yt_dlp/downloader/hls.py

   1 import binascii
   2 import io
   3 import re
   4 import urllib.parse
   5
   6 from . import get_suitable_downloader
   7 from .external import FFmpegFD
   8 from .fragment import FragmentFD
   9 from .. import webvtt
  10 from ..dependencies import Cryptodome
  11 from ..utils import (
  12     bug_reports_message,
  13     parse_m3u8_attributes,
  14     remove_start,
  15     traverse_obj,
  16     update_url_query,
  17     urljoin,
  18 )
  19
  20
  21 class HlsFD(FragmentFD):
  22     """
  23     Download segments in a m3u8 manifest. External downloaders can take over
  24     the fragment downloads by supporting the 'm3u8_frag_urls' protocol and
  25     re-defining 'supports_manifest' function
  26     """
  27
  28     FD_NAME = 'hlsnative'
  29
  30     @staticmethod
  31     def can_download(manifest, info_dict, allow_unplayable_formats=False):
  32         UNSUPPORTED_FEATURES = [
  33             # r'#EXT-X-BYTERANGE',  # playlists composed of byte ranges of media files [2]
  34
  35             # Live streams heuristic does not always work (e.g. geo restricted to Germany
  36             # http://hls-geo.daserste.de/i/videoportal/Film/c_620000/622873/format,716451,716457,716450,716458,716459,.mp4.csmil/index_4_av.m3u8?null=0)
  37             # r'#EXT-X-MEDIA-SEQUENCE:(?!0$)',  # live streams [3]
  38
  39             # This heuristic also is not correct since segments may not be appended as well.
  40             # Twitch vods of finished streams have EXT-X-PLAYLIST-TYPE:EVENT despite
  41             # no segments will definitely be appended to the end of the playlist.
  42             # r'#EXT-X-PLAYLIST-TYPE:EVENT',  # media segments may be appended to the end of
  43             #                                 # event media playlists [4]
  44             # r'#EXT-X-MAP:',  # media initialization [5]
  45             # 1. https://tools.ietf.org/html/draft-pantos-http-live-streaming-17#section-4.3.2.4
  46             # 2. https://tools.ietf.org/html/draft-pantos-http-live-streaming-17#section-4.3.2.2
  47             # 3. https://tools.ietf.org/html/draft-pantos-http-live-streaming-17#section-4.3.3.2
  48             # 4. https://tools.ietf.org/html/draft-pantos-http-live-streaming-17#section-4.3.3.5
  49             # 5. https://tools.ietf.org/html/draft-pantos-http-live-streaming-17#section-4.3.2.5
  50         ]
  51         if not allow_unplayable_formats:
  52             UNSUPPORTED_FEATURES += [
  53                 r'#EXT-X-KEY:METHOD=(?!NONE|AES-128)',  # encrypted streams [1]
  54             ]
  55
  56         def check_results():
  57             yield not info_dict.get('is_live')
  58             for feature in UNSUPPORTED_FEATURES:
  59                 yield not re.search(feature, manifest)
  60         return all(check_results())
  61
  62     def real_download(self, filename, info_dict):
  63         man_url = info_dict['url']
  64         self.to_screen('[%s] Downloading m3u8 manifest' % self.FD_NAME)
  65
  66         urlh = self.ydl.urlopen(self._prepare_url(info_dict, man_url))
  67         man_url = urlh.geturl()
  68         s = urlh.read().decode('utf-8', 'ignore')
  69
  70         can_download, message = self.can_download(s, info_dict, self.params.get('allow_unplayable_formats')), None
  71         if can_download:
  72             has_ffmpeg = FFmpegFD.available()
  73             no_crypto = not Cryptodome.AES and '#EXT-X-KEY:METHOD=AES-128' in s
  74             if no_crypto and has_ffmpeg:
  75                 can_download, message = False, 'The stream has AES-128 encryption and pycryptodomex is not available'
  76             elif no_crypto:
  77                 message = ('The stream has AES-128 encryption and neither ffmpeg nor pycryptodomex are available; '
  78                            'Decryption will be performed natively, but will be extremely slow')
  79             elif info_dict.get('extractor_key') == 'Generic' and re.search(r'(?m)#EXT-X-MEDIA-SEQUENCE:(?!0$)', s):
  80                 install_ffmpeg = '' if has_ffmpeg else 'install ffmpeg and '
  81                 message = ('Live HLS streams are not supported by the native downloader. If this is a livestream, '
  82                            f'please {install_ffmpeg}add "--downloader ffmpeg --hls-use-mpegts" to your command')
  83         if not can_download:
  84             has_drm = re.search('|'.join([
  85                 r'#EXT-X-FAXS-CM:',  # Adobe Flash Access
  86                 r'#EXT-X-(?:SESSION-)?KEY:.*?URI="skd://',  # Apple FairPlay
  87             ]), s)
  88             if has_drm and not self.params.get('allow_unplayable_formats'):
  89                 self.report_error(
  90                     'This video is DRM protected; Try selecting another format with --format or '
  91                     'add --check-formats to automatically fallback to the next best format')
  92                 return False
  93             message = message or 'Unsupported features have been detected'
  94             fd = FFmpegFD(self.ydl, self.params)
  95             self.report_warning(f'{message}; extraction will be delegated to {fd.get_basename()}')
  96             return fd.real_download(filename, info_dict)
  97         elif message:
  98             self.report_warning(message)
  99
 100         is_webvtt = info_dict['ext'] == 'vtt'
 101         if is_webvtt:
 102             real_downloader = None  # Packing the fragments is not currently supported for external downloader
 103         else:
 104             real_downloader = get_suitable_downloader(
 105                 info_dict, self.params, None, protocol='m3u8_frag_urls', to_stdout=(filename == '-'))
 106         if real_downloader and not real_downloader.supports_manifest(s):
 107             real_downloader = None
 108         if real_downloader:
 109             self.to_screen(f'[{self.FD_NAME}] Fragment downloads will be delegated to {real_downloader.get_basename()}')
 110
 111         def is_ad_fragment_start(s):
 112             return (s.startswith('#ANVATO-SEGMENT-INFO') and 'type=ad' in s
 113                     or s.startswith('#UPLYNK-SEGMENT') and s.endswith(',ad'))
 114
 115         def is_ad_fragment_end(s):
 116             return (s.startswith('#ANVATO-SEGMENT-INFO') and 'type=master' in s
 117                     or s.startswith('#UPLYNK-SEGMENT') and s.endswith(',segment'))
 118
 119         fragments = []
 120
 121         media_frags = 0
 122         ad_frags = 0
 123         ad_frag_next = False
 124         for line in s.splitlines():
 125             line = line.strip()
 126             if not line:
 127                 continue
 128             if line.startswith('#'):
 129                 if is_ad_fragment_start(line):
 130                     ad_frag_next = True
 131                 elif is_ad_fragment_end(line):
 132                     ad_frag_next = False
 133                 continue
 134             if ad_frag_next:
 135                 ad_frags += 1
 136                 continue
 137             media_frags += 1
 138
 139         ctx = {
 140             'filename': filename,
 141             'total_frags': media_frags,
 142             'ad_frags': ad_frags,
 143         }
 144
 145         if real_downloader:
 146             self._prepare_external_frag_download(ctx)
 147         else:
 148             self._prepare_and_start_frag_download(ctx, info_dict)
 149
 150         extra_state = ctx.setdefault('extra_state', {})
 151
 152         format_index = info_dict.get('format_index')
 153         extra_query = None
 154         extra_param_to_segment_url = info_dict.get('extra_param_to_segment_url')
 155         if extra_param_to_segment_url:
 156             extra_query = urllib.parse.parse_qs(extra_param_to_segment_url)
 157         i = 0
 158         media_sequence = 0
 159         decrypt_info = {'METHOD': 'NONE'}
 160         external_aes_key = traverse_obj(info_dict, ('hls_aes', 'key'))
 161         if external_aes_key:
 162             external_aes_key = binascii.unhexlify(remove_start(external_aes_key, '0x'))
 163             assert len(external_aes_key) in (16, 24, 32), 'Invalid length for HLS AES-128 key'
 164         external_aes_iv = traverse_obj(info_dict, ('hls_aes', 'iv'))
 165         if external_aes_iv:
 166             external_aes_iv = binascii.unhexlify(remove_start(external_aes_iv, '0x').zfill(32))
 167         byte_range = {}
 168         discontinuity_count = 0
 169         frag_index = 0
 170         ad_frag_next = False
 171         for line in s.splitlines():
 172             line = line.strip()
 173             if line:
 174                 if not line.startswith('#'):
 175                     if format_index and discontinuity_count != format_index:
 176                         continue
 177                     if ad_frag_next:
 178                         continue
 179                     frag_index += 1
 180                     if frag_index <= ctx['fragment_index']:
 181                         continue
 182                     frag_url = urljoin(man_url, line)
 183                     if extra_query:
 184                         frag_url = update_url_query(frag_url, extra_query)
 185
 186                     fragments.append({
 187                         'frag_index': frag_index,
 188                         'url': frag_url,
 189                         'decrypt_info': decrypt_info,
 190                         'byte_range': byte_range,
 191                         'media_sequence': media_sequence,
 192                     })
 193                     media_sequence += 1
 194
 195                 elif line.startswith('#EXT-X-MAP'):
 196                     if format_index and discontinuity_count != format_index:
 197                         continue
 198                     if frag_index > 0:
 199                         self.report_error(
 200                             'Initialization fragment found after media fragments, unable to download')
 201                         return False
 202                     frag_index += 1
 203                     map_info = parse_m3u8_attributes(line[11:])
 204                     frag_url = urljoin(man_url, map_info.get('URI'))
 205                     if extra_query:
 206                         frag_url = update_url_query(frag_url, extra_query)
 207
 208                     if map_info.get('BYTERANGE'):
 209                         splitted_byte_range = map_info.get('BYTERANGE').split('@')
 210                         sub_range_start = int(splitted_byte_range[1]) if len(splitted_byte_range) == 2 else byte_range['end']
 211                         byte_range = {
 212                             'start': sub_range_start,
 213                             'end': sub_range_start + int(splitted_byte_range[0]),
 214                         }
 215
 216                     fragments.append({
 217                         'frag_index': frag_index,
 218                         'url': frag_url,
 219                         'decrypt_info': decrypt_info,
 220                         'byte_range': byte_range,
 221                         'media_sequence': media_sequence
 222                     })
 223                     media_sequence += 1
 224
 225                 elif line.startswith('#EXT-X-KEY'):
 226                     decrypt_url = decrypt_info.get('URI')
 227                     decrypt_info = parse_m3u8_attributes(line[11:])
 228                     if decrypt_info['METHOD'] == 'AES-128':
 229                         if external_aes_iv:
 230                             decrypt_info['IV'] = external_aes_iv
 231                         elif 'IV' in decrypt_info:
 232                             decrypt_info['IV'] = binascii.unhexlify(decrypt_info['IV'][2:].zfill(32))
 233                         if external_aes_key:
 234                             decrypt_info['KEY'] = external_aes_key
 235                         else:
 236                             decrypt_info['URI'] = urljoin(man_url, decrypt_info['URI'])
 237                             if extra_query:
 238                                 decrypt_info['URI'] = update_url_query(decrypt_info['URI'], extra_query)
 239                             if decrypt_url != decrypt_info['URI']:
 240                                 decrypt_info['KEY'] = None
 241
 242                 elif line.startswith('#EXT-X-MEDIA-SEQUENCE'):
 243                     media_sequence = int(line[22:])
 244                 elif line.startswith('#EXT-X-BYTERANGE'):
 245                     splitted_byte_range = line[17:].split('@')
 246                     sub_range_start = int(splitted_byte_range[1]) if len(splitted_byte_range) == 2 else byte_range['end']
 247                     byte_range = {
 248                         'start': sub_range_start,
 249                         'end': sub_range_start + int(splitted_byte_range[0]),
 250                     }
 251                 elif is_ad_fragment_start(line):
 252                     ad_frag_next = True
 253                 elif is_ad_fragment_end(line):
 254                     ad_frag_next = False
 255                 elif line.startswith('#EXT-X-DISCONTINUITY'):
 256                     discontinuity_count += 1
 257                 i += 1
 258
 259         # We only download the first fragment during the test
 260         if self.params.get('test', False):
 261             fragments = [fragments[0] if fragments else None]
 262
 263         if real_downloader:
 264             info_dict['fragments'] = fragments
 265             fd = real_downloader(self.ydl, self.params)
 266             # TODO: Make progress updates work without hooking twice
 267             # for ph in self._progress_hooks:
 268             #     fd.add_progress_hook(ph)
 269             return fd.real_download(filename, info_dict)
 270
 271         if is_webvtt:
 272             def pack_fragment(frag_content, frag_index):
 273                 output = io.StringIO()
 274                 adjust = 0
 275                 overflow = False
 276                 mpegts_last = None
 277                 for block in webvtt.parse_fragment(frag_content):
 278                     if isinstance(block, webvtt.CueBlock):
 279                         extra_state['webvtt_mpegts_last'] = mpegts_last
 280                         if overflow:
 281                             extra_state['webvtt_mpegts_adjust'] += 1
 282                             overflow = False
 283                         block.start += adjust
 284                         block.end += adjust
 285
 286                         dedup_window = extra_state.setdefault('webvtt_dedup_window', [])
 287
 288                         ready = []
 289
 290                         i = 0
 291                         is_new = True
 292                         while i < len(dedup_window):
 293                             wcue = dedup_window[i]
 294                             wblock = webvtt.CueBlock.from_json(wcue)
 295                             i += 1
 296                             if wblock.hinges(block):
 297                                 wcue['end'] = block.end
 298                                 is_new = False
 299                                 continue
 300                             if wblock == block:
 301                                 is_new = False
 302                                 continue
 303                             if wblock.end > block.start:
 304                                 continue
 305                             ready.append(wblock)
 306                             i -= 1
 307                             del dedup_window[i]
 308
 309                         if is_new:
 310                             dedup_window.append(block.as_json)
 311                         for block in ready:
 312                             block.write_into(output)
 313
 314                         # we only emit cues once they fall out of the duplicate window
 315                         continue
 316                     elif isinstance(block, webvtt.Magic):
 317                         # take care of MPEG PES timestamp overflow
 318                         if block.mpegts is None:
 319                             block.mpegts = 0
 320                         extra_state.setdefault('webvtt_mpegts_adjust', 0)
 321                         block.mpegts += extra_state['webvtt_mpegts_adjust'] << 33
 322                         if block.mpegts < extra_state.get('webvtt_mpegts_last', 0):
 323                             overflow = True
 324                             block.mpegts += 1 << 33
 325                         mpegts_last = block.mpegts
 326
 327                         if frag_index == 1:
 328                             extra_state['webvtt_mpegts'] = block.mpegts or 0
 329                             extra_state['webvtt_local'] = block.local or 0
 330                             # XXX: block.local = block.mpegts = None ?
 331                         else:
 332                             if block.mpegts is not None and block.local is not None:
 333                                 adjust = (
 334                                     (block.mpegts - extra_state.get('webvtt_mpegts', 0))
 335                                     - (block.local - extra_state.get('webvtt_local', 0))
 336                                 )
 337                             continue
 338                     elif isinstance(block, webvtt.HeaderBlock):
 339                         if frag_index != 1:
 340                             # XXX: this should probably be silent as well
 341                             # or verify that all segments contain the same data
 342                             self.report_warning(bug_reports_message(
 343                                 'Discarding a %s block found in the middle of the stream; '
 344                                 'if the subtitles display incorrectly,'
 345                                 % (type(block).__name__)))
 346                             continue
 347                     block.write_into(output)
 348
 349                 return output.getvalue().encode()
 350
 351             def fin_fragments():
 352                 dedup_window = extra_state.get('webvtt_dedup_window')
 353                 if not dedup_window:
 354                     return b''
 355
 356                 output = io.StringIO()
 357                 for cue in dedup_window:
 358                     webvtt.CueBlock.from_json(cue).write_into(output)
 359
 360                 return output.getvalue().encode()
 361
 362             self.download_and_append_fragments(
 363                 ctx, fragments, info_dict, pack_func=pack_fragment, finish_func=fin_fragments)
 364         else:
 365             return self.download_and_append_fragments(ctx, fragments, info_dict)