feat(task): 添加转场效果相关属性和方法

- 新增 get_transition_type、get_transition_ms、has_transition 方法用于处理转场类型和时长
- 新增 get_overlap_tail_ms、get_transition_in_type、get_transition_in_ms 等方法处理入场转场
- 新增 get_transition_out_type、get_transition_out_ms、has_transition_out 等方法处理出场转场
- 新增 get_overlap_head_ms、get_overlap_tail_ms_v2 方法计算头部和尾部重叠时长
- 更新渲染视频处理器中使用新的转场相关方法计算 overlap 时长

domain/task.py

@@ -361,6 +361,69 @@ class Task:
         """获取输出规格"""
         return OutputSpec.from_dict(self.payload.get('output'))
 
+    def get_transition_type(self) -> Optional[str]:
+        """获取转场类型（来自 TaskPayload 顶层）"""
+        return self.payload.get('transitionType')
+
+    def get_transition_ms(self) -> int:
+        """获取转场时长（毫秒，来自 TaskPayload 顶层）"""
+        return int(self.payload.get('transitionMs', 0))
+
+    def has_transition(self) -> bool:
+        """是否有转场效果"""
+        return self.get_transition_ms() > 0
+
+    def get_overlap_tail_ms(self) -> int:
+        """
+        获取尾部 overlap 时长（毫秒）
+
+        转场发生在当前片段与下一片段之间，当前片段需要在尾部多渲染 overlap 帧。
+        overlap = transitionMs / 2
+        """
+        return self.get_transition_ms() // 2
+
+    def get_transition_in_type(self) -> Optional[str]:
+        """获取入场转场类型（来自前一片段的出场转场）"""
+        return self.payload.get('transitionInType')
+
+    def get_transition_in_ms(self) -> int:
+        """获取入场转场时长（毫秒）"""
+        return int(self.payload.get('transitionInMs', 0))
+
+    def get_transition_out_type(self) -> Optional[str]:
+        """获取出场转场类型（当前片段的转场配置）"""
+        return self.payload.get('transitionOutType')
+
+    def get_transition_out_ms(self) -> int:
+        """获取出场转场时长（毫秒）"""
+        return int(self.payload.get('transitionOutMs', 0))
+
+    def has_transition_in(self) -> bool:
+        """是否有入场转场"""
+        return self.get_transition_in_ms() > 0
+
+    def has_transition_out(self) -> bool:
+        """是否有出场转场"""
+        return self.get_transition_out_ms() > 0
+
+    def get_overlap_head_ms(self) -> int:
+        """
+        获取头部 overlap 时长（毫秒）
+
+        入场转场来自前一个片段，当前片段需要在头部多渲染 overlap 帧。
+        overlap = transitionInMs / 2
+        """
+        return self.get_transition_in_ms() // 2
+
+    def get_overlap_tail_ms_v2(self) -> int:
+        """
+        获取尾部 overlap 时长（毫秒）- 使用新的字段名
+
+        出场转场用于当前片段与下一片段之间，当前片段需要在尾部多渲染 overlap 帧。
+        overlap = transitionOutMs / 2
+        """
+        return self.get_transition_out_ms() // 2
+
     def get_bgm_url(self) -> Optional[str]:
         """获取 BGM URL"""
         return self.payload.get('bgmUrl')

handlers/render_video.py

@@ -78,9 +78,11 @@ class RenderSegmentVideoHandler(BaseHandler):
                     logger.warning(f"[task:{task.task_id}] Failed to download overlay, continuing without it")
                     overlay_file = None
 
-            # 4. 计算 overlap 时长
-            overlap_head_ms = render_spec.get_overlap_head_ms()
-            overlap_tail_ms = render_spec.get_overlap_tail_ms()
+            # 4. 计算 overlap 时长（用于转场帧冻结）
+            # 头部 overlap: 来自前一片段的出场转场
+            overlap_head_ms = task.get_overlap_head_ms()
+            # 尾部 overlap: 当前片段的出场转场
+            overlap_tail_ms = task.get_overlap_tail_ms_v2()
 
             # 5. 构建 FFmpeg 命令
             output_file = os.path.join(work_dir, 'output.mp4')