Add -f m4a

youtube_dl/YoutubeDL.py

@@ -708,7 +708,7 @@ class YoutubeDL(object):
             if video_formats:
                 return video_formats[0]
         else:
-            extensions = ['mp4', 'flv', 'webm', '3gp']
+            extensions = ['mp4', 'flv', 'webm', '3gp', 'm4a']
             if format_spec in extensions:
                 filter_f = lambda f: f['ext'] == format_spec
             else:

youtube_dl/options.py

@@ -218,7 +218,7 @@ def parseOpts(overrideArguments=None):
 
     video_format.add_option('-f', '--format',
             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", "bestvideo", "bestaudio", "worst", "worstvideo" and "worstaudio". By default, youtube-dl will pick the best quality.')
+            help='video format code, specify the order of preference using slashes: -f 22/17/18 .  -f mp4 , -f m4a and  -f flv  are also supported. You can also use the special names "best", "bestvideo", "bestaudio", "worst", "worstvideo" and "worstaudio". By default, youtube-dl will pick the best quality.')
     video_format.add_option('--all-formats',
             action='store_const', dest='format', help='download all available video formats', const='all')
     video_format.add_option('--prefer-free-formats',