yt_dlp/downloader/fragment.py

   1 from __future__ import division, unicode_literals
   2
   3 import os
   4 import time
   5 import json
   6
   7 from .common import FileDownloader
   8 from .http import HttpFD
   9 from ..utils import (
  10     error_to_compat_str,
  11     encodeFilename,
  12     sanitize_open,
  13     sanitized_Request,
  14 )
  15
  16
  17 class HttpQuietDownloader(HttpFD):
  18     def to_screen(self, *args, **kargs):
  19         pass
  20
  21
  22 class FragmentFD(FileDownloader):
  23     """
  24     A base file downloader class for fragmented media (e.g. f4m/m3u8 manifests).
  25
  26     Available options:
  27
  28     fragment_retries:   Number of times to retry a fragment for HTTP error (DASH
  29                         and hlsnative only)
  30     skip_unavailable_fragments:
  31                         Skip unavailable fragments (DASH and hlsnative only)
  32     keep_fragments:     Keep downloaded fragments on disk after downloading is
  33                         finished
  34
  35     For each incomplete fragment download yt-dlp keeps on disk a special
  36     bookkeeping file with download state and metadata (in future such files will
  37     be used for any incomplete download handled by yt-dlp). This file is
  38     used to properly handle resuming, check download file consistency and detect
  39     potential errors. The file has a .ytdl extension and represents a standard
  40     JSON file of the following format:
  41
  42     extractor:
  43         Dictionary of extractor related data. TBD.
  44
  45     downloader:
  46         Dictionary of downloader related data. May contain following data:
  47             current_fragment:
  48                 Dictionary with current (being downloaded) fragment data:
  49                 index:  0-based index of current fragment among all fragments
  50             fragment_count:
  51                 Total count of fragments
  52
  53     This feature is experimental and file format may change in future.
  54     """
  55
  56     def report_retry_fragment(self, err, frag_index, count, retries):
  57         self.to_screen(
  58             '[download] Got server HTTP error: %s. Retrying fragment %d (attempt %d of %s)...'
  59             % (error_to_compat_str(err), frag_index, count, self.format_retries(retries)))
  60
  61     def report_skip_fragment(self, frag_index):
  62         self.to_screen('[download] Skipping fragment %d...' % frag_index)
  63
  64     def _prepare_url(self, info_dict, url):
  65         headers = info_dict.get('http_headers')
  66         return sanitized_Request(url, None, headers) if headers else url
  67
  68     def _prepare_and_start_frag_download(self, ctx):
  69         self._prepare_frag_download(ctx)
  70         self._start_frag_download(ctx)
  71
  72     @staticmethod
  73     def __do_ytdl_file(ctx):
  74         return not ctx['live'] and not ctx['tmpfilename'] == '-'
  75
  76     def _read_ytdl_file(self, ctx):
  77         assert 'ytdl_corrupt' not in ctx
  78         stream, _ = sanitize_open(self.ytdl_filename(ctx['filename']), 'r')
  79         try:
  80             ctx['fragment_index'] = json.loads(stream.read())['downloader']['current_fragment']['index']
  81         except Exception:
  82             ctx['ytdl_corrupt'] = True
  83         finally:
  84             stream.close()
  85
  86     def _write_ytdl_file(self, ctx):
  87         frag_index_stream, _ = sanitize_open(self.ytdl_filename(ctx['filename']), 'w')
  88         downloader = {
  89             'current_fragment': {
  90                 'index': ctx['fragment_index'],
  91             },
  92         }
  93         if ctx.get('fragment_count') is not None:
  94             downloader['fragment_count'] = ctx['fragment_count']
  95         frag_index_stream.write(json.dumps({'downloader': downloader}))
  96         frag_index_stream.close()
  97
  98     def _download_fragment(self, ctx, frag_url, info_dict, headers=None, request_data=None):
  99         fragment_filename = '%s-Frag%d' % (ctx['tmpfilename'], ctx['fragment_index'])
 100         fragment_info_dict = {
 101             'url': frag_url,
 102             'http_headers': headers or info_dict.get('http_headers'),
 103             'request_data': request_data,
 104         }
 105         success = ctx['dl'].download(fragment_filename, fragment_info_dict)
 106         if not success:
 107             return False, None
 108         if fragment_info_dict.get('filetime'):
 109             ctx['fragment_filetime'] = fragment_info_dict.get('filetime')
 110         down, frag_sanitized = sanitize_open(fragment_filename, 'rb')
 111         ctx['fragment_filename_sanitized'] = frag_sanitized
 112         frag_content = down.read()
 113         down.close()
 114         return True, frag_content
 115
 116     def _append_fragment(self, ctx, frag_content):
 117         try:
 118             ctx['dest_stream'].write(frag_content)
 119             ctx['dest_stream'].flush()
 120         finally:
 121             if self.__do_ytdl_file(ctx):
 122                 self._write_ytdl_file(ctx)
 123             if not self.params.get('keep_fragments', False):
 124                 os.remove(encodeFilename(ctx['fragment_filename_sanitized']))
 125             del ctx['fragment_filename_sanitized']
 126
 127     def _prepare_frag_download(self, ctx):
 128         if 'live' not in ctx:
 129             ctx['live'] = False
 130         if not ctx['live']:
 131             total_frags_str = '%d' % ctx['total_frags']
 132             ad_frags = ctx.get('ad_frags', 0)
 133             if ad_frags:
 134                 total_frags_str += ' (not including %d ad)' % ad_frags
 135         else:
 136             total_frags_str = 'unknown (live)'
 137         self.to_screen(
 138             '[%s] Total fragments: %s' % (self.FD_NAME, total_frags_str))
 139         self.report_destination(ctx['filename'])
 140         dl = HttpQuietDownloader(
 141             self.ydl,
 142             {
 143                 'continuedl': True,
 144                 'quiet': True,
 145                 'noprogress': True,
 146                 'ratelimit': self.params.get('ratelimit'),
 147                 'retries': self.params.get('retries', 0),
 148                 'nopart': self.params.get('nopart', False),
 149                 'test': self.params.get('test', False),
 150             }
 151         )
 152         tmpfilename = self.temp_name(ctx['filename'])
 153         open_mode = 'wb'
 154         resume_len = 0
 155
 156         # Establish possible resume length
 157         if os.path.isfile(encodeFilename(tmpfilename)):
 158             open_mode = 'ab'
 159             resume_len = os.path.getsize(encodeFilename(tmpfilename))
 160
 161         # Should be initialized before ytdl file check
 162         ctx.update({
 163             'tmpfilename': tmpfilename,
 164             'fragment_index': 0,
 165         })
 166
 167         if self.__do_ytdl_file(ctx):
 168             if os.path.isfile(encodeFilename(self.ytdl_filename(ctx['filename']))):
 169                 self._read_ytdl_file(ctx)
 170                 is_corrupt = ctx.get('ytdl_corrupt') is True
 171                 is_inconsistent = ctx['fragment_index'] > 0 and resume_len == 0
 172                 if is_corrupt or is_inconsistent:
 173                     message = (
 174                         '.ytdl file is corrupt' if is_corrupt else
 175                         'Inconsistent state of incomplete fragment download')
 176                     self.report_warning(
 177                         '%s. Restarting from the beginning...' % message)
 178                     ctx['fragment_index'] = resume_len = 0
 179                     if 'ytdl_corrupt' in ctx:
 180                         del ctx['ytdl_corrupt']
 181                     self._write_ytdl_file(ctx)
 182             else:
 183                 self._write_ytdl_file(ctx)
 184                 assert ctx['fragment_index'] == 0
 185
 186         dest_stream, tmpfilename = sanitize_open(tmpfilename, open_mode)
 187
 188         ctx.update({
 189             'dl': dl,
 190             'dest_stream': dest_stream,
 191             'tmpfilename': tmpfilename,
 192             # Total complete fragments downloaded so far in bytes
 193             'complete_frags_downloaded_bytes': resume_len,
 194         })
 195
 196     def _start_frag_download(self, ctx):
 197         resume_len = ctx['complete_frags_downloaded_bytes']
 198         total_frags = ctx['total_frags']
 199         # This dict stores the download progress, it's updated by the progress
 200         # hook
 201         state = {
 202             'status': 'downloading',
 203             'downloaded_bytes': resume_len,
 204             'fragment_index': ctx['fragment_index'],
 205             'fragment_count': total_frags,
 206             'filename': ctx['filename'],
 207             'tmpfilename': ctx['tmpfilename'],
 208         }
 209
 210         start = time.time()
 211         ctx.update({
 212             'started': start,
 213             # Amount of fragment's bytes downloaded by the time of the previous
 214             # frag progress hook invocation
 215             'prev_frag_downloaded_bytes': 0,
 216         })
 217
 218         def frag_progress_hook(s):
 219             if s['status'] not in ('downloading', 'finished'):
 220                 return
 221
 222             time_now = time.time()
 223             state['elapsed'] = time_now - start
 224             frag_total_bytes = s.get('total_bytes') or 0
 225             if not ctx['live']:
 226                 estimated_size = (
 227                     (ctx['complete_frags_downloaded_bytes'] + frag_total_bytes)
 228                     / (state['fragment_index'] + 1) * total_frags)
 229                 state['total_bytes_estimate'] = estimated_size
 230
 231             if s['status'] == 'finished':
 232                 state['fragment_index'] += 1
 233                 ctx['fragment_index'] = state['fragment_index']
 234                 state['downloaded_bytes'] += frag_total_bytes - ctx['prev_frag_downloaded_bytes']
 235                 ctx['complete_frags_downloaded_bytes'] = state['downloaded_bytes']
 236                 ctx['prev_frag_downloaded_bytes'] = 0
 237             else:
 238                 frag_downloaded_bytes = s['downloaded_bytes']
 239                 state['downloaded_bytes'] += frag_downloaded_bytes - ctx['prev_frag_downloaded_bytes']
 240                 if not ctx['live']:
 241                     state['eta'] = self.calc_eta(
 242                         start, time_now, estimated_size - resume_len,
 243                         state['downloaded_bytes'] - resume_len)
 244                 state['speed'] = s.get('speed') or ctx.get('speed')
 245                 ctx['speed'] = state['speed']
 246                 ctx['prev_frag_downloaded_bytes'] = frag_downloaded_bytes
 247             self._hook_progress(state)
 248
 249         ctx['dl'].add_progress_hook(frag_progress_hook)
 250
 251         return start
 252
 253     def _finish_frag_download(self, ctx):
 254         ctx['dest_stream'].close()
 255         if self.__do_ytdl_file(ctx):
 256             ytdl_filename = encodeFilename(self.ytdl_filename(ctx['filename']))
 257             if os.path.isfile(ytdl_filename):
 258                 os.remove(ytdl_filename)
 259         elapsed = time.time() - ctx['started']
 260
 261         if ctx['tmpfilename'] == '-':
 262             downloaded_bytes = ctx['complete_frags_downloaded_bytes']
 263         else:
 264             self.try_rename(ctx['tmpfilename'], ctx['filename'])
 265             if self.params.get('updatetime', True):
 266                 filetime = ctx.get('fragment_filetime')
 267                 if filetime:
 268                     try:
 269                         os.utime(ctx['filename'], (time.time(), filetime))
 270                     except Exception:
 271                         pass
 272             downloaded_bytes = os.path.getsize(encodeFilename(ctx['filename']))
 273
 274         self._hook_progress({
 275             'downloaded_bytes': downloaded_bytes,
 276             'total_bytes': downloaded_bytes,
 277             'filename': ctx['filename'],
 278             'status': 'finished',
 279             'elapsed': elapsed,
 280         })
 281
 282     def _prepare_external_frag_download(self, ctx):
 283         if 'live' not in ctx:
 284             ctx['live'] = False
 285         if not ctx['live']:
 286             total_frags_str = '%d' % ctx['total_frags']
 287             ad_frags = ctx.get('ad_frags', 0)
 288             if ad_frags:
 289                 total_frags_str += ' (not including %d ad)' % ad_frags
 290         else:
 291             total_frags_str = 'unknown (live)'
 292         self.to_screen(
 293             '[%s] Total fragments: %s' % (self.FD_NAME, total_frags_str))
 294
 295         tmpfilename = self.temp_name(ctx['filename'])
 296
 297         # Should be initialized before ytdl file check
 298         ctx.update({
 299             'tmpfilename': tmpfilename,
 300             'fragment_index': 0,
 301         })