fix: 恢复被误回退的后端文件（#1519 #1520）

apps/api/app/api/routes/generation_tasks.py

@@ -169,8 +169,22 @@ def _writeback_edit_plan_config(
         current_config = plan_model.config if isinstance(plan_model.config, dict) else {}
         merged = dict(current_config)
         merged["generation_task_id"] = task_id
+        
+        # 检查标题是否发生变化，如果变化则清除 cover 字段强制重新生成封面
         if title_config:
+            old_title_config = merged.get("title_config", {}) or {}
+            old_title_text = (old_title_config.get("text") or "").strip()
+            new_title_text = (title_config.get("text") or "").strip()
+            if old_title_text != new_title_text:
+                # 标题变化，清除旧封面
+                if "cover" in merged:
+                    del merged["cover"]
+                    logger.info(
+                        "[生成任务] 标题变化，清除旧封面: plan_id=%s old_title=%s new_title=%s",
+                        plan_id, old_title_text, new_title_text,
+                    )
             merged["title_config"] = title_config
+        
         plan_model.config = merged
         db.commit()
         logger.info(

apps/worker/video_processing/render_adapter.py

@@ -598,7 +598,7 @@ class RenderAdapter:
             # 抽帧天然带标题，因此这里传空字符串，避免 Pillow 二次叠加导致重影。
             # Pillow 叠加仅用于 API 从源素材抽帧（源素材本身无标题）的兜底场景。
             cover_candidates = extract_and_upload_cover_frames(
-                str(result.output_path), plan_id, num_frames=3, title_text=""
+                str(result.output_path), plan_id, task_id=job_id, num_frames=3, title_text=""
             )
             if cover_candidates:
                 logger.info(

apps/worker/video_processing/thumbnail_generator.py

@@ -278,6 +278,7 @@ def extract_and_upload_cover_frames(
     video_path: str,
     plan_id: str,
     *,
+    task_id: str = "",
     num_frames: int = 3,
     title_text: str = "",
     title_color: str = "#ffffff",
@@ -291,6 +292,7 @@ def extract_and_upload_cover_frames(
     Args:
         video_path: 视频文件路径
         plan_id: 编辑计划 ID（用于生成 storage key）
+        task_id: 任务 ID（用于生成独立的 storage key，避免标题变更时封面冲突）
         num_frames: 抽取帧数（默认 3）
         title_text: 标题文字；非空时用 Pillow 叠加到每帧。
             从已渲染视频抽帧时通常传空（标题已烧录）；从源素材抽帧时传标题。
@@ -338,7 +340,7 @@ def extract_and_upload_cover_frames(
                         font_size=title_font_size,
                     )
 
-                storage_key = f"covers/{plan_id}/mediakit_frame_{i}.jpg"
+                storage_key = f"covers/{plan_id}/{task_id}/mediakit_frame_{i}.jpg"
                 url = upload_to_oss(tmp.name, storage_key)
                 if url:
                     seek_time = frame.get("timestamp", 0.0)
@@ -377,7 +379,7 @@ def extract_and_upload_cover_frames(
                     position=title_position,
                     font_size=title_font_size,
                 )
-            storage_key = f"covers/{plan_id}/frame_{i}.jpg"
+            storage_key = f"covers/{plan_id}/{task_id}/frame_{i}.jpg"
             url = upload_to_oss(frame_path, storage_key)
             if url:
                 seek_time = max(0.5, duration * ratio) if duration > 0 else 0.0

packages/domain/ass_subtitle_builder.py

@@ -224,8 +224,8 @@ def _wrap_title_text(
     if available_width <= 0:
         return text
 
-    # 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)
+    # 换行计算使用原始 font_size，与 CSS 预览一致；1.35x 补偿仅用于 ASS Fontsize 渲染
+
 
     # 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")
@@ -238,7 +238,7 @@ def _wrap_title_text(
 
         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
+            char_width = float(font_size) if ord(ch) > 0x2E80 else font_size * 0.55
 
             if current_width + char_width > available_width and current_line:
                 lines.append(current_line)

tests/unit/domain/test_ass_subtitle_builder.py

@@ -15,6 +15,7 @@ from packages.domain.ass_subtitle_builder import (
     TITLE_MARGIN_BOTTOM,
     TITLE_MARGIN_SIDE,
     TITLE_MARGIN_TOP,
+    _wrap_title_text,
     build_ass_content,
     build_ass_style,
     escape_ass_text,
@@ -579,3 +580,44 @@ class TestConstants:
         assert isinstance(TITLE_MARGIN_TOP, int)
         assert isinstance(TITLE_MARGIN_BOTTOM, int)
         assert isinstance(TITLE_MARGIN_SIDE, int)
+
+# ============================================================
+# _wrap_title_text 换行逻辑验证
+# ============================================================
+
+
+class TestWrapTitleTextFontSizeConsistency:
+    """验证换行计算使用原始 font_size，与 CSS 预览一致。"""
+
+    def test_font_size_113_uses_original_not_compensated(self):
+        """font_size=113 时，每行应容纳8个字（113px字宽），而非6个字（153px字宽）。"""
+        # 标题"永康拾掇脚阔头"共7个字
+        # 可用宽度 = 1080 - 60 - 60 = 960px
+        # 用 font_size=113：char_width=113，960/113 ≈ 8.5，每行8个字
+        # 7个字 < 8个字，应该在一行内
+        title = "永康拾掇脚阔头"
+        result = _wrap_title_text(title, video_width=1080, font_size=113, margin_l=60, margin_r=60)
+        # 不应该有换行
+        assert "\\N" not in result
+        assert result == title
+
+    def test_long_title_wraps_correctly(self):
+        """长标题应该按 font_size 字宽正确换行。"""
+        # 16个中文字，每行8个字，应该换行为2行
+        title = "永康拾掇脚阔头来一个笑一个哈哈哈"
+        result = _wrap_title_text(title, video_width=1080, font_size=113, margin_l=60, margin_r=60)
+        # 应该有一个换行
+        assert result.count("\\N") == 1
+        # 每行8个字
+        lines = result.split("\\N")
+        assert len(lines) == 2
+        assert len(lines[0]) == 8
+        assert len(lines[1]) == 8
+
+    def test_mixed_cjk_and_ascii(self):
+        """混合中英文时，英文按半角宽度计算。"""
+        # "测试test" = 2个中文(2*113=226) + 4个英文(4*113*0.55=248.6) = 474.6px
+        title = "测试test"
+        result = _wrap_title_text(title, video_width=1080, font_size=113, margin_l=60, margin_r=60)
+        # 总宽度474.6px < 960px，应该在一行内
+        assert "\\N" not in result