_ Git - youtube-dl/blob - youtube_dl/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 youtube-dl 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 youtube-dl). 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         stream, _ = sanitize_open(self.ytdl_filename(ctx['filename']), 'r')
  78         ctx['fragment_index'] = json.loads(stream.read())['downloader']['current_fragment']['index']
  79         stream.close()
  80
  81     def _write_ytdl_file(self, ctx):
  82         frag_index_stream, _ = sanitize_open(self.ytdl_filename(ctx['filename']), 'w')
  83         downloader = {
  84             'current_fragment': {
  85                 'index': ctx['fragment_index'],
  86             },
  87         }
  88         if ctx.get('fragment_count') is not None:
  89             downloader['fragment_count'] = ctx['fragment_count']
  90         frag_index_stream.write(json.dumps({'downloader': downloader}))
  91         frag_index_stream.close()
  92
  93     def _download_fragment(self, ctx, frag_url, info_dict, headers=None):
  94         fragment_filename = '%s-Frag%d' % (ctx['tmpfilename'], ctx['fragment_index'])
  95         success = ctx['dl'].download(fragment_filename, {
  96             'url': frag_url,
  97             'http_headers': headers or info_dict.get('http_headers'),
  98         })
  99         if not success:
 100             return False, None
 101         down, frag_sanitized = sanitize_open(fragment_filename, 'rb')
 102         ctx['fragment_filename_sanitized'] = frag_sanitized
 103         frag_content = down.read()
 104         down.close()
 105         return True, frag_content
 106
 107     def _append_fragment(self, ctx, frag_content):
 108         try:
 109             ctx['dest_stream'].write(frag_content)
 110             ctx['dest_stream'].flush()
 111         finally:
 112             if self.__do_ytdl_file(ctx):
 113                 self._write_ytdl_file(ctx)
 114             if not self.params.get('keep_fragments', False):
 115                 os.remove(encodeFilename(ctx['fragment_filename_sanitized']))
 116             del ctx['fragment_filename_sanitized']
 117
 118     def _prepare_frag_download(self, ctx):
 119         if 'live' not in ctx:
 120             ctx['live'] = False
 121         if not ctx['live']:
 122             total_frags_str = '%d' % ctx['total_frags']
 123             ad_frags = ctx.get('ad_frags', 0)
 124             if ad_frags:
 125                 total_frags_str += ' (not including %d ad)' % ad_frags
 126         else:
 127             total_frags_str = 'unknown (live)'
 128         self.to_screen(
 129             '[%s] Total fragments: %s' % (self.FD_NAME, total_frags_str))
 130         self.report_destination(ctx['filename'])
 131         dl = HttpQuietDownloader(
 132             self.ydl,
 133             {
 134                 'continuedl': True,
 135                 'quiet': True,
 136                 'noprogress': True,
 137                 'ratelimit': self.params.get('ratelimit'),
 138                 'retries': self.params.get('retries', 0),
 139                 'nopart': self.params.get('nopart', False),
 140                 'test': self.params.get('test', False),
 141             }
 142         )
 143         tmpfilename = self.temp_name(ctx['filename'])
 144         open_mode = 'wb'
 145         resume_len = 0
 146
 147         # Establish possible resume length
 148         if os.path.isfile(encodeFilename(tmpfilename)):
 149             open_mode = 'ab'
 150             resume_len = os.path.getsize(encodeFilename(tmpfilename))
 151
 152         # Should be initialized before ytdl file check
 153         ctx.update({
 154             'tmpfilename': tmpfilename,
 155             'fragment_index': 0,
 156         })
 157
 158         if self.__do_ytdl_file(ctx):
 159             if os.path.isfile(encodeFilename(self.ytdl_filename(ctx['filename']))):
 160                 self._read_ytdl_file(ctx)
 161                 if ctx['fragment_index'] > 0 and resume_len == 0:
 162                     self.report_warning(
 163                         'Inconsistent state of incomplete fragment download. '
 164                         'Restarting from the beginning...')
 165                     ctx['fragment_index'] = resume_len = 0
 166                     self._write_ytdl_file(ctx)
 167             else:
 168                 self._write_ytdl_file(ctx)
 169                 assert ctx['fragment_index'] == 0
 170
 171         dest_stream, tmpfilename = sanitize_open(tmpfilename, open_mode)
 172
 173         ctx.update({
 174             'dl': dl,
 175             'dest_stream': dest_stream,
 176             'tmpfilename': tmpfilename,
 177             # Total complete fragments downloaded so far in bytes
 178             'complete_frags_downloaded_bytes': resume_len,
 179         })
 180
 181     def _start_frag_download(self, ctx):
 182         total_frags = ctx['total_frags']
 183         # This dict stores the download progress, it's updated by the progress
 184         # hook
 185         state = {
 186             'status': 'downloading',
 187             'downloaded_bytes': ctx['complete_frags_downloaded_bytes'],
 188             'fragment_index': ctx['fragment_index'],
 189             'fragment_count': total_frags,
 190             'filename': ctx['filename'],
 191             'tmpfilename': ctx['tmpfilename'],
 192         }
 193
 194         start = time.time()
 195         ctx.update({
 196             'started': start,
 197             # Amount of fragment's bytes downloaded by the time of the previous
 198             # frag progress hook invocation
 199             'prev_frag_downloaded_bytes': 0,
 200         })
 201
 202         def frag_progress_hook(s):
 203             if s['status'] not in ('downloading', 'finished'):
 204                 return
 205
 206             time_now = time.time()
 207             state['elapsed'] = time_now - start
 208             frag_total_bytes = s.get('total_bytes') or 0
 209             if not ctx['live']:
 210                 estimated_size = (
 211                     (ctx['complete_frags_downloaded_bytes'] + frag_total_bytes) /
 212                     (state['fragment_index'] + 1) * total_frags)
 213                 state['total_bytes_estimate'] = estimated_size
 214
 215             if s['status'] == 'finished':
 216                 state['fragment_index'] += 1
 217                 ctx['fragment_index'] = state['fragment_index']
 218                 state['downloaded_bytes'] += frag_total_bytes - ctx['prev_frag_downloaded_bytes']
 219                 ctx['complete_frags_downloaded_bytes'] = state['downloaded_bytes']
 220                 ctx['prev_frag_downloaded_bytes'] = 0
 221             else:
 222                 frag_downloaded_bytes = s['downloaded_bytes']
 223                 state['downloaded_bytes'] += frag_downloaded_bytes - ctx['prev_frag_downloaded_bytes']
 224                 if not ctx['live']:
 225                     state['eta'] = self.calc_eta(
 226                         start, time_now, estimated_size,
 227                         state['downloaded_bytes'])
 228                 state['speed'] = s.get('speed') or ctx.get('speed')
 229                 ctx['speed'] = state['speed']
 230                 ctx['prev_frag_downloaded_bytes'] = frag_downloaded_bytes
 231             self._hook_progress(state)
 232
 233         ctx['dl'].add_progress_hook(frag_progress_hook)
 234
 235         return start
 236
 237     def _finish_frag_download(self, ctx):
 238         ctx['dest_stream'].close()
 239         if self.__do_ytdl_file(ctx):
 240             ytdl_filename = encodeFilename(self.ytdl_filename(ctx['filename']))
 241             if os.path.isfile(ytdl_filename):
 242                 os.remove(ytdl_filename)
 243         elapsed = time.time() - ctx['started']
 244         self.try_rename(ctx['tmpfilename'], ctx['filename'])
 245         fsize = os.path.getsize(encodeFilename(ctx['filename']))
 246
 247         self._hook_progress({
 248             'downloaded_bytes': fsize,
 249             'total_bytes': fsize,
 250             'filename': ctx['filename'],
 251             'status': 'finished',
 252             'elapsed': elapsed,
 253         })