Add support for merging video and chat with configurable layout options

modules/downloader.py

@@ -136,6 +136,17 @@ class ContentDownloader:
             print(f'{Fore.RED}✗ Chat JSON file not found: {json_path}{Style.RESET_ALL}')
             return False
         
+        # Validate JSON file has content (check if file size is reasonable)
+        try:
+            file_size = os.path.getsize(json_path)
+            if file_size < 100:  # Less than 100 bytes means likely empty or invalid
+                print(f'{Fore.RED}✗ Chat JSON file is too small or incomplete ({file_size} bytes){Style.RESET_ALL}')
+                print(f'{Fore.YELLOW}  This can happen when stream recording is interrupted{Style.RESET_ALL}')
+                return False
+        except Exception as e:
+            print(f'{Fore.RED}✗ Error checking chat JSON file: {str(e)}{Style.RESET_ALL}')
+            return False
+        
         bin_path = get_bin_path()
         
         # Chat rendering settings
@@ -148,19 +159,20 @@ class ContentDownloader:
             '--font-size', '22',
             '--update-rate', '1.0',
             '--offline',
-            '--output-args', output_args,
             '--ffmpeg-path', self.ffmpeg_path,
             '--temp-path', os.path.join(bin_path, 'temp'),
             '--collision', 'Rename'
         ]
         
+        # Add output args using = syntax to avoid parsing issues
+        if output_args:
+            chat_settings.append(f'--output-args={output_args}')
+        
         try:
             print(f'{Fore.YELLOW}Rendering chat video...{Style.RESET_ALL}')
             
-            # Debug output
+            # Build complete command
             full_cmd = [self.twitch_downloader_path, 'chatrender', '-i', json_path, '-o', video_path] + chat_settings
-            print(f'{Fore.CYAN}DEBUG - Chat render command:{Style.RESET_ALL}')
-            print(f'{Fore.CYAN}  Output args passed: {repr(output_args)}{Style.RESET_ALL}')
             
             result = subprocess.call(full_cmd)