -am test`。
+
+## 风险 / 边界
+
+- 本次只对合并后的新转码任务生效，不回跑历史任务。
+- 配置中的顶层 `enabled` 会持久化并返回；本单不改变既有队列消费开关语义，
+  worker 仍以 `worker-enabled` 决定是否消费任务。
+- 雪碧图生成依赖 ffmpeg `tile` 滤镜；真实产物由 worker 门禁和 PM 后续环境验收，
+  本任务不启动服务、不改客户端。

docs/plans/PROGRESS.md

@@ -24740,3 +24740,74 @@ mvn -pl fruitshorts-admin-api -am test
 
 解读：已推送历史不改写；身份合规靠命令级覆盖防复发；本条仅文档留痕，无代码改动。
 
+---
+
+## 2026-10-22 | 转码档位配置、雪碧图与播放缩略图轴
+
+### 开工确认与计划
+
+- 仓库：FruitServer
+- 基线：`develop` / `origin/develop` = `70da939`
+- 工作区：开工前干净
+- 分支：`feature/media-transcode-profile-sprite`
+- 计划：`docs/plans/2026-10-22-media-transcode-profile-sprite.md`
+
+```text
+$ git status --short --branch && git rev-parse --short HEAD
+## develop...origin/develop
+70da939
+```
+
+解读：基于指定 develop 基线创建隔离工作树。现有权限点无 `media:transcode`，
+本次复用 `episode:upload`，不新增菜单或权限初始化数据。
+
+### 实现与门禁
+
+- 新增 `media.transcode.profile` JSON 模型、统一校验与 30 秒 worker 缓存；
+  后台 GET 每次直读，PUT 校验通过后才写 `sys_config`。
+- 新增幂等迁移 `sql/patch-2026-10-22-media-thumbnail.sql`，包含该表、
+  唯一索引、更新时间触发器与默认四档配置；同步 `schema-phase1.sql` / `data-phase1.sql`。
+- worker 产出 `thumbnails/thumbnails.vtt` 与按需多张 `sprite_%03d.jpg`；
+  失败以 `media_thumbnail.status=FAILED`、`error_msg` 留存，主 HLS 仍成功。
+- 播放与详情增加 `thumbnailsUrl`；详情按剧集 ID 批量查询后统一签名。
+- 首次 reactor 测试暴露 4 个既有 App 测试未跟随 `DramaService` 新增
+  `EpisodePriceSync` 构造参数，已在测试准备代码补齐替身，未改内容服务生产逻辑。
+
+```text
+$ mvn -pl fruitshorts-transcode-worker,fruitshorts-admin-api,fruitshorts-app-api -am -DskipTests compile
+[INFO] fruitshorts-module-media ............................ SUCCESS
+[INFO] fruitshorts-admin-api ............................... SUCCESS
+[INFO] fruitshorts-app-api ................................. SUCCESS
+[INFO] fruitshorts-transcode-worker ........................ SUCCESS
+[INFO] BUILD SUCCESS
+```
+
+解读：新增 media→system 依赖和全部生产代码编译通过。
+
+```text
+$ mvn -pl fruitshorts-transcode-worker,fruitshorts-admin-api,fruitshorts-app-api -am test
+[INFO] Tests run: 41, Failures: 0, Errors: 0, Skipped: 0
+[INFO] Tests run: 103, Failures: 0, Errors: 0, Skipped: 0
+[INFO] Tests run: 19, Failures: 0, Errors: 0, Skipped: 0
+[INFO] BUILD SUCCESS
+```
+
+解读：admin 41、app-api 103、worker 19 全过；worker 包含真实 ffmpeg smoke，
+验证 2 秒样本产出 HLS、封面、VTT 与 `sprite_001.jpg`。
+
+```text
+$ mvn test
+[INFO] Reactor Summary for fruitshorts 1.0.0-SNAPSHOT:
+[INFO] fruitshorts-admin-api .............................. SUCCESS
+[INFO] fruitshorts-app-api ................................ SUCCESS
+[INFO] fruitshorts-transcode-worker ....................... SUCCESS
+[INFO] BUILD SUCCESS
+[INFO] Total time:  24.439 s
+$ sed -n '38,43p' sql/patch-2026-10-22-media-thumbnail.sql | ... | jq -e '.ladder | length == 4'
+true
+```
+
+解读：仓库根全量 14 个 reactor 模块测试通过。迁移脚本按要求只写文件、
+默认配置 JSON 解析为 4 档；未执行数据库变更；未启动 8080/8081/worker，
+未操作真机，未改 Web/Flutter。
+

fruitshorts-admin-api/src/main/java/com/fruitshorts/admin/controller/MediaController.java

@@ -5,7 +5,10 @@ package com.fruitshorts.admin.controller;
 import com.fruitshorts.common.pojo.Result;
 import com.fruitshorts.framework.security.SecurityUtils;
 import com.fruitshorts.framework.security.ImpersonationGuard;
+import com.fruitshorts.framework.log.OperationLog;
+import com.fruitshorts.media.config.MediaTranscodeProfile;
 import com.fruitshorts.media.service.MediaService;
+import com.fruitshorts.media.service.MediaTranscodeProfileService;
 import com.fruitshorts.media.vo.MediaAssetRespVO;
 import com.fruitshorts.media.vo.UploadCompleteReqVO;
 import com.fruitshorts.media.vo.UploadInitReqVO;
@@ -19,6 +22,7 @@ import org.springframework.security.access.prepost.PreAuthorize;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestParam;
@@ -35,6 +39,7 @@ import org.springframework.web.multipart.MultipartFile;
 public class MediaController {
 
     private final MediaService mediaService;
+    private final MediaTranscodeProfileService profileService;
 
     @Operation(summary = "初始化分片上传")
     @PostMapping("/upload/init")
@@ -78,4 +83,21 @@ public class MediaController {
     public Result<MediaAssetRespVO> get(@PathVariable Long id) {
         return Result.ok(mediaService.get(id));
     }
+
+    @Operation(summary = "读取转码档位配置")
+    @GetMapping("/transcode-profile")
+    @PreAuthorize("@ss.hasPermission('episode:upload')")
+    public Result<MediaTranscodeProfile> transcodeProfile() {
+        return Result.ok(profileService.readConfiguredProfile());
+    }
+
+    @Operation(summary = "保存转码档位配置")
+    @PutMapping("/transcode-profile")
+    @PreAuthorize("@ss.hasPermission('episode:upload')")
+    @OperationLog(module = "后台管理", action = "修改转码设置")
+    public Result<MediaTranscodeProfile> saveTranscodeProfile(
+            @Valid @RequestBody MediaTranscodeProfile profile) {
+        ImpersonationGuard.rejectWrite();
+        return Result.ok(profileService.save(profile));
+    }
 }

fruitshorts-admin-api/src/test/java/com/fruitshorts/admin/controller/MediaTranscodeProfileContractTest.java

@@ -0,0 +1,98 @@
+// Author: fruit.com.cn
+
+package com.fruitshorts.admin.controller;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fruitshorts.admin.support.ControllerContractSupport;
+import com.fruitshorts.media.config.MediaTranscodeProfile;
+import com.fruitshorts.media.config.TranscodeProperties;
+import com.fruitshorts.media.service.MediaService;
+import com.fruitshorts.media.service.MediaTranscodeProfileService;
+import com.fruitshorts.system.service.ConfigService;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.mockito.ArgumentCaptor;
+import org.springframework.http.MediaType;
+import org.springframework.test.web.servlet.MockMvc;
+
+import java.util.Map;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+/**
+ * 后台转码配置接口：默认值、非法拒绝与成功落库。
+ */
+class MediaTranscodeProfileContractTest {
+
+    private ConfigService configService;
+    private ObjectMapper objectMapper;
+    private MockMvc mockMvc;
+
+    @BeforeEach
+    void setUp() {
+        configService = mock(ConfigService.class);
+        objectMapper = new ObjectMapper();
+        MediaTranscodeProfileService profileService = new MediaTranscodeProfileService(
+                configService, objectMapper, new TranscodeProperties());
+        MediaController controller = new MediaController(mock(MediaService.class), profileService);
+        mockMvc = ControllerContractSupport.mockMvcOf(controller);
+        given(configService.get(eq(MediaTranscodeProfileService.CONFIG_KEY), anyString()))
+                .willReturn("");
+    }
+
+    @Test
+    void should_return_default_profile_when_config_is_missing() throws Exception {
+        mockMvc.perform(get("/admin/media/transcode-profile"))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.code").value(0))
+                .andExpect(jsonPath("$.data.segmentSeconds").value(6))
+                .andExpect(jsonPath("$.data.ladder.length()").value(4))
+                .andExpect(jsonPath("$.data.ladder[0].quality").value("360p"))
+                .andExpect(jsonPath("$.data.sprite.columns").value(10));
+    }
+
+    @Test
+    void should_reject_illegal_profile_without_writing_config() throws Exception {
+        MediaTranscodeProfile profile = new MediaTranscodeProfile();
+        profile.getLadder().get(0).setWidth(641);
+
+        mockMvc.perform(put("/admin/media/transcode-profile")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content(objectMapper.writeValueAsString(profile)))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.code").value(400))
+                .andExpect(jsonPath("$.message").value("宽高必须为正偶数"));
+
+        verify(configService, never()).update(any());
+    }
+
+    @Test
+    void should_persist_profile_when_request_is_valid() throws Exception {
+        MediaTranscodeProfile profile = new MediaTranscodeProfile();
+        profile.setSegmentSeconds(4);
+
+        mockMvc.perform(put("/admin/media/transcode-profile")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content(objectMapper.writeValueAsString(profile)))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.code").value(0))
+                .andExpect(jsonPath("$.data.segmentSeconds").value(4));
+
+        @SuppressWarnings("unchecked")
+        ArgumentCaptor<Map<String, String>> captor = ArgumentCaptor.forClass(Map.class);
+        verify(configService).update(captor.capture());
+        assertThat(captor.getValue().get(MediaTranscodeProfileService.CONFIG_KEY))
+                .contains("\"segmentSeconds\":4");
+    }
+}

fruitshorts-app-api/src/main/java/com/fruitshorts/app/service/AppCatalogService.java

@@ -20,6 +20,7 @@ import com.fruitshorts.content.service.DramaService;
 import com.fruitshorts.content.service.EpisodeService;
 import com.fruitshorts.interaction.service.CommentService;
 import com.fruitshorts.media.service.PlaybackSigner;
+import com.fruitshorts.media.service.ThumbnailUrlResolver;
 import com.fruitshorts.content.vo.DramaCategoryRespVO;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
@@ -50,6 +51,7 @@ public class AppCatalogService {
     private final DramaCategoryService dramaCategoryService;
     private final PlaybackSigner playbackSigner;
     private final CommentService commentService;
+    private final ThumbnailUrlResolver thumbnailUrlResolver;
 
     public AppFeedVO homeFeed() {
         Map<Long, String> categoryNames = categoryNameMap();
@@ -110,6 +112,8 @@ public class AppCatalogService {
         List<DramaEpisode> episodes = episodeService.listPublishedByDrama(dramaId);
         Map<Long, Long> episodeCommentCounts = commentService.countByEpisodes(
                 episodes.stream().map(DramaEpisode::getId).sorted().toList());
+        Map<Long, String> thumbnailUrls = thumbnailUrlResolver.resolveAll(
+                episodes.stream().map(DramaEpisode::getId).sorted().toList());
         String categoryName = categoryNameMap().getOrDefault(drama.getCategoryId(), "");
 
         AppDramaDetailVO detail = new AppDramaDetailVO();
@@ -128,7 +132,7 @@ public class AppCatalogService {
         detail.setFavoriteCount(drama.getFavoriteCount());
         detail.setCommentCount(commentService.countByDrama(dramaId));
         detail.setEpisodes(episodes.stream()
-                .map(episode -> toEpisode(episode, episodeCommentCounts))
+                .map(episode -> toEpisode(episode, episodeCommentCounts, thumbnailUrls))
                 .toList());
         return detail;
     }
@@ -176,14 +180,18 @@ public class AppCatalogService {
         Map<Long, DramaEpisode> previews = episodeService.firstPlayableByDramas(ids);
         Map<Long, Long> commentCounts = commentService.countByEpisodes(
                 previews.values().stream().map(DramaEpisode::getId).sorted().toList());
+        Map<Long, String> thumbnailUrls = thumbnailUrlResolver.resolveAll(
+                previews.values().stream().map(DramaEpisode::getId).sorted().toList());
         return dramas.stream()
                 .map(drama -> toCard(
-                        drama, categoryNames, previews.get(drama.getId()), commentCounts))
+                        drama, categoryNames, previews.get(drama.getId()), commentCounts,
+                        thumbnailUrls))
                 .toList();
     }
 
     private AppDramaCardVO toCard(Drama drama, Map<Long, String> categoryNames,
-                                  DramaEpisode preview, Map<Long, Long> commentCounts) {
+                                  DramaEpisode preview, Map<Long, Long> commentCounts,
+                                  Map<Long, String> thumbnailUrls) {
         AppDramaCardVO card = new AppDramaCardVO();
         card.setId(drama.getId());
         card.setTitle(drama.getTitle());
@@ -201,11 +209,13 @@ public class AppCatalogService {
                 ? 0L : commentCounts.getOrDefault(preview.getId(), 0L));
         card.setLanguage(drama.getLanguage());
         card.setDramaType(drama.getDramaType());
-        card.setPreview(preview == null ? null : toEpisode(preview, commentCounts));
+        card.setPreview(preview == null
+                ? null : toEpisode(preview, commentCounts, thumbnailUrls));
         return card;
     }
 
-    private AppEpisodeVO toEpisode(DramaEpisode episode, Map<Long, Long> commentCounts) {
+    private AppEpisodeVO toEpisode(DramaEpisode episode, Map<Long, Long> commentCounts,
+                                   Map<Long, String> thumbnailUrls) {
         AppEpisodeVO vo = new AppEpisodeVO();
         vo.setId(episode.getId());
         vo.setNumber(episode.getEpNo());
@@ -219,6 +229,7 @@ public class AppCatalogService {
         vo.setUnlockCoin(episode.getUnlockCoin());
         vo.setLikeCount(episode.getLikeCount() == null ? 0L : episode.getLikeCount());
         vo.setCommentCount(commentCounts.getOrDefault(episode.getId(), 0L));
+        vo.setThumbnailsUrl(thumbnailUrls.get(episode.getId()));
         if (free) {
             // 播放地址统一在这里签名：客户端拿不到可长期复用的裸地址
             vo.setPlayUrl(playbackSigner.sign(playableSource(episode)));

fruitshorts-app-api/src/main/java/com/fruitshorts/app/vo/AppEpisodeVO.java

@@ -24,4 +24,6 @@ public class AppEpisodeVO {
      * 详情页拿到就能直接播，不必按集再请求一次播放票据。
      */
     private String playUrl;
+    /** 雪碧图 WebVTT 时间轴地址；没有产物时为 null */
+    private String thumbnailsUrl;
 }

fruitshorts-app-api/src/test/java/com/fruitshorts/app/controller/AppPlaybackContractTest.java

@@ -15,6 +15,7 @@ import org.springframework.test.web.servlet.MockMvc;
 import java.util.List;
 import java.util.Map;
 
+import static org.hamcrest.Matchers.nullValue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.ArgumentMatchers.isNull;
@@ -55,7 +56,9 @@ class AppPlaybackContractTest {
     @Test
     void should_return_free_access_when_episode_is_free() throws Exception {
         given(playbackService.play(isNull(), eq(11L), any(), any()))
-                .willReturn(ticket(11L, true, PlaybackService.ACCESS_FREE, "/files/ep.mp4?s=1"));
+                .willReturn(ticket(11L, true, PlaybackService.ACCESS_FREE,
+                        "/files/ep.mp4?s=1",
+                        "/files/transcoded/11/thumbnails/thumbnails.vtt?e=1&s=sig"));
 
         mockMvc.perform(get("/app/episodes/11/play").header("X-Device-Id", "device-9"))
                 .andExpect(status().isOk())
@@ -66,13 +69,15 @@ class AppPlaybackContractTest {
                 .andExpect(jsonPath("$.data.accessible").value(true))
                 .andExpect(jsonPath("$.data.accessType").value(PlaybackService.ACCESS_FREE))
                 .andExpect(jsonPath("$.data.playUrl").value("/files/ep.mp4?s=1"))
+                .andExpect(jsonPath("$.data.thumbnailsUrl")
+                        .value("/files/transcoded/11/thumbnails/thumbnails.vtt?e=1&s=sig"))
                 .andExpect(jsonPath("$.data.likeCount").value("88"))
                 .andExpect(jsonPath("$.data.commentCount").value("0"));
     }
 
     @Test
     void should_return_coin_required_when_episode_is_locked_and_not_entitled() throws Exception {
-        PlayRespVO locked = ticket(12L, false, PlaybackService.ACCESS_COIN_REQUIRED, "");
+        PlayRespVO locked = ticket(12L, false, PlaybackService.ACCESS_COIN_REQUIRED, "", null);
         locked.setUnlockCoin(60);
         given(playbackService.play(isNull(), eq(12L), any(), any())).willReturn(locked);
 
@@ -81,13 +86,15 @@ class AppPlaybackContractTest {
                 .andExpect(jsonPath("$.data.accessible").value(false))
                 .andExpect(jsonPath("$.data.accessType").value(PlaybackService.ACCESS_COIN_REQUIRED))
                 .andExpect(jsonPath("$.data.playUrl").value(""))
+                .andExpect(jsonPath("$.data.thumbnailsUrl").value(nullValue()))
                 .andExpect(jsonPath("$.data.unlockCoin").value(60));
     }
 
     @Test
     void should_pass_episode_id_and_device_header_when_play_is_requested() throws Exception {
         given(playbackService.play(isNull(), eq(13L), eq("device-9"), any()))
-                .willReturn(ticket(13L, true, PlaybackService.ACCESS_FREE, "/files/ep13.mp4?s=1"));
+                .willReturn(ticket(13L, true, PlaybackService.ACCESS_FREE,
+                        "/files/ep13.mp4?s=1", null));
 
         mockMvc.perform(get("/app/episodes/13/play").header("X-Device-Id", "device-9"))
                 .andExpect(status().isOk());
@@ -95,7 +102,8 @@ class AppPlaybackContractTest {
         verify(playbackService).play(isNull(), eq(13L), eq("device-9"), any());
     }
 
-    private PlayRespVO ticket(Long episodeId, boolean accessible, String accessType, String playUrl) {
+    private PlayRespVO ticket(Long episodeId, boolean accessible, String accessType,
+                              String playUrl, String thumbnailsUrl) {
         PlayRespVO vo = new PlayRespVO();
         vo.setEpisodeId(episodeId);
         vo.setDramaId(7L);
@@ -105,6 +113,7 @@ class AppPlaybackContractTest {
         vo.setAccessible(accessible);
         vo.setAccessType(accessType);
         vo.setPlayUrl(playUrl);
+        vo.setThumbnailsUrl(thumbnailsUrl);
         vo.setQualities(List.of("AUTO"));
         vo.setUnlockCoin(0);
         vo.setPreviewSeconds(0);

fruitshorts-app-api/src/test/java/com/fruitshorts/app/service/AppCatalogServiceTest.java

@@ -12,6 +12,7 @@ import com.fruitshorts.content.service.DramaService;
 import com.fruitshorts.content.service.EpisodeService;
 import com.fruitshorts.interaction.service.CommentService;
 import com.fruitshorts.media.service.PlaybackSigner;
+import com.fruitshorts.media.service.ThumbnailUrlResolver;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
@@ -35,6 +36,7 @@ class AppCatalogServiceTest {
     private EpisodeService episodeService;
     private DramaCategoryService dramaCategoryService;
     private CommentService commentService;
+    private ThumbnailUrlResolver thumbnailUrlResolver;
     private AppCatalogService catalogService;
 
     @BeforeEach
@@ -44,9 +46,11 @@ class AppCatalogServiceTest {
         BannerService bannerService = mock(BannerService.class);
         dramaCategoryService = mock(DramaCategoryService.class);
         PlaybackSigner playbackSigner = mock(PlaybackSigner.class);
+        thumbnailUrlResolver = mock(ThumbnailUrlResolver.class);
+        given(thumbnailUrlResolver.resolveAll(any())).willReturn(Map.of());
         commentService = mock(CommentService.class);
         catalogService = new AppCatalogService(dramaService, episodeService, bannerService,
-                dramaCategoryService, playbackSigner, commentService);
+                dramaCategoryService, playbackSigner, commentService, thumbnailUrlResolver);
     }
 
     @Test
@@ -66,6 +70,8 @@ class AppCatalogServiceTest {
         given(commentService.countByDrama(42L)).willReturn(96L);
         given(commentService.countByEpisodes(List.of(11L, 22L)))
                 .willReturn(Map.of(11L, 2L, 22L, 4L));
+        given(thumbnailUrlResolver.resolveAll(List.of(11L, 22L)))
+                .willReturn(Map.of(22L, "/files/transcoded/22/thumbnails/thumbnails.vtt"));
 
         AppDramaDetailVO detail = catalogService.dramaDetail(42L);
 
@@ -75,7 +81,10 @@ class AppCatalogServiceTest {
         assertThat(detail.getCommentCount()).isEqualTo(96L);
         assertThat(detail.getEpisodes().get(0).getLikeCount()).isEqualTo(66L);
         assertThat(detail.getEpisodes().get(0).getCommentCount()).isEqualTo(4L);
+        assertThat(detail.getEpisodes().get(0).getThumbnailsUrl())
+                .isEqualTo("/files/transcoded/22/thumbnails/thumbnails.vtt");
         verify(commentService).countByDrama(42L);
+        verify(thumbnailUrlResolver).resolveAll(List.of(11L, 22L));
     }
 
     @Test

fruitshorts-app-api/src/test/java/com/fruitshorts/app/service/DramaServiceFavoriteCountTest.java

@@ -12,6 +12,7 @@ import com.fruitshorts.content.dal.mapper.DramaMapper;
 import com.fruitshorts.content.dal.mapper.DramaReviewRecordMapper;
 import com.fruitshorts.content.service.DramaCategoryService;
 import com.fruitshorts.content.service.DramaService;
+import com.fruitshorts.content.service.EpisodePriceSync;
 import org.apache.ibatis.builder.MapperBuilderAssistant;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
@@ -41,7 +42,8 @@ class DramaServiceFavoriteCountTest {
                 dramaMapper,
                 mock(DramaEpisodeMapper.class),
                 mock(DramaReviewRecordMapper.class),
-                mock(DramaCategoryService.class));
+                mock(DramaCategoryService.class),
+                mock(EpisodePriceSync.class));
         given(dramaMapper.update(isNull(), any())).willReturn(1);
         ArgumentCaptor<Wrapper<Drama>> captor = ArgumentCaptor.forClass(Wrapper.class);
 

fruitshorts-app-api/src/test/java/com/fruitshorts/app/service/DramaServiceFeedTest.java

@@ -11,6 +11,7 @@ import com.fruitshorts.content.dal.mapper.DramaMapper;
 import com.fruitshorts.content.dal.mapper.DramaReviewRecordMapper;
 import com.fruitshorts.content.service.DramaCategoryService;
 import com.fruitshorts.content.service.DramaService;
+import com.fruitshorts.content.service.EpisodePriceSync;
 import org.apache.ibatis.builder.MapperBuilderAssistant;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.BeforeEach;
@@ -45,7 +46,8 @@ class DramaServiceFeedTest {
                 dramaMapper,
                 mock(DramaEpisodeMapper.class),
                 mock(DramaReviewRecordMapper.class),
-                mock(DramaCategoryService.class));
+                mock(DramaCategoryService.class),
+                mock(EpisodePriceSync.class));
     }
 
     @Test

fruitshorts-app-api/src/test/java/com/fruitshorts/app/service/DramaServiceK88Test.java

@@ -12,6 +12,7 @@ import com.fruitshorts.content.dal.mapper.DramaMapper;
 import com.fruitshorts.content.dal.mapper.DramaReviewRecordMapper;
 import com.fruitshorts.content.service.DramaCategoryService;
 import com.fruitshorts.content.service.DramaService;
+import com.fruitshorts.content.service.EpisodePriceSync;
 import com.fruitshorts.content.vo.DramaSaveReqVO;
 import org.apache.ibatis.builder.MapperBuilderAssistant;
 import org.junit.jupiter.api.BeforeAll;
@@ -46,7 +47,8 @@ class DramaServiceK88Test {
                 dramaMapper,
                 mock(DramaEpisodeMapper.class),
                 mock(DramaReviewRecordMapper.class),
-                mock(DramaCategoryService.class));
+                mock(DramaCategoryService.class),
+                mock(EpisodePriceSync.class));
     }
 
     @Test

fruitshorts-app-api/src/test/java/com/fruitshorts/app/service/DramaServiceMultiTagTest.java

@@ -13,6 +13,7 @@ import com.fruitshorts.content.dal.mapper.DramaMapper;
 import com.fruitshorts.content.dal.mapper.DramaReviewRecordMapper;
 import com.fruitshorts.content.service.DramaCategoryService;
 import com.fruitshorts.content.service.DramaService;
+import com.fruitshorts.content.service.EpisodePriceSync;
 import com.fruitshorts.content.vo.DramaPageReqVO;
 import com.fruitshorts.content.vo.DramaRespVO;
 import com.fruitshorts.content.vo.DramaSaveReqVO;
@@ -54,7 +55,8 @@ class DramaServiceMultiTagTest {
                 dramaMapper,
                 mock(DramaEpisodeMapper.class),
                 mock(DramaReviewRecordMapper.class),
-                categoryService);
+                categoryService,
+                mock(EpisodePriceSync.class));
     }
 
     @Test

fruitshorts-app-api/src/test/java/com/fruitshorts/app/service/PlaybackServiceTest.java

@@ -6,6 +6,7 @@ import com.fruitshorts.content.dal.entity.DramaEpisode;
 import com.fruitshorts.content.service.DramaService;
 import com.fruitshorts.content.service.EpisodeService;
 import com.fruitshorts.media.service.PlaybackSigner;
+import com.fruitshorts.media.service.ThumbnailUrlResolver;
 import com.fruitshorts.media.service.TranscodeService;
 import com.fruitshorts.playback.dal.entity.PlaybackTicket;
 import com.fruitshorts.playback.dal.mapper.PlaybackTicketMapper;
@@ -42,6 +43,7 @@ class PlaybackServiceTest {
     private PlaybackSigner signer;
     private EntitlementPort entitlementPort;
     private TranscodeService transcodeService;
+    private ThumbnailUrlResolver thumbnailUrlResolver;
     private PlaybackService playbackService;
 
     @BeforeEach
@@ -52,10 +54,12 @@ class PlaybackServiceTest {
         signer = mock(PlaybackSigner.class);
         entitlementPort = mock(EntitlementPort.class);
         transcodeService = mock(TranscodeService.class);
+        thumbnailUrlResolver = mock(ThumbnailUrlResolver.class);
         playbackService = new PlaybackService(episodeService, dramaService, ticketMapper, signer,
-                entitlementPort, transcodeService);
+                entitlementPort, transcodeService, thumbnailUrlResolver);
         given(dramaService.getPublished(anyLong())).willReturn(drama());
         given(transcodeService.listRenditions(anyLong())).willReturn(List.of());
+        given(thumbnailUrlResolver.resolve(anyLong())).willReturn(null);
         given(signer.sign(anyString())).willReturn("/files/episode/1.mp4?e=1&s=sig");
     }
 
@@ -72,6 +76,27 @@ class PlaybackServiceTest {
         verify(ticketMapper, never()).insert(any(PlaybackTicket.class));
     }
 
+    @Test
+    void should_return_signed_thumbnails_url_when_thumbnail_exists() {
+        given(episodeService.getPublished(11L)).willReturn(episode(11L, 1, 0, "/files/episode/1.mp4"));
+        given(thumbnailUrlResolver.resolve(11L))
+                .willReturn("/files/transcoded/1/thumbnails/thumbnails.vtt?e=1&s=sig");
+
+        PlayRespVO resp = playbackService.play(null, 11L, "device-9", "203.0.113.8");
+
+        assertThat(resp.getThumbnailsUrl())
+                .isEqualTo("/files/transcoded/1/thumbnails/thumbnails.vtt?e=1&s=sig");
+    }
+
+    @Test
+    void should_return_null_thumbnails_url_when_thumbnail_is_absent() {
+        given(episodeService.getPublished(11L)).willReturn(episode(11L, 1, 0, "/files/episode/1.mp4"));
+
+        PlayRespVO resp = playbackService.play(null, 11L, "device-9", "203.0.113.8");
+
+        assertThat(resp.getThumbnailsUrl()).isNull();
+    }
+
     @Test
     void should_return_coin_required_when_episode_is_locked_and_not_entitled() {
         given(episodeService.getPublished(12L)).willReturn(episode(12L, 0, 60, "/files/episode/2.mp4"));

fruitshorts-app-api/src/test/java/com/fruitshorts/app/service/ThumbnailUrlResolverTest.java

@@ -0,0 +1,55 @@
+// Author: fruit.com.cn
+
+package com.fruitshorts.app.service;
+
+import com.fruitshorts.media.dal.entity.MediaThumbnail;
+import com.fruitshorts.media.service.MediaStorageService;
+import com.fruitshorts.media.service.PlaybackSigner;
+import com.fruitshorts.media.service.ThumbnailUrlResolver;
+import com.fruitshorts.media.service.TranscodeService;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+
+/**
+ * 缩略图 objectKey 到公开签名地址的转换。
+ */
+class ThumbnailUrlResolverTest {
+
+    private TranscodeService transcodeService;
+    private MediaStorageService storageService;
+    private PlaybackSigner signer;
+    private ThumbnailUrlResolver resolver;
+
+    @BeforeEach
+    void setUp() {
+        transcodeService = mock(TranscodeService.class);
+        storageService = mock(MediaStorageService.class);
+        signer = mock(PlaybackSigner.class);
+        resolver = new ThumbnailUrlResolver(transcodeService, storageService, signer);
+    }
+
+    @Test
+    void should_sign_vtt_public_url_when_ready_thumbnail_exists() {
+        MediaThumbnail thumbnail = new MediaThumbnail();
+        thumbnail.setVttObjectKey("transcoded/88/thumbnails/thumbnails.vtt");
+        given(transcodeService.findReadyThumbnail(11L)).willReturn(thumbnail);
+        given(storageService.toPublicUrl(thumbnail.getVttObjectKey()))
+                .willReturn("/files/transcoded/88/thumbnails/thumbnails.vtt");
+        given(signer.sign("/files/transcoded/88/thumbnails/thumbnails.vtt"))
+                .willReturn("/files/transcoded/88/thumbnails/thumbnails.vtt?e=1&s=sig");
+
+        assertThat(resolver.resolve(11L))
+                .isEqualTo("/files/transcoded/88/thumbnails/thumbnails.vtt?e=1&s=sig");
+        verify(signer).sign("/files/transcoded/88/thumbnails/thumbnails.vtt");
+    }
+
+    @Test
+    void should_return_null_when_thumbnail_record_is_absent() {
+        assertThat(resolver.resolve(12L)).isNull();
+    }
+}

fruitshorts-module-media/pom.xml

@@ -21,5 +21,9 @@
             <groupId>com.fruitshorts</groupId>
             <artifactId>fruitshorts-framework</artifactId>
         </dependency>
+        <dependency>
+            <groupId>com.fruitshorts</groupId>
+            <artifactId>fruitshorts-module-system</artifactId>
+        </dependency>
     </dependencies>
 </project>

fruitshorts-module-media/src/main/java/com/fruitshorts/media/config/MediaTranscodeProfile.java

@@ -0,0 +1,61 @@
+// Author: fruit.com.cn
+
+package com.fruitshorts.media.config;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * 后台可配置的转码档位与雪碧图参数。
+ */
+@Data
+@NoArgsConstructor
+public class MediaTranscodeProfile {
+
+    public static final int DEFAULT_SEGMENT_SECONDS = 6;
+    public static final int DEFAULT_SPRITE_INTERVAL = 1;
+    public static final int DEFAULT_SPRITE_COLUMNS = 10;
+    public static final int DEFAULT_THUMB_WIDTH = 160;
+
+    private boolean enabled = true;
+    private int segmentSeconds = DEFAULT_SEGMENT_SECONDS;
+    private List<Rung> ladder = defaultLadder();
+    private Sprite sprite = new Sprite();
+
+    /** 默认四档与第一阶段 yml 保持一致。 */
+    public static List<Rung> defaultLadder() {
+        List<Rung> ladder = new ArrayList<>(4);
+        ladder.add(new Rung("360p", 640, 360, 400, 64, true));
+        ladder.add(new Rung("480p", 854, 480, 800, 64, true));
+        ladder.add(new Rung("720p", 1280, 720, 1600, 96, true));
+        ladder.add(new Rung("1080p", 1920, 1080, 3200, 128, true));
+        return ladder;
+    }
+
+    /** 一档清晰度。 */
+    @Data
+    @NoArgsConstructor
+    @AllArgsConstructor
+    public static class Rung {
+        private String quality;
+        private int width;
+        private int height;
+        private int videoBitrateKbps;
+        private int audioBitrateKbps;
+        private boolean enabled = true;
+    }
+
+    /** 雪碧图采样参数。 */
+    @Data
+    @NoArgsConstructor
+    public static class Sprite {
+        private boolean enabled = true;
+        private int intervalSeconds = DEFAULT_SPRITE_INTERVAL;
+        private int columns = DEFAULT_SPRITE_COLUMNS;
+        private int thumbWidth = DEFAULT_THUMB_WIDTH;
+    }
+}

fruitshorts-module-media/src/main/java/com/fruitshorts/media/config/MediaTranscodeProfileValidator.java

@@ -0,0 +1,99 @@
+// Author: fruit.com.cn
+
+package com.fruitshorts.media.config;
+
+import com.fruitshorts.common.exception.ErrorCode;
+import com.fruitshorts.common.exception.ServiceException;
+
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * 转码配置合法性校验。
+ */
+public final class MediaTranscodeProfileValidator {
+
+    private static final int MIN_SEGMENT_SECONDS = 2;
+    private static final int MAX_SEGMENT_SECONDS = 10;
+    private static final int MIN_SPRITE_INTERVAL = 1;
+    private static final int MAX_SPRITE_INTERVAL = 10;
+    private static final int MIN_COLUMNS = 5;
+    private static final int MAX_COLUMNS = 20;
+    private static final int MIN_THUMB_WIDTH = 120;
+    private static final int MAX_THUMB_WIDTH = 240;
+    private static final int MAX_QUALITY_LENGTH = 16;
+    private static final int EVEN_DIVISOR = 2;
+
+    private MediaTranscodeProfileValidator() {
+    }
+
+    /** 非法配置转成统一 400；调用方必须在持久化前执行。 */
+    public static void validate(MediaTranscodeProfile profile) {
+        if (profile == null) {
+            throw invalid("转码配置不能为空");
+        }
+        validateSegment(profile.getSegmentSeconds());
+        validateLadder(profile.getLadder());
+        validateSprite(profile.getSprite());
+    }
+
+    private static void validateSegment(int value) {
+        if (value < MIN_SEGMENT_SECONDS || value > MAX_SEGMENT_SECONDS) {
+            throw invalid("segmentSeconds 必须在 2-10 之间");
+        }
+    }
+
+    private static void validateLadder(Iterable<MediaTranscodeProfile.Rung> ladder) {
+        if (ladder == null) {
+            throw invalid("ladder 不能为空");
+        }
+        Set<String> qualities = new HashSet<>();
+        boolean hasEnabled = false;
+        for (MediaTranscodeProfile.Rung rung : ladder) {
+            validateRung(rung, qualities);
+            hasEnabled = hasEnabled || rung.isEnabled();
+        }
+        if (!hasEnabled) {
+            throw invalid("至少需要启用一档清晰度");
+        }
+    }
+
+    private static void validateRung(MediaTranscodeProfile.Rung rung,
+                                     Set<String> qualities) {
+        if (rung == null || rung.getQuality() == null || rung.getQuality().isBlank()) {
+            throw invalid("quality 不能为空");
+        }
+        String quality = rung.getQuality().trim();
+        if (quality.length() > MAX_QUALITY_LENGTH || !qualities.add(quality)) {
+            throw invalid("quality 必须唯一且不超过 16 个字符");
+        }
+        if (rung.getWidth() <= 0 || rung.getWidth() % EVEN_DIVISOR != 0
+                || rung.getHeight() <= 0 || rung.getHeight() % EVEN_DIVISOR != 0) {
+            throw invalid("宽高必须为正偶数");
+        }
+        if (rung.getVideoBitrateKbps() <= 0 || rung.getAudioBitrateKbps() <= 0) {
+            throw invalid("音视频码率必须大于 0");
+        }
+    }
+
+    private static void validateSprite(MediaTranscodeProfile.Sprite sprite) {
+        if (sprite == null) {
+            throw invalid("sprite 配置不能为空");
+        }
+        if (sprite.getIntervalSeconds() < MIN_SPRITE_INTERVAL
+                || sprite.getIntervalSeconds() > MAX_SPRITE_INTERVAL) {
+            throw invalid("intervalSeconds 必须在 1-10 之间");
+        }
+        if (sprite.getColumns() < MIN_COLUMNS || sprite.getColumns() > MAX_COLUMNS) {
+            throw invalid("columns 必须在 5-20 之间");
+        }
+        if (sprite.getThumbWidth() < MIN_THUMB_WIDTH
+                || sprite.getThumbWidth() > MAX_THUMB_WIDTH) {
+            throw invalid("thumbWidth 必须在 120-240 之间");
+        }
+    }
+
+    private static ServiceException invalid(String message) {
+        return new ServiceException(ErrorCode.BAD_REQUEST, message);
+    }
+}

fruitshorts-module-media/src/main/java/com/fruitshorts/media/config/TranscodeProperties.java

@@ -60,6 +60,8 @@ public class TranscodeProperties {
         private int height;
         private int videoBitrateKbps;
         private int audioBitrateKbps;
+        /** 单档开关；yml 未填写时保持启用，兼容既有四档配置。 */
+        private boolean enabled = true;
 
         public Rung() {
         }
@@ -71,5 +73,11 @@ public class TranscodeProperties {
             this.videoBitrateKbps = videoBitrateKbps;
             this.audioBitrateKbps = audioBitrateKbps;
         }
+
+        public Rung(String quality, int width, int height, int videoBitrateKbps,
+                    int audioBitrateKbps, boolean enabled) {
+            this(quality, width, height, videoBitrateKbps, audioBitrateKbps);
+            this.enabled = enabled;
+        }
     }
 }

fruitshorts-module-media/src/main/java/com/fruitshorts/media/dal/entity/MediaThumbnail.java

@@ -0,0 +1,46 @@
+// Author: fruit.com.cn
+
+package com.fruitshorts.media.dal.entity;
+
+import com.baomidou.mybatisplus.annotation.FieldStrategy;
+import com.baomidou.mybatisplus.annotation.IdType;
+import com.baomidou.mybatisplus.annotation.TableField;
+import com.baomidou.mybatisplus.annotation.TableId;
+import com.baomidou.mybatisplus.annotation.TableLogic;
+import com.baomidou.mybatisplus.annotation.TableName;
+import lombok.Data;
+
+import java.time.LocalDateTime;
+
+/** 单集缩略图雪碧图与 VTT 时间轴。 */
+@Data
+@TableName("media_thumbnail")
+public class MediaThumbnail {
+
+    public static final String STATUS_READY = "READY";
+    public static final String STATUS_FAILED = "FAILED";
+
+    @TableId(type = IdType.ASSIGN_ID)
+    private Long id;
+    private Long episodeId;
+    private Long dramaId;
+    private String vttObjectKey;
+    private String spritePrefix;
+    private Integer intervalSec;
+    private Integer columns;
+    private Integer rows;
+    private Integer thumbWidth;
+    private Integer thumbHeight;
+    private Integer frameCount;
+    private Integer durationSec;
+    private Long sizeBytes;
+    private String status;
+    private String errorMsg;
+    private LocalDateTime createdAt;
+
+    @TableField(updateStrategy = FieldStrategy.NEVER)
+    private LocalDateTime updatedAt;
+
+    @TableLogic
+    private Integer deleted;
+}

fruitshorts-module-media/src/main/java/com/fruitshorts/media/dal/mapper/MediaThumbnailMapper.java

@@ -0,0 +1,12 @@
+// Author: fruit.com.cn
+
+package com.fruitshorts.media.dal.mapper;
+
+import com.baomidou.mybatisplus.core.mapper.BaseMapper;
+import com.fruitshorts.media.dal.entity.MediaThumbnail;
+
+/**
+ * 缩略图时间轴数据访问。
+ */
+public interface MediaThumbnailMapper extends BaseMapper<MediaThumbnail> {
+}

fruitshorts-module-media/src/main/java/com/fruitshorts/media/service/MediaTranscodeProfileService.java

@@ -0,0 +1,122 @@
+// Author: fruit.com.cn
+
+package com.fruitshorts.media.service;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fruitshorts.common.exception.ErrorCode;
+import com.fruitshorts.common.exception.ServiceException;
+import com.fruitshorts.media.config.MediaTranscodeProfile;
+import com.fruitshorts.media.config.MediaTranscodeProfileValidator;
+import com.fruitshorts.media.config.TranscodeProperties;
+import com.fruitshorts.system.service.ConfigService;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.util.Map;
+
+/**
+ * 转码配置读写：后台立即落库，worker 每 30 秒感知一次；异常配置回退 yml。
+ */
+@Slf4j
+@Service
+@RequiredArgsConstructor
+public class MediaTranscodeProfileService {
+
+    public static final String CONFIG_KEY = "media.transcode.profile";
+    public static final Duration CACHE_TTL = Duration.ofSeconds(30);
+
+    private final ConfigService configService;
+    private final ObjectMapper objectMapper;
+    private final TranscodeProperties defaults;
+    private volatile CachedProfile cached;
+
+    /** 读取当前有效配置；缺省或非法时回退 yml 默认。 */
+    public MediaTranscodeProfile currentProfile() {
+        CachedProfile current = cached;
+        Instant now = Instant.now();
+        if (current != null && current.expiresAt().isAfter(now)) {
+            return current.profile();
+        }
+        MediaTranscodeProfile loaded = loadProfile();
+        cached = new CachedProfile(loaded, now.plus(CACHE_TTL));
+        return loaded;
+    }
+
+    /** 后台读取不做 30 秒缓存，确保直接改库后刷新页面即可看到最新值。 */
+    public MediaTranscodeProfile readConfiguredProfile() {
+        return loadProfile();
+    }
+
+    /** 保存前校验；非法配置不会触发 sys_config 写操作。 */
+    @Transactional(rollbackFor = Exception.class)
+    public MediaTranscodeProfile save(MediaTranscodeProfile profile) {
+        MediaTranscodeProfileValidator.validate(profile);
+        String json = writeJson(profile);
+        configService.update(Map.of(CONFIG_KEY, json));
+        cached = new CachedProfile(profile, Instant.now().plus(CACHE_TTL));
+        return profile;
+    }
+
+    /** yml/代码默认配置，后台缺省值也使用这一份。 */
+    public MediaTranscodeProfile defaultProfile() {
+        MediaTranscodeProfile profile = new MediaTranscodeProfile();
+        profile.setEnabled(true);
+        profile.setSegmentSeconds(defaults.getSegmentSeconds());
+        profile.setLadder(defaults.getLadder().stream()
+                .map(rung -> new MediaTranscodeProfile.Rung(
+                        rung.getQuality(), rung.getWidth(), rung.getHeight(),
+                        rung.getVideoBitrateKbps(), rung.getAudioBitrateKbps(),
+                        rung.isEnabled()))
+                .toList());
+        return profile;
+    }
+
+    /** worker 的 ffmpeg 路径仍以 yml 为运行环境配置。 */
+    public String ffmpegPath() {
+        return defaults.getFfmpegPath();
+    }
+
+    public String ffprobePath() {
+        return defaults.getFfprobePath();
+    }
+
+    public int posterSecond() {
+        return defaults.getPosterSecond();
+    }
+
+    public int timeoutSeconds() {
+        return defaults.getTimeoutSeconds();
+    }
+
+    private MediaTranscodeProfile loadProfile() {
+        try {
+            String json = configService.get(CONFIG_KEY, "");
+            if (json == null || json.isBlank()) {
+                return defaultProfile();
+            }
+            MediaTranscodeProfile profile =
+                    objectMapper.readValue(json, MediaTranscodeProfile.class);
+            MediaTranscodeProfileValidator.validate(profile);
+            return profile;
+        } catch (Exception ex) {
+            log.warn("转码配置无效，回退 yml 默认：{}", ex.getMessage());
+            return defaultProfile();
+        }
+    }
+
+    private String writeJson(MediaTranscodeProfile profile) {
+        try {
+            return objectMapper.writeValueAsString(profile);
+        } catch (JsonProcessingException ex) {
+            throw new ServiceException(ErrorCode.INTERNAL_ERROR, "转码配置序列化失败");
+        }
+    }
+
+    private record CachedProfile(MediaTranscodeProfile profile, Instant expiresAt) {
+    }
+}

fruitshorts-module-media/src/main/java/com/fruitshorts/media/service/ThumbnailUrlResolver.java

@@ -0,0 +1,52 @@
+// Author: fruit.com.cn
+
+package com.fruitshorts.media.service;
+
+import com.fruitshorts.media.dal.entity.MediaThumbnail;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Component;
+import org.springframework.util.StringUtils;
+
+import java.util.Collection;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+/**
+ * 把 READY 缩略图记录解析成公开且已签名的 VTT 地址。
+ */
+@Component
+@RequiredArgsConstructor
+public class ThumbnailUrlResolver {
+
+    private final TranscodeService transcodeService;
+    private final MediaStorageService storageService;
+    private final PlaybackSigner signer;
+
+    /** 单集播放使用。 */
+    public String resolve(Long episodeId) {
+        return toUrl(transcodeService.findReadyThumbnail(episodeId));
+    }
+
+    /** 详情列表一次批量解析，禁止 N+1。 */
+    public Map<Long, String> resolveAll(Collection<Long> episodeIds) {
+        Map<Long, MediaThumbnail> thumbnails =
+                transcodeService.listReadyThumbnails(episodeIds);
+        Map<Long, String> result = new LinkedHashMap<>();
+        thumbnails.forEach((episodeId, thumbnail) -> {
+            String url = toUrl(thumbnail);
+            if (url != null) {
+                result.put(episodeId, url);
+            }
+        });
+        return result;
+    }
+
+    private String toUrl(MediaThumbnail thumbnail) {
+        if (thumbnail == null || !StringUtils.hasText(thumbnail.getVttObjectKey())) {
+            return null;
+        }
+        String publicUrl = storageService.toPublicUrl(thumbnail.getVttObjectKey());
+        String signed = signer.sign(publicUrl);
+        return StringUtils.hasText(signed) ? signed : null;
+    }
+}

fruitshorts-module-media/src/main/java/com/fruitshorts/media/service/TranscodeService.java

@@ -6,8 +6,10 @@ import com.baomidou.mybatisplus.core.toolkit.Wrappers;
 import com.fruitshorts.common.exception.ErrorCode;
 import com.fruitshorts.common.exception.ServiceException;
 import com.fruitshorts.media.dal.entity.MediaRendition;
+import com.fruitshorts.media.dal.entity.MediaThumbnail;
 import com.fruitshorts.media.dal.entity.TranscodeTask;
 import com.fruitshorts.media.dal.mapper.MediaRenditionMapper;
+import com.fruitshorts.media.dal.mapper.MediaThumbnailMapper;
 import com.fruitshorts.media.dal.mapper.TranscodeTaskMapper;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
@@ -17,6 +19,7 @@ import java.time.LocalDateTime;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Collection;
 
 /**
  * 转码任务编排。
@@ -38,6 +41,7 @@ public class TranscodeService {
 
     private final TranscodeTaskMapper transcodeTaskMapper;
     private final MediaRenditionMapper mediaRenditionMapper;
+    private final MediaThumbnailMapper mediaThumbnailMapper;
 
     /** 上传完成后入队；同一媒资重复入队时复用未完成的任务，避免重复转码。 */
     @Transactional(rollbackFor = Exception.class)
@@ -82,6 +86,13 @@ public class TranscodeService {
 
     @Transactional(rollbackFor = Exception.class)
     public void succeed(Long taskId, List<MediaRendition> renditions) {
+        succeed(taskId, renditions, null);
+    }
+
+    /** 主转码成功：登记码率产物、缩略图结果并完成任务。 */
+    @Transactional(rollbackFor = Exception.class)
+    public void succeed(Long taskId, List<MediaRendition> renditions,
+                        MediaThumbnail thumbnail) {
         TranscodeTask task = getExisting(taskId);
         for (MediaRendition rendition : renditions) {
             rendition.setMediaAssetId(task.getMediaAssetId());
@@ -90,9 +101,14 @@ public class TranscodeService {
             rendition.setStatus("ready");
             mediaRenditionMapper.insert(rendition);
         }
+        if (thumbnail != null) {
+            upsertThumbnail(task, thumbnail);
+        }
         task.setStatus(STATUS_SUCCESS);
         task.setProgress(100);
         task.setFinishedAt(LocalDateTime.now());
+        task.setErrorMsg(thumbnail == null || thumbnail.getErrorMsg() == null
+                ? "" : thumbnail.getErrorMsg());
         transcodeTaskMapper.updateById(task);
     }
 
@@ -123,6 +139,31 @@ public class TranscodeService {
                 .orderByAsc(MediaRendition::getVideoBitrate));
     }
 
+    /** 播放侧查询单集 READY 缩略图轴。 */
+    public MediaThumbnail findReadyThumbnail(Long episodeId) {
+        if (episodeId == null) {
+            return null;
+        }
+        return mediaThumbnailMapper.selectOne(Wrappers.<MediaThumbnail>lambdaQuery()
+                .eq(MediaThumbnail::getEpisodeId, episodeId)
+                .eq(MediaThumbnail::getStatus, MediaThumbnail.STATUS_READY)
+                .last("limit 1"));
+    }
+
+    /** 详情页一次批量取回，避免按集 N+1。 */
+    public Map<Long, MediaThumbnail> listReadyThumbnails(Collection<Long> episodeIds) {
+        if (episodeIds == null || episodeIds.isEmpty()) {
+            return Map.of();
+        }
+        List<MediaThumbnail> rows = mediaThumbnailMapper.selectList(
+                Wrappers.<MediaThumbnail>lambdaQuery()
+                        .in(MediaThumbnail::getEpisodeId, episodeIds.stream().sorted().toList())
+                        .eq(MediaThumbnail::getStatus, MediaThumbnail.STATUS_READY));
+        Map<Long, MediaThumbnail> result = new LinkedHashMap<>();
+        rows.forEach(row -> result.put(row.getEpisodeId(), row));
+        return result;
+    }
+
     /**
      * 转码看板数据。
      *
@@ -154,6 +195,24 @@ public class TranscodeService {
                 .eq(TranscodeTask::getStatus, status));
     }
 
+    private void upsertThumbnail(TranscodeTask task, MediaThumbnail thumbnail) {
+        if (task.getEpisodeId() == null || task.getEpisodeId() <= 0) {
+            return;
+        }
+        MediaThumbnail existing = mediaThumbnailMapper.selectOne(
+                Wrappers.<MediaThumbnail>lambdaQuery()
+                        .eq(MediaThumbnail::getEpisodeId, task.getEpisodeId())
+                        .last("limit 1"));
+        thumbnail.setDramaId(task.getDramaId() == null ? 0L : task.getDramaId());
+        thumbnail.setEpisodeId(task.getEpisodeId());
+        if (existing == null) {
+            mediaThumbnailMapper.insert(thumbnail);
+            return;
+        }
+        thumbnail.setId(existing.getId());
+        mediaThumbnailMapper.updateById(thumbnail);
+    }
+
     private TranscodeTask getExisting(Long id) {
         TranscodeTask task = id == null ? null : transcodeTaskMapper.selectById(id);
         if (task == null) {

fruitshorts-module-media/src/main/java/com/fruitshorts/media/service/transcode/FfmpegThumbnailGenerator.java

@@ -0,0 +1,178 @@
+// Author: fruit.com.cn
+
+package com.fruitshorts.media.service.transcode;
+
+import com.fruitshorts.common.exception.ErrorCode;
+import com.fruitshorts.common.exception.ServiceException;
+import lombok.extern.slf4j.Slf4j;
+
+import javax.imageio.ImageIO;
+import java.awt.image.BufferedImage;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.Stream;
+
+/**
+ * 从源视频生成雪碧图与 WebVTT；失败只返回 FAILED 元数据，不阻断 HLS。
+ */
+@Slf4j
+public class FfmpegThumbnailGenerator {
+
+    private static final String STATUS_READY = "READY";
+    private static final String STATUS_FAILED = "FAILED";
+    private static final String THUMBNAIL_DIR = "thumbnails";
+    private static final String VTT_FILE = "thumbnails.vtt";
+    private static final String SPRITE_PATTERN = "sprite_%03d.jpg";
+    private static final int STDERR_TAIL = 600;
+    private static final int JPEG_QUALITY = 3;
+
+    /** 生成缩略图轴；禁用时返回 null。 */
+    public TranscodeRunner.ProducedThumbnail generate(
+            TranscodeRunner.TranscodeRequest request, int durationSec) {
+        if (request.sprite() == null || !request.sprite().enabled()) {
+            return null;
+        }
+        try {
+            return generateFiles(request, durationSec);
+        } catch (Exception ex) {
+            log.warn("缩略图生成失败 task={}：{}", request.taskId(), ex.getMessage());
+            return failed(request, durationSec, ex.getMessage());
+        }
+    }
+
+    private TranscodeRunner.ProducedThumbnail generateFiles(
+            TranscodeRunner.TranscodeRequest request, int durationSec) throws IOException {
+        Path thumbnailDir = request.outputDir().resolve(THUMBNAIL_DIR);
+        createDirectories(thumbnailDir);
+        TranscodeRunner.SpriteOptions sprite = request.sprite();
+        int frames = ThumbnailVttBuilder.frameCount(durationSec, sprite.intervalSeconds());
+        int rows = ThumbnailVttBuilder.rows(frames, sprite.columns());
+        runFfmpeg(request, thumbnailDir, rows);
+
+        Path firstSprite = thumbnailDir.resolve(String.format(SPRITE_PATTERN, 1));
+        BufferedImage image = ImageIO.read(firstSprite.toFile());
+        if (image == null || image.getWidth() <= 0 || image.getHeight() <= 0) {
+            throw new ServiceException(ErrorCode.INTERNAL_ERROR, "ffmpeg 未产出有效雪碧图");
+        }
+        ThumbnailVttBuilder.Layout layout = new ThumbnailVttBuilder.Layout(
+                durationSec, sprite.intervalSeconds(), sprite.columns(), rows,
+                image.getWidth(), image.getHeight());
+        Path vtt = thumbnailDir.resolve(VTT_FILE);
+        Files.writeString(vtt, ThumbnailVttBuilder.build(layout), StandardCharsets.UTF_8);
+
+        return new TranscodeRunner.ProducedThumbnail(
+                joinKey(request.objectKeyPrefix(), THUMBNAIL_DIR + "/" + VTT_FILE),
+                joinKey(request.objectKeyPrefix(), THUMBNAIL_DIR + "/sprite_"),
+                sprite.intervalSeconds(), sprite.columns(), rows, image.getWidth(),
+                image.getHeight(), frames, durationSec, sizeOf(thumbnailDir),
+                STATUS_READY, "");
+    }
+
+    private void runFfmpeg(TranscodeRunner.TranscodeRequest request, Path dir, int rows) {
+        TranscodeRunner.SpriteOptions sprite = request.sprite();
+        String filter = "fps=1/" + sprite.intervalSeconds()
+                + ",scale=" + sprite.thumbWidth() + ":-2"
+                + ",tile=" + sprite.columns() + "x" + rows;
+        List<String> command = List.of(
+                request.ffmpegPath(), "-y",
+                "-i", request.sourceFile().toString(),
+                "-vf", filter,
+                "-q:v", String.valueOf(JPEG_QUALITY),
+                dir.resolve(SPRITE_PATTERN).toString());
+        runProcess(command, request.timeoutSeconds(), "生成缩略图失败");
+    }
+
+    private TranscodeRunner.ProducedThumbnail failed(
+            TranscodeRunner.TranscodeRequest request, int durationSec, String message) {
+        TranscodeRunner.SpriteOptions sprite = request.sprite();
+        Path thumbnailDir = request.outputDir().resolve(THUMBNAIL_DIR);
+        int frames = ThumbnailVttBuilder.frameCount(durationSec, sprite.intervalSeconds());
+        int rows = ThumbnailVttBuilder.rows(frames, sprite.columns());
+        return new TranscodeRunner.ProducedThumbnail(
+                joinKey(request.objectKeyPrefix(), THUMBNAIL_DIR + "/" + VTT_FILE),
+                joinKey(request.objectKeyPrefix(), THUMBNAIL_DIR + "/sprite_"),
+                sprite.intervalSeconds(), sprite.columns(), rows, sprite.thumbWidth(), 0,
+                frames, durationSec, sizeOf(thumbnailDir), STATUS_FAILED,
+                message == null ? "缩略图生成失败" : message);
+    }
+
+    private String runProcess(List<String> command, int timeoutSeconds, String errorPrefix) {
+        Path logFile = null;
+        try {
+            logFile = Files.createTempFile("fruitshorts-thumbnail-", ".log");
+            Process process = new ProcessBuilder(command)
+                    .redirectErrorStream(true)
+                    .redirectOutput(logFile.toFile())
+                    .start();
+            if (!process.waitFor(timeoutSeconds, TimeUnit.SECONDS)) {
+                process.destroyForcibly();
+                throw new ServiceException(ErrorCode.INTERNAL_ERROR, errorPrefix + "：超时");
+            }
+            String output = Files.readString(logFile, StandardCharsets.UTF_8);
+            if (process.exitValue() != 0) {
+                throw new ServiceException(ErrorCode.INTERNAL_ERROR,
+                        errorPrefix + "：" + tail(output));
+            }
+            return output;
+        } catch (ServiceException ex) {
+            throw ex;
+        } catch (IOException ex) {
+            throw new ServiceException(ErrorCode.INTERNAL_ERROR,
+                    errorPrefix + "：" + ex.getMessage());
+        } catch (InterruptedException ex) {
+            Thread.currentThread().interrupt();
+            throw new ServiceException(ErrorCode.INTERNAL_ERROR, errorPrefix + "：被中断");
+        } finally {
+            deleteQuietly(logFile);
+        }
+    }
+
+    private void createDirectories(Path path) throws IOException {
+        Files.createDirectories(path);
+    }
+
+    private long sizeOf(Path dir) {
+        if (!Files.isDirectory(dir)) {
+            return 0L;
+        }
+        try (Stream<Path> files = Files.walk(dir)) {
+            return files.filter(Files::isRegularFile)
+                    .mapToLong(path -> {
+                        try {
+                            return Files.size(path);
+                        } catch (IOException ex) {
+                            return 0L;
+                        }
+                    })
+                    .sum();
+        } catch (IOException ex) {
+            return 0L;
+        }
+    }
+
+    private void deleteQuietly(Path path) {
+        if (path == null) {
+            return;
+        }
+        try {
+            Files.deleteIfExists(path);
+        } catch (IOException ignored) {
+            // 临时日志清理失败不影响业务结果
+        }
+    }
+
+    private String tail(String output) {
+        String trimmed = output == null ? "" : output.trim();
+        return trimmed.length() <= STDERR_TAIL
+                ? trimmed : trimmed.substring(trimmed.length() - STDERR_TAIL);
+    }
+
+    private String joinKey(String prefix, String relative) {
+        String cleanPrefix = prefix == null ? "" : prefix.replaceAll("/+$", "");
+        return cleanPrefix.isEmpty() ? relative : cleanPrefix + "/" + relative;
+    }
+}

fruitshorts-module-media/src/main/java/com/fruitshorts/media/service/transcode/FfmpegTranscodeRunner.java

@@ -35,6 +35,7 @@ public class FfmpegTranscodeRunner implements TranscodeRunner {
     private static final String VARIANT_PLAYLIST = "index.m3u8";
     private static final String POSTER_FILE = "poster.jpg";
     private static final int STDERR_TAIL = 800;
+    private final FfmpegThumbnailGenerator thumbnailGenerator = new FfmpegThumbnailGenerator();
 
     @Override
     public TranscodeResult run(TranscodeRequest request) {
@@ -51,10 +52,12 @@ public class FfmpegTranscodeRunner implements TranscodeRunner {
         }
         writeMasterPlaylist(request, renditions);
         ProducedRendition poster = extractPoster(request);
-        log.info("转码完成 task={}：{} 档 HLS + 封面，时长 {}s",
-                request.taskId(), renditions.size(), durationSec);
+        ProducedThumbnail thumbnail = thumbnailGenerator.generate(request, durationSec);
+        log.info("转码完成 task={}：{} 档 HLS + 封面 + 缩略图状态={}，时长 {}s",
+                request.taskId(), renditions.size(),
+                thumbnail == null ? "DISABLED" : thumbnail.status(), durationSec);
         return new TranscodeResult(joinKey(request.objectKeyPrefix(), MASTER_PLAYLIST), renditions,
-                poster.objectKey(), durationSec);
+                poster.objectKey(), durationSec, thumbnail);
     }
 
     private ProducedRendition transcodeRung(TranscodeRequest request, LadderRung rung) {

fruitshorts-module-media/src/main/java/com/fruitshorts/media/service/transcode/ThumbnailVttBuilder.java

@@ -0,0 +1,74 @@
+// Author: fruit.com.cn
+
+package com.fruitshorts.media.service.transcode;
+
+/**
+ * 生成 WebVTT 缩略图索引；每个 cue 指向雪碧图中的 xywh 区域。
+ */
+public final class ThumbnailVttBuilder {
+
+    private static final String HEADER = "WEBVTT\n\n";
+    private static final int SECONDS_PER_MINUTE = 60;
+    private static final int MINUTES_PER_HOUR = 60;
+
+    private ThumbnailVttBuilder() {
+    }
+
+    /** 雪碧图布局与尺寸。 */
+    public record Layout(int durationSec, int intervalSec, int columns, int rows,
+                         int thumbWidth, int thumbHeight) {
+    }
+
+    /** 按固定 tile 布局生成所有 cue。 */
+    public static String build(Layout layout) {
+        int frames = frameCount(layout.durationSec(), layout.intervalSec());
+        int framesPerSprite = layout.columns() * layout.rows();
+        int duration = layout.durationSec() > 0
+                ? layout.durationSec() : layout.intervalSec();
+        StringBuilder body = new StringBuilder(HEADER);
+        for (int index = 0; index < frames; index++) {
+            appendCue(body, layout, duration, index, framesPerSprite);
+        }
+        return body.toString();
+    }
+
+    /** 采样帧数，未知时长也保留一帧。 */
+    public static int frameCount(int durationSec, int intervalSec) {
+        if (durationSec <= 0 || intervalSec <= 0) {
+            return 1;
+        }
+        return Math.max(1, (durationSec + intervalSec - 1) / intervalSec);
+    }
+
+    /** 根据帧数和列数计算 tile 行数。 */
+    public static int rows(int frameCount, int columns) {
+        if (frameCount <= 0 || columns <= 0) {
+            return 1;
+        }
+        int required = Math.max(1, (frameCount + columns - 1) / columns);
+        return Math.min(columns, required);
+    }
+
+    private static void appendCue(StringBuilder body, Layout layout, int duration,
+                                  int index, int framesPerSprite) {
+        int sheet = index / framesPerSprite + 1;
+        int frameInSheet = index % framesPerSprite;
+        int column = frameInSheet % layout.columns();
+        int row = frameInSheet / layout.columns();
+        int start = index * layout.intervalSec();
+        int end = Math.min(start + layout.intervalSec(), duration);
+        body.append(formatTimestamp(start)).append(" --> ")
+                .append(formatTimestamp(end)).append('\n')
+                .append(String.format("sprite_%03d.jpg#xywh=%d,%d,%d,%d",
+                        sheet, column * layout.thumbWidth(), row * layout.thumbHeight(),
+                        layout.thumbWidth(), layout.thumbHeight()))
+                .append("\n\n");
+    }
+
+    private static String formatTimestamp(int totalSeconds) {
+        int hours = totalSeconds / (SECONDS_PER_MINUTE * MINUTES_PER_HOUR);
+        int minutes = totalSeconds / SECONDS_PER_MINUTE % MINUTES_PER_HOUR;
+        int seconds = totalSeconds % SECONDS_PER_MINUTE;
+        return String.format("%02d:%02d:%02d.%03d", hours, minutes, seconds, 0);
+    }
+}

fruitshorts-module-media/src/main/java/com/fruitshorts/media/service/transcode/TranscodeRunner.java

@@ -29,7 +29,24 @@ public interface TranscodeRunner {
      */
     record TranscodeRequest(Long taskId, Path sourceFile, Path outputDir, String objectKeyPrefix,
                             List<LadderRung> ladder, String ffmpegPath, String ffprobePath,
-                            int segmentSeconds, int posterSecond, int timeoutSeconds) {
+                            int segmentSeconds, int posterSecond, int timeoutSeconds,
+                            SpriteOptions sprite) {
+
+        /** 兼容未启用缩略图的既有调用。 */
+        public TranscodeRequest(Long taskId, Path sourceFile, Path outputDir, String objectKeyPrefix,
+                                List<LadderRung> ladder, String ffmpegPath, String ffprobePath,
+                                int segmentSeconds, int posterSecond, int timeoutSeconds) {
+            this(taskId, sourceFile, outputDir, objectKeyPrefix, ladder, ffmpegPath, ffprobePath,
+                    segmentSeconds, posterSecond, timeoutSeconds, SpriteOptions.disabled());
+        }
+    }
+
+    /** 雪碧图采样参数。 */
+    record SpriteOptions(boolean enabled, int intervalSeconds, int columns, int thumbWidth) {
+
+        public static SpriteOptions disabled() {
+            return new SpriteOptions(false, 1, 10, 160);
+        }
     }
 
     /** 一档产物。 */
@@ -37,14 +54,29 @@ public interface TranscodeRunner {
                              int audioBitrateKbps, String objectKey, long sizeBytes, int segmentCount) {
     }
 
+    /** 雪碧图与 VTT 产物；失败也返回本记录，保证主转码可继续成功。 */
+    record ProducedThumbnail(String vttObjectKey, String spritePrefix, int intervalSec,
+                             int columns, int rows, int thumbWidth, int thumbHeight,
+                             int frameCount, int durationSec, long sizeBytes,
+                             String status, String errorMessage) {
+    }
+
     /**
      * 转码产物。
      *
      * @param masterObjectKey HLS 主播放列表的 objectKey（客户端可播入口）
      * @param posterObjectKey 封面截图 objectKey
      * @param durationSec     视频时长（ffprobe 读出，0 表示读不到）
+     * @param thumbnail       缩略图产物；未启用时为 null
      */
     record TranscodeResult(String masterObjectKey, List<ProducedRendition> renditions,
-                           String posterObjectKey, int durationSec) {
+                           String posterObjectKey, int durationSec,
+                           ProducedThumbnail thumbnail) {
+
+        /** 兼容既有测试与未启用缩略图的调用。 */
+        public TranscodeResult(String masterObjectKey, List<ProducedRendition> renditions,
+                               String posterObjectKey, int durationSec) {
+            this(masterObjectKey, renditions, posterObjectKey, durationSec, null);
+        }
     }
 }

fruitshorts-module-media/src/main/java/com/fruitshorts/media/service/transcode/TranscodeWorker.java

@@ -2,10 +2,12 @@
 
 package com.fruitshorts.media.service.transcode;
 
-import com.fruitshorts.media.config.TranscodeProperties;
+import com.fruitshorts.media.config.MediaTranscodeProfile;
+import com.fruitshorts.media.dal.entity.MediaThumbnail;
 import com.fruitshorts.media.dal.entity.TranscodeTask;
 import com.fruitshorts.media.service.MediaService;
 import com.fruitshorts.media.service.MediaStorageService;
+import com.fruitshorts.media.service.MediaTranscodeProfileService;
 import com.fruitshorts.media.service.TranscodeService;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
@@ -39,7 +41,7 @@ public class TranscodeWorker {
     private final MediaService mediaService;
     private final MediaStorageService storageService;
     private final TranscodeRunner transcodeRunner;
-    private final TranscodeProperties properties;
+    private final MediaTranscodeProfileService profileService;
 
     /** 定时轮询：队列空就按 poll-delay 再来一轮；上一轮没跑完不会被下一轮叠加（fixedDelay）。 */
     @Scheduled(fixedDelayString = "${fruitshorts.media.transcode.poll-delay-ms:5000}")
@@ -71,14 +73,17 @@ public class TranscodeWorker {
         long startedAt = System.currentTimeMillis();
         String objectKeyPrefix = outputPrefix(task);
         try {
+            MediaTranscodeProfile profile = profileService.currentProfile();
             Path sourceFile = storageService.fileFor(storageService.objectKeyOf(task.getSourceUrl()));
             Path outputDir = storageService.fileFor(objectKeyPrefix);
             TranscodeRunner.TranscodeResult result = transcodeRunner.run(new TranscodeRunner.TranscodeRequest(
-                    task.getId(), sourceFile, outputDir, objectKeyPrefix, ladder(), properties.getFfmpegPath(),
-                    properties.getFfprobePath(), properties.getSegmentSeconds(), properties.getPosterSecond(),
-                    properties.getTimeoutSeconds()));
+                    task.getId(), sourceFile, outputDir, objectKeyPrefix, ladder(profile),
+                    profileService.ffmpegPath(), profileService.ffprobePath(),
+                    profile.getSegmentSeconds(), profileService.posterSecond(),
+                    profileService.timeoutSeconds(), spriteOptions(profile)));
 
-            transcodeService.succeed(task.getId(), toRenditions(result));
+            transcodeService.succeed(task.getId(), toRenditions(result),
+                    toThumbnail(task, result.thumbnail()));
             if (task.getMediaAssetId() != null && task.getMediaAssetId() > 0) {
                 mediaService.markReady(task.getMediaAssetId(),
                         storageService.toPublicUrl(result.masterObjectKey()),
@@ -88,6 +93,7 @@ public class TranscodeWorker {
             log.info("转码成功 task={} asset={} 档数={} 耗时={}ms 产物前缀={}",
                     task.getId(), task.getMediaAssetId(), result.renditions().size(),
                     System.currentTimeMillis() - startedAt, objectKeyPrefix);
+            logThumbnailResult(result.thumbnail());
         } catch (Exception ex) {
             String reason = ex.getMessage() == null ? ex.getClass().getSimpleName() : ex.getMessage();
             int attempt = (task.getRetryCount() == null ? 0 : task.getRetryCount()) + 1;
@@ -107,15 +113,61 @@ public class TranscodeWorker {
         return "transcoded/" + task.getId();
     }
 
-    private List<TranscodeRunner.LadderRung> ladder() {
+    private List<TranscodeRunner.LadderRung> ladder(MediaTranscodeProfile profile) {
         List<TranscodeRunner.LadderRung> ladder = new ArrayList<>();
-        for (TranscodeProperties.Rung rung : properties.getLadder()) {
+        for (MediaTranscodeProfile.Rung rung : profile.getLadder()) {
+            if (!rung.isEnabled()) {
+                continue;
+            }
             ladder.add(new TranscodeRunner.LadderRung(rung.getQuality(), rung.getWidth(), rung.getHeight(),
                     rung.getVideoBitrateKbps(), rung.getAudioBitrateKbps()));
         }
         return ladder;
     }
 
+    private TranscodeRunner.SpriteOptions spriteOptions(MediaTranscodeProfile profile) {
+        MediaTranscodeProfile.Sprite sprite = profile.getSprite();
+        return new TranscodeRunner.SpriteOptions(
+                sprite.isEnabled(), sprite.getIntervalSeconds(),
+                sprite.getColumns(), sprite.getThumbWidth());
+    }
+
+    private MediaThumbnail toThumbnail(
+            TranscodeTask task, TranscodeRunner.ProducedThumbnail produced) {
+        if (produced == null) {
+            return null;
+        }
+        MediaThumbnail thumbnail = new MediaThumbnail();
+        thumbnail.setEpisodeId(task.getEpisodeId());
+        thumbnail.setDramaId(task.getDramaId());
+        thumbnail.setVttObjectKey(produced.vttObjectKey());
+        thumbnail.setSpritePrefix(produced.spritePrefix());
+        thumbnail.setIntervalSec(produced.intervalSec());
+        thumbnail.setColumns(produced.columns());
+        thumbnail.setRows(produced.rows());
+        thumbnail.setThumbWidth(produced.thumbWidth());
+        thumbnail.setThumbHeight(produced.thumbHeight());
+        thumbnail.setFrameCount(produced.frameCount());
+        thumbnail.setDurationSec(produced.durationSec());
+        thumbnail.setSizeBytes(produced.sizeBytes());
+        thumbnail.setStatus(produced.status());
+        thumbnail.setErrorMsg(produced.errorMessage());
+        return thumbnail;
+    }
+
+    private void logThumbnailResult(TranscodeRunner.ProducedThumbnail thumbnail) {
+        if (thumbnail == null) {
+            log.info("缩略图未启用");
+            return;
+        }
+        if (MediaThumbnail.STATUS_FAILED.equals(thumbnail.status())) {
+            log.warn("主转码成功但缩略图失败：{}", thumbnail.errorMessage());
+            return;
+        }
+        log.info("缩略图完成：{} 帧，{}x{}", thumbnail.frameCount(),
+                thumbnail.columns(), thumbnail.rows());
+    }
+
     private List<com.fruitshorts.media.dal.entity.MediaRendition> toRenditions(
             TranscodeRunner.TranscodeResult result) {
         List<com.fruitshorts.media.dal.entity.MediaRendition> renditions = new ArrayList<>();

fruitshorts-module-playback/src/main/java/com/fruitshorts/playback/service/PlaybackService.java

@@ -8,6 +8,7 @@ import com.fruitshorts.content.service.DramaService;
 import com.fruitshorts.content.service.EpisodeService;
 import com.fruitshorts.media.dal.entity.MediaRendition;
 import com.fruitshorts.media.service.PlaybackSigner;
+import com.fruitshorts.media.service.ThumbnailUrlResolver;
 import com.fruitshorts.media.service.TranscodeService;
 import com.fruitshorts.playback.dal.entity.PlaybackTicket;
 import com.fruitshorts.playback.dal.mapper.PlaybackTicketMapper;
@@ -46,6 +47,7 @@ public class PlaybackService {
     private final PlaybackSigner signer;
     private final EntitlementPort entitlementPort;
     private final TranscodeService transcodeService;
+    private final ThumbnailUrlResolver thumbnailUrlResolver;
 
     @Transactional(rollbackFor = Exception.class)
     public PlayRespVO play(Long userId, Long episodeId, String deviceId, String clientIp) {
@@ -65,6 +67,7 @@ public class PlaybackService {
         vo.setUnlockCoin(episode.getUnlockCoin());
         vo.setPreviewSeconds(episode.getPreviewSeconds());
         vo.setQualities(qualitiesOf(episode.getId()));
+        vo.setThumbnailsUrl(thumbnailUrlResolver.resolve(episode.getId()));
 
         if (!StringUtils.hasText(source)) {
             // 还没转码或没上传片源：明确告诉客户端"没有片源"，而不是给一个播不了的地址

fruitshorts-module-playback/src/main/java/com/fruitshorts/playback/vo/PlayRespVO.java

@@ -23,6 +23,8 @@ public class PlayRespVO {
     private String playUrl;
     /** 可用的清晰度档位 */
     private List<String> qualities;
+    /** 雪碧图 WebVTT 时间轴地址；没有产物时为 null */
+    private String thumbnailsUrl;
     /** 需要多少金币解锁 */
     private Integer unlockCoin;
     /** 试看秒数，0 表示不限制 */

fruitshorts-transcode-worker/src/test/java/com/fruitshorts/worker/FfmpegTranscodeRunnerSmokeTest.java

@@ -45,7 +45,8 @@ class FfmpegTranscodeRunnerSmokeTest {
                     1L, sample, output, "transcoded/smoke",
                     List.of(new TranscodeRunner.LadderRung("360p", 640, 360, 400, 64),
                             new TranscodeRunner.LadderRung("480p", 854, 480, 800, 64)),
-                    ffmpeg, ffprobe, 2, 1, 120));
+                    ffmpeg, ffprobe, 2, 1, 120,
+                    new TranscodeRunner.SpriteOptions(true, 1, 10, 160)));
 
             assertThat(Files.exists(output.resolve("master.m3u8"))).isTrue();
             assertThat(Files.exists(output.resolve("poster.jpg"))).isTrue();
@@ -59,6 +60,10 @@ class FfmpegTranscodeRunnerSmokeTest {
                 assertThat(rendition.sizeBytes()).isGreaterThan(0L);
             }
             assertThat(result.durationSec()).isBetween(1, 5);
+            assertThat(result.thumbnail()).isNotNull();
+            assertThat(result.thumbnail().status()).isEqualTo("READY");
+            assertThat(Files.exists(output.resolve("thumbnails/thumbnails.vtt"))).isTrue();
+            assertThat(Files.exists(output.resolve("thumbnails/sprite_001.jpg"))).isTrue();
             assertThat(readLines(output.resolve("master.m3u8")))
                     .anyMatch(line -> line.contains("360p/index.m3u8"))
                     .anyMatch(line -> line.contains("480p/index.m3u8"));

fruitshorts-transcode-worker/src/test/java/com/fruitshorts/worker/MediaTranscodeProfileServiceTest.java

@@ -0,0 +1,65 @@
+// Author: fruit.com.cn
+
+package com.fruitshorts.worker;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fruitshorts.media.config.MediaTranscodeProfile;
+import com.fruitshorts.media.config.TranscodeProperties;
+import com.fruitshorts.media.service.MediaTranscodeProfileService;
+import com.fruitshorts.system.service.ConfigService;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+/**
+ * 后台转码配置的解析、缓存与非法回退。
+ */
+class MediaTranscodeProfileServiceTest {
+
+    private ConfigService configService;
+    private MediaTranscodeProfileService service;
+
+    @BeforeEach
+    void setUp() {
+        configService = mock(ConfigService.class);
+        service = new MediaTranscodeProfileService(
+                configService, new ObjectMapper(), new TranscodeProperties());
+    }
+
+    @Test
+    void should_read_valid_profile_and_cache_for_30_seconds() throws Exception {
+        MediaTranscodeProfile profile = new MediaTranscodeProfile();
+        profile.setSegmentSeconds(4);
+        profile.getLadder().get(0).setVideoBitrateKbps(500);
+        given(configService.get(eq(MediaTranscodeProfileService.CONFIG_KEY), anyString()))
+                .willReturn(new ObjectMapper().writeValueAsString(profile));
+
+        MediaTranscodeProfile first = service.currentProfile();
+        MediaTranscodeProfile second = service.currentProfile();
+
+        assertThat(first.getSegmentSeconds()).isEqualTo(4);
+        assertThat(first.getLadder().get(0).getVideoBitrateKbps()).isEqualTo(500);
+        assertThat(second).isSameAs(first);
+        verify(configService, times(1))
+                .get(eq(MediaTranscodeProfileService.CONFIG_KEY), anyString());
+    }
+
+    @Test
+    void should_fallback_to_yml_default_when_profile_is_illegal() {
+        given(configService.get(eq(MediaTranscodeProfileService.CONFIG_KEY), anyString()))
+                .willReturn("{\"segmentSeconds\":1,\"ladder\":[]}");
+
+        MediaTranscodeProfile profile = service.currentProfile();
+
+        assertThat(profile.getSegmentSeconds()).isEqualTo(6);
+        assertThat(profile.getLadder()).extracting(MediaTranscodeProfile.Rung::getQuality)
+                .containsExactly("360p", "480p", "720p", "1080p");
+    }
+}

fruitshorts-transcode-worker/src/test/java/com/fruitshorts/worker/ThumbnailVttBuilderTest.java

@@ -0,0 +1,44 @@
+// Author: fruit.com.cn
+
+package com.fruitshorts.worker;
+
+import com.fruitshorts.media.service.transcode.ThumbnailVttBuilder;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * WebVTT cue 时间与雪碧图行列坐标。
+ */
+class ThumbnailVttBuilderTest {
+
+    @Test
+    void should_write_time_ranges_and_xywh_coordinates() {
+        String vtt = ThumbnailVttBuilder.build(
+                new ThumbnailVttBuilder.Layout(3, 1, 10, 1, 160, 90));
+
+        assertThat(vtt).startsWith("WEBVTT");
+        assertThat(vtt).contains("00:00:00.000 --> 00:00:01.000\n"
+                + "sprite_001.jpg#xywh=0,0,160,90");
+        assertThat(vtt).contains("00:00:01.000 --> 00:00:02.000\n"
+                + "sprite_001.jpg#xywh=160,0,160,90");
+        assertThat(vtt).contains("00:00:02.000 --> 00:00:03.000\n"
+                + "sprite_001.jpg#xywh=320,0,160,90");
+    }
+
+    @Test
+    void should_switch_to_second_sprite_after_full_tile() {
+        String vtt = ThumbnailVttBuilder.build(
+                new ThumbnailVttBuilder.Layout(101, 1, 10, 10, 160, 90));
+
+        assertThat(vtt).contains("00:01:40.000 --> 00:01:41.000\n"
+                + "sprite_002.jpg#xywh=0,0,160,90");
+    }
+
+    @Test
+    void should_cap_tile_rows_at_column_count() {
+        assertThat(ThumbnailVttBuilder.frameCount(21, 1)).isEqualTo(21);
+        assertThat(ThumbnailVttBuilder.rows(21, 10)).isEqualTo(3);
+        assertThat(ThumbnailVttBuilder.rows(121, 10)).isEqualTo(10);
+    }
+}

fruitshorts-transcode-worker/src/test/java/com/fruitshorts/worker/TranscodeClaimAndStorageTest.java

@@ -6,8 +6,11 @@ import com.baomidou.mybatisplus.core.MybatisConfiguration;
 import com.baomidou.mybatisplus.core.metadata.TableInfoHelper;
 import com.fruitshorts.common.exception.ServiceException;
 import com.fruitshorts.media.config.MediaProperties;
+import com.fruitshorts.media.dal.entity.MediaRendition;
+import com.fruitshorts.media.dal.entity.MediaThumbnail;
 import com.fruitshorts.media.dal.entity.TranscodeTask;
 import com.fruitshorts.media.dal.mapper.MediaRenditionMapper;
+import com.fruitshorts.media.dal.mapper.MediaThumbnailMapper;
 import com.fruitshorts.media.dal.mapper.TranscodeTaskMapper;
 import com.fruitshorts.media.service.MediaStorageService;
 import com.fruitshorts.media.service.TranscodeService;
@@ -39,12 +42,16 @@ class TranscodeClaimAndStorageTest {
      */
     @BeforeAll
     static void initTableInfoCache() {
-        TableInfoHelper.initTableInfo(
-                new MapperBuilderAssistant(new MybatisConfiguration(), ""), TranscodeTask.class);
+        MapperBuilderAssistant assistant =
+                new MapperBuilderAssistant(new MybatisConfiguration(), "");
+        TableInfoHelper.initTableInfo(assistant, TranscodeTask.class);
+        TableInfoHelper.initTableInfo(assistant, MediaRendition.class);
+        TableInfoHelper.initTableInfo(assistant, MediaThumbnail.class);
     }
 
     private TranscodeTaskMapper transcodeTaskMapper;
     private MediaRenditionMapper mediaRenditionMapper;
+    private MediaThumbnailMapper mediaThumbnailMapper;
     private TranscodeService transcodeService;
     private MediaProperties mediaProperties;
     private MediaStorageService storageService;
@@ -53,7 +60,9 @@ class TranscodeClaimAndStorageTest {
     void setUp() {
         transcodeTaskMapper = mock(TranscodeTaskMapper.class);
         mediaRenditionMapper = mock(MediaRenditionMapper.class);
-        transcodeService = new TranscodeService(transcodeTaskMapper, mediaRenditionMapper);
+        mediaThumbnailMapper = mock(MediaThumbnailMapper.class);
+        transcodeService = new TranscodeService(
+                transcodeTaskMapper, mediaRenditionMapper, mediaThumbnailMapper);
         mediaProperties = new MediaProperties();
         mediaProperties.setRootDir("/tmp/fruitshorts-storage-test");
         mediaProperties.setPublicPrefix("/files");
@@ -88,6 +97,24 @@ class TranscodeClaimAndStorageTest {
         verify(transcodeTaskMapper, never()).update(any(), any());
     }
 
+    @Test
+    void should_insert_thumbnail_when_main_transcode_succeeds() {
+        TranscodeTask task = task(3L);
+        task.setDramaId(7L);
+        task.setEpisodeId(11L);
+        given(transcodeTaskMapper.selectById(3L)).willReturn(task);
+        MediaThumbnail thumbnail = new MediaThumbnail();
+        thumbnail.setEpisodeId(11L);
+        thumbnail.setVttObjectKey("transcoded/3/thumbnails/thumbnails.vtt");
+        thumbnail.setStatus(MediaThumbnail.STATUS_READY);
+
+        transcodeService.succeed(3L, java.util.List.of(), thumbnail);
+
+        verify(mediaThumbnailMapper).insert(thumbnail);
+        assertThat(task.getStatus()).isEqualTo(TranscodeService.STATUS_SUCCESS);
+        verify(transcodeTaskMapper).updateById(task);
+    }
+
     @Test
     void should_reject_object_key_that_escapes_the_storage_root() {
         assertThatThrownBy(() -> storageService.fileFor("../../etc/passwd"))

fruitshorts-transcode-worker/src/test/java/com/fruitshorts/worker/TranscodeWorkerTest.java

@@ -2,11 +2,13 @@
 
 package com.fruitshorts.worker;
 
-import com.fruitshorts.media.config.TranscodeProperties;
+import com.fruitshorts.media.config.MediaTranscodeProfile;
 import com.fruitshorts.media.dal.entity.MediaRendition;
+import com.fruitshorts.media.dal.entity.MediaThumbnail;
 import com.fruitshorts.media.dal.entity.TranscodeTask;
 import com.fruitshorts.media.service.MediaService;
 import com.fruitshorts.media.service.MediaStorageService;
+import com.fruitshorts.media.service.MediaTranscodeProfileService;
 import com.fruitshorts.media.service.TranscodeService;
 import com.fruitshorts.media.service.transcode.TranscodeRunner;
 import com.fruitshorts.media.service.transcode.TranscodeWorker;
@@ -41,6 +43,7 @@ class TranscodeWorkerTest {
     private MediaService mediaService;
     private MediaStorageService storageService;
     private StubRunner runner;
+    private MediaTranscodeProfileService profileService;
     private TranscodeWorker worker;
 
     @BeforeEach
@@ -48,9 +51,15 @@ class TranscodeWorkerTest {
         transcodeService = mock(TranscodeService.class);
         mediaService = mock(MediaService.class);
         storageService = mock(MediaStorageService.class);
+        profileService = mock(MediaTranscodeProfileService.class);
         runner = new StubRunner();
         worker = new TranscodeWorker(transcodeService, mediaService, storageService, runner,
-                new TranscodeProperties());
+                profileService);
+        given(profileService.currentProfile()).willReturn(new MediaTranscodeProfile());
+        given(profileService.ffmpegPath()).willReturn("ffmpeg");
+        given(profileService.ffprobePath()).willReturn("ffprobe");
+        given(profileService.posterSecond()).willReturn(1);
+        given(profileService.timeoutSeconds()).willReturn(120);
         given(storageService.objectKeyOf(anyString())).willReturn("episode/202610/1.mp4");
         given(storageService.fileFor(anyString())).willReturn(Paths.get("/tmp/fruitshorts-test/1.mp4"));
         given(storageService.toPublicUrl(anyString()))
@@ -65,11 +74,17 @@ class TranscodeWorkerTest {
 
         @SuppressWarnings("unchecked")
         ArgumentCaptor<List<MediaRendition>> captor = ArgumentCaptor.forClass(List.class);
-        verify(transcodeService).succeed(eq(TASK_ID), captor.capture());
+        @SuppressWarnings("unchecked")
+        ArgumentCaptor<MediaThumbnail> thumbnailCaptor =
+                ArgumentCaptor.forClass(MediaThumbnail.class);
+        verify(transcodeService).succeed(eq(TASK_ID), captor.capture(),
+                thumbnailCaptor.capture());
         assertThat(captor.getValue()).hasSize(2);
         // 对外地址一律经 MediaStorageService，worker 不自己拼磁盘路径
         assertThat(captor.getValue().get(0).getPlayUrl()).startsWith("/files/transcoded/88/");
         assertThat(captor.getValue().get(0).getFormat()).isEqualTo("HLS");
+        assertThat(thumbnailCaptor.getValue().getStatus())
+                .isEqualTo(MediaThumbnail.STATUS_READY);
         verify(mediaService).markReady(eq(ASSET_ID), eq("/files/transcoded/88/master.m3u8"),
                 eq("/files/transcoded/88/poster.jpg"), eq(120));
         verify(transcodeService, never()).fail(any(), anyString());
@@ -87,6 +102,31 @@ class TranscodeWorkerTest {
         assertThat(runner.request.objectKeyPrefix()).isEqualTo("transcoded/88");
     }
 
+    @Test
+    void should_keep_main_transcode_successful_when_thumbnail_generation_fails() {
+        given(transcodeService.claimNext()).willReturn(queuedTask());
+        runner.thumbnail = new TranscodeRunner.ProducedThumbnail(
+                "transcoded/88/thumbnails/thumbnails.vtt",
+                "transcoded/88/thumbnails/sprite_",
+                1, 10, 1, 160, 0, 120, 120, 0L,
+                MediaThumbnail.STATUS_FAILED, "tile 滤镜失败");
+
+        worker.processOne();
+
+        @SuppressWarnings("unchecked")
+        ArgumentCaptor<List<MediaRendition>> renditions =
+                ArgumentCaptor.forClass(List.class);
+        ArgumentCaptor<MediaThumbnail> thumbnail =
+                ArgumentCaptor.forClass(MediaThumbnail.class);
+        verify(transcodeService).succeed(eq(TASK_ID), renditions.capture(),
+                thumbnail.capture());
+        assertThat(thumbnail.getValue().getStatus())
+                .isEqualTo(MediaThumbnail.STATUS_FAILED);
+        assertThat(thumbnail.getValue().getErrorMsg()).contains("tile");
+        verify(mediaService).markReady(eq(ASSET_ID), anyString(), anyString(), eq(120));
+        verify(transcodeService, never()).fail(any(), anyString());
+    }
+
     @Test
     void should_keep_task_queued_and_record_reason_when_transcode_fails_before_max_retry() {
         TranscodeTask task = queuedTask();
@@ -144,6 +184,7 @@ class TranscodeWorkerTest {
     private static final class StubRunner implements TranscodeRunner {
         private TranscodeRequest request;
         private RuntimeException failure;
+        private ProducedThumbnail thumbnail;
         private boolean called;
 
         @Override
@@ -153,13 +194,20 @@ class TranscodeWorkerTest {
             if (failure != null) {
                 throw failure;
             }
+            ProducedThumbnail resultThumbnail = thumbnail == null
+                    ? new ProducedThumbnail(
+                            request.objectKeyPrefix() + "/thumbnails/thumbnails.vtt",
+                            request.objectKeyPrefix() + "/thumbnails/sprite_",
+                            1, 10, 1, 160, 90, 120, 120, 2048L,
+                            MediaThumbnail.STATUS_READY, "")
+                    : thumbnail;
             return new TranscodeResult(
                     request.objectKeyPrefix() + "/master.m3u8",
                     List.of(new ProducedRendition("360p", 640, 360, 400, 64,
                                     request.objectKeyPrefix() + "/360p/index.m3u8", 1024L, 4),
                             new ProducedRendition("480p", 854, 480, 800, 64,
                                     request.objectKeyPrefix() + "/480p/index.m3u8", 2048L, 4)),
-                    request.objectKeyPrefix() + "/poster.jpg", 120);
+                    request.objectKeyPrefix() + "/poster.jpg", 120, resultThumbnail);
         }
     }
 }

sql/data-phase1.sql

@@ -338,5 +338,17 @@ INSERT INTO sys_config (id, config_key, config_value, remark) VALUES
   (4, 'app.register.max-per-device-per-day', '0', '0=不限制；生产建议 3')
 ON CONFLICT (config_key) DO NOTHING;
 
+INSERT INTO sys_config (id, config_key, config_value, remark) VALUES
+  (2026102201,
+   'media.transcode.profile',
+   '{"enabled":true,"segmentSeconds":6,"ladder":[' ||
+   '{"quality":"360p","width":640,"height":360,"videoBitrateKbps":400,"audioBitrateKbps":64,"enabled":true},' ||
+   '{"quality":"480p","width":854,"height":480,"videoBitrateKbps":800,"audioBitrateKbps":64,"enabled":true},' ||
+   '{"quality":"720p","width":1280,"height":720,"videoBitrateKbps":1600,"audioBitrateKbps":96,"enabled":true},' ||
+   '{"quality":"1080p","width":1920,"height":1080,"videoBitrateKbps":3200,"audioBitrateKbps":128,"enabled":true}],' ||
+   '"sprite":{"enabled":true,"intervalSeconds":1,"columns":10,"thumbWidth":160}}',
+   '转码档位与缩略图轴配置')
+ON CONFLICT (config_key) DO NOTHING;
+
 -- K23：二级菜单统一只显示文字，历史图标值也一并清空。
 UPDATE sys_menu SET icon = '' WHERE type = 'MENU';

sql/patch-2026-10-22-media-thumbnail.sql

@@ -0,0 +1,45 @@
+-- Author: fruit.com.cn
+-- 转码缩略图轴：默认档位配置 + 单集雪碧图/VTT 元数据（幂等）
+
+CREATE TABLE IF NOT EXISTS media_thumbnail (
+  id             BIGINT PRIMARY KEY,
+  episode_id     BIGINT       NOT NULL,
+  drama_id       BIGINT       NOT NULL DEFAULT 0,
+  vtt_object_key VARCHAR(512) NOT NULL DEFAULT '',
+  sprite_prefix  VARCHAR(512) NOT NULL DEFAULT '',
+  interval_sec   INT          NOT NULL DEFAULT 1,
+  columns        INT          NOT NULL DEFAULT 10,
+  rows           INT          NOT NULL DEFAULT 1,
+  thumb_width    INT          NOT NULL DEFAULT 160,
+  thumb_height   INT          NOT NULL DEFAULT 0,
+  frame_count    INT          NOT NULL DEFAULT 0,
+  duration_sec   INT          NOT NULL DEFAULT 0,
+  size_bytes     BIGINT       NOT NULL DEFAULT 0,
+  status         VARCHAR(16)  NOT NULL DEFAULT 'FAILED',
+  error_msg      VARCHAR(500) NOT NULL DEFAULT '',
+  created_at     TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  updated_at     TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  deleted        SMALLINT     NOT NULL DEFAULT 0
+);
+CREATE UNIQUE INDEX IF NOT EXISTS uk_media_thumbnail_episode
+  ON media_thumbnail (episode_id);
+CREATE INDEX IF NOT EXISTS idx_media_thumbnail_drama
+  ON media_thumbnail (drama_id);
+COMMENT ON TABLE media_thumbnail IS '单集缩略图雪碧图与 VTT 时间轴';
+
+DROP TRIGGER IF EXISTS trg_media_thumbnail_updated_at ON media_thumbnail;
+CREATE TRIGGER trg_media_thumbnail_updated_at
+BEFORE UPDATE ON media_thumbnail
+FOR EACH ROW EXECUTE FUNCTION set_updated_at();
+
+INSERT INTO sys_config (id, config_key, config_value, remark) VALUES
+  (2026102201,
+   'media.transcode.profile',
+   '{"enabled":true,"segmentSeconds":6,"ladder":[' ||
+   '{"quality":"360p","width":640,"height":360,"videoBitrateKbps":400,"audioBitrateKbps":64,"enabled":true},' ||
+   '{"quality":"480p","width":854,"height":480,"videoBitrateKbps":800,"audioBitrateKbps":64,"enabled":true},' ||
+   '{"quality":"720p","width":1280,"height":720,"videoBitrateKbps":1600,"audioBitrateKbps":96,"enabled":true},' ||
+   '{"quality":"1080p","width":1920,"height":1080,"videoBitrateKbps":3200,"audioBitrateKbps":128,"enabled":true}],' ||
+   '"sprite":{"enabled":true,"intervalSeconds":1,"columns":10,"thumbWidth":160}}',
+   '转码档位与缩略图轴配置')
+ON CONFLICT (config_key) DO NOTHING;

sql/schema-phase1.sql

@@ -785,6 +785,32 @@ CREATE UNIQUE INDEX IF NOT EXISTS uk_rendition ON media_rendition (media_asset_i
 CREATE INDEX IF NOT EXISTS idx_rendition_episode ON media_rendition (episode_id);
 COMMENT ON TABLE media_rendition IS '多码率产物；播放票据按此生成 master playlist';
 
+CREATE TABLE IF NOT EXISTS media_thumbnail (
+  id             BIGINT PRIMARY KEY,
+  episode_id     BIGINT       NOT NULL,
+  drama_id       BIGINT       NOT NULL DEFAULT 0,
+  vtt_object_key VARCHAR(512) NOT NULL DEFAULT '',
+  sprite_prefix  VARCHAR(512) NOT NULL DEFAULT '',
+  interval_sec   INT          NOT NULL DEFAULT 1,
+  columns        INT          NOT NULL DEFAULT 10,
+  rows           INT          NOT NULL DEFAULT 1,
+  thumb_width    INT          NOT NULL DEFAULT 160,
+  thumb_height   INT          NOT NULL DEFAULT 0,
+  frame_count    INT          NOT NULL DEFAULT 0,
+  duration_sec   INT          NOT NULL DEFAULT 0,
+  size_bytes     BIGINT       NOT NULL DEFAULT 0,
+  status         VARCHAR(16)  NOT NULL DEFAULT 'FAILED',
+  error_msg      VARCHAR(500) NOT NULL DEFAULT '',
+  created_at     TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  updated_at     TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  deleted        SMALLINT     NOT NULL DEFAULT 0
+);
+CREATE UNIQUE INDEX IF NOT EXISTS uk_media_thumbnail_episode
+  ON media_thumbnail (episode_id);
+CREATE INDEX IF NOT EXISTS idx_media_thumbnail_drama
+  ON media_thumbnail (drama_id);
+COMMENT ON TABLE media_thumbnail IS '单集缩略图雪碧图与 VTT 时间轴';
+
 -- ============================================================
 -- 八、运营补充（PRD 08 平台运营后台 / 10 上线）
 -- ============================================================
@@ -858,7 +884,7 @@ BEGIN
     'wallet', 'product', 'orders', 'store_receipt', 'entitlement', 'refund_record',
     'reconcile_task', 'creator', 'creator_document', 'content_submission',
     'creator_stat_daily', 'creator_settlement',
-    'transcode_task', 'media_rendition',
+    'transcode_task', 'media_rendition', 'media_thumbnail',
     'ops_notice', 'ops_daily_stat'
   ]
   LOOP