Update app.py

app.py

@@ -7,6 +7,7 @@ import requests
 from ultralytics import YOLO
 import time
 import numpy as np
+import imageio_ffmpeg as ffmpeg
 
 # Page config first
 st.set_page_config(
@@ -139,10 +140,20 @@ if process_button and source_file and model:
         
         if st.session_state.processed_frames:
             out_path = tempfile.NamedTemporaryFile(suffix='.mp4', delete=False).name
-            writer = cv2.VideoWriter(out_path, cv2.VideoWriter_fourcc(*'mp4v'), output_fps or orig_fps, (width, height))
+            # Use imageio-ffmpeg instead of cv2 for more reliable MP4 output
+            writer = ffmpeg.write_frames(
+                out_path,
+                (width, height),
+                fps=output_fps or orig_fps,
+                codec='libx264',  # Widely supported codec
+                pix_fmt_in='bgr24',  # Match OpenCV frame format
+                pix_fmt_out='yuv420p'  # Standard for MP4
+            )
+            writer.send(None)  # Initialize writer
+            
             for frame in st.session_state.processed_frames:
-                writer.write(frame)
-            writer.release()
+                writer.send(frame)
+            writer.close()
             
             with open(out_path, 'rb') as f:
                 st.session_state.processed_video = f.read()