yt_dlp/downloader/dash.py

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