_ Git - youtube-dl/blob - youtube_dl/downloader/f4m.py

   1 from __future__ import division, unicode_literals
   2
   3 import base64
   4 import io
   5 import itertools
   6 import os
   7 import time
   8
   9 from .fragment import FragmentFD
  10 from ..compat import (
  11     compat_etree_fromstring,
  12     compat_urlparse,
  13     compat_urllib_error,
  14     compat_urllib_parse_urlparse,
  15     compat_struct_pack,
  16     compat_struct_unpack,
  17 )
  18 from ..utils import (
  19     encodeFilename,
  20     fix_xml_ampersands,
  21     sanitize_open,
  22     xpath_text,
  23 )
  24
  25
  26 class DataTruncatedError(Exception):
  27     pass
  28
  29
  30 class FlvReader(io.BytesIO):
  31     """
  32     Reader for Flv files
  33     The file format is documented in https://www.adobe.com/devnet/f4v.html
  34     """
  35
  36     def read_bytes(self, n):
  37         data = self.read(n)
  38         if len(data) < n:
  39             raise DataTruncatedError(
  40                 'FlvReader error: need %d bytes while only %d bytes got' % (
  41                     n, len(data)))
  42         return data
  43
  44     # Utility functions for reading numbers and strings
  45     def read_unsigned_long_long(self):
  46         return compat_struct_unpack('!Q', self.read_bytes(8))[0]
  47
  48     def read_unsigned_int(self):
  49         return compat_struct_unpack('!I', self.read_bytes(4))[0]
  50
  51     def read_unsigned_char(self):
  52         return compat_struct_unpack('!B', self.read_bytes(1))[0]
  53
  54     def read_string(self):
  55         res = b''
  56         while True:
  57             char = self.read_bytes(1)
  58             if char == b'\x00':
  59                 break
  60             res += char
  61         return res
  62
  63     def read_box_info(self):
  64         """
  65         Read a box and return the info as a tuple: (box_size, box_type, box_data)
  66         """
  67         real_size = size = self.read_unsigned_int()
  68         box_type = self.read_bytes(4)
  69         header_end = 8
  70         if size == 1:
  71             real_size = self.read_unsigned_long_long()
  72             header_end = 16
  73         return real_size, box_type, self.read_bytes(real_size - header_end)
  74
  75     def read_asrt(self):
  76         # version
  77         self.read_unsigned_char()
  78         # flags
  79         self.read_bytes(3)
  80         quality_entry_count = self.read_unsigned_char()
  81         # QualityEntryCount
  82         for i in range(quality_entry_count):
  83             self.read_string()
  84
  85         segment_run_count = self.read_unsigned_int()
  86         segments = []
  87         for i in range(segment_run_count):
  88             first_segment = self.read_unsigned_int()
  89             fragments_per_segment = self.read_unsigned_int()
  90             segments.append((first_segment, fragments_per_segment))
  91
  92         return {
  93             'segment_run': segments,
  94         }
  95
  96     def read_afrt(self):
  97         # version
  98         self.read_unsigned_char()
  99         # flags
 100         self.read_bytes(3)
 101         # time scale
 102         self.read_unsigned_int()
 103
 104         quality_entry_count = self.read_unsigned_char()
 105         # QualitySegmentUrlModifiers
 106         for i in range(quality_entry_count):
 107             self.read_string()
 108
 109         fragments_count = self.read_unsigned_int()
 110         fragments = []
 111         for i in range(fragments_count):
 112             first = self.read_unsigned_int()
 113             first_ts = self.read_unsigned_long_long()
 114             duration = self.read_unsigned_int()
 115             if duration == 0:
 116                 discontinuity_indicator = self.read_unsigned_char()
 117             else:
 118                 discontinuity_indicator = None
 119             fragments.append({
 120                 'first': first,
 121                 'ts': first_ts,
 122                 'duration': duration,
 123                 'discontinuity_indicator': discontinuity_indicator,
 124             })
 125
 126         return {
 127             'fragments': fragments,
 128         }
 129
 130     def read_abst(self):
 131         # version
 132         self.read_unsigned_char()
 133         # flags
 134         self.read_bytes(3)
 135
 136         self.read_unsigned_int()  # BootstrapinfoVersion
 137         # Profile,Live,Update,Reserved
 138         flags = self.read_unsigned_char()
 139         live = flags & 0x20 != 0
 140         # time scale
 141         self.read_unsigned_int()
 142         # CurrentMediaTime
 143         self.read_unsigned_long_long()
 144         # SmpteTimeCodeOffset
 145         self.read_unsigned_long_long()
 146
 147         self.read_string()  # MovieIdentifier
 148         server_count = self.read_unsigned_char()
 149         # ServerEntryTable
 150         for i in range(server_count):
 151             self.read_string()
 152         quality_count = self.read_unsigned_char()
 153         # QualityEntryTable
 154         for i in range(quality_count):
 155             self.read_string()
 156         # DrmData
 157         self.read_string()
 158         # MetaData
 159         self.read_string()
 160
 161         segments_count = self.read_unsigned_char()
 162         segments = []
 163         for i in range(segments_count):
 164             box_size, box_type, box_data = self.read_box_info()
 165             assert box_type == b'asrt'
 166             segment = FlvReader(box_data).read_asrt()
 167             segments.append(segment)
 168         fragments_run_count = self.read_unsigned_char()
 169         fragments = []
 170         for i in range(fragments_run_count):
 171             box_size, box_type, box_data = self.read_box_info()
 172             assert box_type == b'afrt'
 173             fragments.append(FlvReader(box_data).read_afrt())
 174
 175         return {
 176             'segments': segments,
 177             'fragments': fragments,
 178             'live': live,
 179         }
 180
 181     def read_bootstrap_info(self):
 182         total_size, box_type, box_data = self.read_box_info()
 183         assert box_type == b'abst'
 184         return FlvReader(box_data).read_abst()
 185
 186
 187 def read_bootstrap_info(bootstrap_bytes):
 188     return FlvReader(bootstrap_bytes).read_bootstrap_info()
 189
 190
 191 def build_fragments_list(boot_info):
 192     """ Return a list of (segment, fragment) for each fragment in the video """
 193     res = []
 194     segment_run_table = boot_info['segments'][0]
 195     fragment_run_entry_table = boot_info['fragments'][0]['fragments']
 196     first_frag_number = fragment_run_entry_table[0]['first']
 197     fragments_counter = itertools.count(first_frag_number)
 198     for segment, fragments_count in segment_run_table['segment_run']:
 199         for _ in range(fragments_count):
 200             res.append((segment, next(fragments_counter)))
 201
 202     if boot_info['live']:
 203         res = res[-2:]
 204
 205     return res
 206
 207
 208 def write_unsigned_int(stream, val):
 209     stream.write(compat_struct_pack('!I', val))
 210
 211
 212 def write_unsigned_int_24(stream, val):
 213     stream.write(compat_struct_pack('!I', val)[1:])
 214
 215
 216 def write_flv_header(stream):
 217     """Writes the FLV header to stream"""
 218     # FLV header
 219     stream.write(b'FLV\x01')
 220     stream.write(b'\x05')
 221     stream.write(b'\x00\x00\x00\x09')
 222     stream.write(b'\x00\x00\x00\x00')
 223
 224
 225 def write_metadata_tag(stream, metadata):
 226     """Writes optional metadata tag to stream"""
 227     SCRIPT_TAG = b'\x12'
 228     FLV_TAG_HEADER_LEN = 11
 229
 230     if metadata:
 231         stream.write(SCRIPT_TAG)
 232         write_unsigned_int_24(stream, len(metadata))
 233         stream.write(b'\x00\x00\x00\x00\x00\x00\x00')
 234         stream.write(metadata)
 235         write_unsigned_int(stream, FLV_TAG_HEADER_LEN + len(metadata))
 236
 237
 238 def remove_encrypted_media(media):
 239     return list(filter(lambda e: 'drmAdditionalHeaderId' not in e.attrib and
 240                                  'drmAdditionalHeaderSetId' not in e.attrib,
 241                        media))
 242
 243
 244 def _add_ns(prop):
 245     return '{http://ns.adobe.com/f4m/1.0}%s' % prop
 246
 247
 248 class F4mFD(FragmentFD):
 249     """
 250     A downloader for f4m manifests or AdobeHDS.
 251     """
 252
 253     FD_NAME = 'f4m'
 254
 255     def _get_unencrypted_media(self, doc):
 256         media = doc.findall(_add_ns('media'))
 257         if not media:
 258             self.report_error('No media found')
 259         for e in (doc.findall(_add_ns('drmAdditionalHeader')) +
 260                   doc.findall(_add_ns('drmAdditionalHeaderSet'))):
 261             # If id attribute is missing it's valid for all media nodes
 262             # without drmAdditionalHeaderId or drmAdditionalHeaderSetId attribute
 263             if 'id' not in e.attrib:
 264                 self.report_error('Missing ID in f4m DRM')
 265         media = remove_encrypted_media(media)
 266         if not media:
 267             self.report_error('Unsupported DRM')
 268         return media
 269
 270     def _get_bootstrap_from_url(self, bootstrap_url):
 271         bootstrap = self.ydl.urlopen(bootstrap_url).read()
 272         return read_bootstrap_info(bootstrap)
 273
 274     def _update_live_fragments(self, bootstrap_url, latest_fragment):
 275         fragments_list = []
 276         retries = 30
 277         while (not fragments_list) and (retries > 0):
 278             boot_info = self._get_bootstrap_from_url(bootstrap_url)
 279             fragments_list = build_fragments_list(boot_info)
 280             fragments_list = [f for f in fragments_list if f[1] > latest_fragment]
 281             if not fragments_list:
 282                 # Retry after a while
 283                 time.sleep(5.0)
 284                 retries -= 1
 285
 286         if not fragments_list:
 287             self.report_error('Failed to update fragments')
 288
 289         return fragments_list
 290
 291     def _parse_bootstrap_node(self, node, base_url):
 292         # Sometimes non empty inline bootstrap info can be specified along
 293         # with bootstrap url attribute (e.g. dummy inline bootstrap info
 294         # contains whitespace characters in [1]). We will prefer bootstrap
 295         # url over inline bootstrap info when present.
 296         # 1. http://live-1-1.rutube.ru/stream/1024/HDS/SD/C2NKsS85HQNckgn5HdEmOQ/1454167650/S-s604419906/move/four/dirs/upper/1024-576p.f4m
 297         bootstrap_url = node.get('url')
 298         if bootstrap_url:
 299             bootstrap_url = compat_urlparse.urljoin(
 300                 base_url, bootstrap_url)
 301             boot_info = self._get_bootstrap_from_url(bootstrap_url)
 302         else:
 303             bootstrap_url = None
 304             bootstrap = base64.b64decode(node.text.encode('ascii'))
 305             boot_info = read_bootstrap_info(bootstrap)
 306         return boot_info, bootstrap_url
 307
 308     def real_download(self, filename, info_dict):
 309         man_url = info_dict['url']
 310         requested_bitrate = info_dict.get('tbr')
 311         self.to_screen('[%s] Downloading f4m manifest' % self.FD_NAME)
 312         urlh = self.ydl.urlopen(man_url)
 313         man_url = urlh.geturl()
 314         # Some manifests may be malformed, e.g. prosiebensat1 generated manifests
 315         # (see https://github.com/rg3/youtube-dl/issues/6215#issuecomment-121704244
 316         # and https://github.com/rg3/youtube-dl/issues/7823)
 317         manifest = fix_xml_ampersands(urlh.read().decode('utf-8', 'ignore')).strip()
 318
 319         doc = compat_etree_fromstring(manifest)
 320         formats = [(int(f.attrib.get('bitrate', -1)), f)
 321                    for f in self._get_unencrypted_media(doc)]
 322         if requested_bitrate is None or len(formats) == 1:
 323             # get the best format
 324             formats = sorted(formats, key=lambda f: f[0])
 325             rate, media = formats[-1]
 326         else:
 327             rate, media = list(filter(
 328                 lambda f: int(f[0]) == requested_bitrate, formats))[0]
 329
 330         base_url = compat_urlparse.urljoin(man_url, media.attrib['url'])
 331         bootstrap_node = doc.find(_add_ns('bootstrapInfo'))
 332         boot_info, bootstrap_url = self._parse_bootstrap_node(bootstrap_node, base_url)
 333         live = boot_info['live']
 334         metadata_node = media.find(_add_ns('metadata'))
 335         if metadata_node is not None:
 336             metadata = base64.b64decode(metadata_node.text.encode('ascii'))
 337         else:
 338             metadata = None
 339
 340         fragments_list = build_fragments_list(boot_info)
 341         test = self.params.get('test', False)
 342         if test:
 343             # We only download the first fragment
 344             fragments_list = fragments_list[:1]
 345         total_frags = len(fragments_list)
 346         # For some akamai manifests we'll need to add a query to the fragment url
 347         akamai_pv = xpath_text(doc, _add_ns('pv-2.0'))
 348
 349         ctx = {
 350             'filename': filename,
 351             'total_frags': total_frags,
 352             'live': live,
 353         }
 354
 355         self._prepare_frag_download(ctx)
 356
 357         dest_stream = ctx['dest_stream']
 358
 359         write_flv_header(dest_stream)
 360         if not live:
 361             write_metadata_tag(dest_stream, metadata)
 362
 363         base_url_parsed = compat_urllib_parse_urlparse(base_url)
 364
 365         self._start_frag_download(ctx)
 366
 367         frags_filenames = []
 368         while fragments_list:
 369             seg_i, frag_i = fragments_list.pop(0)
 370             name = 'Seg%d-Frag%d' % (seg_i, frag_i)
 371             query = []
 372             if base_url_parsed.query:
 373                 query.append(base_url_parsed.query)
 374             if akamai_pv:
 375                 query.append(akamai_pv.strip(';'))
 376             if info_dict.get('extra_param_to_segment_url'):
 377                 query.append(info_dict['extra_param_to_segment_url'])
 378             url_parsed = base_url_parsed._replace(path=base_url_parsed.path + name, query='&'.join(query))
 379             frag_filename = '%s-%s' % (ctx['tmpfilename'], name)
 380             try:
 381                 success = ctx['dl'].download(frag_filename, {'url': url_parsed.geturl()})
 382                 if not success:
 383                     return False
 384                 (down, frag_sanitized) = sanitize_open(frag_filename, 'rb')
 385                 down_data = down.read()
 386                 down.close()
 387                 reader = FlvReader(down_data)
 388                 while True:
 389                     try:
 390                         _, box_type, box_data = reader.read_box_info()
 391                     except DataTruncatedError:
 392                         if test:
 393                             # In tests, segments may be truncated, and thus
 394                             # FlvReader may not be able to parse the whole
 395                             # chunk. If so, write the segment as is
 396                             # See https://github.com/rg3/youtube-dl/issues/9214
 397                             dest_stream.write(down_data)
 398                             break
 399                         raise
 400                     if box_type == b'mdat':
 401                         dest_stream.write(box_data)
 402                         break
 403                 if live:
 404                     os.remove(encodeFilename(frag_sanitized))
 405                 else:
 406                     frags_filenames.append(frag_sanitized)
 407             except (compat_urllib_error.HTTPError, ) as err:
 408                 if live and (err.code == 404 or err.code == 410):
 409                     # We didn't keep up with the live window. Continue
 410                     # with the next available fragment.
 411                     msg = 'Fragment %d unavailable' % frag_i
 412                     self.report_warning(msg)
 413                     fragments_list = []
 414                 else:
 415                     raise
 416
 417             if not fragments_list and not test and live and bootstrap_url:
 418                 fragments_list = self._update_live_fragments(bootstrap_url, frag_i)
 419                 total_frags += len(fragments_list)
 420                 if fragments_list and (fragments_list[0][1] > frag_i + 1):
 421                     msg = 'Missed %d fragments' % (fragments_list[0][1] - (frag_i + 1))
 422                     self.report_warning(msg)
 423
 424         self._finish_frag_download(ctx)
 425
 426         for frag_file in frags_filenames:
 427             os.remove(encodeFilename(frag_file))
 428
 429         return True