2026-05-18-20-35-32 修复结果视频关键帧空白

backend/main.py

@@ -12,7 +12,7 @@ from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import FileResponse, Response
 from fastapi.staticfiles import StaticFiles
 
-from backend.segmentation import METHOD_DESCRIPTIONS, compare_frame, segment_frame
+from backend.segmentation import METHOD_DESCRIPTIONS, compare_frame, overlay_mask, segment_frame
 
 
 ROOT = Path(__file__).resolve().parents[1]
@@ -213,6 +213,7 @@ def _process_video(
     frame_index = 0
     selected_count = 0
     written_count = 0
+    active_mask = None
     writer = None
     raw_video_path = job_path / f"{method}_overlay.raw.mp4"
     video_path = job_path / f"{method}_overlay.mp4"
@@ -251,6 +252,7 @@ def _process_video(
                         )
                     )
                 video_output = next(item for item in outputs if item.method == "fusion")
+                active_mask = video_output.mask
                 video_frame = video_output.overlay
                 selected_count += 1
             elif should_process:
@@ -267,8 +269,11 @@ def _process_video(
                         frame_index,
                     )
                 )
+                active_mask = video_output.mask
                 video_frame = video_output.overlay
                 selected_count += 1
+            elif active_mask is not None:
+                video_frame = overlay_mask(frame, active_mask)
 
             if writer is None:
                 height, width = frame.shape[:2]