Added -b option and created option groups for help prompt

youtube-dl

@@ -52,6 +52,13 @@ class PostProcessingError(Exception):
 	"""
 	pass
 
+class UnavailableFormatError(Exception):
+	"""Unavailable Format exception.
+
+	This exception will be thrown when a video is requested
+	in a format that is not available for that video.
+	"""
+
 class FileDownloader(object):
 	"""File Downloader class.
 
@@ -260,33 +267,38 @@ class FileDownloader(object):
 		if self.params['nooverwrites'] and os.path.exists(filename):
 			self.to_stderr('WARNING: file exists: %s; skipping' % filename)
 			return
+
 		try:
 			self.pmkdir(filename)
 		except (OSError, IOError), err:
 			self.trouble('ERROR: unable to create directories: %s' % str(err))
 			return
+
 		try:
 			outstream = open(filename, 'wb')
 		except (OSError, IOError), err:
 			self.trouble('ERROR: unable to open for writing: %s' % str(err))
 			return
+
 		try:
 			self._do_download(outstream, info_dict['url'])
 			outstream.close()
 		except (OSError, IOError), err:
+			if info_dict['best_quality']:
+				raise UnavailableFormatError
+			else:
 				self.trouble('ERROR: unable to write video data: %s' % str(err))
 				return
 		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
 			self.trouble('ERROR: unable to download video data: %s' % str(err))
 			return
+
 		try:
 			self.post_process(filename, info_dict)
 		except (PostProcessingError), err:
 			self.trouble('ERROR: postprocessing: %s' % str(err))
 			return
 
-		return
-
 	def download(self, url_list):
 		"""Download a given list of URLs."""
 		if len(url_list) > 1 and self.fixed_template():
@@ -424,6 +436,13 @@ class YoutubeIE(InfoExtractor):
 	_LOGIN_URL = 'http://www.youtube.com/signup?next=/&gl=US&hl=en'
 	_AGE_URL = 'http://www.youtube.com/verify_age?next_url=/&gl=US&hl=en'
 	_NETRC_MACHINE = 'youtube'
+	_available_formats = ['22', '18', '17', '13'] # listed in order of priority for -b flag
+	_video_extensions = {
+		'13': '3gp',
+		'17': 'mp4',
+		'18': 'mp4',
+		'22': 'mp4',
+	}
 
 	@staticmethod
 	def suitable(url):
@@ -476,6 +495,10 @@ class YoutubeIE(InfoExtractor):
 		"""Report extracted video URL."""
 		self._downloader.to_stdout(u'[youtube] %s: URL: %s' % (video_id, video_real_url))
 	
+	def report_unavailable_format(self, video_id, format):
+		"""Report extracted video URL."""
+		self._downloader.to_stdout(u'[youtube] %s: Format %s not available' % (video_id, format))
+	
 	def _real_initialize(self):
 		if self._downloader is None:
 			return
@@ -554,18 +577,20 @@ class YoutubeIE(InfoExtractor):
 		video_id = mobj.group(2)
 
 		# Downloader parameters
+		best_quality = False
 		format_param = None
+		quality_index = 0
 		if self._downloader is not None:
 			params = self._downloader.params
 			format_param = params.get('format', None)
+			if format_param == '0':
+				format_param = self._available_formats[quality_index]
+				best_quality = True
 
+		while True:
+			try:
 				# Extension
-		video_extension = {
+				video_extension = self._video_extensions.get(format_param, 'flv')
-			'13': '3gp',
-			'17': 'mp4',
-			'18': 'mp4',
-			'22': 'mp4',
-		}.get(format_param, 'flv')
 
 				# Normalize URL, including format
 				normalized_url = 'http://www.youtube.com/watch?v=%s&gl=US&hl=en' % video_id
@@ -618,8 +643,22 @@ class YoutubeIE(InfoExtractor):
 					'title':	video_title,
 					'stitle':	simple_title,
 					'ext':		video_extension.decode('utf-8'),
+					'best_quality': best_quality,
 				})
 
+				return
+
+			except UnavailableFormatError:
+				if quality_index == len(self._available_formats) - 1:
+					# I don't ever expect this to happen
+					self._downloader.trouble(u'ERROR: no known formats available for video')
+					return
+				else:
+					self.report_unavailable_format(video_id, format_param)
+					quality_index += 1
+					format_param = self._available_formats[quality_index]
+					continue
+
 class MetacafeIE(InfoExtractor):
 	"""Information Extractor for metacafe.com."""
 
@@ -738,6 +777,7 @@ class MetacafeIE(InfoExtractor):
 			'title':	video_title,
 			'stitle':	simple_title,
 			'ext':		video_extension.decode('utf-8'),
+			'best_quality': False, # TODO
 		})
 
 
@@ -954,44 +994,60 @@ if __name__ == '__main__':
 			version='INTERNAL',
 			conflict_handler='resolve',
 		)
+
 		parser.add_option('-h', '--help',
 				action='help', help='print this help text and exit')
 		parser.add_option('-v', '--version',
 				action='version', help='print program version and exit')
-		parser.add_option('-u', '--username',
-				dest='username', metavar='UN', help='account username')
-		parser.add_option('-p', '--password',
-				dest='password', metavar='PW', help='account password')
-		parser.add_option('-o', '--output',
-				dest='outtmpl', metavar='TPL', help='output filename template')
-		parser.add_option('-q', '--quiet',
-				action='store_true', dest='quiet', help='activates quiet mode', default=False)
-		parser.add_option('-s', '--simulate',
-				action='store_true', dest='simulate', help='do not download video', default=False)
-		parser.add_option('-t', '--title',
-				action='store_true', dest='usetitle', help='use title in file name', default=False)
-		parser.add_option('-l', '--literal',
-				action='store_true', dest='useliteral', help='use literal title in file name', default=False)
-		parser.add_option('-n', '--netrc',
-				action='store_true', dest='usenetrc', help='use .netrc authentication data', default=False)
-		parser.add_option('-g', '--get-url',
-				action='store_true', dest='geturl', help='simulate, quiet but print URL', default=False)
-		parser.add_option('-e', '--get-title',
-				action='store_true', dest='gettitle', help='simulate, quiet but print title', default=False)
-		parser.add_option('-f', '--format',
-				dest='format', metavar='FMT', help='video format code')
-		parser.add_option('-m', '--mobile-version',
-				action='store_const', dest='format', help='alias for -f 17', const='17')
-		parser.add_option('-d', '--high-def',
-				action='store_const', dest='format', help='alias for -f 22', const='22')
 		parser.add_option('-i', '--ignore-errors',
 				action='store_true', dest='ignoreerrors', help='continue on download errors', default=False)
 		parser.add_option('-r', '--rate-limit',
 				dest='ratelimit', metavar='L', help='download rate limit (e.g. 50k or 44.6m)')
-		parser.add_option('-a', '--batch-file',
+
+		authentication = optparse.OptionGroup(parser, 'Authentication Options')
+		authentication.add_option('-u', '--username',
+				dest='username', metavar='UN', help='account username')
+		authentication.add_option('-p', '--password',
+				dest='password', metavar='PW', help='account password')
+		authentication.add_option('-n', '--netrc',
+				action='store_true', dest='usenetrc', help='use .netrc authentication data', default=False)
+		parser.add_option_group(authentication)
+
+		video_format = optparse.OptionGroup(parser, 'Video Format Options')
+		video_format.add_option('-f', '--format',
+				dest='format', metavar='FMT', help='video format code')
+		video_format.add_option('-b', '--best-quality',
+				action='store_const', dest='format', help='download the best quality video possible', const='0')
+		video_format.add_option('-m', '--mobile-version',
+				action='store_const', dest='format', help='alias for -f 17', const='17')
+		video_format.add_option('-d', '--high-def',
+				action='store_const', dest='format', help='alias for -f 22', const='22')
+		parser.add_option_group(video_format)
+
+		verbosity = optparse.OptionGroup(parser, 'Verbosity / Simulation Options')
+		verbosity.add_option('-q', '--quiet',
+				action='store_true', dest='quiet', help='activates quiet mode', default=False)
+		verbosity.add_option('-s', '--simulate',
+				action='store_true', dest='simulate', help='do not download video', default=False)
+		verbosity.add_option('-g', '--get-url',
+				action='store_true', dest='geturl', help='simulate, quiet but print URL', default=False)
+		verbosity.add_option('-e', '--get-title',
+				action='store_true', dest='gettitle', help='simulate, quiet but print title', default=False)
+		verbosity.add_option('-t', '--title',
+				action='store_true', dest='usetitle', help='use title in file name', default=False)
+		verbosity.add_option('-l', '--literal',
+				action='store_true', dest='useliteral', help='use literal title in file name', default=False)
+		parser.add_option_group(verbosity)
+
+		filesystem = optparse.OptionGroup(parser, 'Filesystem Options')
+		filesystem.add_option('-o', '--output',
+				dest='outtmpl', metavar='TPL', help='output filename template')
+		filesystem.add_option('-a', '--batch-file',
 				dest='batchfile', metavar='F', help='file containing URLs to download')
-		parser.add_option('-w', '--no-overwrites',
+		filesystem.add_option('-w', '--no-overwrites',
 				action='store_true', dest='nooverwrites', help='do not overwrite files', default=False)
+		parser.add_option_group(filesystem)
+
 		(opts, args) = parser.parse_args()
 
 		# Batch file verification