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youtube-dl/youtube_dl/downloader/hls.py
Stefan Pöschel 6e65a2a67e
[downloader/hls] Fix incorrect end byte in Range HTTP header for media segments with EXT-X-BYTERANGE (#24512) (closes #14748)
The end of the byte range is the first byte that is NOT part of the to
be downloaded range. So don't include it into the requested HTTP
download range, as this additional byte leads to a broken TS packet and
subsequently to e.g. visible video corruption.

Fixes #14748.
2020-09-18 05:26:56 +07:00

210 lines
9.4 KiB
Python

from __future__ import unicode_literals
import re
import binascii
try:
from Crypto.Cipher import AES
can_decrypt_frag = True
except ImportError:
can_decrypt_frag = False
from .fragment import FragmentFD
from .external import FFmpegFD
from ..compat import (
compat_urllib_error,
compat_urlparse,
compat_struct_pack,
)
from ..utils import (
parse_m3u8_attributes,
update_url_query,
)
class HlsFD(FragmentFD):
""" A limited implementation that does not require ffmpeg """
FD_NAME = 'hlsnative'
@staticmethod
def can_download(manifest, info_dict):
UNSUPPORTED_FEATURES = (
r'#EXT-X-KEY:METHOD=(?!NONE|AES-128)', # encrypted streams [1]
# r'#EXT-X-BYTERANGE', # playlists composed of byte ranges of media files [2]
# Live streams heuristic does not always work (e.g. geo restricted to Germany
# 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)
# r'#EXT-X-MEDIA-SEQUENCE:(?!0$)', # live streams [3]
# This heuristic also is not correct since segments may not be appended as well.
# Twitch vods of finished streams have EXT-X-PLAYLIST-TYPE:EVENT despite
# no segments will definitely be appended to the end of the playlist.
# r'#EXT-X-PLAYLIST-TYPE:EVENT', # media segments may be appended to the end of
# # event media playlists [4]
# 1. https://tools.ietf.org/html/draft-pantos-http-live-streaming-17#section-4.3.2.4
# 2. https://tools.ietf.org/html/draft-pantos-http-live-streaming-17#section-4.3.2.2
# 3. https://tools.ietf.org/html/draft-pantos-http-live-streaming-17#section-4.3.3.2
# 4. https://tools.ietf.org/html/draft-pantos-http-live-streaming-17#section-4.3.3.5
)
check_results = [not re.search(feature, manifest) for feature in UNSUPPORTED_FEATURES]
is_aes128_enc = '#EXT-X-KEY:METHOD=AES-128' in manifest
check_results.append(can_decrypt_frag or not is_aes128_enc)
check_results.append(not (is_aes128_enc and r'#EXT-X-BYTERANGE' in manifest))
check_results.append(not info_dict.get('is_live'))
return all(check_results)
def real_download(self, filename, info_dict):
man_url = info_dict['url']
self.to_screen('[%s] Downloading m3u8 manifest' % self.FD_NAME)
urlh = self.ydl.urlopen(self._prepare_url(info_dict, man_url))
man_url = urlh.geturl()
s = urlh.read().decode('utf-8', 'ignore')
if not self.can_download(s, info_dict):
if info_dict.get('extra_param_to_segment_url') or info_dict.get('_decryption_key_url'):
self.report_error('pycrypto not found. Please install it.')
return False
self.report_warning(
'hlsnative has detected features it does not support, '
'extraction will be delegated to ffmpeg')
fd = FFmpegFD(self.ydl, self.params)
for ph in self._progress_hooks:
fd.add_progress_hook(ph)
return fd.real_download(filename, info_dict)
def is_ad_fragment_start(s):
return (s.startswith('#ANVATO-SEGMENT-INFO') and 'type=ad' in s
or s.startswith('#UPLYNK-SEGMENT') and s.endswith(',ad'))
def is_ad_fragment_end(s):
return (s.startswith('#ANVATO-SEGMENT-INFO') and 'type=master' in s
or s.startswith('#UPLYNK-SEGMENT') and s.endswith(',segment'))
media_frags = 0
ad_frags = 0
ad_frag_next = False
for line in s.splitlines():
line = line.strip()
if not line:
continue
if line.startswith('#'):
if is_ad_fragment_start(line):
ad_frag_next = True
elif is_ad_fragment_end(line):
ad_frag_next = False
continue
if ad_frag_next:
ad_frags += 1
continue
media_frags += 1
ctx = {
'filename': filename,
'total_frags': media_frags,
'ad_frags': ad_frags,
}
self._prepare_and_start_frag_download(ctx)
fragment_retries = self.params.get('fragment_retries', 0)
skip_unavailable_fragments = self.params.get('skip_unavailable_fragments', True)
test = self.params.get('test', False)
extra_query = None
extra_param_to_segment_url = info_dict.get('extra_param_to_segment_url')
if extra_param_to_segment_url:
extra_query = compat_urlparse.parse_qs(extra_param_to_segment_url)
i = 0
media_sequence = 0
decrypt_info = {'METHOD': 'NONE'}
byte_range = {}
frag_index = 0
ad_frag_next = False
for line in s.splitlines():
line = line.strip()
if line:
if not line.startswith('#'):
if ad_frag_next:
continue
frag_index += 1
if frag_index <= ctx['fragment_index']:
continue
frag_url = (
line
if re.match(r'^https?://', line)
else compat_urlparse.urljoin(man_url, line))
if extra_query:
frag_url = update_url_query(frag_url, extra_query)
count = 0
headers = info_dict.get('http_headers', {})
if byte_range:
headers['Range'] = 'bytes=%d-%d' % (byte_range['start'], byte_range['end'] - 1)
while count <= fragment_retries:
try:
success, frag_content = self._download_fragment(
ctx, frag_url, info_dict, headers)
if not success:
return False
break
except compat_urllib_error.HTTPError as err:
# Unavailable (possibly temporary) fragments may be served.
# First we try to retry then either skip or abort.
# See https://github.com/ytdl-org/youtube-dl/issues/10165,
# https://github.com/ytdl-org/youtube-dl/issues/10448).
count += 1
if count <= fragment_retries:
self.report_retry_fragment(err, frag_index, count, fragment_retries)
if count > fragment_retries:
if skip_unavailable_fragments:
i += 1
media_sequence += 1
self.report_skip_fragment(frag_index)
continue
self.report_error(
'giving up after %s fragment retries' % fragment_retries)
return False
if decrypt_info['METHOD'] == 'AES-128':
iv = decrypt_info.get('IV') or compat_struct_pack('>8xq', media_sequence)
decrypt_info['KEY'] = decrypt_info.get('KEY') or self.ydl.urlopen(
self._prepare_url(info_dict, info_dict.get('_decryption_key_url') or decrypt_info['URI'])).read()
frag_content = AES.new(
decrypt_info['KEY'], AES.MODE_CBC, iv).decrypt(frag_content)
self._append_fragment(ctx, frag_content)
# We only download the first fragment during the test
if test:
break
i += 1
media_sequence += 1
elif line.startswith('#EXT-X-KEY'):
decrypt_url = decrypt_info.get('URI')
decrypt_info = parse_m3u8_attributes(line[11:])
if decrypt_info['METHOD'] == 'AES-128':
if 'IV' in decrypt_info:
decrypt_info['IV'] = binascii.unhexlify(decrypt_info['IV'][2:].zfill(32))
if not re.match(r'^https?://', decrypt_info['URI']):
decrypt_info['URI'] = compat_urlparse.urljoin(
man_url, decrypt_info['URI'])
if extra_query:
decrypt_info['URI'] = update_url_query(decrypt_info['URI'], extra_query)
if decrypt_url != decrypt_info['URI']:
decrypt_info['KEY'] = None
elif line.startswith('#EXT-X-MEDIA-SEQUENCE'):
media_sequence = int(line[22:])
elif line.startswith('#EXT-X-BYTERANGE'):
splitted_byte_range = line[17:].split('@')
sub_range_start = int(splitted_byte_range[1]) if len(splitted_byte_range) == 2 else byte_range['end']
byte_range = {
'start': sub_range_start,
'end': sub_range_start + int(splitted_byte_range[0]),
}
elif is_ad_fragment_start(line):
ad_frag_next = True
elif is_ad_fragment_end(line):
ad_frag_next = False
self._finish_frag_download(ctx)
return True