- action='store', dest='format', metavar='FORMAT', default='best',
- help='video format code, specify the order of preference using slashes: "-f 22/17/18". "-f mp4" and "-f flv" are also supported')
+ action='store', dest='format', metavar='FORMAT', default=None,
+ help='video format code, specify the order of preference using slashes: "-f 22/17/18". "-f mp4" and "-f flv" are also supported. You can also use the special names "best", "bestaudio", "worst", and "worstaudio"')