youtube-dl/youtube_dl/PostProcessor.py
2012-11-28 03:34:40 +01:00

201 lines
8.2 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
from __future__ import absolute_import
import os
import subprocess
import sys
import time
from .utils import *
class PostProcessor(object):
"""Post Processor class.
PostProcessor objects can be added to downloaders with their
add_post_processor() method. When the downloader has finished a
successful download, it will take its internal chain of PostProcessors
and start calling the run() method on each one of them, first with
an initial argument and then with the returned value of the previous
PostProcessor.
The chain will be stopped if one of them ever returns None or the end
of the chain is reached.
PostProcessor objects follow a "mutual registration" process similar
to InfoExtractor objects.
"""
_downloader = None
def __init__(self, downloader=None):
self._downloader = downloader
def set_downloader(self, downloader):
"""Sets the downloader for this PP."""
self._downloader = downloader
def run(self, information):
"""Run the PostProcessor.
The "information" argument is a dictionary like the ones
composed by InfoExtractors. The only difference is that this
one has an extra field called "filepath" that points to the
downloaded file.
When this method returns None, the postprocessing chain is
stopped. However, this method may return an information
dictionary that will be passed to the next postprocessing
object in the chain. It can be the one it received after
changing some fields.
In addition, this method may raise a PostProcessingError
exception that will be taken into account by the downloader
it was called from.
"""
return information # by default, do nothing
class AudioConversionError(BaseException):
def __init__(self, message):
self.message = message
class FFmpegExtractAudioPP(PostProcessor):
def __init__(self, downloader=None, preferredcodec=None, preferredquality=None, keepvideo=False):
PostProcessor.__init__(self, downloader)
if preferredcodec is None:
preferredcodec = 'best'
self._preferredcodec = preferredcodec
self._preferredquality = preferredquality
self._keepvideo = keepvideo
self._exes = self.detect_executables()
@staticmethod
def detect_executables():
def executable(exe):
try:
subprocess.Popen([exe, '-version'], stdout=subprocess.PIPE, stderr=subprocess.PIPE).communicate()
except OSError:
return False
return exe
programs = ['avprobe', 'avconv', 'ffmpeg', 'ffprobe']
return dict((program, executable(program)) for program in programs)
def get_audio_codec(self, path):
if not self._exes['ffprobe'] and not self._exes['avprobe']: return None
try:
cmd = [self._exes['avprobe'] or self._exes['ffprobe'], '-show_streams', '--', encodeFilename(path)]
handle = subprocess.Popen(cmd, stderr=file(os.path.devnull, 'w'), stdout=subprocess.PIPE)
output = handle.communicate()[0]
if handle.wait() != 0:
return None
except (IOError, OSError):
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
def run_ffmpeg(self, path, out_path, codec, more_opts):
if not self._exes['ffmpeg'] and not self._exes['avconv']:
raise AudioConversionError('ffmpeg or avconv not found. Please install one.')
if codec is None:
acodec_opts = []
else:
acodec_opts = ['-acodec', codec]
cmd = ([self._exes['avconv'] or self._exes['ffmpeg'], '-y', '-i', encodeFilename(path), '-vn']
+ acodec_opts + more_opts +
['--', encodeFilename(out_path)])
p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
stdout,stderr = p.communicate()
if p.returncode != 0:
msg = stderr.strip().split('\n')[-1]
raise AudioConversionError(msg)
def run(self, information):
path = information['filepath']
filecodec = self.get_audio_codec(path)
if filecodec is None:
self._downloader.to_stderr(u'WARNING: unable to obtain file audio codec with ffprobe')
return None
more_opts = []
if self._preferredcodec == 'best' or self._preferredcodec == filecodec or (self._preferredcodec == 'm4a' and filecodec == 'aac'):
if self._preferredcodec == 'm4a' and filecodec == 'aac':
# Lossless, but in another container
acodec = 'copy'
extension = self._preferredcodec
more_opts = [self._exes['avconv'] and '-bsf:a' or '-absf', 'aac_adtstoasc']
elif filecodec in ['aac', 'mp3', 'vorbis']:
# Lossless if possible
acodec = 'copy'
extension = filecodec
if filecodec == 'aac':
more_opts = ['-f', 'adts']
if filecodec == 'vorbis':
extension = 'ogg'
else:
# MP3 otherwise.
acodec = 'libmp3lame'
extension = 'mp3'
more_opts = []
if self._preferredquality is not None:
if int(self._preferredquality) < 10:
more_opts += [self._exes['avconv'] and '-q:a' or '-aq', self._preferredquality]
else:
more_opts += [self._exes['avconv'] and '-b:a' or '-ab', self._preferredquality + 'k']
else:
# We convert the audio (lossy)
acodec = {'mp3': 'libmp3lame', 'aac': 'aac', 'm4a': 'aac', 'vorbis': 'libvorbis', 'wav': None}[self._preferredcodec]
extension = self._preferredcodec
more_opts = []
if self._preferredquality is not None:
if int(self._preferredquality) < 10:
more_opts += [self._exes['avconv'] and '-q:a' or '-aq', self._preferredquality]
else:
more_opts += [self._exes['avconv'] and '-b:a' or '-ab', self._preferredquality + 'k']
if self._preferredcodec == 'aac':
more_opts += ['-f', 'adts']
if self._preferredcodec == 'm4a':
more_opts += [self._exes['avconv'] and '-bsf:a' or '-absf', 'aac_adtstoasc']
if self._preferredcodec == 'vorbis':
extension = 'ogg'
if self._preferredcodec == 'wav':
extension = 'wav'
more_opts += ['-f', 'wav']
prefix, sep, ext = path.rpartition(u'.') # not os.path.splitext, since the latter does not work on unicode in all setups
new_path = prefix + sep + extension
self._downloader.to_screen(u'[' + (self._exes['avconv'] and 'avconv' or 'ffmpeg') + '] Destination: ' + new_path)
try:
self.run_ffmpeg(path, new_path, acodec, more_opts)
except:
etype,e,tb = sys.exc_info()
if isinstance(e, AudioConversionError):
self._downloader.to_stderr(u'ERROR: audio conversion failed: ' + e.message)
else:
self._downloader.to_stderr(u'ERROR: error running ' + (self._exes['avconv'] and 'avconv' or 'ffmpeg'))
return None
# Try to update the date time for extracted audio file.
if information.get('filetime') is not None:
try:
os.utime(encodeFilename(new_path), (time.time(), information['filetime']))
except:
self._downloader.to_stderr(u'WARNING: Cannot update utime of audio file')
if not self._keepvideo:
try:
os.remove(encodeFilename(path))
except (IOError, OSError):
self._downloader.to_stderr(u'WARNING: Unable to remove downloaded video file')
return None
information['filepath'] = new_path
return information