fix error in long video recording in server/main.py

desktop_env/server/main.py

@@ -2,7 +2,7 @@ import ctypes
 import os
 import platform
 import shlex
-import subprocess
+import subprocess, signal
 from pathlib import Path
 from typing import Any, Optional
 from typing import List, Dict, Tuple
@@ -997,7 +997,7 @@ def start_recording():
 
     start_command = f"ffmpeg -y -f x11grab -draw_mouse 1 -s {screen_width}x{screen_height} -i :0.0 -c:v libx264 -r 30 {recording_path}"
 
-    recording_process = subprocess.Popen(shlex.split(start_command), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    recording_process = subprocess.Popen(shlex.split(start_command), stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
 
     return jsonify({'status': 'success', 'message': 'Started recording.'})
 
@@ -1009,10 +1009,8 @@ def end_recording():
     if not recording_process:
         return jsonify({'status': 'error', 'message': 'No recording in progress to stop.'}), 400
 
-    recording_process.terminate()
+    recording_process.send_signal(signal.SIGINT)
     recording_process.wait()
-    # return_code = recording_process.returncode
-    output, error = recording_process.communicate()
     recording_process = None
 
     # return recording video file