diff --git a/apps/api/app/__init__.py b/apps/api/app/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/apps/api/app/api/routes/assets.py b/apps/api/app/api/routes/assets.py
old mode 100755
new mode 100644
index 7e2f9b1a0..7d90cf9c7
--- a/apps/api/app/api/routes/assets.py
+++ b/apps/api/app/api/routes/assets.py
@@ -71,6 +71,7 @@ def _to_asset_response(item, storage_service=None) -> AssetResponse:
         status=item.status.value,
         classification_status=item.classification_status.value,
         quality_score=item.quality_score,
+        created_at=item.created_at.isoformat() if item.created_at else None,
         uploaded_by_user_id=item.uploaded_by_user_id,
         tag_ids=getattr(item, "tag_ids", []),
     )
diff --git a/apps/api/app/schemas/asset.py b/apps/api/app/schemas/asset.py
index afd5f74be..dd6d15c86 100755
--- a/apps/api/app/schemas/asset.py
+++ b/apps/api/app/schemas/asset.py
@@ -50,6 +50,7 @@ class AssetResponse(BaseModel):
     status: str
     classification_status: str
     quality_score: float | None = None
+    created_at: str
     uploaded_by_user_id: str
     tag_ids: list[str] = Field(default_factory=list)
 
diff --git a/apps/worker/video_processing/render_adapter.py b/apps/worker/video_processing/render_adapter.py
index 7c6955a30..59938a596 100755
--- a/apps/worker/video_processing/render_adapter.py
+++ b/apps/worker/video_processing/render_adapter.py
@@ -258,12 +258,12 @@ class RenderAdapter:
                 plan_id,
                 job_id,
                 exc.returncode,
-                stderr_text[:3000],
+                stderr_text[-2000:] if len(stderr_text) > 2000 else stderr_text,
             )
             return RenderAdapterResult(
                 success=False,
                 error_message=f"FFmpeg渲染失败(exit={exc.returncode}): {stderr_text[:200]}",
-                error_detail=stderr_text[:3000],
+                error_detail=stderr_text[-2000:] if len(stderr_text) > 2000 else stderr_text,
             )
         except Exception as exc:
             logger.exception(
diff --git a/apps/worker/video_processing/unified_render_service.py b/apps/worker/video_processing/unified_render_service.py
index 3e97eeaa3..f97b1aef4 100755
--- a/apps/worker/video_processing/unified_render_service.py
+++ b/apps/worker/video_processing/unified_render_service.py
@@ -1008,7 +1008,7 @@ class UnifiedRenderService:
         else:
             # main / broll: 等比缩放 + 居中留黑边（保持原始比例，不裁剪内容）
             filters.append(f"scale={self.output_width}:{self.output_height}" ":force_original_aspect_ratio=decrease")
-            filters.append(f"pad={self.output_width}:{self.output_height}:(ow-iw)/2:(oh-ih)/2:black")
+            filters.append(f"pad={self.output_width}:{self.output_height}:trunc((ow-iw)/2):trunc((oh-ih)/2):black")
 
         # 调色滤镜
         color_grade = ColorGradeConfig.from_dict(clip.config.get("color_grade"))
@@ -1112,12 +1112,15 @@ class UnifiedRenderService:
         try:
             run_ffmpeg(command)
         except subprocess.CalledProcessError as e:
+            stderr_text = (e.stderr or "").strip()
+            stderr_tail = stderr_text[-1500:] if len(stderr_text) > 1500 else stderr_text
             logger.error(
-                "直通渲染失败: plan_id=%s clip=%s exit_code=%d\nvf=%s",
+                "直通渲染失败: plan_id=%s clip=%s exit_code=%d\nvf=%s\nstderr(last 1500):\n%s",
                 self.plan.id,
                 clip.clip_id,
                 e.returncode,
                 vf_str[:2000],
+                stderr_tail,
             )
             raise
 
@@ -1342,7 +1345,7 @@ class UnifiedRenderService:
                 filters.append(
                     f"scale={self.output_width}:{self.output_height}" ":force_original_aspect_ratio=decrease"
                 )
-                filters.append(f"pad={self.output_width}:{self.output_height}:(ow-iw)/2:(oh-ih)/2:black")
+                filters.append(f"pad={self.output_width}:{self.output_height}:trunc((ow-iw)/2):trunc((oh-ih)/2):black")
 
             # 调色滤镜（每个 clip 独立的 color grade 配置）
             color_grade = ColorGradeConfig.from_dict(clip.config.get("color_grade"))
@@ -1576,12 +1579,15 @@ class UnifiedRenderService:
         try:
             run_ffmpeg(command)
         except subprocess.CalledProcessError as e:
-            # 额外记录 filter_complex，方便排查滤镜链构建问题
+            # 额外记录 filter_complex + stderr，方便排查滤镜链构建问题
+            stderr_text = (e.stderr or "").strip()
+            stderr_tail = stderr_text[-1500:] if len(stderr_text) > 1500 else stderr_text
             logger.error(
-                "渲染失败: plan_id=%s exit_code=%d\nfilter_complex:\n%s",
+                "渲染失败: plan_id=%s exit_code=%d\nfilter_complex:\n%s\nstderr(last 1500):\n%s",
                 self.plan.id,
                 e.returncode,
                 filter_complex[:5000],
+                stderr_tail,
             )
             raise
 
diff --git a/tests/unit/test_unified_render_service.py b/tests/unit/test_unified_render_service.py
index a9f025f11..837ff2d0f 100755
--- a/tests/unit/test_unified_render_service.py
+++ b/tests/unit/test_unified_render_service.py
@@ -1801,7 +1801,7 @@ class TestConcatNormalizeVideoResolution:
         # 必须用 pad（留黑边），不能用 crop（裁剪）
         assert "force_original_aspect_ratio=decrease" in fc, "main 层应使用 decrease 模式（等比缩放到画布内）"
         assert "pad=" in fc, "main 层应有 pad 滤镜（留黑边到目标分辨率）"
-        assert "(ow-iw)/2:(oh-ih)/2:black" in fc, "pad 应该居中+黑边"
+        assert "trunc((ow-iw)/2):trunc((oh-ih)/2):black" in fc, "pad 应该居中取整+黑边"
         # 注意：background 层也用 crop，但 main/broll 应该用 pad
         # 检查第一个 [0:v] 处理链（第一个 clip 是 main）
         first_v_chain = fc.split("[v0]")[0]