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  66             warning = 'Your copy of %s is outdated, update %s to version %s or newer if you encounter any errors.'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