+ elif format_spec == 'bestaudio':
+ audio_formats = [
+ f for f in available_formats
+ if f.get('vcodec') == 'none']
+ if audio_formats:
+ return audio_formats[-1]
+ elif format_spec == 'worstaudio':
+ audio_formats = [
+ f for f in available_formats
+ if f.get('vcodec') == 'none']
+ if audio_formats:
+ return audio_formats[0]
+ elif format_spec == 'bestvideo':
+ video_formats = [
+ f for f in available_formats
+ if f.get('acodec') == 'none']
+ if video_formats:
+ return video_formats[-1]
+ elif format_spec == 'worstvideo':
+ video_formats = [
+ f for f in available_formats
+ if f.get('acodec') == 'none']
+ if video_formats:
+ return video_formats[0]