Fix rendering again........

croppa/main.py

@@ -1872,17 +1872,29 @@ class VideoEditor:
                 output_path
             ]
 
-            # Start FFmpeg process with Windows-optimized configuration
+            # Use a more robust approach: write to a temporary file in chunks
+            import tempfile
+            import os
+            
+            # Create a temporary file for the raw video data
+            temp_file = tempfile.NamedTemporaryFile(delete=False, suffix='.raw')
+            temp_file.close()
+            
+            print(f"Using temporary file approach: {temp_file.name}")
+            
+            # Modify FFmpeg command to read from file
+            ffmpeg_cmd[ffmpeg_cmd.index('-i') + 1] = temp_file.name
+            
+            # Start FFmpeg process
             self.ffmpeg_process = subprocess.Popen(
                 ffmpeg_cmd, 
-                stdin=subprocess.PIPE, 
                 stderr=subprocess.PIPE,
-                stdout=subprocess.DEVNULL,  # Discard stdout to prevent hanging
+                stdout=subprocess.DEVNULL,
-                bufsize=65536,  # 64KB buffer to prevent Windows pipe overflow
-                universal_newlines=False,  # Binary mode for Windows
                 creationflags=subprocess.CREATE_NO_WINDOW if hasattr(subprocess, 'CREATE_NO_WINDOW') else 0
             )
             
+            self.temp_file_name = temp_file.name
+
             # OpenCV for frame reading and transformations
             render_cap = cv2.VideoCapture(str(self.video_path))
             render_cap.set(cv2.CAP_PROP_POS_FRAMES, start_frame)
@@ -1894,13 +1906,11 @@ class VideoEditor:
 
             self.render_progress_queue.put(("progress", f"Processing {total_frames} frames...", 0.1, 0.0))
 
+            # Write all frames to temporary file first
+            with open(self.temp_file_name, 'wb') as temp_file:
                 for i in range(total_frames):
                     if self.render_cancelled:
-                    self.ffmpeg_process.stdin.close()
-                    self.ffmpeg_process.terminate()
-                    self.ffmpeg_process.wait()
                         render_cap.release()
-                    self.ffmpeg_process = None
                         self.render_progress_queue.put(("cancelled", "Render cancelled", 0.0, 0.0))
                         return False
 
@@ -1916,20 +1926,10 @@ class VideoEditor:
                             print(f"Processed frame dimensions: {processed_frame.shape[1]}x{processed_frame.shape[0]}")
                             print(f"Expected dimensions: {output_width}x{output_height}")
                         
-                    # Write frame to FFmpeg via pipe
+                        # Write frame to temporary file
-                    try:
+                        temp_file.write(processed_frame.tobytes())
-                        self.ffmpeg_process.stdin.write(processed_frame.tobytes())
                         frames_written += 1
 
-                        # Small delay every 10 frames to prevent Windows pipe overflow
-                        if frames_written % 10 == 0:
-                            time.sleep(0.001)  # 1ms delay
-                            
-                    except BrokenPipeError:
-                        # FFmpeg process died
-                        print("FFmpeg process died - BrokenPipeError")
-                        break
-
                     # Update progress with FPS calculation
                     current_time = time.time()
                     progress = 0.1 + (0.8 * (i + 1) / total_frames)
@@ -1941,13 +1941,22 @@ class VideoEditor:
                         self.render_progress_queue.put(("progress", f"Processed {i+1}/{total_frames} frames", progress, fps_rate))
                         last_progress_update = current_time
 
-            # Close FFmpeg input and wait for completion
+            render_cap.release()
-            self.ffmpeg_process.stdin.close()
+            
+            # Now wait for FFmpeg to finish encoding
+            self.render_progress_queue.put(("progress", "Encoding with FFmpeg...", 0.9, 0.0))
+
+            # Wait for FFmpeg to finish encoding
             stderr = self.ffmpeg_process.communicate()[1]
             return_code = self.ffmpeg_process.returncode
             self.ffmpeg_process = None
             
-            render_cap.release()
+            # Clean up temporary file
+            if hasattr(self, 'temp_file_name') and os.path.exists(self.temp_file_name):
+                try:
+                    os.unlink(self.temp_file_name)
+                except OSError:
+                    pass
 
             if return_code == 0:
                 total_time = time.time() - start_time