Merge pull request 'refactor: streamline ffmpeg command construction in VideoEncoder' (#5) from v1.0.2 into master

Reviewed-on: #5

app.py

@@ -389,8 +389,7 @@ class VideoEncoder:
                 return False, "Invalid video resolution information"
             
             cmd = [
-                'ffmpeg', '-i', input_path, '-c:v', 'libx265', '-c:a', 'copy',
-                '-preset', 'medium', '-crf', '28', '-f', 'matroska'
+                'ffmpeg', '-i', input_path
             ]
             
             # Add scaling filter if target resolution is specified
@@ -404,8 +403,10 @@ class VideoEncoder:
                     # Ensure width is divisible by 2 (required by video codecs)
                     if scale_width % 2 != 0:
                         scale_width -= 1
-                    cmd.insert(2, f'scale={scale_width}:{target_height}')
-                    cmd.insert(2, '-vf')
+                    cmd.extend(['-vf', f'scale={scale_width}:{target_height}'])
+            
+            cmd.extend(['-c:v', 'libx265', '-c:a', 'copy',
+                '-preset', 'medium', '-crf', '28', '-f', 'matroska'])
             
             # Insert user flags if provided
             if ffmpeg_flags: