youtube_dl/downloader/hls.py

   1 from __future__ import unicode_literals
   2
   3 import re
   4 import binascii
   5 try:
   6     from Crypto.Cipher import AES
   7     can_decrypt_frag = True
   8 except ImportError:
   9     can_decrypt_frag = False
  10
  11 from .fragment import FragmentFD
  12 from .external import FFmpegFD
  13
  14 from ..compat import (
  15     compat_urllib_error,
  16     compat_urlparse,
  17     compat_struct_pack,
  18 )
  19 from ..utils import (
  20     parse_m3u8_attributes,
  21     update_url_query,
  22 )
  23
  24
  25 class HlsFD(FragmentFD):
  26     """ A limited implementation that does not require ffmpeg """
  27
  28     FD_NAME = 'hlsnative'
  29
  30     @staticmethod
  31     def can_download(manifest, info_dict):
  32         UNSUPPORTED_FEATURES = (
  33             r'#EXT-X-KEY:METHOD=(?!NONE|AES-128)',  # encrypted streams [1]
  34             # r'#EXT-X-BYTERANGE',  # playlists composed of byte ranges of media files [2]
  35
  36             # Live streams heuristic does not always work (e.g. geo restricted to Germany
  37             # 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)
  38             # r'#EXT-X-MEDIA-SEQUENCE:(?!0$)',  # live streams [3]
  39
  40             # This heuristic also is not correct since segments may not be appended as well.
  41             # Twitch vods of finished streams have EXT-X-PLAYLIST-TYPE:EVENT despite
  42             # no segments will definitely be appended to the end of the playlist.
  43             # r'#EXT-X-PLAYLIST-TYPE:EVENT',  # media segments may be appended to the end of
  44             #                                 # event media playlists [4]
  45
  46             # 1. https://tools.ietf.org/html/draft-pantos-http-live-streaming-17#section-4.3.2.4
  47             # 2. https://tools.ietf.org/html/draft-pantos-http-live-streaming-17#section-4.3.2.2
  48             # 3. https://tools.ietf.org/html/draft-pantos-http-live-streaming-17#section-4.3.3.2
  49             # 4. https://tools.ietf.org/html/draft-pantos-http-live-streaming-17#section-4.3.3.5
  50         )
  51         check_results = [not re.search(feature, manifest) for feature in UNSUPPORTED_FEATURES]
  52         is_aes128_enc = '#EXT-X-KEY:METHOD=AES-128' in manifest
  53         check_results.append(can_decrypt_frag or not is_aes128_enc)
  54         check_results.append(not (is_aes128_enc and r'#EXT-X-BYTERANGE' in manifest))
  55         check_results.append(not info_dict.get('is_live'))
  56         return all(check_results)
  57
  58     def real_download(self, filename, info_dict):
  59         man_url = info_dict['url']
  60         self.to_screen('[%s] Downloading m3u8 manifest' % self.FD_NAME)
  61
  62         urlh = self.ydl.urlopen(self._prepare_url(info_dict, man_url))
  63         man_url = urlh.geturl()
  64         s = urlh.read().decode('utf-8', 'ignore')
  65
  66         if not self.can_download(s, info_dict):
  67             if info_dict.get('extra_param_to_segment_url'):
  68                 self.report_error('pycrypto not found. Please install it.')
  69                 return False
  70             self.report_warning(
  71                 'hlsnative has detected features it does not support, '
  72                 'extraction will be delegated to ffmpeg')
  73             fd = FFmpegFD(self.ydl, self.params)
  74             for ph in self._progress_hooks:
  75                 fd.add_progress_hook(ph)
  76             return fd.real_download(filename, info_dict)
  77
  78         def anvato_ad(s):
  79             return s.startswith('#ANVATO-SEGMENT-INFO') and 'type=ad' in s
  80
  81         media_frags = 0
  82         ad_frags = 0
  83         ad_frag_next = False
  84         for line in s.splitlines():
  85             line = line.strip()
  86             if not line:
  87                 continue
  88             if line.startswith('#'):
  89                 if anvato_ad(line):
  90                     ad_frags += 1
  91                 continue
  92             if ad_frag_next:
  93                 ad_frag_next = False
  94                 continue
  95             media_frags += 1
  96
  97         ctx = {
  98             'filename': filename,
  99             'total_frags': media_frags,
 100             'ad_frags': ad_frags,
 101         }
 102
 103         self._prepare_and_start_frag_download(ctx)
 104
 105         fragment_retries = self.params.get('fragment_retries', 0)
 106         skip_unavailable_fragments = self.params.get('skip_unavailable_fragments', True)
 107         test = self.params.get('test', False)
 108
 109         extra_query = None
 110         extra_param_to_segment_url = info_dict.get('extra_param_to_segment_url')
 111         if extra_param_to_segment_url:
 112             extra_query = compat_urlparse.parse_qs(extra_param_to_segment_url)
 113         i = 0
 114         media_sequence = 0
 115         decrypt_info = {'METHOD': 'NONE'}
 116         byte_range = {}
 117         frag_index = 0
 118         ad_frag_next = False
 119         for line in s.splitlines():
 120             line = line.strip()
 121             if line:
 122                 if not line.startswith('#'):
 123                     if ad_frag_next:
 124                         ad_frag_next = False
 125                         continue
 126                     frag_index += 1
 127                     if frag_index <= ctx['fragment_index']:
 128                         continue
 129                     frag_url = (
 130                         line
 131                         if re.match(r'^https?://', line)
 132                         else compat_urlparse.urljoin(man_url, line))
 133                     if extra_query:
 134                         frag_url = update_url_query(frag_url, extra_query)
 135                     count = 0
 136                     headers = info_dict.get('http_headers', {})
 137                     if byte_range:
 138                         headers['Range'] = 'bytes=%d-%d' % (byte_range['start'], byte_range['end'])
 139                     while count <= fragment_retries:
 140                         try:
 141                             success, frag_content = self._download_fragment(
 142                                 ctx, frag_url, info_dict, headers)
 143                             if not success:
 144                                 return False
 145                             break
 146                         except compat_urllib_error.HTTPError as err:
 147                             # Unavailable (possibly temporary) fragments may be served.
 148                             # First we try to retry then either skip or abort.
 149                             # See https://github.com/rg3/youtube-dl/issues/10165,
 150                             # https://github.com/rg3/youtube-dl/issues/10448).
 151                             count += 1
 152                             if count <= fragment_retries:
 153                                 self.report_retry_fragment(err, frag_index, count, fragment_retries)
 154                     if count > fragment_retries:
 155                         if skip_unavailable_fragments:
 156                             i += 1
 157                             media_sequence += 1
 158                             self.report_skip_fragment(frag_index)
 159                             continue
 160                         self.report_error(
 161                             'giving up after %s fragment retries' % fragment_retries)
 162                         return False
 163                     if decrypt_info['METHOD'] == 'AES-128':
 164                         iv = decrypt_info.get('IV') or compat_struct_pack('>8xq', media_sequence)
 165                         decrypt_info['KEY'] = decrypt_info.get('KEY') or self.ydl.urlopen(decrypt_info['URI']).read()
 166                         frag_content = AES.new(
 167                             decrypt_info['KEY'], AES.MODE_CBC, iv).decrypt(frag_content)
 168                     self._append_fragment(ctx, frag_content)
 169                     # We only download the first fragment during the test
 170                     if test:
 171                         break
 172                     i += 1
 173                     media_sequence += 1
 174                 elif line.startswith('#EXT-X-KEY'):
 175                     decrypt_url = decrypt_info.get('URI')
 176                     decrypt_info = parse_m3u8_attributes(line[11:])
 177                     if decrypt_info['METHOD'] == 'AES-128':
 178                         if 'IV' in decrypt_info:
 179                             decrypt_info['IV'] = binascii.unhexlify(decrypt_info['IV'][2:].zfill(32))
 180                         if not re.match(r'^https?://', decrypt_info['URI']):
 181                             decrypt_info['URI'] = compat_urlparse.urljoin(
 182                                 man_url, decrypt_info['URI'])
 183                         if extra_query:
 184                             decrypt_info['URI'] = update_url_query(decrypt_info['URI'], extra_query)
 185                         if decrypt_url != decrypt_info['URI']:
 186                             decrypt_info['KEY'] = None
 187                 elif line.startswith('#EXT-X-MEDIA-SEQUENCE'):
 188                     media_sequence = int(line[22:])
 189                 elif line.startswith('#EXT-X-BYTERANGE'):
 190                     splitted_byte_range = line[17:].split('@')
 191                     sub_range_start = int(splitted_byte_range[1]) if len(splitted_byte_range) == 2 else byte_range['end']
 192                     byte_range = {
 193                         'start': sub_range_start,
 194                         'end': sub_range_start + int(splitted_byte_range[0]),
 195                     }
 196                 elif anvato_ad(line):
 197                     ad_frag_next = True
 198
 199         self._finish_frag_download(ctx)
 200
 201         return True