Add format fallback

diff --git a/youtube-dl b/youtube-dl
index a2100aa..7483fcf 100755 (executable)
--- a/youtube-dl
+++ b/youtube-dl
@@ -1320,18 +1320,24 @@ class YoutubeIE(InfoExtractor):
                        if len(existing_formats) == 0:
                                self._downloader.trouble(u'ERROR: no known formats available for video')
                                return
-                       if req_format is None:
+                       if req_format is None or req_format == 'best':
                                video_url_list = [(existing_formats[0], url_map[existing_formats[0]])] # Best quality
                        elif req_format == 'worst':
                                video_url_list = [(existing_formats[len(existing_formats)-1], url_map[existing_formats[len(existing_formats)-1]])] # worst quality
-                       elif req_format == '-1':
+                       elif req_format in ('-1', 'all'):
                                video_url_list = [(f, url_map[f]) for f in existing_formats] # All formats
                        else:
-                               # Specific format
-                               if req_format not in url_map:
+                               # Specific formats. We pick the first in a slash-delimeted sequence.
+                               # For example, if '1/2/3/4' is requested and '2' and '4' are available, we pick '2'.
+                               req_formats = req_format.split('/')
+                               video_url_list = None
+                               for rf in req_formats:
+                                       if rf in url_map:
+                                               video_url_list = [(rf, url_map[rf])]
+                                               break
+                               if video_url_list is None:
                                        self._downloader.trouble(u'ERROR: requested format not available')
                                        return
-                               video_url_list = [(req_format, url_map[req_format])] # Specific format
                else:
                        self._downloader.trouble(u'ERROR: no conn or url_encoded_fmt_stream_map information found in video info')
                        return
@@ -3512,7 +3518,7 @@ def parseOpts():
        video_format.add_option('-f', '--format',
                        action='store', dest='format', metavar='FORMAT', help='video format code')
        video_format.add_option('--all-formats',
-                       action='store_const', dest='format', help='download all available video formats', const='-1')
+                       action='store_const', dest='format', help='download all available video formats', const='all')
        video_format.add_option('--max-quality',
                        action='store', dest='format_limit', metavar='FORMAT', help='highest quality format to download')