youtube_dlc/postprocessor/ffmpeg.py

   1 from __future__ import unicode_literals
   2
   3 import io
   4 import os
   5 import subprocess
   6 import time
   7 import re
   8 import json
   9
  10
  11 from .common import AudioConversionError, PostProcessor
  12
  13 from ..utils import (
  14     encodeArgument,
  15     encodeFilename,
  16     get_exe_version,
  17     is_outdated_version,
  18     PostProcessingError,
  19     prepend_extension,
  20     shell_quote,
  21     subtitles_filename,
  22     dfxp2srt,
  23     ISO639Utils,
  24     process_communicate_or_kill,
  25     replace_extension,
  26     traverse_dict,
  27 )
  28
  29
  30 EXT_TO_OUT_FORMATS = {
  31     'aac': 'adts',
  32     'flac': 'flac',
  33     'm4a': 'ipod',
  34     'mka': 'matroska',
  35     'mkv': 'matroska',
  36     'mpg': 'mpeg',
  37     'ogv': 'ogg',
  38     'ts': 'mpegts',
  39     'wma': 'asf',
  40     'wmv': 'asf',
  41 }
  42 ACODECS = {
  43     'mp3': 'libmp3lame',
  44     'aac': 'aac',
  45     'flac': 'flac',
  46     'm4a': 'aac',
  47     'opus': 'libopus',
  48     'vorbis': 'libvorbis',
  49     'wav': None,
  50 }
  51
  52
  53 class FFmpegPostProcessorError(PostProcessingError):
  54     pass
  55
  56
  57 class FFmpegPostProcessor(PostProcessor):
  58     def __init__(self, downloader=None):
  59         PostProcessor.__init__(self, downloader)
  60         self._determine_executables()
  61
  62     def check_version(self):
  63         if not self.available:
  64             raise FFmpegPostProcessorError('ffmpeg not found. Please install')
  65
  66         required_version = '10-0' if self.basename == 'avconv' else '1.0'
  67         if is_outdated_version(
  68                 self._versions[self.basename], required_version):
  69             warning = 'Your copy of %s is outdated, update %s to version %s or newer if you encounter any errors.' % (
  70                 self.basename, self.basename, required_version)
  71             self.report_warning(warning)
  72
  73     @staticmethod
  74     def get_versions(downloader=None):
  75         return FFmpegPostProcessor(downloader)._versions
  76
  77     def _determine_executables(self):
  78         programs = ['avprobe', 'avconv', 'ffmpeg', 'ffprobe']
  79         prefer_ffmpeg = True
  80
  81         def get_ffmpeg_version(path):
  82             ver = get_exe_version(path, args=['-version'])
  83             if ver:
  84                 regexs = [
  85                     r'(?:\d+:)?([0-9.]+)-[0-9]+ubuntu[0-9.]+$',  # Ubuntu, see [1]
  86                     r'n([0-9.]+)$',  # Arch Linux
  87                     # 1. http://www.ducea.com/2006/06/17/ubuntu-package-version-naming-explanation/
  88                 ]
  89                 for regex in regexs:
  90                     mobj = re.match(regex, ver)
  91                     if mobj:
  92                         ver = mobj.group(1)
  93             return ver
  94
  95         self.basename = None
  96         self.probe_basename = None
  97
  98         self._paths = None
  99         self._versions = None
 100         if self._downloader:
 101             prefer_ffmpeg = self.get_param('prefer_ffmpeg', True)
 102             location = self.get_param('ffmpeg_location')
 103             if location is not None:
 104                 if not os.path.exists(location):
 105                     self.report_warning(
 106                         'ffmpeg-location %s does not exist! '
 107                         'Continuing without ffmpeg.' % (location))
 108                     self._versions = {}
 109                     return
 110                 elif not os.path.isdir(location):
 111                     basename = os.path.splitext(os.path.basename(location))[0]
 112                     if basename not in programs:
 113                         self.report_warning(
 114                             'Cannot identify executable %s, its basename should be one of %s. '
 115                             'Continuing without ffmpeg.' %
 116                             (location, ', '.join(programs)))
 117                         self._versions = {}
 118                         return None
 119                     location = os.path.dirname(os.path.abspath(location))
 120                     if basename in ('ffmpeg', 'ffprobe'):
 121                         prefer_ffmpeg = True
 122
 123                 self._paths = dict(
 124                     (p, os.path.join(location, p)) for p in programs)
 125                 self._versions = dict(
 126                     (p, get_ffmpeg_version(self._paths[p])) for p in programs)
 127         if self._versions is None:
 128             self._versions = dict(
 129                 (p, get_ffmpeg_version(p)) for p in programs)
 130             self._paths = dict((p, p) for p in programs)
 131
 132         if prefer_ffmpeg is False:
 133             prefs = ('avconv', 'ffmpeg')
 134         else:
 135             prefs = ('ffmpeg', 'avconv')
 136         for p in prefs:
 137             if self._versions[p]:
 138                 self.basename = p
 139                 break
 140
 141         if prefer_ffmpeg is False:
 142             prefs = ('avprobe', 'ffprobe')
 143         else:
 144             prefs = ('ffprobe', 'avprobe')
 145         for p in prefs:
 146             if self._versions[p]:
 147                 self.probe_basename = p
 148                 break
 149
 150     @property
 151     def available(self):
 152         return self.basename is not None
 153
 154     @property
 155     def executable(self):
 156         return self._paths[self.basename]
 157
 158     @property
 159     def probe_available(self):
 160         return self.probe_basename is not None
 161
 162     @property
 163     def probe_executable(self):
 164         return self._paths[self.probe_basename]
 165
 166     def get_audio_codec(self, path):
 167         if not self.probe_available and not self.available:
 168             raise PostProcessingError('ffprobe and ffmpeg not found. Please install')
 169         try:
 170             if self.probe_available:
 171                 cmd = [
 172                     encodeFilename(self.probe_executable, True),
 173                     encodeArgument('-show_streams')]
 174             else:
 175                 cmd = [
 176                     encodeFilename(self.executable, True),
 177                     encodeArgument('-i')]
 178             cmd.append(encodeFilename(self._ffmpeg_filename_argument(path), True))
 179             self.write_debug('%s command line: %s' % (self.basename, shell_quote(cmd)))
 180             handle = subprocess.Popen(
 181                 cmd, stderr=subprocess.PIPE,
 182                 stdout=subprocess.PIPE, stdin=subprocess.PIPE)
 183             stdout_data, stderr_data = process_communicate_or_kill(handle)
 184             expected_ret = 0 if self.probe_available else 1
 185             if handle.wait() != expected_ret:
 186                 return None
 187         except (IOError, OSError):
 188             return None
 189         output = (stdout_data if self.probe_available else stderr_data).decode('ascii', 'ignore')
 190         if self.probe_available:
 191             audio_codec = None
 192             for line in output.split('\n'):
 193                 if line.startswith('codec_name='):
 194                     audio_codec = line.split('=')[1].strip()
 195                 elif line.strip() == 'codec_type=audio' and audio_codec is not None:
 196                     return audio_codec
 197         else:
 198             # Stream #FILE_INDEX:STREAM_INDEX[STREAM_ID](LANGUAGE): CODEC_TYPE: CODEC_NAME
 199             mobj = re.search(
 200                 r'Stream\s*#\d+:\d+(?:\[0x[0-9a-f]+\])?(?:\([a-z]{3}\))?:\s*Audio:\s*([0-9a-z]+)',
 201                 output)
 202             if mobj:
 203                 return mobj.group(1)
 204         return None
 205
 206     def get_metadata_object(self, path, opts=[]):
 207         if self.probe_basename != 'ffprobe':
 208             if self.probe_available:
 209                 self.report_warning('Only ffprobe is supported for metadata extraction')
 210             raise PostProcessingError('ffprobe not found. Please install.')
 211         self.check_version()
 212
 213         cmd = [
 214             encodeFilename(self.probe_executable, True),
 215             encodeArgument('-hide_banner'),
 216             encodeArgument('-show_format'),
 217             encodeArgument('-show_streams'),
 218             encodeArgument('-print_format'),
 219             encodeArgument('json'),
 220         ]
 221
 222         cmd += opts
 223         cmd.append(encodeFilename(self._ffmpeg_filename_argument(path), True))
 224         self.write_debug('ffprobe command line: %s' % shell_quote(cmd))
 225         p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
 226         stdout, stderr = p.communicate()
 227         return json.loads(stdout.decode('utf-8', 'replace'))
 228
 229     def get_stream_number(self, path, keys, value):
 230         streams = self.get_metadata_object(path)['streams']
 231         num = next(
 232             (i for i, stream in enumerate(streams) if traverse_dict(stream, keys, casesense=False) == value),
 233             None)
 234         return num, len(streams)
 235
 236     def run_ffmpeg_multiple_files(self, input_paths, out_path, opts):
 237         self.check_version()
 238
 239         oldest_mtime = min(
 240             os.stat(encodeFilename(path)).st_mtime for path in input_paths)
 241
 242         opts += self._configuration_args(exe=self.basename)
 243
 244         files_cmd = []
 245         for path in input_paths:
 246             files_cmd.extend([
 247                 encodeArgument('-i'),
 248                 encodeFilename(self._ffmpeg_filename_argument(path), True)
 249             ])
 250         cmd = [encodeFilename(self.executable, True), encodeArgument('-y')]
 251         # avconv does not have repeat option
 252         if self.basename == 'ffmpeg':
 253             cmd += [encodeArgument('-loglevel'), encodeArgument('repeat+info')]
 254         cmd += (files_cmd
 255                 + [encodeArgument(o) for o in opts]
 256                 + [encodeFilename(self._ffmpeg_filename_argument(out_path), True)])
 257
 258         self.write_debug('ffmpeg command line: %s' % shell_quote(cmd))
 259         p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
 260         stdout, stderr = process_communicate_or_kill(p)
 261         if p.returncode != 0:
 262             stderr = stderr.decode('utf-8', 'replace').strip()
 263             if self.get_param('verbose', False):
 264                 self.report_error(stderr)
 265             raise FFmpegPostProcessorError(stderr.split('\n')[-1])
 266         self.try_utime(out_path, oldest_mtime, oldest_mtime)
 267         return stderr.decode('utf-8', 'replace')
 268
 269     def run_ffmpeg(self, path, out_path, opts):
 270         return self.run_ffmpeg_multiple_files([path], out_path, opts)
 271
 272     def _ffmpeg_filename_argument(self, fn):
 273         # Always use 'file:' because the filename may contain ':' (ffmpeg
 274         # interprets that as a protocol) or can start with '-' (-- is broken in
 275         # ffmpeg, see https://ffmpeg.org/trac/ffmpeg/ticket/2127 for details)
 276         # Also leave '-' intact in order not to break streaming to stdout.
 277         if fn.startswith(('http://', 'https://')):
 278             return fn
 279         return 'file:' + fn if fn != '-' else fn
 280
 281
 282 class FFmpegExtractAudioPP(FFmpegPostProcessor):
 283     COMMON_AUDIO_EXTENSIONS = ('wav', 'flac', 'm4a', 'aiff', 'mp3', 'ogg', 'mka', 'opus', 'wma')
 284
 285     def __init__(self, downloader=None, preferredcodec=None, preferredquality=None, nopostoverwrites=False):
 286         FFmpegPostProcessor.__init__(self, downloader)
 287         if preferredcodec is None:
 288             preferredcodec = 'best'
 289         self._preferredcodec = preferredcodec
 290         self._preferredquality = preferredquality
 291         self._nopostoverwrites = nopostoverwrites
 292
 293     def run_ffmpeg(self, path, out_path, codec, more_opts):
 294         if codec is None:
 295             acodec_opts = []
 296         else:
 297             acodec_opts = ['-acodec', codec]
 298         opts = ['-vn'] + acodec_opts + more_opts
 299         try:
 300             FFmpegPostProcessor.run_ffmpeg(self, path, out_path, opts)
 301         except FFmpegPostProcessorError as err:
 302             raise AudioConversionError(err.msg)
 303
 304     def run(self, information):
 305         path = information['filepath']
 306         orig_ext = information['ext']
 307
 308         if self._preferredcodec == 'best' and orig_ext in self.COMMON_AUDIO_EXTENSIONS:
 309             self.to_screen('Skipping audio extraction since the file is already in a common audio format')
 310             return [], information
 311
 312         filecodec = self.get_audio_codec(path)
 313         if filecodec is None:
 314             raise PostProcessingError('WARNING: unable to obtain file audio codec with ffprobe')
 315
 316         more_opts = []
 317         if self._preferredcodec == 'best' or self._preferredcodec == filecodec or (self._preferredcodec == 'm4a' and filecodec == 'aac'):
 318             if filecodec == 'aac' and self._preferredcodec in ['m4a', 'best']:
 319                 # Lossless, but in another container
 320                 acodec = 'copy'
 321                 extension = 'm4a'
 322                 more_opts = ['-bsf:a', 'aac_adtstoasc']
 323             elif filecodec in ['aac', 'flac', 'mp3', 'vorbis', 'opus']:
 324                 # Lossless if possible
 325                 acodec = 'copy'
 326                 extension = filecodec
 327                 if filecodec == 'aac':
 328                     more_opts = ['-f', 'adts']
 329                 if filecodec == 'vorbis':
 330                     extension = 'ogg'
 331             else:
 332                 # MP3 otherwise.
 333                 acodec = 'libmp3lame'
 334                 extension = 'mp3'
 335                 more_opts = []
 336                 if self._preferredquality is not None:
 337                     if int(self._preferredquality) < 10:
 338                         more_opts += ['-q:a', self._preferredquality]
 339                     else:
 340                         more_opts += ['-b:a', self._preferredquality + 'k']
 341         else:
 342             # We convert the audio (lossy if codec is lossy)
 343             acodec = ACODECS[self._preferredcodec]
 344             extension = self._preferredcodec
 345             more_opts = []
 346             if self._preferredquality is not None:
 347                 # The opus codec doesn't support the -aq option
 348                 if int(self._preferredquality) < 10 and extension != 'opus':
 349                     more_opts += ['-q:a', self._preferredquality]
 350                 else:
 351                     more_opts += ['-b:a', self._preferredquality + 'k']
 352             if self._preferredcodec == 'aac':
 353                 more_opts += ['-f', 'adts']
 354             if self._preferredcodec == 'm4a':
 355                 more_opts += ['-bsf:a', 'aac_adtstoasc']
 356             if self._preferredcodec == 'vorbis':
 357                 extension = 'ogg'
 358             if self._preferredcodec == 'wav':
 359                 extension = 'wav'
 360                 more_opts += ['-f', 'wav']
 361
 362         prefix, sep, ext = path.rpartition('.')  # not os.path.splitext, since the latter does not work on unicode in all setups
 363         new_path = prefix + sep + extension
 364
 365         information['filepath'] = new_path
 366         information['ext'] = extension
 367
 368         # If we download foo.mp3 and convert it to... foo.mp3, then don't delete foo.mp3, silly.
 369         if (new_path == path
 370                 or (self._nopostoverwrites and os.path.exists(encodeFilename(new_path)))):
 371             self.to_screen('Post-process file %s exists, skipping' % new_path)
 372             return [], information
 373
 374         try:
 375             self.to_screen('Destination: ' + new_path)
 376             self.run_ffmpeg(path, new_path, acodec, more_opts)
 377         except AudioConversionError as e:
 378             raise PostProcessingError(
 379                 'audio conversion failed: ' + e.msg)
 380         except Exception:
 381             raise PostProcessingError('error running ' + self.basename)
 382
 383         # Try to update the date time for extracted audio file.
 384         if information.get('filetime') is not None:
 385             self.try_utime(
 386                 new_path, time.time(), information['filetime'],
 387                 errnote='Cannot update utime of audio file')
 388
 389         return [path], information
 390
 391
 392 class FFmpegVideoRemuxerPP(FFmpegPostProcessor):
 393     def __init__(self, downloader=None, preferedformat=None):
 394         super(FFmpegVideoRemuxerPP, self).__init__(downloader)
 395         self._preferedformats = preferedformat.lower().split('/')
 396
 397     def run(self, information):
 398         path = information['filepath']
 399         sourceext, targetext = information['ext'].lower(), None
 400         for pair in self._preferedformats:
 401             kv = pair.split('>')
 402             if len(kv) == 1 or kv[0].strip() == sourceext:
 403                 targetext = kv[-1].strip()
 404                 break
 405
 406         _skip_msg = (
 407             'could not find a mapping for %s' if not targetext
 408             else 'already is in target format %s' if sourceext == targetext
 409             else None)
 410         if _skip_msg:
 411             self.to_screen('Not remuxing media file %s; %s' % (path, _skip_msg % sourceext))
 412             return [], information
 413
 414         options = ['-c', 'copy', '-map', '0', '-dn']
 415         if targetext in ['mp4', 'm4a', 'mov']:
 416             options.extend(['-movflags', '+faststart'])
 417         prefix, sep, oldext = path.rpartition('.')
 418         outpath = prefix + sep + targetext
 419         self.to_screen('Remuxing video from %s to %s; Destination: %s' % (sourceext, targetext, outpath))
 420         self.run_ffmpeg(path, outpath, options)
 421         information['filepath'] = outpath
 422         information['format'] = targetext
 423         information['ext'] = targetext
 424         return [path], information
 425
 426
 427 class FFmpegVideoConvertorPP(FFmpegPostProcessor):
 428     def __init__(self, downloader=None, preferedformat=None):
 429         super(FFmpegVideoConvertorPP, self).__init__(downloader)
 430         self._preferedformat = preferedformat
 431
 432     def run(self, information):
 433         path = information['filepath']
 434         if information['ext'] == self._preferedformat:
 435             self.to_screen('Not converting video file %s - already is in target format %s' % (path, self._preferedformat))
 436             return [], information
 437         options = []
 438         if self._preferedformat == 'avi':
 439             options.extend(['-c:v', 'libxvid', '-vtag', 'XVID'])
 440         prefix, sep, ext = path.rpartition('.')
 441         outpath = prefix + sep + self._preferedformat
 442         self.to_screen('Converting video from %s to %s, Destination: ' % (information['ext'], self._preferedformat) + outpath)
 443         self.run_ffmpeg(path, outpath, options)
 444         information['filepath'] = outpath
 445         information['format'] = self._preferedformat
 446         information['ext'] = self._preferedformat
 447         return [path], information
 448
 449
 450 class FFmpegEmbedSubtitlePP(FFmpegPostProcessor):
 451     def __init__(self, downloader=None, already_have_subtitle=False):
 452         super(FFmpegEmbedSubtitlePP, self).__init__(downloader)
 453         self._already_have_subtitle = already_have_subtitle
 454
 455     def run(self, information):
 456         if information['ext'] not in ('mp4', 'webm', 'mkv'):
 457             self.to_screen('Subtitles can only be embedded in mp4, webm or mkv files')
 458             return [], information
 459         subtitles = information.get('requested_subtitles')
 460         if not subtitles:
 461             self.to_screen('There aren\'t any subtitles to embed')
 462             return [], information
 463
 464         filename = information['filepath']
 465
 466         ext = information['ext']
 467         sub_langs = []
 468         sub_filenames = []
 469         webm_vtt_warn = False
 470         mp4_ass_warn = False
 471
 472         for lang, sub_info in subtitles.items():
 473             sub_ext = sub_info['ext']
 474             if sub_ext == 'json':
 475                 self.report_warning('JSON subtitles cannot be embedded')
 476             elif ext != 'webm' or ext == 'webm' and sub_ext == 'vtt':
 477                 sub_langs.append(lang)
 478                 sub_filenames.append(subtitles_filename(filename, lang, sub_ext, ext))
 479             else:
 480                 if not webm_vtt_warn and ext == 'webm' and sub_ext != 'vtt':
 481                     webm_vtt_warn = True
 482                     self.report_warning('Only WebVTT subtitles can be embedded in webm files')
 483             if not mp4_ass_warn and ext == 'mp4' and sub_ext == 'ass':
 484                 mp4_ass_warn = True
 485                 self.report_warning('ASS subtitles cannot be properly embedded in mp4 files; expect issues')
 486
 487         if not sub_langs:
 488             return [], information
 489
 490         input_files = [filename] + sub_filenames
 491
 492         opts = [
 493             '-c', 'copy', '-map', '0', '-dn',
 494             # Don't copy the existing subtitles, we may be running the
 495             # postprocessor a second time
 496             '-map', '-0:s',
 497             # Don't copy Apple TV chapters track, bin_data (see #19042, #19024,
 498             # https://trac.ffmpeg.org/ticket/6016)
 499             '-map', '-0:d',
 500         ]
 501         if information['ext'] == 'mp4':
 502             opts += ['-c:s', 'mov_text']
 503         for (i, lang) in enumerate(sub_langs):
 504             opts.extend(['-map', '%d:0' % (i + 1)])
 505             lang_code = ISO639Utils.short2long(lang) or lang
 506             opts.extend(['-metadata:s:s:%d' % i, 'language=%s' % lang_code])
 507
 508         temp_filename = prepend_extension(filename, 'temp')
 509         self.to_screen('Embedding subtitles in "%s"' % filename)
 510         self.run_ffmpeg_multiple_files(input_files, temp_filename, opts)
 511         os.remove(encodeFilename(filename))
 512         os.rename(encodeFilename(temp_filename), encodeFilename(filename))
 513
 514         files_to_delete = [] if self._already_have_subtitle else sub_filenames
 515         return files_to_delete, information
 516
 517
 518 class FFmpegMetadataPP(FFmpegPostProcessor):
 519     def run(self, info):
 520         metadata = {}
 521
 522         def add(meta_list, info_list=None):
 523             if not info_list:
 524                 info_list = meta_list
 525             if not isinstance(meta_list, (list, tuple)):
 526                 meta_list = (meta_list,)
 527             if not isinstance(info_list, (list, tuple)):
 528                 info_list = (info_list,)
 529             for info_f in info_list:
 530                 if info.get(info_f) is not None:
 531                     for meta_f in meta_list:
 532                         metadata[meta_f] = info[info_f]
 533                     break
 534
 535         # See [1-4] for some info on media metadata/metadata supported
 536         # by ffmpeg.
 537         # 1. https://kdenlive.org/en/project/adding-meta-data-to-mp4-video/
 538         # 2. https://wiki.multimedia.cx/index.php/FFmpeg_Metadata
 539         # 3. https://kodi.wiki/view/Video_file_tagging
 540
 541         add('title', ('track', 'title'))
 542         add('date', 'upload_date')
 543         add(('description', 'comment'), 'description')
 544         add('purl', 'webpage_url')
 545         add('track', 'track_number')
 546         add('artist', ('artist', 'creator', 'uploader', 'uploader_id'))
 547         add('genre')
 548         add('album')
 549         add('album_artist')
 550         add('disc', 'disc_number')
 551         add('show', 'series')
 552         add('season_number')
 553         add('episode_id', ('episode', 'episode_id'))
 554         add('episode_sort', 'episode_number')
 555
 556         if not metadata:
 557             self.to_screen('There isn\'t any metadata to add')
 558             return [], info
 559
 560         filename = info['filepath']
 561         temp_filename = prepend_extension(filename, 'temp')
 562         in_filenames = [filename]
 563         options = ['-map', '0', '-dn']
 564
 565         if info['ext'] == 'm4a':
 566             options.extend(['-vn', '-acodec', 'copy'])
 567         else:
 568             options.extend(['-c', 'copy'])
 569
 570         for (name, value) in metadata.items():
 571             options.extend(['-metadata', '%s=%s' % (name, value)])
 572
 573         chapters = info.get('chapters', [])
 574         if chapters:
 575             metadata_filename = replace_extension(filename, 'meta')
 576             with io.open(metadata_filename, 'wt', encoding='utf-8') as f:
 577                 def ffmpeg_escape(text):
 578                     return re.sub(r'(=|;|#|\\|\n)', r'\\\1', text)
 579
 580                 metadata_file_content = ';FFMETADATA1\n'
 581                 for chapter in chapters:
 582                     metadata_file_content += '[CHAPTER]\nTIMEBASE=1/1000\n'
 583                     metadata_file_content += 'START=%d\n' % (chapter['start_time'] * 1000)
 584                     metadata_file_content += 'END=%d\n' % (chapter['end_time'] * 1000)
 585                     chapter_title = chapter.get('title')
 586                     if chapter_title:
 587                         metadata_file_content += 'title=%s\n' % ffmpeg_escape(chapter_title)
 588                 f.write(metadata_file_content)
 589                 in_filenames.append(metadata_filename)
 590                 options.extend(['-map_metadata', '1'])
 591
 592         if '__infojson_filename' in info and info['ext'] in ('mkv', 'mka'):
 593             old_stream, new_stream = self.get_stream_number(
 594                 filename, ('tags', 'mimetype'), 'application/json')
 595             if old_stream is not None:
 596                 options.extend(['-map', '-0:%d' % old_stream])
 597                 new_stream -= 1
 598
 599             options.extend([
 600                 '-attach', info['__infojson_filename'],
 601                 '-metadata:s:%d' % new_stream, 'mimetype=application/json'
 602             ])
 603
 604         self.to_screen('Adding metadata to \'%s\'' % filename)
 605         self.run_ffmpeg_multiple_files(in_filenames, temp_filename, options)
 606         if chapters:
 607             os.remove(metadata_filename)
 608         os.remove(encodeFilename(filename))
 609         os.rename(encodeFilename(temp_filename), encodeFilename(filename))
 610         return [], info
 611
 612
 613 class FFmpegMergerPP(FFmpegPostProcessor):
 614     def run(self, info):
 615         filename = info['filepath']
 616         temp_filename = prepend_extension(filename, 'temp')
 617         args = ['-c', 'copy']
 618         for (i, fmt) in enumerate(info['requested_formats']):
 619             if fmt.get('acodec') != 'none':
 620                 args.extend(['-map', '%u:a:0' % (i)])
 621             if fmt.get('vcodec') != 'none':
 622                 args.extend(['-map', '%u:v:0' % (i)])
 623         self.to_screen('Merging formats into "%s"' % filename)
 624         self.run_ffmpeg_multiple_files(info['__files_to_merge'], temp_filename, args)
 625         os.rename(encodeFilename(temp_filename), encodeFilename(filename))
 626         return info['__files_to_merge'], info
 627
 628     def can_merge(self):
 629         # TODO: figure out merge-capable ffmpeg version
 630         if self.basename != 'avconv':
 631             return True
 632
 633         required_version = '10-0'
 634         if is_outdated_version(
 635                 self._versions[self.basename], required_version):
 636             warning = ('Your copy of %s is outdated and unable to properly mux separate video and audio files, '
 637                        'youtube-dlc will download single file media. '
 638                        'Update %s to version %s or newer to fix this.') % (
 639                            self.basename, self.basename, required_version)
 640             self.report_warning(warning)
 641             return False
 642         return True
 643
 644
 645 class FFmpegFixupStretchedPP(FFmpegPostProcessor):
 646     def run(self, info):
 647         stretched_ratio = info.get('stretched_ratio')
 648         if stretched_ratio is None or stretched_ratio == 1:
 649             return [], info
 650
 651         filename = info['filepath']
 652         temp_filename = prepend_extension(filename, 'temp')
 653
 654         options = ['-c', 'copy', '-map', '0', '-dn', '-aspect', '%f' % stretched_ratio]
 655         self.to_screen('Fixing aspect ratio in "%s"' % filename)
 656         self.run_ffmpeg(filename, temp_filename, options)
 657
 658         os.remove(encodeFilename(filename))
 659         os.rename(encodeFilename(temp_filename), encodeFilename(filename))
 660
 661         return [], info
 662
 663
 664 class FFmpegFixupM4aPP(FFmpegPostProcessor):
 665     def run(self, info):
 666         if info.get('container') != 'm4a_dash':
 667             return [], info
 668
 669         filename = info['filepath']
 670         temp_filename = prepend_extension(filename, 'temp')
 671
 672         options = ['-c', 'copy', '-map', '0', '-dn', '-f', 'mp4']
 673         self.to_screen('Correcting container in "%s"' % filename)
 674         self.run_ffmpeg(filename, temp_filename, options)
 675
 676         os.remove(encodeFilename(filename))
 677         os.rename(encodeFilename(temp_filename), encodeFilename(filename))
 678
 679         return [], info
 680
 681
 682 class FFmpegFixupM3u8PP(FFmpegPostProcessor):
 683     def run(self, info):
 684         filename = info['filepath']
 685         if self.get_audio_codec(filename) == 'aac':
 686             temp_filename = prepend_extension(filename, 'temp')
 687
 688             options = ['-c', 'copy', '-map', '0', '-dn', '-f', 'mp4', '-bsf:a', 'aac_adtstoasc']
 689             self.to_screen('Fixing malformed AAC bitstream in "%s"' % filename)
 690             self.run_ffmpeg(filename, temp_filename, options)
 691
 692             os.remove(encodeFilename(filename))
 693             os.rename(encodeFilename(temp_filename), encodeFilename(filename))
 694         return [], info
 695
 696
 697 class FFmpegSubtitlesConvertorPP(FFmpegPostProcessor):
 698     def __init__(self, downloader=None, format=None):
 699         super(FFmpegSubtitlesConvertorPP, self).__init__(downloader)
 700         self.format = format
 701
 702     def run(self, info):
 703         subs = info.get('requested_subtitles')
 704         filename = info['filepath']
 705         new_ext = self.format
 706         new_format = new_ext
 707         if new_format == 'vtt':
 708             new_format = 'webvtt'
 709         if subs is None:
 710             self.to_screen('There aren\'t any subtitles to convert')
 711             return [], info
 712         self.to_screen('Converting subtitles')
 713         sub_filenames = []
 714         for lang, sub in subs.items():
 715             ext = sub['ext']
 716             if ext == new_ext:
 717                 self.to_screen('Subtitle file for %s is already in the requested format' % new_ext)
 718                 continue
 719             elif ext == 'json':
 720                 self.to_screen(
 721                     'You have requested to convert json subtitles into another format, '
 722                     'which is currently not possible')
 723                 continue
 724             old_file = subtitles_filename(filename, lang, ext, info.get('ext'))
 725             sub_filenames.append(old_file)
 726             new_file = subtitles_filename(filename, lang, new_ext, info.get('ext'))
 727
 728             if ext in ('dfxp', 'ttml', 'tt'):
 729                 self.report_warning(
 730                     'You have requested to convert dfxp (TTML) subtitles into another format, '
 731                     'which results in style information loss')
 732
 733                 dfxp_file = old_file
 734                 srt_file = subtitles_filename(filename, lang, 'srt', info.get('ext'))
 735
 736                 with open(dfxp_file, 'rb') as f:
 737                     srt_data = dfxp2srt(f.read())
 738
 739                 with io.open(srt_file, 'wt', encoding='utf-8') as f:
 740                     f.write(srt_data)
 741                 old_file = srt_file
 742
 743                 subs[lang] = {
 744                     'ext': 'srt',
 745                     'data': srt_data
 746                 }
 747
 748                 if new_ext == 'srt':
 749                     continue
 750                 else:
 751                     sub_filenames.append(srt_file)
 752
 753             self.run_ffmpeg(old_file, new_file, ['-f', new_format])
 754
 755             with io.open(new_file, 'rt', encoding='utf-8') as f:
 756                 subs[lang] = {
 757                     'ext': new_ext,
 758                     'data': f.read(),
 759                 }
 760
 761         return sub_filenames, info