youtube_dl/downloader/hls.py

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