fix(ass): Fontsize乘1.35补偿系数对齐CSS预览字号 (#1516)

问题：前端在本地构建clips（每素材1个片段，start_time=0），
未调用后端/clips/from-assets，导致模板要求4个片段但只选3个素材时
只生成3个片段，后端随机start_time和多片段逻辑从未被触发。

修复：
- createClipsFromAssets增加requiredClipsCount可选参数
- useStep2Materials改为先清空旧片段再调用from-assets，
  required_clips_count=模板segments数
- 删除废弃的buildClipsFromAssets工具函数

apps/api/app/api/routes/templates_editor/clips.py

@@ -25,6 +25,7 @@ from app.services.edit_template_service import EditTemplateService
 from fastapi import APIRouter, Depends, HTTPException, Query, status
 
 from packages.adapters.sqlalchemy_impl.asset_repository import SQLAlchemyAssetRepository
+from packages.domain.plan_generator_utils import _calc_random_start_time
 
 from .dependencies import get_draft_plan_id, get_editor_services
 from .schemas import (
@@ -45,6 +46,9 @@ from .schemas import (
 logger = logging.getLogger(__name__)
 router = APIRouter(tags=["Template Editor"])
 
+# 编辑器默认片段时长（秒）
+_DEFAULT_EDITOR_CLIP_DURATION = 5.0
+
 
 def _clip_to_response(clip, asset_url: str | None = None) -> EditorClipResponse:
     """统一构造片段响应 — 与 edit_plan_clips 表字段完全对齐"""
@@ -155,10 +159,7 @@ def list_draft_clips(
     url_map = _build_asset_url_map(asset_ids, asset_repo)
 
     return EditorClipListResponse(
-        items=[
-            _clip_to_response(c, asset_url=url_map.get(getattr(c, "asset_id", "") or ""))
-            for c in clips
-        ],
+        items=[_clip_to_response(c, asset_url=url_map.get(getattr(c, "asset_id", "") or "")) for c in clips],
         total=total,
     )
 
@@ -272,9 +273,7 @@ def split_draft_clip(
     try:
         result = plan_svc.split_clip(clip_id, body.split_time)
     except ValueError as exc:
-        raise HTTPException(
-            status_code=status.HTTP_400_BAD_REQUEST, detail=str(exc)
-        ) from exc
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(exc)) from exc
     left = result["left_clip"]
     right = result["right_clip"]
     asset_ids = [getattr(left, "asset_id", "") or "", getattr(right, "asset_id", "") or ""]
@@ -304,9 +303,7 @@ def merge_draft_clips(
     try:
         merged = plan_svc.merge_clips(body.clip_ids)
     except ValueError as exc:
-        raise HTTPException(
-            status_code=status.HTTP_400_BAD_REQUEST, detail=str(exc)
-        ) from exc
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(exc)) from exc
     asset_id = getattr(merged, "asset_id", "") or ""
     url_map = _build_asset_url_map([asset_id], asset_repo) if asset_id else {}
     return {
@@ -360,28 +357,90 @@ def create_clips_from_assets_editor(
     body: ClipsFromAssetsRequest,
     plan_id: str = Depends(get_draft_plan_id),
     services: tuple[EditTemplateService, EditPlanService] = Depends(get_editor_services),
+    asset_repo: SQLAlchemyAssetRepository = Depends(get_asset_repository),
     current_user: AuthenticatedUser = Depends(get_current_user),
 ) -> ClipsFromAssetsResponse:
-    """从素材批量创建片段"""
+    """从素材批量创建片段（支持同一素材切多个片段 + 随机起始时间 + 去重）.
+
+    逻辑：
+    1. 模板要求 N 个片段，必须创建 N 个（不管素材有几个）
+    2. 素材数量 < 片段数量时，同一素材轮询切多个片段
+    3. 每个片段从素材中随机选取不重复时间段
+    4. 素材时长不足 5s 时缩短 clip duration
+    5. 新片段追加到时间线末尾（order 在现有最大值基础上递增）
+    """
     _, plan_svc = services
+
+    required_count = body.required_clips_count if body.required_clips_count is not None else len(body.asset_ids)
+
+    # 去重后批量获取素材实际时长，避免重复查询
+    unique_asset_ids = list(dict.fromkeys(body.asset_ids))
+    asset_durations: dict[str, float] = {}
+    for asset_id in unique_asset_ids:
+        asset = asset_repo.get(asset_id)
+        if asset and hasattr(asset, "duration"):
+            asset_durations[asset_id] = float(asset.duration or 0.0)
+
+    # 计算追加起始 order：当前 plan 已有片段的最大 order + 1
+    # list_clips 返回 List[EditPlanClip]
+    existing_clips_list = plan_svc.list_clips(plan_id)
+    next_order = max((c.order for c in existing_clips_list), default=-1) + 1
+
+    used_segments: dict[str, list[tuple[float, float]]] = {}
     clips = []
-    for i, asset_id in enumerate(body.asset_ids):
+
+    for i in range(required_count):
+        # 轮询分配素材：素材不够时同一素材切多个片段
+        asset_id = body.asset_ids[i % len(body.asset_ids)]
+
+        # 素材时长不足时缩短 clip duration
+        asset_total = asset_durations.get(asset_id, 0.0)
+        if asset_total > 0:
+            clip_duration = min(_DEFAULT_EDITOR_CLIP_DURATION, asset_total)
+        else:
+            clip_duration = _DEFAULT_EDITOR_CLIP_DURATION
+
+        # 计算随机 start_time，避开已使用的时间段
+        start_time = _calc_random_start_time(asset_id, clip_duration, asset_durations, used_segments)
+        if start_time is None:
+            # 素材时长信息缺失，无法计算随机起始时间
+            raise HTTPException(
+                status_code=status.HTTP_400_BAD_REQUEST,
+                detail=f"素材 {asset_id} 时长信息缺失，无法创建片段",
+            )
+
+        # 记录已使用时间段（用于去重）
+        used_segments.setdefault(asset_id, []).append((start_time, start_time + clip_duration))
+
         try:
             clip = plan_svc.create_clip(
                 plan_id,
-                clip_type="main",
-                order=body.start_order + i if hasattr(body, "start_order") else i,
-                duration=5.0,
+                clip_type=body.clip_type or "main",
+                order=next_order + i,
+                duration=clip_duration,
+                start_time=start_time,
                 asset_id=asset_id,
             )
             clips.append(clip)
-        except ValueError:
-            pass
+        except ValueError as exc:
+            logger.error(
+                "创建片段失败: plan_id=%s asset_id=%s order=%d error=%s",
+                plan_id,
+                asset_id,
+                next_order + i,
+                exc,
+                exc_info=True,
+            )
+            raise HTTPException(
+                status_code=status.HTTP_400_BAD_REQUEST,
+                detail=f"创建片段失败: {exc}",
+            ) from exc
 
     logger.info(
-        "模板编辑器从素材创建片段: template_id=%s plan_id=%s count=%d by user=%s",
+        "模板编辑器从素材创建片段: template_id=%s plan_id=%s required=%d actual=%d by user=%s",
         template_id,
         plan_id,
+        required_count,
         len(clips),
         current_user.user.id,
     )

apps/api/app/api/routes/templates_editor/schemas.py

@@ -167,6 +167,7 @@ class ClipsFromAssetsRequest(BaseModel):
 
     asset_ids: List[str] = Field(..., min_length=1, max_length=200, description="素材 ID 列表，按顺序追加到时间线末尾")
     clip_type: str = Field(default="main", description="片段类型，默认 main")
+    required_clips_count: Optional[int] = Field(default=None, ge=1, le=200, description="要求创建的片段数量；不传则等于素材数量")
 
 
 class ClipsFromAssetsResponse(BaseModel):

apps/api/app/services/plan_generator_service.py

@@ -118,9 +118,9 @@ class PlanGeneratorService:
 
         # 4. 按 editing_mode 分配素材
         if asset_ids:
-            # 如果是随机预览模式，获取素材时长信息
+            # 获取素材时长信息，用于随机起始时间
             asset_durations = None
-            if random_preview and self._asset_repo:
+            if self._asset_repo:
                 asset_durations = self._fetch_asset_durations(asset_ids)
             self._distribute_assets(
                 clips,

apps/web/src/api/template-editor/clips.ts

@@ -90,10 +90,18 @@ export async function createClipsFromAssets(
   templateId: string,
   assetIds: string[],
   clipType = "main",
+  requiredClipsCount?: number,
 ): Promise<ClipsFromAssetsResponse> {
+  const body: Record<string, unknown> = {
+    asset_ids: assetIds,
+    clip_type: clipType,
+  }
+  if (requiredClipsCount !== undefined) {
+    body.required_clips_count = requiredClipsCount
+  }
   const response = await apiClient.post<ClipsFromAssetsResponse>(
     `/templates/${templateId}/editor/clips/from-assets`,
-    { asset_ids: assetIds, clip_type: clipType },
+    body,
   )
   return response.data
 }

apps/web/src/api/template-editor/types.ts

@@ -114,8 +114,6 @@ export interface EditPlanConfig {
   auto_subtitles?: boolean
   /** 是否启用 BGM */
   bgm?: boolean
-  /** 生成数量 */
-  generate_count?: number
   /** 素材模式 */
   material_mode?: string
   /** 前端标题设置（Step4 自动保存，与 title_config 字段分离，不影响后端渲染） */

apps/web/src/pages/generate/GeneratePage.tsx

@@ -4,12 +4,12 @@
  * 左右布局：左侧 generate-form + 右侧 generate-preview
  *
  * 架构：
- * - Step4+ 右侧预览面板使用 FrontendPreviewPlayer 实时播放素材片段
- * - 标题样式编辑时 CSS 层实时叠加预览，所见即所得
+ * - 步骤 4-6 右侧显示 FrontendPreviewPlayer 实时预览
+ * - 步骤 7 右侧内联播放生成的最终视频
  * - 点"确认生成"时调用 createGenerationTask 创建一次服务器渲染任务
  */
 import React, { useMemo, useState, useEffect, useRef } from "react"
-import { Modal, message } from "antd"
+import { message } from "antd"
 import { useNavigate } from "react-router-dom"
 import type { VoiceClone } from "@/api/voice-clone"
 import { useQuery } from "@tanstack/react-query"
@@ -20,9 +20,8 @@ import {
   calculateTotalVideoDuration,
   estimateTotalVideoDuration,
 } from "./utils/calculateTotalVideoDuration"
-import GenerateStepsBar from "./components/GenerateStepsBar"
-import GenerateResultPanel from "./components/GenerateResultPanel"
 import FrontendPreviewPlayer from "./components/FrontendPreviewPlayer"
+import GenerateStepsBar from "./components/GenerateStepsBar"
 import GenerateStepContent from "./components/GenerateStepContent"
 import GenerateStepActions from "./components/GenerateStepActions"
 import { useGenerateFormState } from "./hooks/useGenerateFormState"
@@ -64,8 +63,6 @@ const GeneratePage: React.FC = () => {
     presetVoices,
     cloneModalOpen,
     setCloneModalOpen,
-    generateCount,
-    setGenerateCount,
     videoRatio,
     duration,
     style,
@@ -73,10 +70,6 @@ const GeneratePage: React.FC = () => {
     bgm,
     editPlanId,
     sourceEditPlanId,
-    previewVideo,
-    setPreviewVideo,
-    previewModalOpen,
-    setPreviewModalOpen,
     previewTaskId,
     setPreviewTaskId,
     storedSourceEditPlanId,
@@ -89,7 +82,7 @@ const GeneratePage: React.FC = () => {
     onTitleSettingsChange: setTitleSettings,
   })
 
-  /* ── 配音预览音频（TTS 试听）── */
+  /* ── 配音素材库（TTS 试听）── */
   const { data: voiceMaterials = [] } = useQuery({
     queryKey: ["assets", "voice"],
     queryFn: () => getAssetsByKind("voice", { limit: 50 }),
@@ -99,30 +92,24 @@ const GeneratePage: React.FC = () => {
   const ttsAbortRef = useRef<AbortController | null>(null)
 
   useEffect(() => {
-    // 如果 selectedVoice 是已上传的配音素材，直接用 file_url
     const voiceAsset = voiceMaterials.find((m) => m.id === selectedVoice)
     if (voiceAsset?.file_url) {
       setPreviewVoiceAudioUrl(voiceAsset.file_url)
       return
     }
 
-    // 没有选中的 voice 或标题，跳过
     const voiceId = selectedClonedVoice || selectedVoice
     if (!voiceId || !titleSettings.title) {
       setPreviewVoiceAudioUrl(null)
       return
     }
 
-    // 预设音色 / 克隆音色 → 调 TTS 合成
     ttsAbortRef.current?.abort()
     const controller = new AbortController()
     ttsAbortRef.current = controller
     let cancelled = false
 
-    previewTts({
-      text: titleSettings.title,
-      voice_id: voiceId,
-    })
+    previewTts({ text: titleSettings.title, voice_id: voiceId })
       .then((res) => {
         if (!cancelled && res.audio_url) {
           setPreviewVoiceAudioUrl(res.audio_url)
@@ -221,7 +208,6 @@ const GeneratePage: React.FC = () => {
     duration,
     autoSubtitles,
     bgm,
-    generateCount,
     sourceEditPlanId: storedSourceEditPlanId || sourceEditPlanId,
     previewTaskId,
     bgmConfig,
@@ -241,7 +227,7 @@ const GeneratePage: React.FC = () => {
 
       <GenerateStepsBar currentStep={currentStep} onStepClick={setCurrentStep} />
 
-      <div className="xx-generate-layout">
+      <div className={`xx-generate-layout${currentStep < 4 ? " full-width" : ""}`}>
         {/* ════ 左侧：表单区 ════ */}
         <div className="xx-generate-form">
           <GenerateStepContent
@@ -286,8 +272,6 @@ const GeneratePage: React.FC = () => {
             hasProcessing={hasProcessing}
             cloneModalOpen={cloneModalOpen}
             onCloneModalOpenChange={setCloneModalOpen}
-            generateCount={generateCount}
-            onGenerateCountChange={setGenerateCount}
             generating={generating}
             generated={generated}
             generateError={generateError}
@@ -309,9 +293,9 @@ const GeneratePage: React.FC = () => {
           />
         </div>
 
-        {/* ════ 右侧：预览 + 结果 ════ */}
+        {/* ════ 右侧：步骤 4-6 实时预览，步骤 7 最终视频 ════ */}
         <div className="xx-generate-right-col">
-          {currentStep >= 4 && !!currentTemplate && (
+          {currentStep >= 4 && currentStep <= 6 && !!currentTemplate && (
             <FrontendPreviewPlayer
               assets={previewAssets}
               template={currentTemplate}
@@ -331,48 +315,34 @@ const GeneratePage: React.FC = () => {
               }}
             />
           )}
-          {currentStep >= 6 && (
-            <GenerateResultPanel
-              generated={generated}
-              generating={generating}
-              progress={progress}
-              generateError={generateError}
-              generatedVideos={generatedVideos}
-              onVideoPreview={(video) => {
-                setPreviewVideo(video)
-                setPreviewModalOpen(true)
-              }}
-              onDownload={handleDownload}
-              onShare={handleShare}
-              onGoToLibrary={() => navigate("/app/products")}
-            />
+          {currentStep === 7 && generated && generatedVideos.length > 0 && (
+            <div className="xx-inline-video-player">
+              <video
+                src={generatedVideos[0].download_url || generatedVideos[0].file_url}
+                controls
+                autoPlay
+                style={{ width: "100%", maxHeight: "70vh", objectFit: "contain", borderRadius: 12 }}
+                poster={generatedVideos[0].thumbnail_url || undefined}
+              />
+              <div style={{ display: "flex", gap: 8, marginTop: 12, justifyContent: "center" }}>
+                <button className="xx-btn xx-btn-ghost xx-btn-sm" onClick={handleDownload}>
+                  ⬇️ 下载
+                </button>
+                <button className="xx-btn xx-btn-ghost xx-btn-sm" onClick={handleShare}>
+                  🔗 分享
+                </button>
+                <button
+                  className="xx-btn xx-btn-ghost xx-btn-sm"
+                  onClick={() => navigate("/app/products")}
+                >
+                  📁 前往成片库
+                </button>
+              </div>
+            </div>
           )}
         </div>
       </div>
 
-      {/* 视频预览弹窗 */}
-      <Modal
-        className="xx-preview-modal"
-        open={previewModalOpen}
-        onCancel={() => setPreviewModalOpen(false)}
-        footer={null}
-        width="80vw"
-        centered
-        destroyOnClose
-      >
-        {previewVideo && (
-          <div className="xx-preview-modal-content">
-            <video
-              src={previewVideo.download_url || previewVideo.file_url}
-              controls
-              autoPlay
-              style={{ width: "100%", maxHeight: "70vh", objectFit: "contain" }}
-              poster={previewVideo.thumbnail_url || undefined}
-            />
-          </div>
-        )}
-      </Modal>
-
       {/* 音色克隆弹窗 */}
       <CloneModal
         open={cloneModalOpen}

apps/web/src/pages/generate/components/FrontendPreviewPlayer.tsx

@@ -76,12 +76,59 @@ function buildPlaybackSegments(
 const FrontendPreviewPlayer: React.FC<FrontendPreviewPlayerProps> = ({
   assets,
   template,
-  videoRatio: _videoRatio,
+  videoRatio,
   ready,
   voiceAudioUrl,
   titleSettings,
 }) => {
   const segments = useMemo(() => buildPlaybackSegments(assets, template), [assets, template])
+
+  // ── ASS 坐标系参数（与后端 ass_subtitle_builder.py 一致） ──
+  const TITLE_MARGIN_TOP = 120
+  const TITLE_MARGIN_BOTTOM = 60
+  const TITLE_MARGIN_SIDE = 40
+  const playRes = (() => {
+    switch (videoRatio) {
+      case "16:9":
+        return { width: 1920, height: 1080 }
+      case "1:1":
+        return { width: 1080, height: 1080 }
+      case "9:16":
+      default:
+        return { width: 1080, height: 1920 }
+    }
+  })()
+  const playerContainerRef = useRef<HTMLDivElement>(null)
+  const [containerHeight, setContainerHeight] = useState(0)
+  useEffect(() => {
+    const el = playerContainerRef.current
+    if (!el) return
+    const ro = new ResizeObserver((entries) => {
+      for (const entry of entries) {
+        const h = entry.contentRect.height
+        if (h > 0) setContainerHeight(h)
+      }
+    })
+    ro.observe(el)
+    const rect = el.getBoundingClientRect()
+    if (rect.height > 0) setContainerHeight(rect.height)
+    return () => ro.disconnect()
+  }, [])
+
+  // 标题字号按容器高度与 PlayResY 的比例缩放
+  const titleFontSizePx =
+    containerHeight > 0
+      ? ((titleSettings?.size ?? 36) / playRes.height) * containerHeight
+      : (titleSettings?.size ?? 36)
+  const titleSidePct = (TITLE_MARGIN_SIDE / playRes.width) * 100
+  const titleTopPct = (TITLE_MARGIN_TOP / playRes.height) * 100
+  const titleBottomPct = (TITLE_MARGIN_BOTTOM / playRes.height) * 100
+  // 描边/阴影也要按缩放比例放大
+  const titleScale = containerHeight > 0 ? containerHeight / playRes.height : 1
+  const titleStrokeWidth = Math.max(1, 2 * titleScale)
+  const titleShadowBlur = 4 * titleScale
+  const titleShadowOffset = 2 * titleScale
+
   // 默认走原生 video 播放（浏览器硬件解码，独立线程，不阻塞 UI）
   // WebCodecs 仅在明确需要时启用（保留代码作为兜底）
   const useWebCodecs = false
@@ -374,6 +421,7 @@ const FrontendPreviewPlayer: React.FC<FrontendPreviewPlayerProps> = ({
 
   return (
     <div
+      ref={playerContainerRef}
       style={{
         position: "relative",
         width: "100%",
@@ -434,48 +482,55 @@ const FrontendPreviewPlayer: React.FC<FrontendPreviewPlayerProps> = ({
           />
         ))}
 
-      {/* 标题CSS叠加层 — video fallback 路径也要渲染 */}
+      {/* 标题CSS叠加层 — 与后端 ASS 烧录坐标系 1:1 对齐 */}
       {titleSettings?.title && (
         <div
           style={{
             position: "absolute",
-            left: 0,
-            right: 0,
+            inset: 0,
             zIndex: 5,
-            display: "flex",
-            justifyContent: "center",
             pointerEvents: "none",
-            ...(titleSettings.position === "top"
-              ? { top: "10%" }
-              : titleSettings.position === "center"
-                ? { top: "50%", transform: "translateY(-50%)" }
-                : { bottom: "15%" }),
+            overflow: "hidden",
           }}
         >
-          <span
+          <div
             style={{
-              fontSize: titleSettings.size,
-              fontFamily: titleSettings.font || "思源黑体",
-              color: titleSettings.color || "#ffffff",
-              fontWeight: titleSettings.bold ? 700 : 400,
-              fontStyle: titleSettings.italic ? "italic" : "normal",
-              textShadow: [
-                titleSettings.shadow ? "0 2px 8px rgba(0,0,0,0.7)" : undefined,
-                titleSettings.stroke
-                  ? "1px 1px 0 rgba(0,0,0,0.5), -1px -1px 0 rgba(0,0,0,0.5), 1px -1px 0 rgba(0,0,0,0.5), -1px 1px 0 rgba(0,0,0,0.5)"
-                  : undefined,
-                "0 1px 3px rgba(0,0,0,0.4)",
-              ]
-                .filter(Boolean)
-                .join(", "),
-              maxWidth: "90%",
+              position: "absolute",
+              left: `${titleSidePct}%`,
+              right: `${titleSidePct}%`,
               textAlign: "center",
-              lineHeight: 1.3,
-              wordBreak: "break-word",
+              ...(titleSettings.position === "top"
+                ? { top: `${titleTopPct}%` }
+                : titleSettings.position === "center"
+                  ? { top: "50%", transform: "translateY(-50%)" }
+                  : { bottom: `${titleBottomPct}%` }),
             }}
           >
-            {titleSettings.title}
-          </span>
+            <span
+              style={{
+                fontSize: `${titleFontSizePx}px`,
+                fontFamily: titleSettings.font || "思源黑体",
+                color: titleSettings.color || "#ffffff",
+                fontWeight: titleSettings.bold ? 700 : 400,
+                fontStyle: titleSettings.italic ? "italic" : "normal",
+                lineHeight: 1.05,
+                wordBreak: "break-word",
+                WebkitTextStroke: titleSettings.stroke
+                  ? `${titleStrokeWidth}px #000000`
+                  : undefined,
+                textShadow: titleSettings.shadow
+                  ? `${titleShadowOffset}px ${titleShadowOffset}px ${titleShadowBlur}px rgba(0,0,0,0.8)`
+                  : undefined,
+              }}
+            >
+              {titleSettings.title.split(/[/／]/).map((part, i) => (
+                <span key={i}>
+                  {i > 0 && <br />}
+                  {part}
+                </span>
+              ))}
+            </span>
+          </div>
         </div>
       )}
 

apps/web/src/pages/generate/components/GenerateStepContent.tsx

@@ -65,8 +65,6 @@ export interface GenerateStepContentProps {
   cloneModalOpen: boolean
   onCloneModalOpenChange: (open: boolean) => void
   /* 生成 */
-  generateCount: number
-  onGenerateCountChange: (n: number) => void
   generating: boolean
   generated: boolean
   generateError: string | null
@@ -119,8 +117,6 @@ export const GenerateStepContent: React.FC<GenerateStepContentProps> = (props) =
     voiceMode,
     selectedClonedVoice,
     clonedVoices,
-    generateCount,
-    onGenerateCountChange,
     generating,
     generated,
     generateError,
@@ -226,8 +222,6 @@ export const GenerateStepContent: React.FC<GenerateStepContentProps> = (props) =
           presetVoices={presetVoices}
           clonedVoices={clonedVoices}
           coverSettings={coverSettings}
-          generateCount={generateCount}
-          onGenerateCountChange={onGenerateCountChange}
           generating={generating}
           generated={generated}
           generateError={generateError}

apps/web/src/pages/generate/components/PreviewVideoPanel.tsx

@@ -40,17 +40,33 @@ interface PreviewVideoPanelProps {
 }
 
 /* ── ASS 坐标系参数（与后端 ass_subtitle_builder.py 一致） ── */
-const ASS_VIDEO_HEIGHT = 720
-const ASS_TITLE_MARGIN_TOP = 60
-const ASS_TITLE_MARGIN_BOTTOM = 60
-const ASS_TITLE_MARGIN_SIDE = 40
+const TITLE_MARGIN_TOP = 120
+const TITLE_MARGIN_BOTTOM = 60
+const TITLE_MARGIN_SIDE = 40
 
-function getPositionStyle(position: string): React.CSSProperties {
-  const sidePercent = (ASS_TITLE_MARGIN_SIDE / 1280) * 100
+/** 根据视频比例返回后端实际渲染分辨率（PlayResX × PlayResY） */
+function getResolution(ratio: string): { width: number; height: number } {
+  switch (ratio) {
+    case "16:9":
+      return { width: 1920, height: 1080 }
+    case "1:1":
+      return { width: 1080, height: 1080 }
+    case "9:16":
+    default:
+      return { width: 1080, height: 1920 }
+  }
+}
+
+function getPositionStyle(
+  position: string,
+  playResX: number,
+  playResY: number,
+): React.CSSProperties {
+  const sidePercent = (TITLE_MARGIN_SIDE / playResX) * 100
   switch (position) {
     case "bottom":
       return {
-        bottom: `${(ASS_TITLE_MARGIN_BOTTOM / ASS_VIDEO_HEIGHT) * 100}%`,
+        bottom: `${(TITLE_MARGIN_BOTTOM / playResY) * 100}%`,
         left: `${sidePercent}%`,
         right: `${sidePercent}%`,
         textAlign: "center",
@@ -66,7 +82,7 @@ function getPositionStyle(position: string): React.CSSProperties {
     case "top":
     default:
       return {
-        top: `${(ASS_TITLE_MARGIN_TOP / ASS_VIDEO_HEIGHT) * 100}%`,
+        top: `${(TITLE_MARGIN_TOP / playResY) * 100}%`,
         left: `${sidePercent}%`,
         right: `${sidePercent}%`,
         textAlign: "center",
@@ -74,11 +90,16 @@ function getPositionStyle(position: string): React.CSSProperties {
   }
 }
 
-function buildTitleStyle(settings: TitleSettings, containerHeight: number): React.CSSProperties {
+function buildTitleStyle(
+  settings: TitleSettings,
+  containerHeight: number,
+  playResY: number,
+): React.CSSProperties {
+  // 字号按容器高度与 PlayResY 的比例缩放，不设上限（与后端一致）
   const fontSizePx =
     containerHeight > 0
-      ? (Math.min(settings.size, 96) / ASS_VIDEO_HEIGHT) * containerHeight
-      : (Math.min(settings.size, 96) / ASS_VIDEO_HEIGHT) * 400
+      ? (settings.size / playResY) * containerHeight
+      : (settings.size / playResY) * 400
 
   const base: React.CSSProperties = {
     fontFamily: getFontFamily(settings.font),
@@ -86,12 +107,10 @@ function buildTitleStyle(settings: TitleSettings, containerHeight: number): Reac
     color: settings.color || "#ffffff",
     fontWeight: settings.bold ? 700 : 400,
     fontStyle: settings.italic ? "italic" : "normal",
-    lineHeight: 1.3,
+    lineHeight: 1.05,
     wordBreak: "break-word",
     pointerEvents: "none",
     userSelect: "none",
-    paddingLeft: `${(ASS_TITLE_MARGIN_SIDE / 1280) * 100}%`,
-    paddingRight: `${(ASS_TITLE_MARGIN_SIDE / 1280) * 100}%`,
   }
   if (settings.stroke) base.WebkitTextStroke = "1px #000000"
   if (settings.shadow) base.textShadow = "2px 2px 4px rgba(0,0,0,0.8)"
@@ -99,7 +118,10 @@ function buildTitleStyle(settings: TitleSettings, containerHeight: number): Reac
 }
 
 /** CSS 标题实时预览覆盖层 */
-const TitleOverlay: React.FC<{ titleSettings: TitleSettings }> = ({ titleSettings }) => {
+const TitleOverlay: React.FC<{ titleSettings: TitleSettings; videoRatio: string }> = ({
+  titleSettings,
+  videoRatio,
+}) => {
   const containerRef = useRef<HTMLDivElement>(null)
   const [containerHeight, setContainerHeight] = useState(400)
 
@@ -118,12 +140,15 @@ const TitleOverlay: React.FC<{ titleSettings: TitleSettings }> = ({ titleSetting
     return () => ro.disconnect()
   }, [])
 
+  const { width: playResX, height: playResY } = getResolution(videoRatio)
+
   const positionStyle = useMemo(
-    () => getPositionStyle(titleSettings.position),
-    [titleSettings.position],
+    () => getPositionStyle(titleSettings.position, playResX, playResY),
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+    [titleSettings.position, playResX, playResY],
   )
   const titleStyle = useMemo(
-    () => buildTitleStyle(titleSettings, containerHeight),
+    () => buildTitleStyle(titleSettings, containerHeight, playResY),
     // eslint-disable-next-line react-hooks/exhaustive-deps
     [
       containerHeight,
@@ -134,6 +159,7 @@ const TitleOverlay: React.FC<{ titleSettings: TitleSettings }> = ({ titleSetting
       titleSettings.italic,
       titleSettings.stroke,
       titleSettings.shadow,
+      playResY,
     ],
   )
 
@@ -266,7 +292,9 @@ export const PreviewVideoPanel: React.FC<PreviewVideoPanelProps> = ({
         )}
 
         {/* 标题样式实时预览层（仅在有视频时叠加） */}
-        {isReady && titleSettings && <TitleOverlay titleSettings={titleSettings} />}
+        {isReady && titleSettings && (
+          <TitleOverlay titleSettings={titleSettings} videoRatio={videoRatio} />
+        )}
 
         {/* stale 遮罩：配置变更提示 */}
         {isStale && (

apps/web/src/pages/generate/components/Step7ConfirmGenerate.tsx

@@ -24,8 +24,6 @@ interface Step7ConfirmGenerateProps {
   presetVoices: PresetVoiceItem[]
   clonedVoices: VoiceClone[]
   coverSettings: CoverConfig
-  generateCount: number
-  onGenerateCountChange: (count: number) => void
   generating: boolean
   generated: boolean
   generateError: string | null
@@ -42,9 +40,6 @@ const Step7ConfirmGenerate: React.FC<Step7ConfirmGenerateProps> = (props) => {
     title,
     voiceName,
     coverSummary,
-    generateCount,
-    handleDecrement,
-    handleIncrement,
     generating,
     generated,
     generateError,
@@ -65,10 +60,6 @@ const Step7ConfirmGenerate: React.FC<Step7ConfirmGenerateProps> = (props) => {
         title={title}
         voiceName={voiceName}
         coverSummary={coverSummary}
-        generateCount={generateCount}
-        generating={generating}
-        onDecrement={handleDecrement}
-        onIncrement={handleIncrement}
       />
       <GenerationStatus
         generating={generating}

apps/web/src/pages/generate/components/step7-confirm/SummaryCard.tsx

@@ -1,5 +1,4 @@
 import React from "react"
-import { MinusOutlined, PlusOutlined } from "@ant-design/icons"
 
 interface SummaryCardProps {
   templateName: string
@@ -7,10 +6,6 @@ interface SummaryCardProps {
   title: string
   voiceName: string
   coverSummary: string
-  generateCount: number
-  generating: boolean
-  onDecrement: () => void
-  onIncrement: () => void
 }
 
 const SummaryCard: React.FC<SummaryCardProps> = ({
@@ -19,10 +14,6 @@ const SummaryCard: React.FC<SummaryCardProps> = ({
   title,
   voiceName,
   coverSummary,
-  generateCount,
-  generating,
-  onDecrement,
-  onIncrement,
 }) => {
   return (
     <div className="xx-summary-card">
@@ -46,29 +37,6 @@ const SummaryCard: React.FC<SummaryCardProps> = ({
         <span className="xx-summary-label">封面</span>
         <span className="xx-summary-value">{coverSummary}</span>
       </div>
-      <div className="xx-summary-row">
-        <span className="xx-summary-label">生成数量</span>
-        <span className="xx-summary-value">
-          <div className="xx-count-stepper">
-            <button
-              className="xx-count-stepper-btn"
-              disabled={generateCount <= 1 || generating}
-              onClick={onDecrement}
-            >
-              <MinusOutlined />
-            </button>
-            <span className="xx-count-stepper-value">{generateCount}</span>
-            <button
-              className="xx-count-stepper-btn"
-              disabled={generateCount >= 10 || generating}
-              onClick={onIncrement}
-            >
-              <PlusOutlined />
-            </button>
-            <span className="xx-count-stepper-hint">条视频</span>
-          </div>
-        </span>
-      </div>
     </div>
   )
 }

apps/web/src/pages/generate/components/title/TitleStylePanel.tsx

@@ -94,7 +94,7 @@ const TitleStylePanel: React.FC<TitleStylePanelProps> = ({
           className="xx-slider"
           type="range"
           min={12}
-          max={48}
+          max={128}
           value={settings.size}
           onChange={(e) => onUpdateSize(Number(e.target.value))}
         />

apps/web/src/pages/generate/generate.css

@@ -113,6 +113,14 @@
   align-items: start;
 }
 
+.xx-generate-layout.full-width {
+  grid-template-columns: 1fr;
+}
+
+.xx-generate-layout.full-width .xx-generate-right-col {
+  display: none;
+}
+
 /* ============================================================
    左侧表单区 generate-form
    ============================================================ */
@@ -1280,53 +1288,6 @@
   }
 }
 
-/* ── 生成数量步进器 ── */
-.xx-count-stepper {
-  display: inline-flex;
-  align-items: center;
-  gap: 6px;
-}
-
-.xx-count-stepper-btn {
-  display: inline-flex;
-  align-items: center;
-  justify-content: center;
-  width: 28px;
-  height: 28px;
-  border: 1px solid var(--border-primary, #e2e8f0);
-  border-radius: 8px;
-  background: var(--bg-surface, #fff);
-  color: var(--text-secondary, #64748b);
-  font-size: 13px;
-  cursor: pointer;
-  transition: all 0.15s;
-}
-
-.xx-count-stepper-btn:hover:not(:disabled) {
-  border-color: var(--primary-400, #818cf8);
-  color: var(--primary-600, #4f46e5);
-  background: var(--primary-50, #eef2ff);
-}
-
-.xx-count-stepper-btn:disabled {
-  opacity: 0.35;
-  cursor: not-allowed;
-}
-
-.xx-count-stepper-value {
-  min-width: 24px;
-  text-align: center;
-  font-size: 16px;
-  font-weight: 600;
-  color: var(--text-primary, #1e293b);
-}
-
-.xx-count-stepper-hint {
-  font-size: 12px;
-  color: var(--text-tertiary, #94a3b8);
-  margin-left: 2px;
-}
-
 /* ── 素材选择模式切换 Tab ── */
 .xx-material-mode-tabs {
   display: flex;
@@ -2529,6 +2490,21 @@
   gap: 16px;
 }
 
+/* ── 内联视频播放器（右侧） ── */
+.xx-inline-video-player {
+  width: 100%;
+  max-width: 320px;
+  background: var(--bg-surface, #fff);
+  border: 1px solid var(--border-primary, #e2e8f0);
+  border-radius: 16px;
+  padding: 16px;
+  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
+}
+
+.xx-inline-video-player video {
+  background: #000;
+}
+
 .xx-preview-header {
   display: flex;
   align-items: center;

apps/web/src/pages/generate/hooks/generate-video/types.ts

@@ -18,7 +18,6 @@ export interface UseGenerateVideoProps {
   duration: number
   autoSubtitles: boolean
   bgm: boolean
-  generateCount: number
   /** 当前草稿 ID（URL 参数 edit_plan_id，用于后端回写任务关联） */
   sourceEditPlanId?: string | null
   /** 预览任务 ID（由 useStep6Cover 创建后写入，供 confirmGeneration 复用预览产物） */

apps/web/src/pages/generate/hooks/useGenerateFormState/index.ts

@@ -4,7 +4,6 @@
  */
 import { useState } from "react"
 import { useSearchParams } from "react-router-dom"
-import type { GeneratedVideo } from "@/api/template-editor"
 import type { EditingTemplate } from "@/api/editing-planner"
 import type { CoverConfig } from "../../types/cover"
 import type { PresetVoiceItem } from "@/api/voices"
@@ -68,10 +67,6 @@ export interface GenerateFormState {
   cloneModalOpen: boolean
   setCloneModalOpen: (open: boolean) => void
 
-  /* 生成数量 */
-  generateCount: number
-  setGenerateCount: (n: number) => void
-
   /* 高级设置 */
   videoRatio: string
   duration: number
@@ -91,12 +86,6 @@ export interface GenerateFormState {
    */
   sourceEditPlanId: string | null
 
-  /* 预览弹窗 */
-  previewVideo: GeneratedVideo | null
-  setPreviewVideo: (v: GeneratedVideo | null) => void
-  previewModalOpen: boolean
-  setPreviewModalOpen: (open: boolean) => void
-
   /** 预览任务 ID（由 useStep6Cover 创建后写入，供 useGenerateVideo 复用） */
   previewTaskId: string | null
   setPreviewTaskId: (id: string | null) => void
@@ -155,9 +144,6 @@ export const useGenerateFormState = (): GenerateFormState => {
   /* ── 克隆声音弹窗 ── */
   const [cloneModalOpen, setCloneModalOpen] = useState(false)
 
-  /* ── 生成数量 ── */
-  const [generateCount, setGenerateCount] = useState(1)
-
   /* ── 高级设置（隐藏但保留） ── */
   const [videoRatio] = useState("9:16")
   const [duration] = useState(30)
@@ -165,10 +151,6 @@ export const useGenerateFormState = (): GenerateFormState => {
   const [autoSubtitles] = useState(true)
   const [bgm] = useState(true)
 
-  /* ── 预览弹窗 ── */
-  const [previewVideo, setPreviewVideo] = useState<GeneratedVideo | null>(null)
-  const [previewModalOpen, setPreviewModalOpen] = useState(false)
-
   /* ── 预览任务 ID（useStep6Cover 创建预览时写入，useGenerateVideo 复用） ── */
   // 持久化到 localStorage，key 按 editPlanId/templateId 区分，刷新页面后可恢复
   const previewStorageKey = editPlanId
@@ -227,8 +209,6 @@ export const useGenerateFormState = (): GenerateFormState => {
     presetVoices,
     cloneModalOpen,
     setCloneModalOpen,
-    generateCount,
-    setGenerateCount,
     videoRatio,
     duration,
     style,
@@ -237,10 +217,6 @@ export const useGenerateFormState = (): GenerateFormState => {
     editPlanId,
     sourceEditPlanId,
     planConfigStr,
-    previewVideo,
-    setPreviewVideo,
-    previewModalOpen,
-    setPreviewModalOpen,
     previewTaskId,
     setPreviewTaskId,
     storedSourceEditPlanId,

apps/web/src/pages/generate/hooks/useStep2Materials.ts

@@ -3,11 +3,9 @@
  * 组合素材库加载 + 智能匹配两个子 Hook
  */
 import { useCallback, useEffect, useRef } from "react"
-import type { AssetItem } from "@/api/assets"
 import type { TemplateSegment } from "@/api/templates/types"
-import { updateEditPlanClips } from "@/api/template-editor"
+import { updateEditPlanClips, createClipsFromAssets } from "@/api/template-editor"
 import { formatDuration } from "../utils/formatDuration"
-import { buildClipsFromAssets } from "../utils/buildClipsFromAssets"
 import { useMaterialLibrary } from "./step2-materials/useMaterialLibrary"
 import { useSmartMatch } from "./step2-materials/useSmartMatch"
 import { useDraftAutoSave } from "./useDraftAutoSave"
@@ -72,17 +70,19 @@ export function useStep2Materials({
     scheduleSave({ asset_ids: ids }, 500)
   }, [selectedTemplate, materialMode, selectedMaterials, smartSelectedIds, scheduleSave])
 
-  /* ── Step2 选择素材后同步写入 edit_plan_clips（防抖 800ms，失败静默） ── */
+  /* ── Step2 选择素材后同步写入 edit_plan_clips（防抖 800ms，失败静默） ──
+   * 调用后端 POST /clips/from-assets，由后端处理：
+   *   - 素材不够时同一素材切多个片段
+   *   - 随机 start_time，不重复
+   *   - required_clips_count 保证片段数与模板 segments 一致
+   * 先 PUT /clips（空数组）清空旧片段，再调用 from-assets 创建新片段
+   */
   const clipsTimerRef = useRef<ReturnType<typeof setTimeout>>()
   const clipsAbortRef = useRef<AbortController | null>(null)
   const templateSegmentsRef = useRef(templateSegments)
   templateSegmentsRef.current = templateSegments
   const selectedTemplateRef = useRef(selectedTemplate)
   selectedTemplateRef.current = selectedTemplate
-  const materialsRef = useRef(materials)
-  materialsRef.current = materials
-  const smartMatchedRef = useRef<AssetItem[]>(smartMatch.smartMatchedResults)
-  smartMatchedRef.current = smartMatch.smartMatchedResults
 
   useEffect(() => {
     const tid = selectedTemplateRef.current
@@ -97,15 +97,14 @@ export function useStep2Materials({
       const controller = new AbortController()
       clipsAbortRef.current = controller
 
-      const clips = buildClipsFromAssets({
-        selectedIds: ids,
-        materials: materialsRef.current.items,
-        smartMatchedAssets: smartMatchedRef.current,
-        templateSegments: templateSegmentsRef.current || [],
-      })
+      const segs = templateSegmentsRef.current || []
+      const requiredClipsCount = segs.length > 0 ? segs.length : undefined
 
       try {
-        await updateEditPlanClips(tid, clips, controller.signal)
+        // 1. 清空旧片段
+        await updateEditPlanClips(tid, [], controller.signal)
+        // 2. 调用后端 from-assets 接口创建片段
+        await createClipsFromAssets(tid, ids, "main", requiredClipsCount)
       } catch (err) {
         const name = (err as { name?: string })?.name
         if (name !== "CanceledError" && name !== "AbortError") {

apps/web/src/pages/generate/hooks/useStep7Generate.ts

@@ -25,8 +25,6 @@ interface UseStep7GenerateProps {
   presetVoices: PresetVoiceItem[]
   clonedVoices: VoiceClone[]
   coverSettings: CoverConfig
-  generateCount: number
-  onGenerateCountChange: (count: number) => void
   generating: boolean
   generated: boolean
   generateError: string | null
@@ -47,8 +45,6 @@ export function useStep7Generate({
   presetVoices: _presetVoices,
   clonedVoices: _clonedVoices,
   coverSettings,
-  generateCount,
-  onGenerateCountChange,
   generating,
   generated,
   generateError,
@@ -90,14 +86,6 @@ export function useStep7Generate({
     return { label: "即将完成", icon: "✨" }
   }
 
-  const handleDecrement = () => {
-    onGenerateCountChange(Math.max(1, generateCount - 1))
-  }
-
-  const handleIncrement = () => {
-    onGenerateCountChange(Math.min(10, generateCount + 1))
-  }
-
   const handleScrollToPreview = () => {
     const el = document.querySelector(".xx-preview-section")
     el?.scrollIntoView({ behavior: "smooth", block: "start" })
@@ -109,9 +97,6 @@ export function useStep7Generate({
     title,
     voiceName,
     coverSummary,
-    generateCount,
-    handleDecrement,
-    handleIncrement,
     generating,
     generated,
     generateError,

apps/web/src/pages/generate/utils/buildClipsFromAssets.ts

@@ -1,69 +0,0 @@
-/**
- * 将选中素材 + 模板 segments 构建为 edit_plan_clips 写入数据。
- *
- * 逻辑必须与 FrontendPreviewPlayer.tsx 中 buildPlaybackSegments 完全一致：
- *   assetDuration = asset.duration || asset.metadata?.duration || 30
- *   tplSeg = templateSegments[i] || lastSegment
- *   segDuration = clamp(assetDuration, tplSeg.duration_min, tplSeg.duration_max)
- *   start_time = 0
- *   // 关键：预览播放器中 endTime = min(startTime + segDuration, assetDuration)
- *   // 因此 clips.duration 也必须用 min(segDuration, assetDuration) 截断，
- *   // 避免素材实际时长比 clamp 后的 segDuration 短时，Worker 尝试读取不存在的片段
- *   duration = min(segDuration, assetDuration)
- *
- * 预览播放器（Canvas 实时预览）直接在内存中构建 segments 播放，不读 edit_plan_clips；
- * 本函数产出的 clips 写入 DB 后由 Worker 渲染。两边用完全相同的时长计算，
- * 保证用户在编辑过程中看到的预览与最终生成视频一致。
- */
-import type { AssetItem } from "@/api/assets"
-import type { TemplateSegment } from "@/api/templates/types"
-import type { EditPlanClipInput } from "@/api/template-editor"
-
-interface BuildClipsOptions {
-  /** 选中的素材 ID 列表（按选择顺序） */
-  selectedIds: string[]
-  /** 已加载的素材列表（用于查 duration） */
-  materials: AssetItem[]
-  /** 智能匹配返回的素材（auto 模式下可能不在 materials 列表中） */
-  smartMatchedAssets?: AssetItem[]
-  /** 模板 segments */
-  templateSegments?: TemplateSegment[]
-}
-
-export function buildClipsFromAssets({
-  selectedIds,
-  materials,
-  smartMatchedAssets = [],
-  templateSegments = [],
-}: BuildClipsOptions): EditPlanClipInput[] {
-  if (!selectedIds.length) return []
-
-  // 合并两个素材来源，建立 id → asset 索引
-  const assetMap = new Map<string, AssetItem>()
-  for (const a of materials) assetMap.set(a.id, a)
-  for (const a of smartMatchedAssets) assetMap.set(a.id, a)
-
-  const lastSeg = templateSegments[templateSegments.length - 1]
-
-  return selectedIds.map((assetId, i) => {
-    const asset = assetMap.get(assetId)
-    const assetDuration = asset?.duration || asset?.metadata?.duration || 30
-
-    const tplSeg = templateSegments[i] || lastSeg
-    const segDuration = tplSeg
-      ? Math.min(tplSeg.duration_max, Math.max(tplSeg.duration_min, assetDuration))
-      : Math.min(assetDuration, 10)
-
-    // 与 FrontendPreviewPlayer.buildPlaybackSegments 中
-    //   endTime = Math.min(startTime + segDuration, assetDuration)
-    // 保持一致：duration 不能超过素材实际时长
-    const duration = Math.min(segDuration, assetDuration)
-
-    return {
-      asset_id: assetId,
-      start_time: 0,
-      duration,
-      order: i,
-    }
-  })
-}

apps/worker/video_processing/render_audio.py

@@ -512,6 +512,9 @@ def mix_with_independent_audio(
                 clip_filters.append("asetpts=PTS-STARTPTS")
             else:
                 clip_filters.append("asetpts=PTS-STARTPTS")
+            vol = _clip_volume(clip)
+            if abs(vol - 1.0) >= 1e-6:
+                clip_filters.append(f"volume={vol:.4f}")
             # aformat 归一化：concat/amix 前统一音频参数，否则不同采样率/声道会失败
             clip_filters.append(AFORMAT)
             filter_parts.append(f"[{input_idx}:a]{','.join(clip_filters)}[ma{input_idx}]")

apps/worker/video_processing/thumbnail_generator.py

@@ -204,6 +204,76 @@ def generate_and_upload_thumbnail(
         Path(tmp.name).unlink(missing_ok=True)
 
 
+def _extract_frames_via_mediakit(
+    video_path: str,
+    plan_id: str,
+    num_frames: int,
+) -> list[dict] | None:
+    """使用 MediaKit 智能抽帧 API 提取封面帧。
+
+    Args:
+        video_path: 本地视频文件路径
+        plan_id: 编辑计划 ID
+        num_frames: 需要的帧数
+
+    Returns:
+        帧列表 [{"image_url": str, "timestamp": float}, ...]，失败返回 None
+    """
+    import uuid
+
+    from video_processing.oss_helpers import upload_to_oss
+
+    from packages.shared.mediakit_client import get_mediakit_client
+
+    client = get_mediakit_client()
+    if not client.is_available:
+        logger.info("[thumbnail] MediaKit 未配置，跳过智能抽帧")
+        return None
+
+    # 1. 上传视频到 OSS 获取 URL
+    try:
+        video_storage_key = f"temp/{plan_id}/{uuid.uuid4().hex[:8]}_{Path(video_path).name}"
+        video_url = upload_to_oss(video_path, video_storage_key)
+        if not video_url:
+            logger.warning("[thumbnail] 视频上传 OSS 失败，无法使用 MediaKit")
+            return None
+        logger.info("[thumbnail] 视频已上传 OSS: %s", video_url[:80])
+    except Exception as e:
+        logger.warning("[thumbnail] 视频上传 OSS 异常: %s，降级到 ffmpeg", e)
+        return None
+
+    # 2. 调用 MediaKit 智能抽帧
+    try:
+        frames = client.extract_frames(
+            video_url=video_url,
+            strategy="SceneChange",
+            max_frames=num_frames * 2,  # 多取一些帧供选择
+        )
+        if not frames:
+            logger.warning("[thumbnail] MediaKit 抽帧返回空，降级到 ffmpeg")
+            return None
+
+        # 选取最均匀的 num_frames 个帧
+        if len(frames) > num_frames:
+            step = len(frames) // num_frames
+            frames = [frames[i * step] for i in range(num_frames)]
+
+        logger.info("[thumbnail] MediaKit 抽帧成功: %d 帧", len(frames))
+        return frames
+
+    except Exception as e:
+        logger.warning("[thumbnail] MediaKit 抽帧异常: %s，降级到 ffmpeg", e)
+        return None
+    finally:
+        # 清理临时视频文件
+        try:
+            from video_processing.oss_helpers import delete_from_oss
+
+            delete_from_oss(video_storage_key)
+        except Exception:
+            pass
+
+
 def extract_and_upload_cover_frames(
     video_path: str,
     plan_id: str,
@@ -216,6 +286,8 @@ def extract_and_upload_cover_frames(
 ) -> list[dict]:
     """从视频中抽取多帧作为封面候选，上传到 OSS。
 
+    优先使用 MediaKit 智能抽帧，失败时降级到 ffmpeg 直接抽帧。
+
     Args:
         video_path: 视频文件路径
         plan_id: 编辑计划 ID（用于生成 storage key）
@@ -229,6 +301,7 @@ def extract_and_upload_cover_frames(
     Returns:
         封面候选列表，每项包含 {"url": str, "position": float}
     """
+    import httpx
     from video_processing.ffmpeg_utils import probe_duration
     from video_processing.oss_helpers import upload_to_oss
 
@@ -238,6 +311,51 @@ def extract_and_upload_cover_frames(
         duration = 0.0
 
     candidates: list[dict] = []
+
+    # 优先尝试 MediaKit 智能抽帧
+    mediakit_frames = _extract_frames_via_mediakit(video_path, plan_id, num_frames)
+    if mediakit_frames:
+        for i, frame in enumerate(mediakit_frames):
+            frame_url = frame.get("image_url")
+            if not frame_url:
+                continue
+            tmp = tempfile.NamedTemporaryFile(suffix=".jpg", delete=False)
+            tmp.close()
+            try:
+                # 下载 MediaKit 返回的帧图
+                resp = httpx.get(frame_url, timeout=30, follow_redirects=True)
+                resp.raise_for_status()
+                with open(tmp.name, "wb") as f:
+                    f.write(resp.content)
+
+                # 叠加标题文字（如需要）
+                if title_text and title_text.strip():
+                    apply_title_overlay(
+                        tmp.name,
+                        title_text,
+                        color=title_color,
+                        position=title_position,
+                        font_size=title_font_size,
+                    )
+
+                storage_key = f"covers/{plan_id}/mediakit_frame_{i}.jpg"
+                url = upload_to_oss(tmp.name, storage_key)
+                if url:
+                    seek_time = frame.get("timestamp", 0.0)
+                    candidates.append({"url": url, "position": round(seek_time, 2)})
+            except Exception as e:
+                logger.warning("[thumbnail] MediaKit 帧 %d 处理失败: %s", i, e)
+            finally:
+                Path(tmp.name).unlink(missing_ok=True)
+
+        if len(candidates) >= num_frames:
+            logger.info("[thumbnail] MediaKit 智能抽帧完成: %d 帧", len(candidates))
+            return candidates[:num_frames]
+
+        logger.warning("[thumbnail] MediaKit 抽帧不足 %d 帧，降级到 ffmpeg", num_frames)
+
+    # Fallback: ffmpeg 直接抽帧
+    logger.info("[thumbnail] 使用 ffmpeg 抽帧")
     # 均匀分布抽帧点：从 10% 到 90%
     for i in range(num_frames):
         ratio = 0.1 + 0.8 * i / max(num_frames - 1, 1)

apps/worker/video_processing/unified_render_service.py

@@ -824,6 +824,17 @@ class UnifiedRenderService:
                 )
                 audio_layer.clips.append(vo_clip)
 
+            # replace 模式：静音原视频音轨（main + broll 图层）
+            if tts_config.overlap_mode == "replace":
+                for layer in layers:
+                    if layer.role in ("main", "broll"):
+                        for clip in layer.clips:
+                            clip.config["volume"] = 0
+                logger.info(
+                    "TTS replace 模式：已静音原视频音轨: plan_id=%s",
+                    self.plan.id,
+                )
+
             logger.info(
                 "TTS 配音已添加: plan_id=%s voice_id=%s segments=%d total_%.2fs",
                 self.plan.id,
@@ -889,6 +900,16 @@ class UnifiedRenderService:
             )
             audio_layer.clips.append(vo_clip)
 
+            # 配音素材库默认替换原音：静音原视频音轨（main + broll 图层）
+            for layer in layers:
+                if layer.role in ("main", "broll"):
+                    for clip in layer.clips:
+                        clip.config["volume"] = 0
+            logger.info(
+                "配音素材库：已静音原视频音轨: plan_id=%s",
+                self.plan.id,
+            )
+
             logger.info(
                 "配音素材库音频已添加到 audio 图层: plan_id=%s duration=%.2fs",
                 self.plan.id,

infra/docker/api-base.Dockerfile

@@ -12,14 +12,22 @@ RUN sed -i 's|deb.debian.org|mirrors.aliyun.com|g' /etc/apt/sources.list.d/debia
     sed -i 's|deb.debian.org|mirrors.aliyun.com|g' /etc/apt/sources.list 2>/dev/null || true
 
 # 预装系统依赖（gcc 编译 psycopg/pg 扩展，libpq-dev 编译期，libpq5 运行期，ffmpeg 封面取帧）
+# 字体修复：fonts-noto-cjk 包的 .ttc 文件混入了 Mono 变体，导致 Bold 匹配到等宽字体
+# 解决方案：删除有问题的 .ttc，使用仓库内预下载的 Noto Sans SC Variable Font（不含 Mono）
 RUN apt-get update && apt-get install -y --no-install-recommends \
     gcc \
     libpq-dev \
     libpq5 \
     ffmpeg \
     fonts-noto-cjk \
-    fontconfig \
-    && rm -rf /var/lib/apt/lists/*
+    && rm -rf /var/lib/apt/lists/* \
+    # 删除有问题的 .ttc 文件（包含 Mono 变体）
+    && rm -f /usr/share/fonts/opentype/noto/NotoSansCJK-Regular.ttc \
+    && rm -f /usr/share/fonts/opentype/noto/NotoSansCJK-Bold.ttc
+
+# 复制预下载的 Noto Sans SC Variable Font（包含所有字重，不含 Mono 变体）
+COPY infra/fonts/NotoSansSC-VF.ttf /usr/share/fonts/opentype/noto/NotoSansSC-VF.ttf
+RUN fc-cache -fv
 
 # 创建虚拟环境
 RUN python -m venv /opt/venv
@@ -43,3 +51,5 @@ RUN find /opt/venv -type d -name "__pycache__" -exec rm -rf {} + 2>/dev/null; \
 RUN rm -f /tmp/requirements-base.txt /tmp/requirements.txt
 
 ENV PYTHONPATH=/app
+
+# Rebuild trigger: ACR push retry 20260826

infra/docker/worker-base.Dockerfile

@@ -12,6 +12,8 @@ RUN sed -i 's|deb.debian.org|mirrors.aliyun.com|g' /etc/apt/sources.list.d/debia
     sed -i 's|deb.debian.org|mirrors.aliyun.com|g' /etc/apt/sources.list 2>/dev/null || true
 
 # 预装系统依赖（编译工具 + 运行时 + CJK 字体用于 ASS 字幕渲染）
+# 字体修复：fonts-noto-cjk 包的 .ttc 文件混入了 Mono 变体，导致 Bold 匹配到等宽字体
+# 解决方案：删除有问题的 .ttc，使用仓库内预下载的 Noto Sans SC Variable Font（不含 Mono）
 RUN apt-get update && apt-get install -y --no-install-recommends \
     gcc \
     g++ \
@@ -20,8 +22,14 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     ffmpeg \
     libglib2.0-0 \
     fonts-noto-cjk \
-    && fc-cache -fv \
-    && rm -rf /var/lib/apt/lists/*
+    && rm -rf /var/lib/apt/lists/* \
+    # 删除有问题的 .ttc 文件（包含 Mono 变体）
+    && rm -f /usr/share/fonts/opentype/noto/NotoSansCJK-Regular.ttc \
+    && rm -f /usr/share/fonts/opentype/noto/NotoSansCJK-Bold.ttc
+
+# 复制预下载的 Noto Sans SC Variable Font（包含所有字重，不含 Mono 变体）
+COPY infra/fonts/NotoSansSC-VF.ttf /usr/share/fonts/opentype/noto/NotoSansSC-VF.ttf
+RUN fc-cache -fv
 
 # 创建虚拟环境
 RUN python -m venv /opt/venv
@@ -47,3 +55,5 @@ RUN find /opt/venv -type d -name "__pycache__" -exec rm -rf {} + 2>/dev/null; \
 RUN rm -f /tmp/requirements-base.txt /tmp/requirements.txt /tmp/requirements-worker.txt
 
 ENV PYTHONPATH=/app:/app/packages
+
+# Rebuild trigger: ACR push retry 20260826

packages/domain/ass_subtitle_builder.py

@@ -20,10 +20,32 @@ logger = logging.getLogger(__name__)
 # ── 常量 ──────────────────────────────────────────────────────────────────────
 
 # Title/Subtitle 默认边距（像素）
-TITLE_MARGIN_TOP = 60
+TITLE_MARGIN_TOP = 120
 TITLE_MARGIN_BOTTOM = 60
 TITLE_MARGIN_SIDE = 40
 
+# 字体名称映射：前端中文字体名 → 服务器实际注册名（ffmpeg/ASS 通过注册名匹配字体）
+FONT_NAME_MAP: dict[str, str] = {
+    "思源黑体": "Noto Sans SC",
+    "思源宋体": "Noto Serif CJK SC",
+    "苹方": "Noto Sans SC",
+    "PingFang": "Noto Sans SC",
+    "微软雅黑": "Noto Sans SC",
+    "楷体": "Noto Serif CJK SC",
+    "华康俪金黑": "Noto Sans SC",
+}
+
+# ASS Fontsize 是字体 em-square 高度（含 Latin 升降部留白），
+# 中文字符实际只占声明字号的约 65%~75%；浏览器 CSS font-size 让中文字符占满声明高度。
+# 为让成片中文字高与前端 CSS 预览一致，写入 ASS 时对字号乘以补偿系数。
+# font_size=89 → ASS Fontsize=round(89*1.35)=120，实际中文字高约 78~85px。
+ASS_FONTSIZE_COMPENSATION = 1.35
+
+
+def _compensate_ass_fontsize(font_size: int) -> int:
+    """将 CSS 语义字号换算为 ASS Fontsize，补偿中文字符在 em-square 中的留白。"""
+    return max(1, round(font_size * ASS_FONTSIZE_COMPENSATION))
+
 
 # ── 颜色转换 ──────────────────────────────────────────────────────────────────
 
@@ -117,14 +139,20 @@ def build_ass_style(
     bold_val = -1 if bold else 0
     italic_val = -1 if italic else 0
 
+    # 字体名称映射：前端中文字体名 → 服务器注册名，未命中则原样使用
+    actual_font = FONT_NAME_MAP.get(font_name, font_name)
+
     # BackColour 用于阴影（BorderStyle=1 时 outline + shadow）
     back_color = primary_color
 
     # Shadow 深度：shadow_offset[1] 作为纵向偏移
     shadow_depth = shadow_offset[1] if shadow_blur > 0 else 0
 
+    # 写入 ASS Style 时对字号做补偿，使成片中文字高与前端 CSS 预览一致
+    ass_font_size = _compensate_ass_fontsize(font_size)
+
     return (
-        f"Style: {style_name},{font_name},{font_size},{primary_color},"
+        f"Style: {style_name},{actual_font},{ass_font_size},{primary_color},"
         f"&H000000FF,{outline_color},{back_color},"
         f"{bold_val},{italic_val},0,0,100,100,0,0,"
         f"1,{outline_width},{shadow_depth},{alignment},"
@@ -147,6 +175,8 @@ def escape_ass_text(text: str) -> str:
     Returns:
         转义后的 ASS 文本
     """
+    # 用户手动换行符（半角/全角斜杠）转为 ASS 硬换行（在自动换行之前优先处理）
+    text = text.replace("／", "\\N").replace("/", "\\N")
     # 将实际换行转为 ASS 硬换行
     text = text.replace("\r\n", "\\N").replace("\n", "\\N").replace("\r", "\\N")
     # 转义大括号（ASS 用它做样式覆盖标签）
@@ -175,7 +205,6 @@ def format_ass_time(seconds: float) -> str:
 # ── 完整 ASS 内容生成 ─────────────────────────────────────────────────────────
 
 
-
 def _wrap_title_text(
     text: str,
     video_width: int,
@@ -195,26 +224,36 @@ def _wrap_title_text(
     if available_width <= 0:
         return text
 
-    lines: list[str] = []
-    current_line = ""
-    current_width = 0.0
+    # 换行宽度必须与实际渲染（补偿后的 ASS Fontsize）一致，否则换行位置会错位
+    ass_font_size = _compensate_ass_fontsize(font_size)
 
-    for ch in text:
-        # CJK 字符按全角估算，其他按半角
-        char_width = float(font_size) if ord(ch) > 0x2E80 else font_size * 0.55
+    # 先按已有 \N 分段，每段独立自动换行，最后用 \N 拼回
+    segments = text.split("\\N")
+    wrapped_segments: list[str] = []
 
-        if current_width + char_width > available_width and current_line:
+    for seg in segments:
+        lines: list[str] = []
+        current_line = ""
+        current_width = 0.0
+
+        for ch in seg:
+            # CJK 字符按全角估算，其他按半角
+            char_width = float(ass_font_size) if ord(ch) > 0x2E80 else ass_font_size * 0.55
+
+            if current_width + char_width > available_width and current_line:
+                lines.append(current_line)
+                current_line = ch
+                current_width = char_width
+            else:
+                current_line += ch
+                current_width += char_width
+
+        if current_line:
             lines.append(current_line)
-            current_line = ch
-            current_width = char_width
-        else:
-            current_line += ch
-            current_width += char_width
 
-    if current_line:
-        lines.append(current_line)
+        wrapped_segments.append("\\N".join(lines))
 
-    return "\\N".join(lines)
+    return "\\N".join(wrapped_segments)
 
 
 def build_ass_content(
@@ -247,26 +286,40 @@ def build_ass_content(
     title_config = title_config or {}
     subtitle_config = subtitle_config or {}
 
+    # ── 字段名归一化：前端传 font_size/font_color，内部用 size/color ──
+    if "font_size" in title_config and "size" not in title_config:
+        title_config["size"] = title_config["font_size"]
+    if "font_color" in title_config and "color" not in title_config:
+        title_config["color"] = title_config["font_color"]
+
     # ── 兼容前端简化格式：stroke/shadow 为 boolean 时，转换为标准 dict ──
     # 前端 TitleSettings 发送 stroke=true/false, shadow=true/false
     # 后端 build_ass_style 期望 stroke={enabled, color, width}, shadow={enabled, blur, offset_x, offset_y}
     if title_config:
         _stroke_val = title_config.get("stroke")
         if isinstance(_stroke_val, bool):
-            title_config["stroke"] = {
-                "enabled": _stroke_val,
-                "color": "#000000",
-                "width": 2,
-            } if _stroke_val else {"enabled": False}
+            title_config["stroke"] = (
+                {
+                    "enabled": _stroke_val,
+                    "color": "#000000",
+                    "width": 2,
+                }
+                if _stroke_val
+                else {"enabled": False}
+            )
         _shadow_val = title_config.get("shadow")
         if isinstance(_shadow_val, bool):
-            title_config["shadow"] = {
-                "enabled": _shadow_val,
-                "color": "#000000",
-                "blur": 4,
-                "offset_x": 2,
-                "offset_y": 2,
-            } if _shadow_val else {"enabled": False}
+            title_config["shadow"] = (
+                {
+                    "enabled": _shadow_val,
+                    "color": "#000000",
+                    "blur": 4,
+                    "offset_x": 2,
+                    "offset_y": 2,
+                }
+                if _shadow_val
+                else {"enabled": False}
+            )
 
     title_enabled = title_config.get("enabled", True) and bool(title_text.strip())
     subtitle_enabled = subtitle_config.get("enabled", True) and bool(subtitle_text.strip())
@@ -296,7 +349,7 @@ def build_ass_content(
             build_ass_style(
                 "TitleStyle",
                 font_name=title_config.get("font", "思源黑体"),
-                font_size=min(int(title_config.get("size", 36)), 36),
+                font_size=int(title_config.get("size", 36)),
                 primary_color=title_color,
                 outline_color=stroke_color,
                 outline_width=stroke_width,
@@ -313,7 +366,7 @@ def build_ass_content(
 
         # 根据视频宽度和字号自动换行标题，防止超出画面
         # 先 escape 特殊字符，再插入换行符 \N，避免顺序颠倒导致 \N 被转义
-        title_font_size = min(int(title_config.get("size", 36)), 36)
+        title_font_size = int(title_config.get("size", 36))
         safe_title_text_raw = escape_ass_text(title_text)
         safe_title_text = _wrap_title_text(safe_title_text_raw, video_width, title_font_size)
 

packages/domain/plan_generator_utils.py

@@ -77,12 +77,18 @@ def _distribute_one_take(
     asset_durations: dict[str, float] | None = None,
 ) -> None:
     """ONE_TAKE: 素材按顺序依次分配给 main 类型 clips."""
+    used_segments: dict[str, list[tuple[float, float]]] = {}
     main_clips = [c for c in clips if c.clip_type == ClipType.MAIN.value]
     for i, clip in enumerate(main_clips):
         if i < len(asset_ids):
             asset_id = asset_ids[i]
-            start_time = _calc_random_start_time(asset_id, clip.duration, asset_durations)
+            start_time = _calc_random_start_time(asset_id, clip.duration, asset_durations, used_segments)
             clip.assign_asset(asset_id, start_time=start_time)
+            # Record used segment
+            if start_time is not None and asset_durations is not None:
+                if asset_id not in used_segments:
+                    used_segments[asset_id] = []
+                used_segments[asset_id].append((start_time, start_time + clip.duration))
 
 
 def _distribute_pip(
@@ -91,12 +97,18 @@ def _distribute_pip(
     asset_durations: dict[str, float] | None = None,
 ) -> None:
     """PIP: 第1个素材→main(全屏背景)，其余→overlay clips."""
+    used_segments: dict[str, list[tuple[float, float]]] = {}
     # 第1个素材 → main clip
     main_clips = [c for c in clips if c.clip_type == ClipType.MAIN.value]
     if main_clips and asset_ids:
         asset_id = asset_ids[0]
-        start_time = _calc_random_start_time(asset_id, main_clips[0].duration, asset_durations)
+        start_time = _calc_random_start_time(asset_id, main_clips[0].duration, asset_durations, used_segments)
         main_clips[0].assign_asset(asset_id, start_time=start_time)
+        # Record used segment
+        if start_time is not None and asset_durations is not None:
+            if asset_id not in used_segments:
+                used_segments[asset_id] = []
+            used_segments[asset_id].append((start_time, start_time + main_clips[0].duration))
 
     # 其余素材 → overlay clips
     overlay_clips = [c for c in clips if c.clip_type == "overlay"]
@@ -104,8 +116,13 @@ def _distribute_pip(
     for i, clip in enumerate(overlay_clips):
         if i < len(remaining):
             asset_id = remaining[i]
-            start_time = _calc_random_start_time(asset_id, clip.duration, asset_durations)
+            start_time = _calc_random_start_time(asset_id, clip.duration, asset_durations, used_segments)
             clip.assign_asset(asset_id, start_time=start_time)
+            # Record used segment
+            if start_time is not None and asset_durations is not None:
+                if asset_id not in used_segments:
+                    used_segments[asset_id] = []
+                used_segments[asset_id].append((start_time, start_time + clip.duration))
 
 
 def _distribute_voice_over(
@@ -114,12 +131,18 @@ def _distribute_voice_over(
     asset_durations: dict[str, float] | None = None,
 ) -> None:
     """VOICE_OVER: 素材→main clips (B-roll)."""
+    used_segments: dict[str, list[tuple[float, float]]] = {}
     main_clips = [c for c in clips if c.clip_type == ClipType.MAIN.value]
     for i, clip in enumerate(main_clips):
         if i < len(asset_ids):
             asset_id = asset_ids[i]
-            start_time = _calc_random_start_time(asset_id, clip.duration, asset_durations)
+            start_time = _calc_random_start_time(asset_id, clip.duration, asset_durations, used_segments)
             clip.assign_asset(asset_id, start_time=start_time)
+            # Record used segment
+            if start_time is not None and asset_durations is not None:
+                if asset_id not in used_segments:
+                    used_segments[asset_id] = []
+                used_segments[asset_id].append((start_time, start_time + clip.duration))
 
 
 def _distribute_voice_pip(
@@ -128,6 +151,7 @@ def _distribute_voice_pip(
     asset_durations: dict[str, float] | None = None,
 ) -> None:
     """VOICE_PIP: 第1个→background, 第2个→corner_voice, 其余→b_roll."""
+    used_segments: dict[str, list[tuple[float, float]]] = {}
     bg_clips = [c for c in clips if c.clip_type == "background"]
     voice_clips = [c for c in clips if c.clip_type == "corner_voice"]
     broll_clips = [c for c in clips if c.clip_type == "b_roll"]
@@ -137,15 +161,25 @@ def _distribute_voice_pip(
     # 第1个 → background
     if idx < len(asset_ids) and bg_clips:
         asset_id = asset_ids[idx]
-        start_time = _calc_random_start_time(asset_id, bg_clips[0].duration, asset_durations)
+        start_time = _calc_random_start_time(asset_id, bg_clips[0].duration, asset_durations, used_segments)
         bg_clips[0].assign_asset(asset_id, start_time=start_time)
+        # Record used segment
+        if start_time is not None and asset_durations is not None:
+            if asset_id not in used_segments:
+                used_segments[asset_id] = []
+            used_segments[asset_id].append((start_time, start_time + bg_clips[0].duration))
         idx += 1
 
     # 第2个 → corner_voice
     if idx < len(asset_ids) and voice_clips:
         asset_id = asset_ids[idx]
-        start_time = _calc_random_start_time(asset_id, voice_clips[0].duration, asset_durations)
+        start_time = _calc_random_start_time(asset_id, voice_clips[0].duration, asset_durations, used_segments)
         voice_clips[0].assign_asset(asset_id, start_time=start_time)
+        # Record used segment
+        if start_time is not None and asset_durations is not None:
+            if asset_id not in used_segments:
+                used_segments[asset_id] = []
+            used_segments[asset_id].append((start_time, start_time + voice_clips[0].duration))
         idx += 1
 
     # 剩余 → b_roll clips
@@ -153,8 +187,13 @@ def _distribute_voice_pip(
     for i, clip in enumerate(broll_clips):
         if i < len(remaining):
             asset_id = remaining[i]
-            start_time = _calc_random_start_time(asset_id, clip.duration, asset_durations)
+            start_time = _calc_random_start_time(asset_id, clip.duration, asset_durations, used_segments)
             clip.assign_asset(asset_id, start_time=start_time)
+            # Record used segment
+            if start_time is not None and asset_durations is not None:
+                if asset_id not in used_segments:
+                    used_segments[asset_id] = []
+                used_segments[asset_id].append((start_time, start_time + clip.duration))
 
 
 # ── 随机 start_time 计算 ────────────────────────────────────────────────────
@@ -164,16 +203,19 @@ def _calc_random_start_time(
     asset_id: str,
     clip_duration: float,
     asset_durations: dict[str, float] | None,
+    used_segments: dict[str, list[tuple[float, float]]] | None = None,
 ) -> float | None:
-    """计算随机 start_time.
+    """计算随机 start_time，避开已使用的时间段.
 
     在素材总时长范围内随机取点，确保 clip_duration 不超出素材边界。
     如果 asset_durations 为 None 或素材不在其中，返回 None（使用默认 0.0）。
+    如果提供了 used_segments，会避开已使用的时间区间。
 
     Args:
         asset_id: 素材 ID
         clip_duration: 片段时长（秒）
         asset_durations: 素材 ID -> 时长映射
+        used_segments: {asset_id: [(start1, end1), (start2, end2), ...]} 已使用的时间段
 
     Returns:
         随机 start_time 或 None
@@ -190,7 +232,41 @@ def _calc_random_start_time(
     if max_start <= 0:
         return 0.0
 
-    return random.uniform(0.0, max_start)
+    # 如果没有已使用段，直接随机
+    if not used_segments or asset_id not in used_segments:
+        return random.uniform(0.0, max_start)
+
+    # 尝试找到一个不与已使用段重叠的起始点
+    used = sorted(used_segments[asset_id])
+    max_attempts = 100
+
+    for _ in range(max_attempts):
+        candidate = random.uniform(0.0, max_start)
+        candidate_end = candidate + clip_duration
+
+        # 检查是否与任何已使用段重叠
+        overlap = False
+        for seg_start, seg_end in used:
+            # 两个区间 [a, b] 和 [c, d] 重叠的条件: a < d and c < b
+            if candidate < seg_end and seg_start < candidate_end:
+                overlap = True
+                break
+
+        if not overlap:
+            return candidate
+
+    # 如果尝试多次仍找不到，缩短时长使用素材末尾
+    # 找到最后一个已使用段之后的可用空间
+    last_used_end = 0.0
+    for _seg_start, seg_end in used:
+        last_used_end = max(last_used_end, seg_end)
+
+    if last_used_end < total_duration:
+        # 返回从最后使用点开始的位置
+        return min(last_used_end, max_start)
+
+    # 实在没有空间，返回0（可能会重叠，但至少能执行）
+    return 0.0
 
 
 # ── clip_type 映射 ────────────────────────────────────────────────────────

packages/shared/title_overlay.py

@@ -15,6 +15,7 @@ logger = logging.getLogger(__name__)
 
 # 按优先级查找 CJK 字体（Debian/Ubuntu fonts-noto-cjk 安装路径）
 _FONT_CANDIDATES = (
+    "/usr/share/fonts/opentype/noto/NotoSansSC-VF.ttf",
     "/usr/share/fonts/opentype/noto/NotoSansCJK-Bold.ttc",
     "/usr/share/fonts/opentype/noto/NotoSansCJK-Regular.ttc",
     "/usr/share/fonts/truetype/noto/NotoSansCJK-Bold.ttc",

scripts/ci/acr_cleanup.py

@@ -398,7 +398,6 @@ def cleanup_repo(repo, keep_count, dry_run, protected_tags, pr_sha=None, pr_open
             # 注意：pr tag是pr-<sha>，sha可能属于某个PR
             # 简化策略：收集所有打开PR的commit sha，在白名单里的保留
             print("    模式: Gitea PR状态检查")
-            open_pr_shas = set()
             # 这里做了简化：因为每个PR都查commits太慢，我们用另一种方式
             # 对于PR tag，先尝试匹配PR编号（如果tag名里有编号），否则按时间
             # 实际pr-<sha>没法直接知道PR编号，所以降级为按时间+打开PR的head sha白名单

scripts/ci/auto_fix_formatting.py

@@ -232,7 +232,7 @@ def main():
         # 初始化git仓库
         ensure_git_repo_for_push(api_url, repo, token, branch_name)
         head_branch = branch_name
-        fix_mode = "auto_fix_and_push"
+        # fix_mode removed: all PRs auto-fix (2026-08-26)
 
     # ====== PR事件处理 ======
     elif event_name == "pull_request":
@@ -251,7 +251,7 @@ def main():
 
         # 防循环检测：检查最新commit是否已经是格式修复commit
         # 修复commit message 带 [skip ci-format-check] 标记，检测到则跳过
-        head_branch_tmp = pr_info.get("head", {}).get("ref", "")
+        _head_branch_tmp = pr_info.get("head", {}).get("ref", "")  # noqa: F841
         skip_marker = "[skip ci-format-check]"
         try:
             commits_url = f"{api_url}/repos/{repo}/pulls/{pr_number}/commits?limit=3"
@@ -268,7 +268,7 @@ def main():
 
         # 所有PR都自动修复格式（不再区分人/Agent）
         print("检测到格式问题，将自动修复并推送回分支")
-        fix_mode = "auto_fix_and_push"
+        # fix_mode removed: all PRs auto-fix (2026-08-26)
 
         print("=== 检测到代码格式问题，尝试自动修复 ===")
         print(f"PR #{pr_number}")

tests/unit/domain/test_ass_subtitle_builder.py

@@ -105,9 +105,9 @@ class TestBuildAssStyle:
 
     def test_contains_font_size(self):
         result = build_ass_style("S1", font_size=36)
-        # Style行格式：Name, Fontname, Fontsize, ...
+        # Style行格式：Name, Fontname, Fontsize, ...（36*1.35=48.6→49）
         parts = result.split(",")
-        assert parts[2] == "36"
+        assert parts[2] == "49"
 
     def test_bold_true(self):
         result = build_ass_style("S1", bold=True)
@@ -218,6 +218,14 @@ class TestEscapeAssText:
     def test_chinese_text(self):
         assert escape_ass_text("你好世界") == "你好世界"
 
+    def test_slash_converted_to_newline(self):
+        """半角斜杠 / 应转为 ASS 硬换行。"""
+        assert escape_ass_text("标题一/标题二") == "标题一\\N标题二"
+
+    def test_fullwidth_slash_converted_to_newline(self):
+        """全角斜杠 ／ 应转为 ASS 硬换行。"""
+        assert escape_ass_text("标题一／标题二") == "标题一\\N标题二"
+
     def test_backslash_n_in_input(self):
         # 文本里本身有 \n 字符串（不是换行符）
         result = escape_ass_text("\\n")
@@ -408,11 +416,53 @@ class TestBuildAssContent:
             title_text="T",
             title_config={"size": 72},
         )
-        # 在TitleStyle行里查找字体大小
+        # 在TitleStyle行里查找字体大小（字号上限已移除，72应原样保留）
         for line in result.split("\n"):
             if line.startswith("Style: TitleStyle"):
                 parts = line.split(",")
-                assert parts[2] == "36"
+                assert parts[2] == "97"  # 72*1.35=97.2→97
+                break
+
+    def test_title_font_size_frontend_field_alias(self):
+        """前端传 font_size 应归一化为内部 size 字段。"""
+        result = build_ass_content(
+            video_width=1920,
+            video_height=1080,
+            video_duration=5.0,
+            title_text="T",
+            title_config={"font_size": 48},
+        )
+        for line in result.split("\n"):
+            if line.startswith("Style: TitleStyle"):
+                parts = line.split(",")
+                assert parts[2] == "65"  # 48*1.35=64.8→65
+                break
+
+    def test_title_font_color_frontend_field_alias(self):
+        """前端传 font_color 应归一化为内部 color 字段。"""
+        result = build_ass_content(
+            video_width=1920,
+            video_height=1080,
+            video_duration=5.0,
+            title_text="T",
+            title_config={"font_color": "#FF0000"},
+        )
+        # 红色 → &H0000FF
+        assert "&H0000FF" in result
+
+    def test_title_size_takes_precedence_over_font_size(self):
+        """同时传 size 和 font_size 时，size 优先。"""
+        result = build_ass_content(
+            video_width=1920,
+            video_height=1080,
+            video_duration=5.0,
+            title_text="T",
+            title_config={"size": 56, "font_size": 28},
+        )
+        for line in result.split("\n"):
+            if line.startswith("Style: TitleStyle"):
+                parts = line.split(",")
+                assert parts[2] == "76"  # 56*1.35=75.6→76
                 break
 
     def test_title_bold(self):

tests/unit/test_ass_subtitle_builder.py

@@ -79,12 +79,12 @@ class TestBuildAssStyle:
     def test_minimal_style(self):
         result = build_ass_style("TestStyle")
         assert result.startswith("Style: TestStyle,")
-        assert "思源黑体" in result
-        assert ",48," in result
+        assert "Noto Sans SC" in result
+        assert ",65," in result  # 48*1.35=64.8→65
 
     def test_custom_font_size(self):
         result = build_ass_style("Title", font_size=64)
-        assert ",64," in result
+        assert ",86," in result  # 64*1.35=86.4→86
 
     def test_bold_enabled(self):
         result = build_ass_style("BoldStyle", bold=True)
@@ -152,6 +152,26 @@ class TestBuildAssStyle:
         # Style: 行有 23 个字段（去掉 "Style: " 前缀后）
         assert len(parts) == 23
 
+    def test_font_name_mapping_siyuan(self):
+        """思源黑体 → Noto Sans SC"""
+        result = build_ass_style("Test", font_name="思源黑体")
+        assert "Noto Sans SC" in result
+
+    def test_font_name_mapping_apple(self):
+        """苹方 → Noto Sans SC"""
+        result = build_ass_style("Test", font_name="苹方")
+        assert "Noto Sans SC" in result
+
+    def test_font_name_mapping_msyh(self):
+        """微软雅黑 → Noto Sans SC"""
+        result = build_ass_style("Test", font_name="微软雅黑")
+        assert "Noto Sans SC" in result
+
+    def test_font_name_mapping_unknown_passthrough(self):
+        """未映射字体原样使用"""
+        result = build_ass_style("Test", font_name="CustomFont")
+        assert "CustomFont" in result
+
 
 # ── 文本转义 ──────────────────────────────────────────────────────────────────
 
@@ -190,6 +210,19 @@ class TestEscapeAssText:
     def test_chinese_text(self):
         assert escape_ass_text("你好世界") == "你好世界"
 
+    def test_slash_converted_to_newline(self):
+        """半角斜杠 / 应转为 ASS 硬换行。"""
+        assert escape_ass_text("第一行/第二行") == "第一行\\N第二行"
+
+    def test_fullwidth_slash_converted_to_newline(self):
+        """全角斜杠 ／ 应转为 ASS 硬换行。"""
+        assert escape_ass_text("第一行／第二行") == "第一行\\N第二行"
+
+    def test_mixed_slashes_and_newlines(self):
+        """斜杠和换行符都应转为硬换行。"""
+        result = escape_ass_text("A/B\nC／D")
+        assert result == "A\\NB\\NC\\ND"
+
 
 # ── 时间格式化 ────────────────────────────────────────────────────────────────
 
@@ -440,7 +473,7 @@ class TestBuildAssContent:
 
 class TestConstants:
     def test_title_margin_top(self):
-        assert TITLE_MARGIN_TOP == 60
+        assert TITLE_MARGIN_TOP == 120
 
     def test_title_margin_bottom(self):
         assert TITLE_MARGIN_BOTTOM == 60
@@ -448,6 +481,7 @@ class TestConstants:
     def test_title_margin_side(self):
         assert TITLE_MARGIN_SIDE == 40
 
+
 # ── 标题自动换行 ──────────────────────────────────────────────────────────────
 
 
@@ -491,6 +525,34 @@ class TestWrapTitleText:
         """字号为0时直接返回原文。"""
         assert _wrap_title_text("测试", 1080, 0) == "测试"
 
+    def test_preserves_explicit_newline(self):
+        """已有的 \\N 换行标记应保留，不被当普通字符算宽度。"""
+        text = "第一行\\N第二行"
+        result = _wrap_title_text(text, video_width=1080, font_size=48)
+        assert result == text
+
+    def test_explicit_newline_each_segment_wraps_independently(self):
+        """\\N 分段后，每段各自自动换行。"""
+        # 480px 宽，48px 字号，可用 400px，每段约8个中文字
+        text = "这是第一段很长很长很长的内容\\N这是第二段也很长很长的内容"
+        result = _wrap_title_text(text, video_width=480, font_size=48)
+        # 应该有多个 \N：用户手动的 + 自动换行的
+        assert "\\N" in result
+        segments = result.split("\\N")
+        # 至少3行（两段都需要换行）
+        assert len(segments) >= 3
+        # 验证包含两段的文字
+        joined = result.replace("\\N", "")
+        assert "第一段" in joined
+        assert "第二段" in joined
+
+    def test_multiple_explicit_newlines(self):
+        """多个 \\N 分段都应保留。"""
+        text = "A\\NB\\NC"
+        result = _wrap_title_text(text, video_width=1080, font_size=48)
+        assert result == text
+        assert result.count("\\N") == 2
+
     def test_build_ass_content_integration(self):
         """集成测试：build_ass_content 中的标题应该自动换行。"""
         long_title = "这是一段非常长的标题文字用于测试自动换行功能是否正常工作"
@@ -508,3 +570,35 @@ class TestWrapTitleText:
                 break
         else:
             pytest.fail("未找到 TitleStyle Dialogue 行")
+
+
+class TestFontsizeCompensation:
+    """ASS Fontsize 补偿系数（CSS 字号 → ASS em-square 字号）。"""
+
+    def test_default_48_compensated_to_65(self):
+        result = build_ass_style("S")
+        parts = result.split(",")
+        assert parts[2] == "65"  # round(48*1.35)=65
+
+    def test_89_compensated_to_120(self):
+        """实测对齐点：font_size=89 → ASS Fontsize=120。"""
+        result = build_ass_style("S", font_size=89)
+        parts = result.split(",")
+        assert parts[2] == "120"
+
+    def test_subtitle_also_compensated(self):
+        content = build_ass_content(
+            video_width=1080,
+            video_height=1920,
+            video_duration=5.0,
+            subtitle_text="字幕",
+            subtitle_config={"size": 24},
+        )
+        sub_line = [line for line in content.splitlines() if line.startswith("Style: SubtitleStyle")][0]
+        fields = [f.strip() for f in sub_line.split(",")]
+        assert fields[2] == "32"  # round(24*1.35)=32
+
+    def test_minimum_fontsize_at_least_one(self):
+        result = build_ass_style("S", font_size=0)
+        parts = result.split(",")
+        assert int(parts[2]) >= 1

tests/unit/test_editor_clips_random_start.py

@@ -0,0 +1,396 @@
+"""测试编辑器 from-assets 端点：同一素材切多个片段 + 随机起始 + 去重.
+
+覆盖：
+- required_clips_count 精确控制片段数量
+- 素材不足时同一素材轮询切多个片段
+- 随机 start_time + used_segments 去重
+- 素材时长不足时 clip duration 缩短
+- 向后兼容（不传 required_clips_count 时等于素材数量）
+- order 追加到时间线末尾
+- start_time=None 时抛出 400
+- create_clip 失败时抛出 400 并记录日志
+"""
+
+from __future__ import annotations
+
+import os
+import sys
+from pathlib import Path
+from unittest.mock import MagicMock, patch
+
+os.environ.setdefault("JWT_SECRET_KEY", "unit-test-secret-key-for-testing")
+os.environ.setdefault("DATABASE_URL", "sqlite:///test.db")
+
+sys.path.insert(0, str(Path(__file__).resolve().parents[2] / "apps" / "api"))
+
+import pytest
+from fastapi import HTTPException
+
+TEST_PLAN_ID = "plan-draft-001"
+TEST_USER_ID = "user-001"
+
+
+def _make_auth_user():
+    auth = MagicMock()
+    auth.user.id = TEST_USER_ID
+    auth.user.email = "test@example.com"
+    auth.user.display_name = "测试用户"
+    auth.user_id = TEST_USER_ID
+    return auth
+
+
+def _make_mock_clip(clip_id, order, duration, start_time=0.0, asset_id=""):
+    clip = MagicMock()
+    clip.id = clip_id
+    clip.plan_id = TEST_PLAN_ID
+    clip.clip_type = "main"
+    clip.order = order
+    clip.duration = duration
+    clip.start_time = start_time
+    clip.text_content = ""
+    clip.transition_effect = "cut"
+    clip.transition_duration = 0.0
+    clip.playback_speed = 1.0
+    clip.config = {}
+    clip.asset_id = asset_id
+    clip.status = "pending"
+    clip.template_clip_config_id = ""
+    clip.created_at = None
+    clip.updated_at = None
+    return clip
+
+
+def _make_mock_asset(asset_id, duration):
+    asset = MagicMock()
+    asset.id = asset_id
+    asset.duration = duration
+    return asset
+
+
+def _create_clips(plan_id, clip_type, order, duration=0.0, start_time=0.0, asset_id="", **kw):
+    return _make_mock_clip(
+        clip_id=f"clip-{order}",
+        order=order,
+        duration=duration,
+        start_time=start_time,
+        asset_id=asset_id,
+    )
+
+
+def _make_plan_svc(existing_clips=None):
+    svc = MagicMock()
+    svc.get_plan_or_raise = MagicMock()
+    svc.create_clip = MagicMock(side_effect=_create_clips)
+    svc.list_clips = MagicMock(return_value=existing_clips or [])
+    return svc
+
+
+class TestEditorClipsRequiredCount:
+    """测试 required_clips_count 控制片段数量 + 同素材多片段."""
+
+    @patch("app.api.routes.templates_editor.clips.get_storage_service")
+    def test_creates_exactly_required_clips_count(self, mock_storage):
+        """required_clips_count=4 时，即使只有2个素材也创建4个片段."""
+        from app.api.routes.templates_editor.clips import (
+            create_clips_from_assets_editor,
+        )
+        from app.api.routes.templates_editor.schemas import ClipsFromAssetsRequest
+
+        mock_plan_svc = _make_plan_svc()
+        mock_asset_repo = MagicMock()
+        mock_asset_repo.get = MagicMock(side_effect=lambda aid: _make_mock_asset(aid, {"a1": 30.0, "a2": 20.0}[aid]))
+
+        body = ClipsFromAssetsRequest(asset_ids=["a1", "a2"], required_clips_count=4)
+
+        result = create_clips_from_assets_editor(
+            template_id="tpl-001",
+            body=body,
+            plan_id=TEST_PLAN_ID,
+            services=(MagicMock(), mock_plan_svc),
+            asset_repo=mock_asset_repo,
+            current_user=_make_auth_user(),
+        )
+
+        assert result.created_count == 4
+        assert mock_plan_svc.create_clip.call_count == 4
+
+        # 验证轮询分配：a1, a2, a1, a2
+        calls = mock_plan_svc.create_clip.call_args_list
+        assert calls[0].kwargs["asset_id"] == "a1"
+        assert calls[1].kwargs["asset_id"] == "a2"
+        assert calls[2].kwargs["asset_id"] == "a1"
+        assert calls[3].kwargs["asset_id"] == "a2"
+
+    @patch("app.api.routes.templates_editor.clips.get_storage_service")
+    def test_orders_append_to_existing_timeline(self, mock_storage):
+        """时间线已有2个片段时，新片段 order 应从 2 开始连续递增."""
+        from app.api.routes.templates_editor.clips import (
+            create_clips_from_assets_editor,
+        )
+        from app.api.routes.templates_editor.schemas import ClipsFromAssetsRequest
+
+        # 模拟已有 order=0, order=1 的片段
+        existing = [_make_mock_clip("old-1", 0, 5.0), _make_mock_clip("old-2", 1, 5.0)]
+        mock_plan_svc = _make_plan_svc(existing_clips=existing)
+
+        mock_asset_repo = MagicMock()
+        mock_asset_repo.get = MagicMock(return_value=_make_mock_asset("a1", 30.0))
+
+        body = ClipsFromAssetsRequest(asset_ids=["a1"], required_clips_count=3)
+
+        create_clips_from_assets_editor(
+            template_id="tpl-001",
+            body=body,
+            plan_id=TEST_PLAN_ID,
+            services=(MagicMock(), mock_plan_svc),
+            asset_repo=mock_asset_repo,
+            current_user=_make_auth_user(),
+        )
+
+        calls = mock_plan_svc.create_clip.call_args_list
+        assert calls[0].kwargs["order"] == 2
+        assert calls[1].kwargs["order"] == 3
+        assert calls[2].kwargs["order"] == 4
+
+    @patch("app.api.routes.templates_editor.clips.get_storage_service")
+    def test_orders_start_at_zero_when_empty(self, mock_storage):
+        """空时间线时 order 从 0 开始."""
+        from app.api.routes.templates_editor.clips import (
+            create_clips_from_assets_editor,
+        )
+        from app.api.routes.templates_editor.schemas import ClipsFromAssetsRequest
+
+        mock_plan_svc = _make_plan_svc(existing_clips=[])
+
+        mock_asset_repo = MagicMock()
+        mock_asset_repo.get = MagicMock(return_value=_make_mock_asset("a1", 30.0))
+
+        body = ClipsFromAssetsRequest(asset_ids=["a1"], required_clips_count=3)
+
+        create_clips_from_assets_editor(
+            template_id="tpl-001",
+            body=body,
+            plan_id=TEST_PLAN_ID,
+            services=(MagicMock(), mock_plan_svc),
+            asset_repo=mock_asset_repo,
+            current_user=_make_auth_user(),
+        )
+
+        calls = mock_plan_svc.create_clip.call_args_list
+        assert calls[0].kwargs["order"] == 0
+        assert calls[1].kwargs["order"] == 1
+        assert calls[2].kwargs["order"] == 2
+
+    @patch("app.api.routes.templates_editor.clips.get_storage_service")
+    def test_backward_compatible_default_count(self, mock_storage):
+        """不传 required_clips_count 时，片段数等于素材数（向后兼容）."""
+        from app.api.routes.templates_editor.clips import (
+            create_clips_from_assets_editor,
+        )
+        from app.api.routes.templates_editor.schemas import ClipsFromAssetsRequest
+
+        mock_plan_svc = _make_plan_svc()
+        mock_asset_repo = MagicMock()
+        mock_asset_repo.get = MagicMock(side_effect=lambda aid: _make_mock_asset(aid, 30.0))
+
+        body = ClipsFromAssetsRequest(asset_ids=["a1", "a2", "a3"])
+
+        result = create_clips_from_assets_editor(
+            template_id="tpl-001",
+            body=body,
+            plan_id=TEST_PLAN_ID,
+            services=(MagicMock(), mock_plan_svc),
+            asset_repo=mock_asset_repo,
+            current_user=_make_auth_user(),
+        )
+
+        assert result.created_count == 3
+        assert mock_plan_svc.create_clip.call_count == 3
+
+
+class TestEditorClipsDurationAndStartTime:
+    """测试素材时长获取、clip duration 缩短、start_time 传入."""
+
+    @patch("app.api.routes.templates_editor.clips.get_storage_service")
+    def test_clip_duration_shortened_for_short_assets(self, mock_storage):
+        """素材只有 3s 时 clip duration 缩短到 3.0."""
+        from app.api.routes.templates_editor.clips import (
+            create_clips_from_assets_editor,
+        )
+        from app.api.routes.templates_editor.schemas import ClipsFromAssetsRequest
+
+        mock_plan_svc = _make_plan_svc()
+        mock_asset_repo = MagicMock()
+        mock_asset_repo.get = MagicMock(return_value=_make_mock_asset("short", 3.0))
+
+        body = ClipsFromAssetsRequest(asset_ids=["short"])
+
+        create_clips_from_assets_editor(
+            template_id="tpl-001",
+            body=body,
+            plan_id=TEST_PLAN_ID,
+            services=(MagicMock(), mock_plan_svc),
+            asset_repo=mock_asset_repo,
+            current_user=_make_auth_user(),
+        )
+
+        calls = mock_plan_svc.create_clip.call_args_list
+        assert len(calls) == 1
+        assert calls[0].kwargs["duration"] == 3.0
+
+    @patch("app.api.routes.templates_editor.clips.get_storage_service")
+    def test_start_time_passed_to_create_clip(self, mock_storage):
+        """验证 _calc_random_start_time 返回值被传入 create_clip."""
+        from app.api.routes.templates_editor.clips import (
+            create_clips_from_assets_editor,
+        )
+        from app.api.routes.templates_editor.schemas import ClipsFromAssetsRequest
+
+        mock_plan_svc = _make_plan_svc()
+        mock_asset_repo = MagicMock()
+        mock_asset_repo.get = MagicMock(return_value=_make_mock_asset("a1", 30.0))
+
+        body = ClipsFromAssetsRequest(asset_ids=["a1"], required_clips_count=2)
+
+        with patch(
+            "app.api.routes.templates_editor.clips._calc_random_start_time",
+            side_effect=[12.5, 18.0],
+        ) as mock_calc:
+            create_clips_from_assets_editor(
+                template_id="tpl-001",
+                body=body,
+                plan_id=TEST_PLAN_ID,
+                services=(MagicMock(), mock_plan_svc),
+                asset_repo=mock_asset_repo,
+                current_user=_make_auth_user(),
+            )
+
+        assert mock_calc.call_count == 2
+        calls = mock_plan_svc.create_clip.call_args_list
+        assert calls[0].kwargs["start_time"] == 12.5
+        assert calls[1].kwargs["start_time"] == 18.0
+
+    @patch("app.api.routes.templates_editor.clips.get_storage_service")
+    def test_asset_durations_deduped(self, mock_storage):
+        """asset_ids 有重复时只查询一次素材时长."""
+        from app.api.routes.templates_editor.clips import (
+            create_clips_from_assets_editor,
+        )
+        from app.api.routes.templates_editor.schemas import ClipsFromAssetsRequest
+
+        mock_plan_svc = _make_plan_svc()
+        mock_asset_repo = MagicMock()
+        mock_asset_repo.get = MagicMock(return_value=_make_mock_asset("a1", 30.0))
+
+        # a1 出现 3 次，但时长只应查一次
+        body = ClipsFromAssetsRequest(asset_ids=["a1", "a1", "a1"])
+
+        create_clips_from_assets_editor(
+            template_id="tpl-001",
+            body=body,
+            plan_id=TEST_PLAN_ID,
+            services=(MagicMock(), mock_plan_svc),
+            asset_repo=mock_asset_repo,
+            current_user=_make_auth_user(),
+        )
+
+        # 去重后只调用 1 次
+        assert mock_asset_repo.get.call_count == 1
+
+    @patch("app.api.routes.templates_editor.clips.get_storage_service")
+    def test_used_segments_passed_to_calc(self, mock_storage):
+        """同一素材切多个片段时，used_segments 应被维护并传入."""
+        from app.api.routes.templates_editor.clips import (
+            create_clips_from_assets_editor,
+        )
+        from app.api.routes.templates_editor.schemas import ClipsFromAssetsRequest
+
+        mock_plan_svc = _make_plan_svc()
+        mock_asset_repo = MagicMock()
+        mock_asset_repo.get = MagicMock(return_value=_make_mock_asset("a1", 30.0))
+
+        body = ClipsFromAssetsRequest(asset_ids=["a1"], required_clips_count=3)
+
+        captured_used_segments = []
+
+        def fake_calc(asset_id, clip_duration, asset_durations, used_segments):
+            captured_used_segments.append({aid: list(segs) for aid, segs in (used_segments or {}).items()})
+            return (len(captured_used_segments) - 1) * 5.0
+
+        with patch(
+            "app.api.routes.templates_editor.clips._calc_random_start_time",
+            side_effect=fake_calc,
+        ):
+            create_clips_from_assets_editor(
+                template_id="tpl-001",
+                body=body,
+                plan_id=TEST_PLAN_ID,
+                services=(MagicMock(), mock_plan_svc),
+                asset_repo=mock_asset_repo,
+                current_user=_make_auth_user(),
+            )
+
+        assert captured_used_segments[0] == {}
+        assert captured_used_segments[1] == {"a1": [(0.0, 5.0)]}
+        assert captured_used_segments[2] == {"a1": [(0.0, 5.0), (5.0, 10.0)]}
+
+
+class TestEditorClipsErrorHandling:
+    """测试异常处理."""
+
+    @patch("app.api.routes.templates_editor.clips.get_storage_service")
+    def test_none_start_time_raises_400(self, mock_storage):
+        """_calc_random_start_time 返回 None 时应抛出 HTTPException 400."""
+        from app.api.routes.templates_editor.clips import (
+            create_clips_from_assets_editor,
+        )
+        from app.api.routes.templates_editor.schemas import ClipsFromAssetsRequest
+
+        mock_plan_svc = _make_plan_svc()
+        # asset_repo.get 返回 None → asset_durations 为空 → _calc_random_start_time 返回 None
+        mock_asset_repo = MagicMock()
+        mock_asset_repo.get = MagicMock(return_value=None)
+
+        body = ClipsFromAssetsRequest(asset_ids=["missing-asset"])
+
+        with pytest.raises(HTTPException) as exc_info:
+            create_clips_from_assets_editor(
+                template_id="tpl-001",
+                body=body,
+                plan_id=TEST_PLAN_ID,
+                services=(MagicMock(), mock_plan_svc),
+                asset_repo=mock_asset_repo,
+                current_user=_make_auth_user(),
+            )
+
+        assert exc_info.value.status_code == 400
+        assert "时长信息缺失" in exc_info.value.detail
+
+    @patch("app.api.routes.templates_editor.clips.get_storage_service")
+    def test_create_clip_value_error_raises_400(self, mock_storage):
+        """create_clip 抛出 ValueError 时应转为 HTTPException 400."""
+        from app.api.routes.templates_editor.clips import (
+            create_clips_from_assets_editor,
+        )
+        from app.api.routes.templates_editor.schemas import ClipsFromAssetsRequest
+
+        mock_plan_svc = _make_plan_svc()
+        mock_plan_svc.create_clip = MagicMock(side_effect=ValueError("计划不存在"))
+
+        mock_asset_repo = MagicMock()
+        mock_asset_repo.get = MagicMock(return_value=_make_mock_asset("a1", 30.0))
+
+        body = ClipsFromAssetsRequest(asset_ids=["a1"])
+
+        with pytest.raises(HTTPException) as exc_info:
+            create_clips_from_assets_editor(
+                template_id="tpl-001",
+                body=body,
+                plan_id=TEST_PLAN_ID,
+                services=(MagicMock(), mock_plan_svc),
+                asset_repo=mock_asset_repo,
+                current_user=_make_auth_user(),
+            )
+
+        assert exc_info.value.status_code == 400
+        assert "创建片段失败" in exc_info.value.detail

tests/unit/test_generated_video_creation_logic.py

@@ -321,6 +321,27 @@ class TestThumbnailInDedupHelpers:
         video_processing.dedup = mock_dedup
         video_processing.thumbnail_generator = mock_thumb
 
+    @classmethod
+    def teardown_class(cls):
+        """恢复 setup_class 中替换的模块，避免污染后续测试。"""
+        import sys
+
+        import video_processing
+
+        # 从 sys.modules 移除 mock 模块
+        for mod_name in ("video_processing.thumbnail_generator", "video_processing.dedup"):
+            sys.modules.pop(mod_name, None)
+
+        # 重新导入真实模块以恢复 sys.modules
+        try:
+            import video_processing.thumbnail_generator  # noqa: F401
+        except Exception:
+            pass
+        try:
+            import video_processing.dedup  # noqa: F401
+        except Exception:
+            pass
+
     def test_pre_generated_thumbnail_url_is_reused(self):
         """传入 thumbnail_url 时直接复用，统一封面管道不再自动生成缩略图。"""
         from video_processing.dedup_helpers import create_video_record_and_dedup

tests/unit/test_plan_generator.py

@@ -886,3 +886,120 @@ class TestTemplateConfigPropagation:
         assert clip_cfg.get("speed_ratio") == 1.2
         assert clip_cfg.get("name") == "开场"
         assert clip_cfg.get("custom_field") == "value"
+
+
+class TestAssetDurationsAlwaysFetched:
+    """验证 asset_durations 不再受 random_preview 条件限制。
+
+    修复前：asset_durations 仅在 random_preview=True 时传入 distribute_assets
+    修复后：只要 _asset_repo 存在，就始终获取 asset_durations
+    """
+
+    def _make_service_with_asset_repo(self):
+        """创建带 mock asset_repo 的 PlanGeneratorService"""
+        from apps.api.app.services.plan_generator_service import PlanGeneratorService
+
+        plan_repo = StubEditPlanRepository()
+        clip_repo = StubEditPlanClipRepository()
+
+        # mock asset_repo: 返回带 duration 的素材
+        asset_repo = MagicMock()
+
+        def fake_get(asset_id):
+            mock_asset = MagicMock()
+            mock_asset.duration = 30.0  # 每个素材 30 秒
+            return mock_asset
+
+        asset_repo.get = MagicMock(side_effect=fake_get)
+
+        with (
+            patch(
+                "apps.api.app.services.plan_generator_service.SQLAlchemyEditPlanRepository",
+                return_value=plan_repo,
+            ),
+            patch(
+                "apps.api.app.services.plan_generator_service.SQLAlchemyEditPlanClipRepository",
+                return_value=clip_repo,
+            ),
+        ):
+            db = MagicMock()
+            svc = PlanGeneratorService(db, asset_repo=asset_repo)
+            svc._plan_repo = plan_repo
+            svc._clip_repo = clip_repo
+
+        return svc, asset_repo
+
+    def test_asset_durations_fetched_without_random_preview(self):
+        """random_preview=False 时也应获取 asset_durations"""
+        svc, asset_repo = self._make_service_with_asset_repo()
+
+        template = _make_template("one_take")
+        clip_configs = _make_clip_configs(
+            template_id=template.id,
+            specs=[{"clip_type": ClipType.MAIN, "order": 0, "min_duration": 3.0, "max_duration": 5.0}],
+        )
+
+        # patch distribute_assets 以捕获传入的参数
+        with patch("apps.api.app.services.plan_generator_service.distribute_assets") as mock_distribute:
+            svc.generate_from_template(
+                template=template,
+                clip_configs=clip_configs,
+                asset_ids=["a1", "a2"],
+                random_preview=False,  # 关键：非随机预览模式
+            )
+
+            # 验证 asset_durations 被传入（不是 None）
+            mock_distribute.assert_called_once()
+            call_kwargs = mock_distribute.call_args
+            asset_durations = call_kwargs.kwargs.get("asset_durations", call_kwargs[1].get("asset_durations"))
+            assert asset_durations is not None, "asset_durations should be fetched even when random_preview=False"
+            assert "a1" in asset_durations
+            assert "a2" in asset_durations
+            assert asset_durations["a1"] == 30.0
+
+        # 验证 asset_repo.get 被调用（说明 _fetch_asset_durations 执行了）
+        assert asset_repo.get.call_count >= 2
+
+    def test_asset_durations_fetched_with_random_preview(self):
+        """random_preview=True 时仍正常获取 asset_durations（行为不变）"""
+        svc, asset_repo = self._make_service_with_asset_repo()
+
+        template = _make_template("one_take")
+        clip_configs = _make_clip_configs(
+            template_id=template.id,
+            specs=[{"clip_type": ClipType.MAIN, "order": 0, "min_duration": 3.0, "max_duration": 5.0}],
+        )
+
+        with patch("apps.api.app.services.plan_generator_service.distribute_assets") as mock_distribute:
+            svc.generate_from_template(
+                template=template,
+                clip_configs=clip_configs,
+                asset_ids=["a1"],
+                random_preview=True,
+            )
+
+            call_kwargs = mock_distribute.call_args
+            asset_durations = call_kwargs.kwargs.get("asset_durations", call_kwargs[1].get("asset_durations"))
+            assert asset_durations is not None
+            assert "a1" in asset_durations
+
+    def test_no_asset_repo_means_no_durations(self):
+        """_asset_repo 为 None 时 asset_durations 应为 None"""
+        svc, _, _ = _make_generator()  # 默认不带 asset_repo
+
+        template = _make_template("one_take")
+        clip_configs = _make_clip_configs(
+            template_id=template.id,
+            specs=[{"clip_type": ClipType.MAIN, "order": 0, "min_duration": 3.0, "max_duration": 5.0}],
+        )
+
+        with patch("apps.api.app.services.plan_generator_service.distribute_assets") as mock_distribute:
+            svc.generate_from_template(
+                template=template,
+                clip_configs=clip_configs,
+                asset_ids=["a1"],
+            )
+
+            call_kwargs = mock_distribute.call_args
+            asset_durations = call_kwargs.kwargs.get("asset_durations", call_kwargs[1].get("asset_durations"))
+            assert asset_durations is None

tests/unit/test_plan_generator_utils.py

@@ -10,6 +10,7 @@ from packages.domain.edit_plan_clip import EditPlanClip
 from packages.domain.editing_mode import EditingMode
 from packages.domain.plan_generator_utils import (
     DEFAULT_CLIP_DURATION,
+    _calc_random_start_time,
     create_clips_from_configs,
     distribute_assets,
     generate_default_clips,
@@ -647,3 +648,132 @@ class TestConstants:
     def test_default_duration_value(self):
         """默认片段时长应为 5 秒."""
         assert DEFAULT_CLIP_DURATION == 5.0
+
+
+# ── 随机 start_time 与去重测试 ─────────────────────────────────────────
+
+
+class TestCalcRandomStartTime:
+    """_calc_random_start_time 函数测试."""
+
+    def test_no_durations_returns_none(self):
+        """asset_durations 为 None 时返回 None."""
+        result = _calc_random_start_time("a1", 5.0, None)
+        assert result is None
+
+    def test_asset_not_in_durations_returns_none(self):
+        """素材不在 durations 映射中时返回 None."""
+        result = _calc_random_start_time("a_missing", 5.0, {"a1": 60.0})
+        assert result is None
+
+    def test_zero_duration_returns_none(self):
+        """素材时长为 0 时返回 None."""
+        result = _calc_random_start_time("a1", 5.0, {"a1": 0.0})
+        assert result is None
+
+    def test_clip_longer_than_asset_returns_zero(self):
+        """片段时长 >= 素材时长时返回 0.0."""
+        result = _calc_random_start_time("a1", 60.0, {"a1": 30.0})
+        assert result == 0.0
+
+    def test_returns_value_in_range(self):
+        """返回值在 [0, max_start] 范围内."""
+        for _ in range(50):
+            result = _calc_random_start_time("a1", 5.0, {"a1": 30.0})
+            assert result is not None
+            assert 0.0 <= result <= 25.0
+
+    def test_avoids_used_segments(self):
+        """生成的 start_time 不与已使用段重叠."""
+        used = {"a1": [(10.0, 15.0), (20.0, 25.0)]}
+        for _ in range(100):
+            result = _calc_random_start_time("a1", 3.0, {"a1": 30.0}, used)
+            assert result is not None
+            end = result + 3.0
+            # 不应与 [10,15) 重叠
+            assert not (result < 15.0 and 10.0 < end)
+            # 不应与 [20,25) 重叠
+            assert not (result < 25.0 and 20.0 < end)
+
+    def test_fallback_when_no_space(self):
+        """所有空间都被占用时，回退到最后已使用段之后或 0."""
+        used = {"a1": [(0.0, 28.0)]}
+        result = _calc_random_start_time("a1", 5.0, {"a1": 30.0}, used)
+        assert result is not None
+        # 应该返回 last_used_end (28.0) 但受限于 max_start (25.0)，取 min
+        assert result == 25.0
+
+    def test_no_used_segments_for_asset(self):
+        """used_segments 中没有当前 asset_id 时正常随机."""
+        used = {"a2": [(10.0, 15.0)]}
+        for _ in range(20):
+            result = _calc_random_start_time("a1", 5.0, {"a1": 30.0}, used)
+            assert result is not None
+            assert 0.0 <= result <= 25.0
+
+
+class TestDistributeAssetsOverlapAvoidance:
+    """测试 distribute_assets 中同一素材被多次使用时的去重逻辑."""
+
+    def test_same_asset_reused_no_overlap(self):
+        """同一素材分配给多个 clip 时，start_time 不重叠."""
+        # 2 个 clip 共享同一素材，素材时长足够
+        clips = [
+            EditPlanClip.create(plan_id="p1", clip_type=ClipType.MAIN.value, order=0, duration=5.0),
+            EditPlanClip.create(plan_id="p1", clip_type=ClipType.MAIN.value, order=1, duration=5.0),
+        ]
+        asset_ids = ["a1", "a1"]  # 同一素材用两次
+        durations = {"a1": 60.0}
+
+        distribute_assets(clips, asset_ids, EditingMode.ONE_TAKE.value, asset_durations=durations)
+
+        # 两个 clip 都应有 start_time
+        assert clips[0].start_time is not None
+        assert clips[1].start_time is not None
+        # 两段不应重叠
+        s1, e1 = clips[0].start_time, clips[0].start_time + 5.0
+        s2, e2 = clips[1].start_time, clips[1].start_time + 5.0
+        assert not (s1 < e2 and s2 < e1), f"Segments overlap: [{s1},{e1}) and [{s2},{e2})"
+
+    def test_different_assets_independent(self):
+        """不同素材各自独立随机，互不影响."""
+        clips = [
+            EditPlanClip.create(plan_id="p1", clip_type=ClipType.MAIN.value, order=0, duration=5.0),
+            EditPlanClip.create(plan_id="p1", clip_type=ClipType.MAIN.value, order=1, duration=5.0),
+        ]
+        asset_ids = ["a1", "a2"]
+        durations = {"a1": 60.0, "a2": 60.0}
+
+        distribute_assets(clips, asset_ids, EditingMode.ONE_TAKE.value, asset_durations=durations)
+
+        assert clips[0].asset_id == "a1"
+        assert clips[1].asset_id == "a2"
+        assert clips[0].start_time is not None
+        assert clips[1].start_time is not None
+
+    def test_no_durations_still_works(self):
+        """不传 asset_durations 时仍正常分配（start_time 为 None）."""
+        clips = [
+            EditPlanClip.create(plan_id="p1", clip_type=ClipType.MAIN.value, order=0, duration=5.0),
+        ]
+        distribute_assets(clips, ["a1"], EditingMode.ONE_TAKE.value)
+        assert clips[0].asset_id == "a1"
+        # start_time 默认为 0.0（模型默认值）
+        assert clips[0].start_time == 0.0
+
+    def test_voice_pip_overlap_avoidance(self):
+        """VOICE_PIP 模式下同一素材多次使用时避免重叠."""
+        clips = [
+            EditPlanClip.create(plan_id="p1", clip_type="background", order=0, duration=5.0),
+            EditPlanClip.create(plan_id="p1", clip_type="b_roll", order=1, duration=5.0),
+        ]
+        asset_ids = ["a1", "a1"]  # 同一素材用两次
+        durations = {"a1": 60.0}
+
+        distribute_assets(clips, asset_ids, EditingMode.VOICE_PIP.value, asset_durations=durations)
+
+        assert clips[0].start_time is not None
+        assert clips[1].start_time is not None
+        s1, e1 = clips[0].start_time, clips[0].start_time + 5.0
+        s2, e2 = clips[1].start_time, clips[1].start_time + 5.0
+        assert not (s1 < e2 and s2 < e1), f"Segments overlap: [{s1},{e1}) and [{s2},{e2})"

tests/unit/test_render_audio_pure.py

@@ -11,6 +11,7 @@ from video_processing.render_audio import (
     RenderContext,
     clip_effective_duration,
     clip_has_audio,
+    mix_with_independent_audio,
 )
 from video_processing.unified_render_service import ResolvedClip
 
@@ -153,3 +154,93 @@ class TestRenderContext:
         """音频缓存初始为空."""
         ctx = _make_ctx()
         assert ctx._audio_cache == {}
+
+
+class TestMixWithIndependentAudioVolume:
+    """测试 mix_with_independent_audio 中主视频 clip 音量滤镜是否生效。"""
+
+    def _make_clip(self, volume=None, clip_id="c1", duration=5.0):
+        """创建测试用 ResolvedClip。"""
+        config = {}
+        if volume is not None:
+            config["volume"] = volume
+        return ResolvedClip(
+            clip_id=clip_id,
+            asset_id=f"a_{clip_id}",
+            local_path=Path(f"/tmp/{clip_id}.mp4"),
+            clip_type="main",
+            order=0,
+            duration=duration,
+            actual_duration=duration,
+            config=config,
+        )
+
+    def test_main_clip_volume_zero_applied_in_filter(self):
+        """volume=0 的主视频 clip 应在 filter_complex 中包含 volume=0.0000。"""
+        from unittest.mock import patch
+
+        ctx = _make_ctx()
+        main_clip = self._make_clip(volume=0, clip_id="m1")
+        captured_cmd = {}
+
+        def fake_run_ffmpeg(cmd):
+            captured_cmd["cmd"] = cmd
+
+        with patch("video_processing.render_audio.run_ffmpeg", side_effect=fake_run_ffmpeg):
+            mix_with_independent_audio(
+                ctx=ctx,
+                main_clips=[main_clip],
+                audio_clips=[],
+                output_path=Path("/tmp/out.m4a"),
+                video_duration=5.0,
+            )
+
+        filter_complex = captured_cmd["cmd"][captured_cmd["cmd"].index("-filter_complex") + 1]
+        assert "volume=0.0000" in filter_complex, f"volume filter missing in: {filter_complex}"
+
+    def test_main_clip_default_volume_no_filter(self):
+        """默认 volume=1.0 时不应添加 volume 滤镜。"""
+        from unittest.mock import patch
+
+        ctx = _make_ctx()
+        main_clip = self._make_clip(clip_id="m1")  # no volume set
+        captured_cmd = {}
+
+        def fake_run_ffmpeg(cmd):
+            captured_cmd["cmd"] = cmd
+
+        with patch("video_processing.render_audio.run_ffmpeg", side_effect=fake_run_ffmpeg):
+            mix_with_independent_audio(
+                ctx=ctx,
+                main_clips=[main_clip],
+                audio_clips=[],
+                output_path=Path("/tmp/out.m4a"),
+                video_duration=5.0,
+            )
+
+        filter_complex = captured_cmd["cmd"][captured_cmd["cmd"].index("-filter_complex") + 1]
+        # 默认音量不应出现 volume= 滤镜
+        assert "volume=" not in filter_complex, f"unexpected volume filter in: {filter_complex}"
+
+    def test_main_clip_partial_volume_applied(self):
+        """volume=0.5 的主视频 clip 应包含 volume=0.5000。"""
+        from unittest.mock import patch
+
+        ctx = _make_ctx()
+        main_clip = self._make_clip(volume=0.5, clip_id="m1")
+        captured_cmd = {}
+
+        def fake_run_ffmpeg(cmd):
+            captured_cmd["cmd"] = cmd
+
+        with patch("video_processing.render_audio.run_ffmpeg", side_effect=fake_run_ffmpeg):
+            mix_with_independent_audio(
+                ctx=ctx,
+                main_clips=[main_clip],
+                audio_clips=[],
+                output_path=Path("/tmp/out.m4a"),
+                video_duration=5.0,
+            )
+
+        filter_complex = captured_cmd["cmd"][captured_cmd["cmd"].index("-filter_complex") + 1]
+        assert "volume=0.5000" in filter_complex, f"volume filter missing in: {filter_complex}"

tests/unit/test_render_subtitles.py

@@ -80,13 +80,13 @@ class TestBuildAssStyle:
     def test_basic_style(self):
         style = _build_ass_style("Default")
         assert style.startswith("Style: Default,")
-        assert "思源黑体" in style
-        assert "48" in style  # font_size
+        assert "Noto Sans SC" in style
+        assert "65" in style  # font_size 48*1.35=65
 
     def test_custom_font(self):
         style = _build_ass_style("Custom", font_name="Arial", font_size=32)
         assert "Arial" in style
-        assert ",32," in style
+        assert ",43," in style  # font_size 32*1.35=43
 
     def test_bold(self):
         style = _build_ass_style("Bold", bold=True)

tests/unit/test_render_subtitles_pure.py

@@ -84,8 +84,8 @@ class TestBuildAssStyle:
         """基本样式行包含关键字段."""
         line = _build_ass_style("Default")
         assert line.startswith("Style: Default,")
-        assert "思源黑体" in line
-        assert "48" in line  # font_size
+        assert "Noto Sans SC" in line
+        assert "65" in line  # font_size 48*1.35=65
 
     def test_bold_enabled(self):
         """加粗时Bold=-1."""
@@ -112,7 +112,7 @@ class TestBuildAssStyle:
         """自定义字号."""
         line = _build_ass_style("Big", font_size=72)
         parts = line.split(",")
-        assert parts[2] == "72"  # Fontsize
+        assert parts[2] == "97"  # Fontsize 72*1.35=97
 
     def test_custom_alignment(self):
         """自定义对齐方式."""

tests/unit/test_thumbnail_generator.py

@@ -86,3 +86,138 @@ class TestFormatSeekTime:
         sec_parts = parts[2].split(".")
         assert len(sec_parts) == 2
         assert len(sec_parts[1]) == 2  # 两位小数
+
+
+# ── MediaKit 智能抽帧集成测试 ──────────────────────────────────────────
+
+
+class TestExtractFramesViaMediakit:
+    """_extract_frames_via_mediakit 函数测试."""
+
+    def test_mediakit_not_configured_returns_none(self, tmp_path, monkeypatch):
+        """MediaKit 未配置时返回 None."""
+        from video_processing.thumbnail_generator import _extract_frames_via_mediakit
+
+        # Mock get_mediakit_client 返回不可用客户端
+        class FakeClient:
+            is_available = False
+
+        monkeypatch.setattr(
+            "packages.shared.mediakit_client.get_mediakit_client",
+            lambda: FakeClient(),
+        )
+
+        video_file = tmp_path / "test.mp4"
+        video_file.write_bytes(b"fake video")
+
+        result = _extract_frames_via_mediakit(str(video_file), "plan1", 3)
+        assert result is None
+
+    def test_mediakit_success_returns_frames(self, tmp_path, monkeypatch):
+        """MediaKit 成功时返回帧列表."""
+        from video_processing.thumbnail_generator import _extract_frames_via_mediakit
+
+        class FakeClient:
+            is_available = True
+
+            def extract_frames(self, video_url, strategy, max_frames):
+                return [
+                    {"image_url": "https://example.com/frame1.jpg", "timestamp": 1.5},
+                    {"image_url": "https://example.com/frame2.jpg", "timestamp": 3.2},
+                ]
+
+        monkeypatch.setattr(
+            "packages.shared.mediakit_client.get_mediakit_client",
+            lambda: FakeClient(),
+        )
+        # Mock upload_to_oss
+        monkeypatch.setattr(
+            "video_processing.oss_helpers.upload_to_oss",
+            lambda path, key: f"https://oss.example.com/{key}",
+        )
+        # Mock httpx.get for downloading frame
+        import httpx
+
+        class FakeResponse:
+            status_code = 200
+            content = b"fake image data"
+
+            def raise_for_status(self):
+                pass
+
+        monkeypatch.setattr("httpx.get", lambda url, **kw: FakeResponse())
+
+        video_file = tmp_path / "test.mp4"
+        video_file.write_bytes(b"fake video")
+
+        result = _extract_frames_via_mediakit(str(video_file), "plan1", 2)
+        assert result is not None
+        assert len(result) == 2
+        assert result[0]["timestamp"] == 1.5
+        assert result[1]["timestamp"] == 3.2
+
+    def test_mediakit_failure_returns_none(self, tmp_path, monkeypatch):
+        """MediaKit 调用失败时返回 None."""
+        from video_processing.thumbnail_generator import _extract_frames_via_mediakit
+
+        class FakeClient:
+            is_available = True
+
+            def extract_frames(self, video_url, strategy, max_frames):
+                return None
+
+        monkeypatch.setattr(
+            "packages.shared.mediakit_client.get_mediakit_client",
+            lambda: FakeClient(),
+        )
+        monkeypatch.setattr(
+            "video_processing.oss_helpers.upload_to_oss",
+            lambda path, key: f"https://oss.example.com/{key}",
+        )
+
+        video_file = tmp_path / "test.mp4"
+        video_file.write_bytes(b"fake video")
+
+        result = _extract_frames_via_mediakit(str(video_file), "plan1", 3)
+        assert result is None
+
+
+class TestExtractAndUploadCoverFramesFallback:
+    """extract_and_upload_cover_frames 降级逻辑测试."""
+
+    def test_fallback_to_ffmpeg_when_mediakit_fails(self, tmp_path, monkeypatch):
+        """MediaKit 失败时降级到 ffmpeg 抽帧."""
+        from video_processing.thumbnail_generator import extract_and_upload_cover_frames
+
+        # Mock MediaKit 返回 None（未配置或失败）
+        class FakeClient:
+            is_available = False
+
+        monkeypatch.setattr(
+            "packages.shared.mediakit_client.get_mediakit_client",
+            lambda: FakeClient(),
+        )
+
+        # Mock ffmpeg 抽帧
+        monkeypatch.setattr(
+            "video_processing.thumbnail_generator.extract_first_frame",
+            lambda video_path, output_path, **kw: output_path,
+        )
+        # Mock upload
+        monkeypatch.setattr(
+            "video_processing.oss_helpers.upload_to_oss",
+            lambda path, key: f"https://oss.example.com/{key}",
+        )
+        # Mock probe_duration
+        monkeypatch.setattr(
+            "video_processing.ffmpeg_utils.probe_duration",
+            lambda path: 60.0,
+        )
+
+        video_file = tmp_path / "test.mp4"
+        video_file.write_bytes(b"fake video")
+
+        result = extract_and_upload_cover_frames(str(video_file), "plan1", num_frames=2)
+        assert len(result) == 2
+        assert all("url" in item for item in result)
+        assert all("position" in item for item in result)

tests/unit/test_title_render_consistency.py

@@ -1,7 +1,7 @@
 """标题渲染前后端一致性测试。
 
 验证 build_ass_content 生成的 ASS 样式参数与前端 drawTitleOnCanvas.ts 一致：
-- 字号上限 36px
+- 字号不再设置上限，由前端/调用方控制
 - 描边宽度 2px
 - 阴影 blur=4, offset=2
 - boolean stroke/shadow 自动转换
@@ -10,14 +10,16 @@
 import sys
 from pathlib import Path
 
+import pytest
+
 # Ensure packages is importable
 sys.path.insert(0, str(Path(__file__).resolve().parents[2] / "packages"))
 
 from domain.ass_subtitle_builder import build_ass_content, build_ass_style
 
 
-class TestFontSizeCap:
-    """字号上限应与前端 Math.min(settings.size, 36) 一致。"""
+class TestFontSize:
+    """字号处理：默认值与保留逻辑，不再做上限截断。"""
 
     def test_default_font_size_is_36(self):
         """无 size 字段时，默认字号应为 36。"""
@@ -29,7 +31,7 @@ class TestFontSizeCap:
             title_text="测试标题",
             title_config=config,
         )
-        assert ",36," in content, f"默认字号应为36，实际内容: {content}"
+        assert ",49," in content, f"默认字号36应补偿为49(36*1.35)，实际内容: {content}"
 
     def test_size_32_preserved(self):
         """size=32 应原样使用。"""
@@ -41,10 +43,10 @@ class TestFontSizeCap:
             title_text="测试标题",
             title_config=config,
         )
-        assert ",32," in content
+        assert ",43," in content  # 32*1.35=43
 
-    def test_size_60_capped_at_36(self):
-        """size=60 应被 cap 到 36。"""
+    def test_size_60_preserved(self):
+        """size=60 应原样保留（字号上限已移除）。"""
         config = {"size": 60}
         content = build_ass_content(
             video_width=1080,
@@ -53,14 +55,40 @@ class TestFontSizeCap:
             title_text="测试标题",
             title_config=config,
         )
-        # 解析 Style 行的 Fontsize 字段（第3个字段，索引2）
         style_line = [line for line in content.splitlines() if line.startswith("Style: TitleStyle")][0]
         fields = [f.strip() for f in style_line.split(",")]
         font_size = int(fields[2])
-        assert font_size == 36, f"字号60应被cap到36, 实际={font_size}"
+        assert font_size == 81, f"字号60应补偿为81(60*1.35), 实际={font_size}"
+
+    def test_font_size_alias_normalized(self):
+        """前端传 font_size 应归一化为 size。"""
+        config = {"font_size": 52}
+        content = build_ass_content(
+            video_width=1080,
+            video_height=1920,
+            video_duration=10.0,
+            title_text="测试标题",
+            title_config=config,
+        )
+        style_line = [line for line in content.splitlines() if line.startswith("Style: TitleStyle")][0]
+        fields = [f.strip() for f in style_line.split(",")]
+        assert fields[2] == "70", f"font_size=52 应补偿为70(52*1.35), 实际={fields[2]}"
+
+    def test_font_color_alias_normalized(self):
+        """前端传 font_color 应归一化为 color。"""
+        config = {"font_color": "#00FF00"}
+        content = build_ass_content(
+            video_width=1080,
+            video_height=1920,
+            video_duration=10.0,
+            title_text="测试标题",
+            title_config=config,
+        )
+        # 绿色 → &H00FF00
+        assert "&H00FF00" in content
 
     def test_size_24_preserved(self):
-        """size=24 应原样使用（小于36，不cap）。"""
+        """size=24 应原样使用。"""
         config = {"size": 24}
         content = build_ass_content(
             video_width=1080,
@@ -69,7 +97,7 @@ class TestFontSizeCap:
             title_text="测试标题",
             title_config=config,
         )
-        assert ",24," in content
+        assert ",32," in content  # 24*1.35=32.4→32
 
 
 class TestBooleanStrokeNormalization:
@@ -202,9 +230,9 @@ class TestFullStyleConsistency:
         fields = [f.strip() for f in style_line.split(",")]
 
         # Fontname
-        assert fields[1] == "思源黑体"
-        # Fontsize = 28 (小于36，不cap)
-        assert fields[2] == "28"
+        assert fields[1] == "Noto Sans SC"
+        # Fontsize = 28*1.35=37.8→38
+        assert fields[2] == "38"
         # Bold = -1 (True)
         assert fields[7] == "-1"
         # Outline width = 2 (前端默认 stroke width)
@@ -213,3 +241,39 @@ class TestFullStyleConsistency:
         assert int(fields[17]) == 2
         # Alignment = 8 (top)
         assert int(fields[18]) == 8
+
+
+class TestTitleSlashNewline:
+    """用户输入 / 或 ／ 应触发标题换行。"""
+
+    def test_halfwidth_slash_in_title(self):
+        content = build_ass_content(
+            video_width=1080,
+            video_height=1920,
+            video_duration=10.0,
+            title_text="第一行/第二行",
+            title_config={"size": 48},
+        )
+        for line in content.splitlines():
+            if "Dialogue" in line and "TitleStyle" in line:
+                assert "\\N" in line, f"斜杠应转为换行: {line}"
+                assert "第一行" in line
+                assert "第二行" in line
+                break
+        else:
+            pytest.fail("未找到 TitleStyle Dialogue 行")
+
+    def test_fullwidth_slash_in_title(self):
+        content = build_ass_content(
+            video_width=1080,
+            video_height=1920,
+            video_duration=10.0,
+            title_text="第一行／第二行",
+            title_config={"size": 48},
+        )
+        for line in content.splitlines():
+            if "Dialogue" in line and "TitleStyle" in line:
+                assert "\\N" in line, f"全角斜杠应转为换行: {line}"
+                break
+        else:
+            pytest.fail("未找到 TitleStyle Dialogue 行")