yt_dlp/downloader/dash.py

   1 from __future__ import unicode_literals
   2 import time
   3
   4 from ..downloader import get_suitable_downloader
   5 from .fragment import FragmentFD
   6
   7 from ..utils import urljoin
   8
   9
  10 class DashSegmentsFD(FragmentFD):
  11     """
  12     Download segments in a DASH manifest. External downloaders can take over
  13     the fragment downloads by supporting the 'dash_frag_urls' protocol
  14     """
  15
  16     FD_NAME = 'dashsegments'
  17
  18     def real_download(self, filename, info_dict):
  19         if info_dict.get('is_live') and set(info_dict['protocol'].split('+')) != {'http_dash_segments_generator'}:
  20             self.report_error('Live DASH videos are not supported')
  21
  22         real_start = time.time()
  23         real_downloader = get_suitable_downloader(
  24             info_dict, self.params, None, protocol='dash_frag_urls', to_stdout=(filename == '-'))
  25
  26         requested_formats = [{**info_dict, **fmt} for fmt in info_dict.get('requested_formats', [])]
  27         args = []
  28         for fmt in requested_formats or [info_dict]:
  29             try:
  30                 fragment_count = 1 if self.params.get('test') else len(fmt['fragments'])
  31             except TypeError:
  32                 fragment_count = None
  33             ctx = {
  34                 'filename': fmt.get('filepath') or filename,
  35                 'live': 'is_from_start' if fmt.get('is_from_start') else fmt.get('is_live'),
  36                 'total_frags': fragment_count,
  37             }
  38
  39             if real_downloader:
  40                 self._prepare_external_frag_download(ctx)
  41             else:
  42                 self._prepare_and_start_frag_download(ctx, fmt)
  43             ctx['start'] = real_start
  44
  45             fragments_to_download = self._get_fragments(fmt, ctx)
  46
  47             if real_downloader:
  48                 self.to_screen(
  49                     '[%s] Fragment downloads will be delegated to %s' % (self.FD_NAME, real_downloader.get_basename()))
  50                 info_dict['fragments'] = list(fragments_to_download)
  51                 fd = real_downloader(self.ydl, self.params)
  52                 return fd.real_download(filename, info_dict)
  53
  54             args.append([ctx, fragments_to_download, fmt])
  55
  56         return self.download_and_append_fragments_multiple(*args)
  57
  58     def _resolve_fragments(self, fragments, ctx):
  59         fragments = fragments(ctx) if callable(fragments) else fragments
  60         return [next(iter(fragments))] if self.params.get('test') else fragments
  61
  62     def _get_fragments(self, fmt, ctx):
  63         fragment_base_url = fmt.get('fragment_base_url')
  64         fragments = self._resolve_fragments(fmt['fragments'], ctx)
  65
  66         frag_index = 0
  67         for i, fragment in enumerate(fragments):
  68             frag_index += 1
  69             if frag_index <= ctx['fragment_index']:
  70                 continue
  71             fragment_url = fragment.get('url')
  72             if not fragment_url:
  73                 assert fragment_base_url
  74                 fragment_url = urljoin(fragment_base_url, fragment['path'])
  75
  76             yield {
  77                 'frag_index': frag_index,
  78                 'index': i,
  79                 'url': fragment_url,
  80             }