youtube_dl/postprocessor/ffmpeg.py

   1 from __future__ import unicode_literals
   2
   3 import io
   4 import os
   5 import subprocess
   6 import time
   7
   8
   9 from .common import AudioConversionError, PostProcessor
  10
  11 from ..compat import (
  12     compat_subprocess_get_DEVNULL,
  13 )
  14 from ..utils import (
  15     encodeArgument,
  16     encodeFilename,
  17     get_exe_version,
  18     is_outdated_version,
  19     PostProcessingError,
  20     prepend_extension,
  21     shell_quote,
  22     subtitles_filename,
  23 )
  24
  25
  26 class FFmpegPostProcessorError(PostProcessingError):
  27     pass
  28
  29
  30 class FFmpegPostProcessor(PostProcessor):
  31     def __init__(self, downloader=None):
  32         PostProcessor.__init__(self, downloader)
  33         self._determine_executables()
  34
  35     def check_version(self):
  36         if not self.available:
  37             raise FFmpegPostProcessorError('ffmpeg or avconv not found. Please install one.')
  38
  39         required_version = '10-0' if self.basename == 'avconv' else '1.0'
  40         if is_outdated_version(
  41                 self._versions[self.basename], required_version):
  42             warning = 'Your copy of %s is outdated, update %s to version %s or newer if you encounter any errors.' % (
  43                 self.basename, self.basename, required_version)
  44             if self._downloader:
  45                 self._downloader.report_warning(warning)
  46
  47     @staticmethod
  48     def get_versions(downloader=None):
  49         return FFmpegPostProcessor(downloader)._versions
  50
  51     def _determine_executables(self):
  52         programs = ['avprobe', 'avconv', 'ffmpeg', 'ffprobe']
  53         prefer_ffmpeg = self._downloader.params.get('prefer_ffmpeg', False)
  54
  55         self.basename = None
  56         self.probe_basename = None
  57
  58         self._paths = None
  59         self._versions = None
  60         if self._downloader:
  61             location = self._downloader.params.get('ffmpeg_location')
  62             if location is not None:
  63                 if not os.path.exists(location):
  64                     self._downloader.report_warning(
  65                         'ffmpeg-location %s does not exist! '
  66                         'Continuing without avconv/ffmpeg.' % (location))
  67                     self._versions = {}
  68                     return
  69                 elif not os.path.isdir(location):
  70                     basename = os.path.splitext(os.path.basename(location))[0]
  71                     if basename not in programs:
  72                         self._downloader.report_warning(
  73                             'Cannot identify executable %s, its basename should be one of %s. '
  74                             'Continuing without avconv/ffmpeg.' %
  75                             (location, ', '.join(programs)))
  76                         self._versions = {}
  77                         return None
  78                     location = os.path.dirname(os.path.abspath(location))
  79                     if basename in ('ffmpeg', 'ffprobe'):
  80                         prefer_ffmpeg = True
  81
  82                 self._paths = dict(
  83                     (p, os.path.join(location, p)) for p in programs)
  84                 self._versions = dict(
  85                     (p, get_exe_version(self._paths[p], args=['-version']))
  86                     for p in programs)
  87         if self._versions is None:
  88             self._versions = dict(
  89                 (p, get_exe_version(p, args=['-version'])) for p in programs)
  90             self._paths = dict((p, p) for p in programs)
  91
  92         if prefer_ffmpeg:
  93             prefs = ('ffmpeg', 'avconv')
  94         else:
  95             prefs = ('avconv', 'ffmpeg')
  96         for p in prefs:
  97             if self._versions[p]:
  98                 self.basename = p
  99                 break
 100
 101         if prefer_ffmpeg:
 102             prefs = ('ffprobe', 'avprobe')
 103         else:
 104             prefs = ('avprobe', 'ffprobe')
 105         for p in prefs:
 106             if self._versions[p]:
 107                 self.probe_basename = p
 108                 break
 109
 110     @property
 111     def available(self):
 112         return self.basename is not None
 113
 114     @property
 115     def executable(self):
 116         return self._paths[self.basename]
 117
 118     @property
 119     def probe_available(self):
 120         return self.probe_basename is not None
 121
 122     @property
 123     def probe_executable(self):
 124         return self._paths[self.probe_basename]
 125
 126     def run_ffmpeg_multiple_files(self, input_paths, out_path, opts):
 127         self.check_version()
 128
 129         oldest_mtime = min(
 130             os.stat(encodeFilename(path)).st_mtime for path in input_paths)
 131
 132         files_cmd = []
 133         for path in input_paths:
 134             files_cmd.extend([encodeArgument('-i'), encodeFilename(path, True)])
 135         cmd = ([encodeFilename(self.executable, True), encodeArgument('-y')] +
 136                files_cmd +
 137                [encodeArgument(o) for o in opts] +
 138                [encodeFilename(self._ffmpeg_filename_argument(out_path), True)])
 139
 140         if self._downloader.params.get('verbose', False):
 141             self._downloader.to_screen('[debug] ffmpeg command line: %s' % shell_quote(cmd))
 142         p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
 143         stdout, stderr = p.communicate()
 144         if p.returncode != 0:
 145             stderr = stderr.decode('utf-8', 'replace')
 146             msg = stderr.strip().split('\n')[-1]
 147             raise FFmpegPostProcessorError(msg)
 148         self.try_utime(out_path, oldest_mtime, oldest_mtime)
 149
 150     def run_ffmpeg(self, path, out_path, opts):
 151         self.run_ffmpeg_multiple_files([path], out_path, opts)
 152
 153     def _ffmpeg_filename_argument(self, fn):
 154         # ffmpeg broke --, see https://ffmpeg.org/trac/ffmpeg/ticket/2127 for details
 155         if fn.startswith('-'):
 156             return './' + fn
 157         return fn
 158
 159
 160 class FFmpegExtractAudioPP(FFmpegPostProcessor):
 161     def __init__(self, downloader=None, preferredcodec=None, preferredquality=None, nopostoverwrites=False):
 162         FFmpegPostProcessor.__init__(self, downloader)
 163         if preferredcodec is None:
 164             preferredcodec = 'best'
 165         self._preferredcodec = preferredcodec
 166         self._preferredquality = preferredquality
 167         self._nopostoverwrites = nopostoverwrites
 168
 169     def get_audio_codec(self, path):
 170
 171         if not self.probe_available:
 172             raise PostProcessingError('ffprobe or avprobe not found. Please install one.')
 173         try:
 174             cmd = [
 175                 encodeFilename(self.probe_executable, True),
 176                 encodeArgument('-show_streams'),
 177                 encodeFilename(self._ffmpeg_filename_argument(path), True)]
 178             if self._downloader.params.get('verbose', False):
 179                 self._downloader.to_screen('[debug] %s command line: %s' % (self.basename, shell_quote(cmd)))
 180             handle = subprocess.Popen(cmd, stderr=compat_subprocess_get_DEVNULL(), stdout=subprocess.PIPE, stdin=subprocess.PIPE)
 181             output = handle.communicate()[0]
 182             if handle.wait() != 0:
 183                 return None
 184         except (IOError, OSError):
 185             return None
 186         audio_codec = None
 187         for line in output.decode('ascii', 'ignore').split('\n'):
 188             if line.startswith('codec_name='):
 189                 audio_codec = line.split('=')[1].strip()
 190             elif line.strip() == 'codec_type=audio' and audio_codec is not None:
 191                 return audio_codec
 192         return None
 193
 194     def run_ffmpeg(self, path, out_path, codec, more_opts):
 195         if codec is None:
 196             acodec_opts = []
 197         else:
 198             acodec_opts = ['-acodec', codec]
 199         opts = ['-vn'] + acodec_opts + more_opts
 200         try:
 201             FFmpegPostProcessor.run_ffmpeg(self, path, out_path, opts)
 202         except FFmpegPostProcessorError as err:
 203             raise AudioConversionError(err.msg)
 204
 205     def run(self, information):
 206         path = information['filepath']
 207
 208         filecodec = self.get_audio_codec(path)
 209         if filecodec is None:
 210             raise PostProcessingError('WARNING: unable to obtain file audio codec with ffprobe')
 211
 212         more_opts = []
 213         if self._preferredcodec == 'best' or self._preferredcodec == filecodec or (self._preferredcodec == 'm4a' and filecodec == 'aac'):
 214             if filecodec == 'aac' and self._preferredcodec in ['m4a', 'best']:
 215                 # Lossless, but in another container
 216                 acodec = 'copy'
 217                 extension = 'm4a'
 218                 more_opts = ['-bsf:a', 'aac_adtstoasc']
 219             elif filecodec in ['aac', 'mp3', 'vorbis', 'opus']:
 220                 # Lossless if possible
 221                 acodec = 'copy'
 222                 extension = filecodec
 223                 if filecodec == 'aac':
 224                     more_opts = ['-f', 'adts']
 225                 if filecodec == 'vorbis':
 226                     extension = 'ogg'
 227             else:
 228                 # MP3 otherwise.
 229                 acodec = 'libmp3lame'
 230                 extension = 'mp3'
 231                 more_opts = []
 232                 if self._preferredquality is not None:
 233                     if int(self._preferredquality) < 10:
 234                         more_opts += ['-q:a', self._preferredquality]
 235                     else:
 236                         more_opts += ['-b:a', self._preferredquality + 'k']
 237         else:
 238             # We convert the audio (lossy)
 239             acodec = {'mp3': 'libmp3lame', 'aac': 'aac', 'm4a': 'aac', 'opus': 'opus', 'vorbis': 'libvorbis', 'wav': None}[self._preferredcodec]
 240             extension = self._preferredcodec
 241             more_opts = []
 242             if self._preferredquality is not None:
 243                 # The opus codec doesn't support the -aq option
 244                 if int(self._preferredquality) < 10 and extension != 'opus':
 245                     more_opts += ['-q:a', self._preferredquality]
 246                 else:
 247                     more_opts += ['-b:a', self._preferredquality + 'k']
 248             if self._preferredcodec == 'aac':
 249                 more_opts += ['-f', 'adts']
 250             if self._preferredcodec == 'm4a':
 251                 more_opts += ['-bsf:a', 'aac_adtstoasc']
 252             if self._preferredcodec == 'vorbis':
 253                 extension = 'ogg'
 254             if self._preferredcodec == 'wav':
 255                 extension = 'wav'
 256                 more_opts += ['-f', 'wav']
 257
 258         prefix, sep, ext = path.rpartition('.')  # not os.path.splitext, since the latter does not work on unicode in all setups
 259         new_path = prefix + sep + extension
 260
 261         # If we download foo.mp3 and convert it to... foo.mp3, then don't delete foo.mp3, silly.
 262         if (new_path == path or
 263                 (self._nopostoverwrites and os.path.exists(encodeFilename(new_path)))):
 264             self._downloader.to_screen('[youtube] Post-process file %s exists, skipping' % new_path)
 265             return [], information
 266
 267         try:
 268             self._downloader.to_screen('[' + self.basename + '] Destination: ' + new_path)
 269             self.run_ffmpeg(path, new_path, acodec, more_opts)
 270         except AudioConversionError as e:
 271             raise PostProcessingError(
 272                 'audio conversion failed: ' + e.msg)
 273         except Exception:
 274             raise PostProcessingError('error running ' + self.basename)
 275
 276         # Try to update the date time for extracted audio file.
 277         if information.get('filetime') is not None:
 278             self.try_utime(
 279                 new_path, time.time(), information['filetime'],
 280                 errnote='Cannot update utime of audio file')
 281
 282         information['filepath'] = new_path
 283         information['ext'] = extension
 284
 285         return [path], information
 286
 287
 288 class FFmpegVideoConvertorPP(FFmpegPostProcessor):
 289     def __init__(self, downloader=None, preferedformat=None):
 290         super(FFmpegVideoConvertorPP, self).__init__(downloader)
 291         self._preferedformat = preferedformat
 292
 293     def run(self, information):
 294         path = information['filepath']
 295         prefix, sep, ext = path.rpartition('.')
 296         outpath = prefix + sep + self._preferedformat
 297         if information['ext'] == self._preferedformat:
 298             self._downloader.to_screen('[ffmpeg] Not converting video file %s - already is in target format %s' % (path, self._preferedformat))
 299             return [], information
 300         self._downloader.to_screen('[' + 'ffmpeg' + '] Converting video from %s to %s, Destination: ' % (information['ext'], self._preferedformat) + outpath)
 301         self.run_ffmpeg(path, outpath, [])
 302         information['filepath'] = outpath
 303         information['format'] = self._preferedformat
 304         information['ext'] = self._preferedformat
 305         return [path], information
 306
 307
 308 class FFmpegEmbedSubtitlePP(FFmpegPostProcessor):
 309     # See http://www.loc.gov/standards/iso639-2/ISO-639-2_utf-8.txt
 310     _lang_map = {
 311         'aa': 'aar',
 312         'ab': 'abk',
 313         'ae': 'ave',
 314         'af': 'afr',
 315         'ak': 'aka',
 316         'am': 'amh',
 317         'an': 'arg',
 318         'ar': 'ara',
 319         'as': 'asm',
 320         'av': 'ava',
 321         'ay': 'aym',
 322         'az': 'aze',
 323         'ba': 'bak',
 324         'be': 'bel',
 325         'bg': 'bul',
 326         'bh': 'bih',
 327         'bi': 'bis',
 328         'bm': 'bam',
 329         'bn': 'ben',
 330         'bo': 'bod',
 331         'br': 'bre',
 332         'bs': 'bos',
 333         'ca': 'cat',
 334         'ce': 'che',
 335         'ch': 'cha',
 336         'co': 'cos',
 337         'cr': 'cre',
 338         'cs': 'ces',
 339         'cu': 'chu',
 340         'cv': 'chv',
 341         'cy': 'cym',
 342         'da': 'dan',
 343         'de': 'deu',
 344         'dv': 'div',
 345         'dz': 'dzo',
 346         'ee': 'ewe',
 347         'el': 'ell',
 348         'en': 'eng',
 349         'eo': 'epo',
 350         'es': 'spa',
 351         'et': 'est',
 352         'eu': 'eus',
 353         'fa': 'fas',
 354         'ff': 'ful',
 355         'fi': 'fin',
 356         'fj': 'fij',
 357         'fo': 'fao',
 358         'fr': 'fra',
 359         'fy': 'fry',
 360         'ga': 'gle',
 361         'gd': 'gla',
 362         'gl': 'glg',
 363         'gn': 'grn',
 364         'gu': 'guj',
 365         'gv': 'glv',
 366         'ha': 'hau',
 367         'he': 'heb',
 368         'hi': 'hin',
 369         'ho': 'hmo',
 370         'hr': 'hrv',
 371         'ht': 'hat',
 372         'hu': 'hun',
 373         'hy': 'hye',
 374         'hz': 'her',
 375         'ia': 'ina',
 376         'id': 'ind',
 377         'ie': 'ile',
 378         'ig': 'ibo',
 379         'ii': 'iii',
 380         'ik': 'ipk',
 381         'io': 'ido',
 382         'is': 'isl',
 383         'it': 'ita',
 384         'iu': 'iku',
 385         'ja': 'jpn',
 386         'jv': 'jav',
 387         'ka': 'kat',
 388         'kg': 'kon',
 389         'ki': 'kik',
 390         'kj': 'kua',
 391         'kk': 'kaz',
 392         'kl': 'kal',
 393         'km': 'khm',
 394         'kn': 'kan',
 395         'ko': 'kor',
 396         'kr': 'kau',
 397         'ks': 'kas',
 398         'ku': 'kur',
 399         'kv': 'kom',
 400         'kw': 'cor',
 401         'ky': 'kir',
 402         'la': 'lat',
 403         'lb': 'ltz',
 404         'lg': 'lug',
 405         'li': 'lim',
 406         'ln': 'lin',
 407         'lo': 'lao',
 408         'lt': 'lit',
 409         'lu': 'lub',
 410         'lv': 'lav',
 411         'mg': 'mlg',
 412         'mh': 'mah',
 413         'mi': 'mri',
 414         'mk': 'mkd',
 415         'ml': 'mal',
 416         'mn': 'mon',
 417         'mr': 'mar',
 418         'ms': 'msa',
 419         'mt': 'mlt',
 420         'my': 'mya',
 421         'na': 'nau',
 422         'nb': 'nob',
 423         'nd': 'nde',
 424         'ne': 'nep',
 425         'ng': 'ndo',
 426         'nl': 'nld',
 427         'nn': 'nno',
 428         'no': 'nor',
 429         'nr': 'nbl',
 430         'nv': 'nav',
 431         'ny': 'nya',
 432         'oc': 'oci',
 433         'oj': 'oji',
 434         'om': 'orm',
 435         'or': 'ori',
 436         'os': 'oss',
 437         'pa': 'pan',
 438         'pi': 'pli',
 439         'pl': 'pol',
 440         'ps': 'pus',
 441         'pt': 'por',
 442         'qu': 'que',
 443         'rm': 'roh',
 444         'rn': 'run',
 445         'ro': 'ron',
 446         'ru': 'rus',
 447         'rw': 'kin',
 448         'sa': 'san',
 449         'sc': 'srd',
 450         'sd': 'snd',
 451         'se': 'sme',
 452         'sg': 'sag',
 453         'si': 'sin',
 454         'sk': 'slk',
 455         'sl': 'slv',
 456         'sm': 'smo',
 457         'sn': 'sna',
 458         'so': 'som',
 459         'sq': 'sqi',
 460         'sr': 'srp',
 461         'ss': 'ssw',
 462         'st': 'sot',
 463         'su': 'sun',
 464         'sv': 'swe',
 465         'sw': 'swa',
 466         'ta': 'tam',
 467         'te': 'tel',
 468         'tg': 'tgk',
 469         'th': 'tha',
 470         'ti': 'tir',
 471         'tk': 'tuk',
 472         'tl': 'tgl',
 473         'tn': 'tsn',
 474         'to': 'ton',
 475         'tr': 'tur',
 476         'ts': 'tso',
 477         'tt': 'tat',
 478         'tw': 'twi',
 479         'ty': 'tah',
 480         'ug': 'uig',
 481         'uk': 'ukr',
 482         'ur': 'urd',
 483         'uz': 'uzb',
 484         've': 'ven',
 485         'vi': 'vie',
 486         'vo': 'vol',
 487         'wa': 'wln',
 488         'wo': 'wol',
 489         'xh': 'xho',
 490         'yi': 'yid',
 491         'yo': 'yor',
 492         'za': 'zha',
 493         'zh': 'zho',
 494         'zu': 'zul',
 495     }
 496
 497     @classmethod
 498     def _conver_lang_code(cls, code):
 499         """Convert language code from ISO 639-1 to ISO 639-2/T"""
 500         return cls._lang_map.get(code[:2])
 501
 502     def run(self, information):
 503         if information['ext'] != 'mp4':
 504             self._downloader.to_screen('[ffmpeg] Subtitles can only be embedded in mp4 files')
 505             return [], information
 506         subtitles = information.get('requested_subtitles')
 507         if not subtitles:
 508             self._downloader.to_screen('[ffmpeg] There aren\'t any subtitles to embed')
 509             return [], information
 510
 511         sub_langs = list(subtitles.keys())
 512         filename = information['filepath']
 513         sub_filenames = [subtitles_filename(filename, lang, sub_info['ext']) for lang, sub_info in subtitles.items()]
 514         input_files = [filename] + sub_filenames
 515
 516         opts = [
 517             '-map', '0',
 518             '-c', 'copy',
 519             # Don't copy the existing subtitles, we may be running the
 520             # postprocessor a second time
 521             '-map', '-0:s',
 522             '-c:s', 'mov_text',
 523         ]
 524         for (i, lang) in enumerate(sub_langs):
 525             opts.extend(['-map', '%d:0' % (i + 1)])
 526             lang_code = self._conver_lang_code(lang)
 527             if lang_code is not None:
 528                 opts.extend(['-metadata:s:s:%d' % i, 'language=%s' % lang_code])
 529
 530         temp_filename = prepend_extension(filename, 'temp')
 531         self._downloader.to_screen('[ffmpeg] Embedding subtitles in \'%s\'' % filename)
 532         self.run_ffmpeg_multiple_files(input_files, temp_filename, opts)
 533         os.remove(encodeFilename(filename))
 534         os.rename(encodeFilename(temp_filename), encodeFilename(filename))
 535
 536         return sub_filenames, information
 537
 538
 539 class FFmpegMetadataPP(FFmpegPostProcessor):
 540     def run(self, info):
 541         metadata = {}
 542         if info.get('title') is not None:
 543             metadata['title'] = info['title']
 544         if info.get('upload_date') is not None:
 545             metadata['date'] = info['upload_date']
 546         if info.get('artist') is not None:
 547             metadata['artist'] = info['artist']
 548         elif info.get('uploader') is not None:
 549             metadata['artist'] = info['uploader']
 550         elif info.get('uploader_id') is not None:
 551             metadata['artist'] = info['uploader_id']
 552         if info.get('description') is not None:
 553             metadata['description'] = info['description']
 554             metadata['comment'] = info['description']
 555         if info.get('webpage_url') is not None:
 556             metadata['purl'] = info['webpage_url']
 557         if info.get('album') is not None:
 558             metadata['album'] = info['album']
 559
 560         if not metadata:
 561             self._downloader.to_screen('[ffmpeg] There isn\'t any metadata to add')
 562             return [], info
 563
 564         filename = info['filepath']
 565         temp_filename = prepend_extension(filename, 'temp')
 566
 567         if info['ext'] == 'm4a':
 568             options = ['-vn', '-acodec', 'copy']
 569         else:
 570             options = ['-c', 'copy']
 571
 572         for (name, value) in metadata.items():
 573             options.extend(['-metadata', '%s=%s' % (name, value)])
 574
 575         self._downloader.to_screen('[ffmpeg] Adding metadata to \'%s\'' % filename)
 576         self.run_ffmpeg(filename, temp_filename, options)
 577         os.remove(encodeFilename(filename))
 578         os.rename(encodeFilename(temp_filename), encodeFilename(filename))
 579         return [], info
 580
 581
 582 class FFmpegMergerPP(FFmpegPostProcessor):
 583     def run(self, info):
 584         filename = info['filepath']
 585         temp_filename = prepend_extension(filename, 'temp')
 586         args = ['-c', 'copy', '-map', '0:v:0', '-map', '1:a:0']
 587         self._downloader.to_screen('[ffmpeg] Merging formats into "%s"' % filename)
 588         self.run_ffmpeg_multiple_files(info['__files_to_merge'], temp_filename, args)
 589         os.rename(encodeFilename(temp_filename), encodeFilename(filename))
 590         return info['__files_to_merge'], info
 591
 592
 593 class FFmpegFixupStretchedPP(FFmpegPostProcessor):
 594     def run(self, info):
 595         stretched_ratio = info.get('stretched_ratio')
 596         if stretched_ratio is None or stretched_ratio == 1:
 597             return [], info
 598
 599         filename = info['filepath']
 600         temp_filename = prepend_extension(filename, 'temp')
 601
 602         options = ['-c', 'copy', '-aspect', '%f' % stretched_ratio]
 603         self._downloader.to_screen('[ffmpeg] Fixing aspect ratio in "%s"' % filename)
 604         self.run_ffmpeg(filename, temp_filename, options)
 605
 606         os.remove(encodeFilename(filename))
 607         os.rename(encodeFilename(temp_filename), encodeFilename(filename))
 608
 609         return [], info
 610
 611
 612 class FFmpegFixupM4aPP(FFmpegPostProcessor):
 613     def run(self, info):
 614         if info.get('container') != 'm4a_dash':
 615             return [], info
 616
 617         filename = info['filepath']
 618         temp_filename = prepend_extension(filename, 'temp')
 619
 620         options = ['-c', 'copy', '-f', 'mp4']
 621         self._downloader.to_screen('[ffmpeg] Correcting container in "%s"' % filename)
 622         self.run_ffmpeg(filename, temp_filename, options)
 623
 624         os.remove(encodeFilename(filename))
 625         os.rename(encodeFilename(temp_filename), encodeFilename(filename))
 626
 627         return [], info
 628
 629
 630 class FFmpegSubtitlesConvertorPP(FFmpegPostProcessor):
 631     def __init__(self, downloader=None, format=None):
 632         super(FFmpegSubtitlesConvertorPP, self).__init__(downloader)
 633         self.format = format
 634
 635     def run(self, info):
 636         subs = info.get('requested_subtitles')
 637         filename = info['filepath']
 638         new_ext = self.format
 639         new_format = new_ext
 640         if new_format == 'vtt':
 641             new_format = 'webvtt'
 642         if subs is None:
 643             self._downloader.to_screen('[ffmpeg] There aren\'t any subtitles to convert')
 644             return [], info
 645         self._downloader.to_screen('[ffmpeg] Converting subtitles')
 646         for lang, sub in subs.items():
 647             ext = sub['ext']
 648             if ext == new_ext:
 649                 self._downloader.to_screen(
 650                     '[ffmpeg] Subtitle file for %s is already in the requested'
 651                     'format' % new_ext)
 652                 continue
 653             new_file = subtitles_filename(filename, lang, new_ext)
 654             self.run_ffmpeg(
 655                 subtitles_filename(filename, lang, ext),
 656                 new_file, ['-f', new_format])
 657
 658             with io.open(new_file, 'rt', encoding='utf-8') as f:
 659                 subs[lang] = {
 660                     'ext': ext,
 661                     'data': f.read(),
 662                 }
 663
 664         return [], info