Add an audio extracting PostProcessor using ffmpeg (closes #2)

This commit is contained in:
Ricardo Garcia 2011-02-25 19:06:58 +01:00
parent 87cbd21323
commit 3072fab115
1 changed files with 93 additions and 0 deletions

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@ -2609,6 +2609,85 @@ class PostProcessor(object):
"""
return information # by default, do nothing
class FFmpegExtractAudioPP(PostProcessor):
def __init__(self, downloader=None, preferredcodec=None):
PostProcessor.__init__(self, downloader)
if preferredcodec is None:
preferredcodec = 'best'
self._preferredcodec = preferredcodec
@staticmethod
def get_audio_codec(path):
handle = subprocess.Popen(['ffprobe', '-show_streams', path],
stderr=file(os.path.devnull, 'w'), stdout=subprocess.PIPE)
output = handle.communicate()[0]
if handle.wait() != 0:
return None
audio_codec = None
for line in output.split('\n'):
if line.startswith('codec_name='):
audio_codec = line.split('=')[1].strip()
elif line.strip() == 'codec_type=audio' and audio_codec is not None:
return audio_codec
return None
@staticmethod
def run_ffmpeg(path, out_path, codec, more_opts):
try:
ret = subprocess.call(['ffmpeg', '-y', '-i', path, '-vn', '-acodec', codec] + more_opts + [out_path],
stdout=file(os.path.devnull, 'w'), stderr=subprocess.STDOUT)
return (ret == 0)
except (IOError, OSError):
return False
def run(self, information):
path = information['filepath']
filecodec = self.get_audio_codec(path)
if filecodec is None:
self._downloader.to_stderr(u'WARNING: no audio codec found in file')
return None
more_opts = []
if self._preferredcodec == 'best' or self._preferredcodec == filecodec:
if filecodec == 'aac' or filecodec == 'mp3':
# Lossless if possible
acodec = 'copy'
extension = filecodec
if filecodec == 'aac':
more_opts = ['-f', 'adts']
else:
# MP3 otherwise.
acodec = 'libmp3lame'
extension = 'mp3'
more_opts = ['-ab', '128k']
else:
# We convert the audio (lossy)
acodec = {'mp3': 'libmp3lame', 'aac': 'aac'}[self._preferredcodec]
extension = self._preferredcodec
more_opts = ['-ab', '128k']
if self._preferredcodec == 'aac':
more_opts += ['-f', 'adts']
(prefix, ext) = os.path.splitext(path)
new_path = prefix + '.' + extension
self._downloader.to_screen(u'[ffmpeg] Destination: %s' % new_path)
status = self.run_ffmpeg(path, new_path, acodec, more_opts)
if not status:
self._downloader.to_stderr(u'WARNING: error running ffmpeg' % ret)
return None
try:
os.remove(path)
except (IOError, OSError):
self._downloader.to_stderr(u'WARNING: Unable to remove downloaded video file')
return None
information['filepath'] = new_path
return information
### MAIN PROGRAM ###
if __name__ == '__main__':
try:
@ -2733,6 +2812,13 @@ if __name__ == '__main__':
help='do not use the Last-modified header to set the file modification time', default=True)
parser.add_option_group(filesystem)
postproc = optparse.OptionGroup(parser, 'Post-processing Options')
postproc.add_option('--extract-audio', action='store_true', dest='extractaudio', default=False,
help='convert video files to audio-only files (requires ffmpeg and ffprobe)')
postproc.add_option('--audio-format', metavar='FORMAT', dest='audioformat', default='best',
help='"best", "aac" or "mp3"; best by default')
parser.add_option_group(postproc)
(opts, args) = parser.parse_args()
# Open appropriate CookieJar
@ -2804,6 +2890,9 @@ if __name__ == '__main__':
raise ValueError
except (TypeError, ValueError), err:
parser.error(u'invalid playlist end number specified')
if opts.extractaudio:
if opts.audioformat not in ['best', 'aac', 'mp3']:
parser.error(u'invalid audio format specified')
# Information extractors
youtube_ie = YoutubeIE()
@ -2876,6 +2965,10 @@ if __name__ == '__main__':
# fallback if none of the others work
fd.add_info_extractor(generic_ie)
# PostProcessors
if opts.extractaudio:
fd.add_post_processor(FFmpegExtractAudioPP(preferredcodec=opts.audioformat))
# Update version
if opts.update_self:
update_self(fd, sys.argv[0])