yt_dlp/downloader/f4m.py

   1 from __future__ import division, unicode_literals
   2
   3 import io
   4 import itertools
   5 import time
   6
   7 from .fragment import FragmentFD
   8 from ..compat import (
   9     compat_b64decode,
  10     compat_etree_fromstring,
  11     compat_urlparse,
  12     compat_urllib_error,
  13     compat_urllib_parse_urlparse,
  14     compat_struct_pack,
  15     compat_struct_unpack,
  16 )
  17 from ..utils import (
  18     fix_xml_ampersands,
  19     xpath_text,
  20 )
  21
  22
  23 class DataTruncatedError(Exception):
  24     pass
  25
  26
  27 class FlvReader(io.BytesIO):
  28     """
  29     Reader for Flv files
  30     The file format is documented in https://www.adobe.com/devnet/f4v.html
  31     """
  32
  33     def read_bytes(self, n):
  34         data = self.read(n)
  35         if len(data) < n:
  36             raise DataTruncatedError(
  37                 'FlvReader error: need %d bytes while only %d bytes got' % (
  38                     n, len(data)))
  39         return data
  40
  41     # Utility functions for reading numbers and strings
  42     def read_unsigned_long_long(self):
  43         return compat_struct_unpack('!Q', self.read_bytes(8))[0]
  44
  45     def read_unsigned_int(self):
  46         return compat_struct_unpack('!I', self.read_bytes(4))[0]
  47
  48     def read_unsigned_char(self):
  49         return compat_struct_unpack('!B', self.read_bytes(1))[0]
  50
  51     def read_string(self):
  52         res = b''
  53         while True:
  54             char = self.read_bytes(1)
  55             if char == b'\x00':
  56                 break
  57             res += char
  58         return res
  59
  60     def read_box_info(self):
  61         """
  62         Read a box and return the info as a tuple: (box_size, box_type, box_data)
  63         """
  64         real_size = size = self.read_unsigned_int()
  65         box_type = self.read_bytes(4)
  66         header_end = 8
  67         if size == 1:
  68             real_size = self.read_unsigned_long_long()
  69             header_end = 16
  70         return real_size, box_type, self.read_bytes(real_size - header_end)
  71
  72     def read_asrt(self):
  73         # version
  74         self.read_unsigned_char()
  75         # flags
  76         self.read_bytes(3)
  77         quality_entry_count = self.read_unsigned_char()
  78         # QualityEntryCount
  79         for i in range(quality_entry_count):
  80             self.read_string()
  81
  82         segment_run_count = self.read_unsigned_int()
  83         segments = []
  84         for i in range(segment_run_count):
  85             first_segment = self.read_unsigned_int()
  86             fragments_per_segment = self.read_unsigned_int()
  87             segments.append((first_segment, fragments_per_segment))
  88
  89         return {
  90             'segment_run': segments,
  91         }
  92
  93     def read_afrt(self):
  94         # version
  95         self.read_unsigned_char()
  96         # flags
  97         self.read_bytes(3)
  98         # time scale
  99         self.read_unsigned_int()
 100
 101         quality_entry_count = self.read_unsigned_char()
 102         # QualitySegmentUrlModifiers
 103         for i in range(quality_entry_count):
 104             self.read_string()
 105
 106         fragments_count = self.read_unsigned_int()
 107         fragments = []
 108         for i in range(fragments_count):
 109             first = self.read_unsigned_int()
 110             first_ts = self.read_unsigned_long_long()
 111             duration = self.read_unsigned_int()
 112             if duration == 0:
 113                 discontinuity_indicator = self.read_unsigned_char()
 114             else:
 115                 discontinuity_indicator = None
 116             fragments.append({
 117                 'first': first,
 118                 'ts': first_ts,
 119                 'duration': duration,
 120                 'discontinuity_indicator': discontinuity_indicator,
 121             })
 122
 123         return {
 124             'fragments': fragments,
 125         }
 126
 127     def read_abst(self):
 128         # version
 129         self.read_unsigned_char()
 130         # flags
 131         self.read_bytes(3)
 132
 133         self.read_unsigned_int()  # BootstrapinfoVersion
 134         # Profile,Live,Update,Reserved
 135         flags = self.read_unsigned_char()
 136         live = flags & 0x20 != 0
 137         # time scale
 138         self.read_unsigned_int()
 139         # CurrentMediaTime
 140         self.read_unsigned_long_long()
 141         # SmpteTimeCodeOffset
 142         self.read_unsigned_long_long()
 143
 144         self.read_string()  # MovieIdentifier
 145         server_count = self.read_unsigned_char()
 146         # ServerEntryTable
 147         for i in range(server_count):
 148             self.read_string()
 149         quality_count = self.read_unsigned_char()
 150         # QualityEntryTable
 151         for i in range(quality_count):
 152             self.read_string()
 153         # DrmData
 154         self.read_string()
 155         # MetaData
 156         self.read_string()
 157
 158         segments_count = self.read_unsigned_char()
 159         segments = []
 160         for i in range(segments_count):
 161             box_size, box_type, box_data = self.read_box_info()
 162             assert box_type == b'asrt'
 163             segment = FlvReader(box_data).read_asrt()
 164             segments.append(segment)
 165         fragments_run_count = self.read_unsigned_char()
 166         fragments = []
 167         for i in range(fragments_run_count):
 168             box_size, box_type, box_data = self.read_box_info()
 169             assert box_type == b'afrt'
 170             fragments.append(FlvReader(box_data).read_afrt())
 171
 172         return {
 173             'segments': segments,
 174             'fragments': fragments,
 175             'live': live,
 176         }
 177
 178     def read_bootstrap_info(self):
 179         total_size, box_type, box_data = self.read_box_info()
 180         assert box_type == b'abst'
 181         return FlvReader(box_data).read_abst()
 182
 183
 184 def read_bootstrap_info(bootstrap_bytes):
 185     return FlvReader(bootstrap_bytes).read_bootstrap_info()
 186
 187
 188 def build_fragments_list(boot_info):
 189     """ Return a list of (segment, fragment) for each fragment in the video """
 190     res = []
 191     segment_run_table = boot_info['segments'][0]
 192     fragment_run_entry_table = boot_info['fragments'][0]['fragments']
 193     first_frag_number = fragment_run_entry_table[0]['first']
 194     fragments_counter = itertools.count(first_frag_number)
 195     for segment, fragments_count in segment_run_table['segment_run']:
 196         # In some live HDS streams (for example Rai), `fragments_count` is
 197         # abnormal and causing out-of-memory errors. It's OK to change the
 198         # number of fragments for live streams as they are updated periodically
 199         if fragments_count == 4294967295 and boot_info['live']:
 200             fragments_count = 2
 201         for _ in range(fragments_count):
 202             res.append((segment, next(fragments_counter)))
 203
 204     if boot_info['live']:
 205         res = res[-2:]
 206
 207     return res
 208
 209
 210 def write_unsigned_int(stream, val):
 211     stream.write(compat_struct_pack('!I', val))
 212
 213
 214 def write_unsigned_int_24(stream, val):
 215     stream.write(compat_struct_pack('!I', val)[1:])
 216
 217
 218 def write_flv_header(stream):
 219     """Writes the FLV header to stream"""
 220     # FLV header
 221     stream.write(b'FLV\x01')
 222     stream.write(b'\x05')
 223     stream.write(b'\x00\x00\x00\x09')
 224     stream.write(b'\x00\x00\x00\x00')
 225
 226
 227 def write_metadata_tag(stream, metadata):
 228     """Writes optional metadata tag to stream"""
 229     SCRIPT_TAG = b'\x12'
 230     FLV_TAG_HEADER_LEN = 11
 231
 232     if metadata:
 233         stream.write(SCRIPT_TAG)
 234         write_unsigned_int_24(stream, len(metadata))
 235         stream.write(b'\x00\x00\x00\x00\x00\x00\x00')
 236         stream.write(metadata)
 237         write_unsigned_int(stream, FLV_TAG_HEADER_LEN + len(metadata))
 238
 239
 240 def remove_encrypted_media(media):
 241     return list(filter(lambda e: 'drmAdditionalHeaderId' not in e.attrib
 242                                  and 'drmAdditionalHeaderSetId' not in e.attrib,
 243                        media))
 244
 245
 246 def _add_ns(prop, ver=1):
 247     return '{http://ns.adobe.com/f4m/%d.0}%s' % (ver, prop)
 248
 249
 250 def get_base_url(manifest):
 251     base_url = xpath_text(
 252         manifest, [_add_ns('baseURL'), _add_ns('baseURL', 2)],
 253         'base URL', default=None)
 254     if base_url:
 255         base_url = base_url.strip()
 256     return base_url
 257
 258
 259 class F4mFD(FragmentFD):
 260     """
 261     A downloader for f4m manifests or AdobeHDS.
 262     """
 263
 264     FD_NAME = 'f4m'
 265
 266     def _get_unencrypted_media(self, doc):
 267         media = doc.findall(_add_ns('media'))
 268         if not media:
 269             self.report_error('No media found')
 270         if not self.params.get('allow_unplayable_formats'):
 271             for e in (doc.findall(_add_ns('drmAdditionalHeader'))
 272                       + doc.findall(_add_ns('drmAdditionalHeaderSet'))):
 273                 # If id attribute is missing it's valid for all media nodes
 274                 # without drmAdditionalHeaderId or drmAdditionalHeaderSetId attribute
 275                 if 'id' not in e.attrib:
 276                     self.report_error('Missing ID in f4m DRM')
 277             media = remove_encrypted_media(media)
 278         if not media:
 279             self.report_error('Unsupported DRM')
 280         return media
 281
 282     def _get_bootstrap_from_url(self, bootstrap_url):
 283         bootstrap = self.ydl.urlopen(bootstrap_url).read()
 284         return read_bootstrap_info(bootstrap)
 285
 286     def _update_live_fragments(self, bootstrap_url, latest_fragment):
 287         fragments_list = []
 288         retries = 30
 289         while (not fragments_list) and (retries > 0):
 290             boot_info = self._get_bootstrap_from_url(bootstrap_url)
 291             fragments_list = build_fragments_list(boot_info)
 292             fragments_list = [f for f in fragments_list if f[1] > latest_fragment]
 293             if not fragments_list:
 294                 # Retry after a while
 295                 time.sleep(5.0)
 296                 retries -= 1
 297
 298         if not fragments_list:
 299             self.report_error('Failed to update fragments')
 300
 301         return fragments_list
 302
 303     def _parse_bootstrap_node(self, node, base_url):
 304         # Sometimes non empty inline bootstrap info can be specified along
 305         # with bootstrap url attribute (e.g. dummy inline bootstrap info
 306         # contains whitespace characters in [1]). We will prefer bootstrap
 307         # url over inline bootstrap info when present.
 308         # 1. http://live-1-1.rutube.ru/stream/1024/HDS/SD/C2NKsS85HQNckgn5HdEmOQ/1454167650/S-s604419906/move/four/dirs/upper/1024-576p.f4m
 309         bootstrap_url = node.get('url')
 310         if bootstrap_url:
 311             bootstrap_url = compat_urlparse.urljoin(
 312                 base_url, bootstrap_url)
 313             boot_info = self._get_bootstrap_from_url(bootstrap_url)
 314         else:
 315             bootstrap_url = None
 316             bootstrap = compat_b64decode(node.text)
 317             boot_info = read_bootstrap_info(bootstrap)
 318         return boot_info, bootstrap_url
 319
 320     def real_download(self, filename, info_dict):
 321         man_url = info_dict['url']
 322         requested_bitrate = info_dict.get('tbr')
 323         self.to_screen('[%s] Downloading f4m manifest' % self.FD_NAME)
 324
 325         urlh = self.ydl.urlopen(self._prepare_url(info_dict, man_url))
 326         man_url = urlh.geturl()
 327         # Some manifests may be malformed, e.g. prosiebensat1 generated manifests
 328         # (see https://github.com/ytdl-org/youtube-dl/issues/6215#issuecomment-121704244
 329         # and https://github.com/ytdl-org/youtube-dl/issues/7823)
 330         manifest = fix_xml_ampersands(urlh.read().decode('utf-8', 'ignore')).strip()
 331
 332         doc = compat_etree_fromstring(manifest)
 333         formats = [(int(f.attrib.get('bitrate', -1)), f)
 334                    for f in self._get_unencrypted_media(doc)]
 335         if requested_bitrate is None or len(formats) == 1:
 336             # get the best format
 337             formats = sorted(formats, key=lambda f: f[0])
 338             rate, media = formats[-1]
 339         else:
 340             rate, media = list(filter(
 341                 lambda f: int(f[0]) == requested_bitrate, formats))[0]
 342
 343         # Prefer baseURL for relative URLs as per 11.2 of F4M 3.0 spec.
 344         man_base_url = get_base_url(doc) or man_url
 345
 346         base_url = compat_urlparse.urljoin(man_base_url, media.attrib['url'])
 347         bootstrap_node = doc.find(_add_ns('bootstrapInfo'))
 348         boot_info, bootstrap_url = self._parse_bootstrap_node(
 349             bootstrap_node, man_base_url)
 350         live = boot_info['live']
 351         metadata_node = media.find(_add_ns('metadata'))
 352         if metadata_node is not None:
 353             metadata = compat_b64decode(metadata_node.text)
 354         else:
 355             metadata = None
 356
 357         fragments_list = build_fragments_list(boot_info)
 358         test = self.params.get('test', False)
 359         if test:
 360             # We only download the first fragment
 361             fragments_list = fragments_list[:1]
 362         total_frags = len(fragments_list)
 363         # For some akamai manifests we'll need to add a query to the fragment url
 364         akamai_pv = xpath_text(doc, _add_ns('pv-2.0'))
 365
 366         ctx = {
 367             'filename': filename,
 368             'total_frags': total_frags,
 369             'live': live,
 370         }
 371
 372         self._prepare_frag_download(ctx)
 373
 374         dest_stream = ctx['dest_stream']
 375
 376         if ctx['complete_frags_downloaded_bytes'] == 0:
 377             write_flv_header(dest_stream)
 378             if not live:
 379                 write_metadata_tag(dest_stream, metadata)
 380
 381         base_url_parsed = compat_urllib_parse_urlparse(base_url)
 382
 383         self._start_frag_download(ctx)
 384
 385         frag_index = 0
 386         while fragments_list:
 387             seg_i, frag_i = fragments_list.pop(0)
 388             frag_index += 1
 389             if frag_index <= ctx['fragment_index']:
 390                 continue
 391             name = 'Seg%d-Frag%d' % (seg_i, frag_i)
 392             query = []
 393             if base_url_parsed.query:
 394                 query.append(base_url_parsed.query)
 395             if akamai_pv:
 396                 query.append(akamai_pv.strip(';'))
 397             if info_dict.get('extra_param_to_segment_url'):
 398                 query.append(info_dict['extra_param_to_segment_url'])
 399             url_parsed = base_url_parsed._replace(path=base_url_parsed.path + name, query='&'.join(query))
 400             try:
 401                 success, down_data = self._download_fragment(ctx, url_parsed.geturl(), info_dict)
 402                 if not success:
 403                     return False
 404                 reader = FlvReader(down_data)
 405                 while True:
 406                     try:
 407                         _, box_type, box_data = reader.read_box_info()
 408                     except DataTruncatedError:
 409                         if test:
 410                             # In tests, segments may be truncated, and thus
 411                             # FlvReader may not be able to parse the whole
 412                             # chunk. If so, write the segment as is
 413                             # See https://github.com/ytdl-org/youtube-dl/issues/9214
 414                             dest_stream.write(down_data)
 415                             break
 416                         raise
 417                     if box_type == b'mdat':
 418                         self._append_fragment(ctx, box_data)
 419                         break
 420             except (compat_urllib_error.HTTPError, ) as err:
 421                 if live and (err.code == 404 or err.code == 410):
 422                     # We didn't keep up with the live window. Continue
 423                     # with the next available fragment.
 424                     msg = 'Fragment %d unavailable' % frag_i
 425                     self.report_warning(msg)
 426                     fragments_list = []
 427                 else:
 428                     raise
 429
 430             if not fragments_list and not test and live and bootstrap_url:
 431                 fragments_list = self._update_live_fragments(bootstrap_url, frag_i)
 432                 total_frags += len(fragments_list)
 433                 if fragments_list and (fragments_list[0][1] > frag_i + 1):
 434                     msg = 'Missed %d fragments' % (fragments_list[0][1] - (frag_i + 1))
 435                     self.report_warning(msg)
 436
 437         self._finish_frag_download(ctx)
 438
 439         return True