yt_dlp/downloader/fragment.py

   1 import concurrent.futures
   2 import contextlib
   3 import http.client
   4 import json
   5 import math
   6 import os
   7 import struct
   8 import time
   9 import urllib.error
  10
  11 from .common import FileDownloader
  12 from .http import HttpFD
  13 from ..aes import aes_cbc_decrypt_bytes, unpad_pkcs7
  14 from ..compat import compat_os_name
  15 from ..utils import (
  16     DownloadError,
  17     encodeFilename,
  18     error_to_compat_str,
  19     sanitized_Request,
  20     traverse_obj,
  21 )
  22
  23
  24 class HttpQuietDownloader(HttpFD):
  25     def to_screen(self, *args, **kargs):
  26         pass
  27
  28     to_console_title = to_screen
  29
  30
  31 class FragmentFD(FileDownloader):
  32     """
  33     A base file downloader class for fragmented media (e.g. f4m/m3u8 manifests).
  34
  35     Available options:
  36
  37     fragment_retries:   Number of times to retry a fragment for HTTP error (DASH
  38                         and hlsnative only)
  39     skip_unavailable_fragments:
  40                         Skip unavailable fragments (DASH and hlsnative only)
  41     keep_fragments:     Keep downloaded fragments on disk after downloading is
  42                         finished
  43     concurrent_fragment_downloads:  The number of threads to use for native hls and dash downloads
  44     _no_ytdl_file:      Don't use .ytdl file
  45
  46     For each incomplete fragment download yt-dlp keeps on disk a special
  47     bookkeeping file with download state and metadata (in future such files will
  48     be used for any incomplete download handled by yt-dlp). This file is
  49     used to properly handle resuming, check download file consistency and detect
  50     potential errors. The file has a .ytdl extension and represents a standard
  51     JSON file of the following format:
  52
  53     extractor:
  54         Dictionary of extractor related data. TBD.
  55
  56     downloader:
  57         Dictionary of downloader related data. May contain following data:
  58             current_fragment:
  59                 Dictionary with current (being downloaded) fragment data:
  60                 index:  0-based index of current fragment among all fragments
  61             fragment_count:
  62                 Total count of fragments
  63
  64     This feature is experimental and file format may change in future.
  65     """
  66
  67     def report_retry_fragment(self, err, frag_index, count, retries):
  68         self.to_screen(
  69             '\r[download] Got server HTTP error: %s. Retrying fragment %d (attempt %d of %s) ...'
  70             % (error_to_compat_str(err), frag_index, count, self.format_retries(retries)))
  71         self.sleep_retry('fragment', count)
  72
  73     def report_skip_fragment(self, frag_index, err=None):
  74         err = f' {err};' if err else ''
  75         self.to_screen(f'[download]{err} Skipping fragment {frag_index:d} ...')
  76
  77     def _prepare_url(self, info_dict, url):
  78         headers = info_dict.get('http_headers')
  79         return sanitized_Request(url, None, headers) if headers else url
  80
  81     def _prepare_and_start_frag_download(self, ctx, info_dict):
  82         self._prepare_frag_download(ctx)
  83         self._start_frag_download(ctx, info_dict)
  84
  85     def __do_ytdl_file(self, ctx):
  86         return ctx['live'] is not True and ctx['tmpfilename'] != '-' and not self.params.get('_no_ytdl_file')
  87
  88     def _read_ytdl_file(self, ctx):
  89         assert 'ytdl_corrupt' not in ctx
  90         stream, _ = self.sanitize_open(self.ytdl_filename(ctx['filename']), 'r')
  91         try:
  92             ytdl_data = json.loads(stream.read())
  93             ctx['fragment_index'] = ytdl_data['downloader']['current_fragment']['index']
  94             if 'extra_state' in ytdl_data['downloader']:
  95                 ctx['extra_state'] = ytdl_data['downloader']['extra_state']
  96         except Exception:
  97             ctx['ytdl_corrupt'] = True
  98         finally:
  99             stream.close()
 100
 101     def _write_ytdl_file(self, ctx):
 102         frag_index_stream, _ = self.sanitize_open(self.ytdl_filename(ctx['filename']), 'w')
 103         try:
 104             downloader = {
 105                 'current_fragment': {
 106                     'index': ctx['fragment_index'],
 107                 },
 108             }
 109             if 'extra_state' in ctx:
 110                 downloader['extra_state'] = ctx['extra_state']
 111             if ctx.get('fragment_count') is not None:
 112                 downloader['fragment_count'] = ctx['fragment_count']
 113             frag_index_stream.write(json.dumps({'downloader': downloader}))
 114         finally:
 115             frag_index_stream.close()
 116
 117     def _download_fragment(self, ctx, frag_url, info_dict, headers=None, request_data=None):
 118         fragment_filename = '%s-Frag%d' % (ctx['tmpfilename'], ctx['fragment_index'])
 119         fragment_info_dict = {
 120             'url': frag_url,
 121             'http_headers': headers or info_dict.get('http_headers'),
 122             'request_data': request_data,
 123             'ctx_id': ctx.get('ctx_id'),
 124         }
 125         success, _ = ctx['dl'].download(fragment_filename, fragment_info_dict)
 126         if not success:
 127             return False
 128         if fragment_info_dict.get('filetime'):
 129             ctx['fragment_filetime'] = fragment_info_dict.get('filetime')
 130         ctx['fragment_filename_sanitized'] = fragment_filename
 131         return True
 132
 133     def _read_fragment(self, ctx):
 134         if not ctx.get('fragment_filename_sanitized'):
 135             return None
 136         try:
 137             down, frag_sanitized = self.sanitize_open(ctx['fragment_filename_sanitized'], 'rb')
 138         except FileNotFoundError:
 139             if ctx.get('live'):
 140                 return None
 141             raise
 142         ctx['fragment_filename_sanitized'] = frag_sanitized
 143         frag_content = down.read()
 144         down.close()
 145         return frag_content
 146
 147     def _append_fragment(self, ctx, frag_content):
 148         try:
 149             ctx['dest_stream'].write(frag_content)
 150             ctx['dest_stream'].flush()
 151         finally:
 152             if self.__do_ytdl_file(ctx):
 153                 self._write_ytdl_file(ctx)
 154             if not self.params.get('keep_fragments', False):
 155                 self.try_remove(encodeFilename(ctx['fragment_filename_sanitized']))
 156             del ctx['fragment_filename_sanitized']
 157
 158     def _prepare_frag_download(self, ctx):
 159         if 'live' not in ctx:
 160             ctx['live'] = False
 161         if not ctx['live']:
 162             total_frags_str = '%d' % ctx['total_frags']
 163             ad_frags = ctx.get('ad_frags', 0)
 164             if ad_frags:
 165                 total_frags_str += ' (not including %d ad)' % ad_frags
 166         else:
 167             total_frags_str = 'unknown (live)'
 168         self.to_screen(f'[{self.FD_NAME}] Total fragments: {total_frags_str}')
 169         self.report_destination(ctx['filename'])
 170         dl = HttpQuietDownloader(self.ydl, {
 171             **self.params,
 172             'noprogress': True,
 173             'test': False,
 174         })
 175         tmpfilename = self.temp_name(ctx['filename'])
 176         open_mode = 'wb'
 177         resume_len = 0
 178
 179         # Establish possible resume length
 180         if os.path.isfile(encodeFilename(tmpfilename)):
 181             open_mode = 'ab'
 182             resume_len = os.path.getsize(encodeFilename(tmpfilename))
 183
 184         # Should be initialized before ytdl file check
 185         ctx.update({
 186             'tmpfilename': tmpfilename,
 187             'fragment_index': 0,
 188         })
 189
 190         if self.__do_ytdl_file(ctx):
 191             if os.path.isfile(encodeFilename(self.ytdl_filename(ctx['filename']))):
 192                 self._read_ytdl_file(ctx)
 193                 is_corrupt = ctx.get('ytdl_corrupt') is True
 194                 is_inconsistent = ctx['fragment_index'] > 0 and resume_len == 0
 195                 if is_corrupt or is_inconsistent:
 196                     message = (
 197                         '.ytdl file is corrupt' if is_corrupt else
 198                         'Inconsistent state of incomplete fragment download')
 199                     self.report_warning(
 200                         '%s. Restarting from the beginning ...' % message)
 201                     ctx['fragment_index'] = resume_len = 0
 202                     if 'ytdl_corrupt' in ctx:
 203                         del ctx['ytdl_corrupt']
 204                     self._write_ytdl_file(ctx)
 205             else:
 206                 self._write_ytdl_file(ctx)
 207                 assert ctx['fragment_index'] == 0
 208
 209         dest_stream, tmpfilename = self.sanitize_open(tmpfilename, open_mode)
 210
 211         ctx.update({
 212             'dl': dl,
 213             'dest_stream': dest_stream,
 214             'tmpfilename': tmpfilename,
 215             # Total complete fragments downloaded so far in bytes
 216             'complete_frags_downloaded_bytes': resume_len,
 217         })
 218
 219     def _start_frag_download(self, ctx, info_dict):
 220         resume_len = ctx['complete_frags_downloaded_bytes']
 221         total_frags = ctx['total_frags']
 222         ctx_id = ctx.get('ctx_id')
 223         # This dict stores the download progress, it's updated by the progress
 224         # hook
 225         state = {
 226             'status': 'downloading',
 227             'downloaded_bytes': resume_len,
 228             'fragment_index': ctx['fragment_index'],
 229             'fragment_count': total_frags,
 230             'filename': ctx['filename'],
 231             'tmpfilename': ctx['tmpfilename'],
 232         }
 233
 234         start = time.time()
 235         ctx.update({
 236             'started': start,
 237             'fragment_started': start,
 238             # Amount of fragment's bytes downloaded by the time of the previous
 239             # frag progress hook invocation
 240             'prev_frag_downloaded_bytes': 0,
 241         })
 242
 243         def frag_progress_hook(s):
 244             if s['status'] not in ('downloading', 'finished'):
 245                 return
 246
 247             if not total_frags and ctx.get('fragment_count'):
 248                 state['fragment_count'] = ctx['fragment_count']
 249
 250             if ctx_id is not None and s.get('ctx_id') != ctx_id:
 251                 return
 252
 253             state['max_progress'] = ctx.get('max_progress')
 254             state['progress_idx'] = ctx.get('progress_idx')
 255
 256             time_now = time.time()
 257             state['elapsed'] = time_now - start
 258             frag_total_bytes = s.get('total_bytes') or 0
 259             s['fragment_info_dict'] = s.pop('info_dict', {})
 260             if not ctx['live']:
 261                 estimated_size = (
 262                     (ctx['complete_frags_downloaded_bytes'] + frag_total_bytes)
 263                     / (state['fragment_index'] + 1) * total_frags)
 264                 state['total_bytes_estimate'] = estimated_size
 265
 266             if s['status'] == 'finished':
 267                 state['fragment_index'] += 1
 268                 ctx['fragment_index'] = state['fragment_index']
 269                 state['downloaded_bytes'] += frag_total_bytes - ctx['prev_frag_downloaded_bytes']
 270                 ctx['complete_frags_downloaded_bytes'] = state['downloaded_bytes']
 271                 ctx['speed'] = state['speed'] = self.calc_speed(
 272                     ctx['fragment_started'], time_now, frag_total_bytes)
 273                 ctx['fragment_started'] = time.time()
 274                 ctx['prev_frag_downloaded_bytes'] = 0
 275             else:
 276                 frag_downloaded_bytes = s['downloaded_bytes']
 277                 state['downloaded_bytes'] += frag_downloaded_bytes - ctx['prev_frag_downloaded_bytes']
 278                 if not ctx['live']:
 279                     state['eta'] = self.calc_eta(
 280                         start, time_now, estimated_size - resume_len,
 281                         state['downloaded_bytes'] - resume_len)
 282                 ctx['speed'] = state['speed'] = self.calc_speed(
 283                     ctx['fragment_started'], time_now, frag_downloaded_bytes)
 284                 ctx['prev_frag_downloaded_bytes'] = frag_downloaded_bytes
 285             self._hook_progress(state, info_dict)
 286
 287         ctx['dl'].add_progress_hook(frag_progress_hook)
 288
 289         return start
 290
 291     def _finish_frag_download(self, ctx, info_dict):
 292         ctx['dest_stream'].close()
 293         if self.__do_ytdl_file(ctx):
 294             ytdl_filename = encodeFilename(self.ytdl_filename(ctx['filename']))
 295             if os.path.isfile(ytdl_filename):
 296                 self.try_remove(ytdl_filename)
 297         elapsed = time.time() - ctx['started']
 298
 299         if ctx['tmpfilename'] == '-':
 300             downloaded_bytes = ctx['complete_frags_downloaded_bytes']
 301         else:
 302             self.try_rename(ctx['tmpfilename'], ctx['filename'])
 303             if self.params.get('updatetime', True):
 304                 filetime = ctx.get('fragment_filetime')
 305                 if filetime:
 306                     with contextlib.suppress(Exception):
 307                         os.utime(ctx['filename'], (time.time(), filetime))
 308             downloaded_bytes = os.path.getsize(encodeFilename(ctx['filename']))
 309
 310         self._hook_progress({
 311             'downloaded_bytes': downloaded_bytes,
 312             'total_bytes': downloaded_bytes,
 313             'filename': ctx['filename'],
 314             'status': 'finished',
 315             'elapsed': elapsed,
 316             'ctx_id': ctx.get('ctx_id'),
 317             'max_progress': ctx.get('max_progress'),
 318             'progress_idx': ctx.get('progress_idx'),
 319         }, info_dict)
 320
 321     def _prepare_external_frag_download(self, ctx):
 322         if 'live' not in ctx:
 323             ctx['live'] = False
 324         if not ctx['live']:
 325             total_frags_str = '%d' % ctx['total_frags']
 326             ad_frags = ctx.get('ad_frags', 0)
 327             if ad_frags:
 328                 total_frags_str += ' (not including %d ad)' % ad_frags
 329         else:
 330             total_frags_str = 'unknown (live)'
 331         self.to_screen(f'[{self.FD_NAME}] Total fragments: {total_frags_str}')
 332
 333         tmpfilename = self.temp_name(ctx['filename'])
 334
 335         # Should be initialized before ytdl file check
 336         ctx.update({
 337             'tmpfilename': tmpfilename,
 338             'fragment_index': 0,
 339         })
 340
 341     def decrypter(self, info_dict):
 342         _key_cache = {}
 343
 344         def _get_key(url):
 345             if url not in _key_cache:
 346                 _key_cache[url] = self.ydl.urlopen(self._prepare_url(info_dict, url)).read()
 347             return _key_cache[url]
 348
 349         def decrypt_fragment(fragment, frag_content):
 350             decrypt_info = fragment.get('decrypt_info')
 351             if not decrypt_info or decrypt_info['METHOD'] != 'AES-128':
 352                 return frag_content
 353             iv = decrypt_info.get('IV') or struct.pack('>8xq', fragment['media_sequence'])
 354             decrypt_info['KEY'] = decrypt_info.get('KEY') or _get_key(info_dict.get('_decryption_key_url') or decrypt_info['URI'])
 355             # Don't decrypt the content in tests since the data is explicitly truncated and it's not to a valid block
 356             # size (see https://github.com/ytdl-org/youtube-dl/pull/27660). Tests only care that the correct data downloaded,
 357             # not what it decrypts to.
 358             if self.params.get('test', False):
 359                 return frag_content
 360             return unpad_pkcs7(aes_cbc_decrypt_bytes(frag_content, decrypt_info['KEY'], iv))
 361
 362         return decrypt_fragment
 363
 364     def download_and_append_fragments_multiple(self, *args, pack_func=None, finish_func=None):
 365         '''
 366         @params (ctx1, fragments1, info_dict1), (ctx2, fragments2, info_dict2), ...
 367                 all args must be either tuple or list
 368         '''
 369         interrupt_trigger = [True]
 370         max_progress = len(args)
 371         if max_progress == 1:
 372             return self.download_and_append_fragments(*args[0], pack_func=pack_func, finish_func=finish_func)
 373         max_workers = self.params.get('concurrent_fragment_downloads', 1)
 374         if max_progress > 1:
 375             self._prepare_multiline_status(max_progress)
 376         is_live = any(traverse_obj(args, (..., 2, 'is_live'), default=[]))
 377
 378         def thread_func(idx, ctx, fragments, info_dict, tpe):
 379             ctx['max_progress'] = max_progress
 380             ctx['progress_idx'] = idx
 381             return self.download_and_append_fragments(
 382                 ctx, fragments, info_dict, pack_func=pack_func, finish_func=finish_func,
 383                 tpe=tpe, interrupt_trigger=interrupt_trigger)
 384
 385         class FTPE(concurrent.futures.ThreadPoolExecutor):
 386             # has to stop this or it's going to wait on the worker thread itself
 387             def __exit__(self, exc_type, exc_val, exc_tb):
 388                 pass
 389
 390         if compat_os_name == 'nt':
 391             def future_result(future):
 392                 while True:
 393                     try:
 394                         return future.result(0.1)
 395                     except KeyboardInterrupt:
 396                         raise
 397                     except concurrent.futures.TimeoutError:
 398                         continue
 399         else:
 400             def future_result(future):
 401                 return future.result()
 402
 403         def interrupt_trigger_iter(fg):
 404             for f in fg:
 405                 if not interrupt_trigger[0]:
 406                     break
 407                 yield f
 408
 409         spins = []
 410         for idx, (ctx, fragments, info_dict) in enumerate(args):
 411             tpe = FTPE(math.ceil(max_workers / max_progress))
 412             job = tpe.submit(thread_func, idx, ctx, interrupt_trigger_iter(fragments), info_dict, tpe)
 413             spins.append((tpe, job))
 414
 415         result = True
 416         for tpe, job in spins:
 417             try:
 418                 result = result and future_result(job)
 419             except KeyboardInterrupt:
 420                 interrupt_trigger[0] = False
 421             finally:
 422                 tpe.shutdown(wait=True)
 423         if not interrupt_trigger[0] and not is_live:
 424             raise KeyboardInterrupt()
 425         # we expect the user wants to stop and DO WANT the preceding postprocessors to run;
 426         # so returning a intermediate result here instead of KeyboardInterrupt on live
 427         return result
 428
 429     def download_and_append_fragments(
 430             self, ctx, fragments, info_dict, *, pack_func=None, finish_func=None,
 431             tpe=None, interrupt_trigger=None):
 432         if not interrupt_trigger:
 433             interrupt_trigger = (True, )
 434
 435         fragment_retries = self.params.get('fragment_retries', 0)
 436         is_fatal = (
 437             ((lambda _: False) if info_dict.get('is_live') else (lambda idx: idx == 0))
 438             if self.params.get('skip_unavailable_fragments', True) else (lambda _: True))
 439
 440         if not pack_func:
 441             pack_func = lambda frag_content, _: frag_content
 442
 443         def download_fragment(fragment, ctx):
 444             if not interrupt_trigger[0]:
 445                 return
 446
 447             frag_index = ctx['fragment_index'] = fragment['frag_index']
 448             ctx['last_error'] = None
 449             headers = info_dict.get('http_headers', {}).copy()
 450             byte_range = fragment.get('byte_range')
 451             if byte_range:
 452                 headers['Range'] = 'bytes=%d-%d' % (byte_range['start'], byte_range['end'] - 1)
 453
 454             # Never skip the first fragment
 455             fatal, count = is_fatal(fragment.get('index') or (frag_index - 1)), 0
 456             while count <= fragment_retries:
 457                 try:
 458                     ctx['fragment_count'] = fragment.get('fragment_count')
 459                     if self._download_fragment(ctx, fragment['url'], info_dict, headers):
 460                         break
 461                     return
 462                 except (urllib.error.HTTPError, http.client.IncompleteRead) as err:
 463                     # Unavailable (possibly temporary) fragments may be served.
 464                     # First we try to retry then either skip or abort.
 465                     # See https://github.com/ytdl-org/youtube-dl/issues/10165,
 466                     # https://github.com/ytdl-org/youtube-dl/issues/10448).
 467                     count += 1
 468                     ctx['last_error'] = err
 469                     if count <= fragment_retries:
 470                         self.report_retry_fragment(err, frag_index, count, fragment_retries)
 471                 except DownloadError:
 472                     # Don't retry fragment if error occurred during HTTP downloading
 473                     # itself since it has own retry settings
 474                     if not fatal:
 475                         break
 476                     raise
 477
 478             if count > fragment_retries and fatal:
 479                 ctx['dest_stream'].close()
 480                 self.report_error('Giving up after %s fragment retries' % fragment_retries)
 481
 482         def append_fragment(frag_content, frag_index, ctx):
 483             if frag_content:
 484                 self._append_fragment(ctx, pack_func(frag_content, frag_index))
 485             elif not is_fatal(frag_index - 1):
 486                 self.report_skip_fragment(frag_index, 'fragment not found')
 487             else:
 488                 ctx['dest_stream'].close()
 489                 self.report_error(f'fragment {frag_index} not found, unable to continue')
 490                 return False
 491             return True
 492
 493         decrypt_fragment = self.decrypter(info_dict)
 494
 495         max_workers = math.ceil(
 496             self.params.get('concurrent_fragment_downloads', 1) / ctx.get('max_progress', 1))
 497         if max_workers > 1:
 498             def _download_fragment(fragment):
 499                 ctx_copy = ctx.copy()
 500                 download_fragment(fragment, ctx_copy)
 501                 return fragment, fragment['frag_index'], ctx_copy.get('fragment_filename_sanitized')
 502
 503             self.report_warning('The download speed shown is only of one thread. This is a known issue and patches are welcome')
 504             with tpe or concurrent.futures.ThreadPoolExecutor(max_workers) as pool:
 505                 try:
 506                     for fragment, frag_index, frag_filename in pool.map(_download_fragment, fragments):
 507                         ctx.update({
 508                             'fragment_filename_sanitized': frag_filename,
 509                             'fragment_index': frag_index,
 510                         })
 511                         if not append_fragment(decrypt_fragment(fragment, self._read_fragment(ctx)), frag_index, ctx):
 512                             return False
 513                 except KeyboardInterrupt:
 514                     self._finish_multiline_status()
 515                     self.report_error(
 516                         'Interrupted by user. Waiting for all threads to shutdown...', is_error=False, tb=False)
 517                     pool.shutdown(wait=False)
 518                     raise
 519         else:
 520             for fragment in fragments:
 521                 if not interrupt_trigger[0]:
 522                     break
 523                 try:
 524                     download_fragment(fragment, ctx)
 525                     result = append_fragment(
 526                         decrypt_fragment(fragment, self._read_fragment(ctx)), fragment['frag_index'], ctx)
 527                 except KeyboardInterrupt:
 528                     if info_dict.get('is_live'):
 529                         break
 530                     raise
 531                 if not result:
 532                     return False
 533
 534         if finish_func is not None:
 535             ctx['dest_stream'].write(finish_func())
 536             ctx['dest_stream'].flush()
 537         self._finish_frag_download(ctx, info_dict)
 538         return True