Bug fix: video write failure on $pred_only == True

Bug: $pred_only output failed to write to video file.
Cause: $output_width always set to double width plus margin, despite $pred_only output being $frame_width sized.
Fix: Conditional check for $pred_only before setting $output_width.

run_video.py

@@ -59,6 +59,11 @@ if __name__ == '__main__':
         frame_rate = int(raw_video.get(cv2.CAP_PROP_FPS))
         output_width = frame_width * 2 + margin_width
         
+        if args.pred_only: 
+            output_width = frame_width
+        else: 
+            output_width = frame_width * 2 + margin_width
+        
         output_path = os.path.join(args.outdir, os.path.splitext(os.path.basename(filename))[0] + '.mp4')
         out = cv2.VideoWriter(output_path, cv2.VideoWriter_fourcc(*"mp4v"), frame_rate, (output_width, frame_height))