yt_dlp/downloader/dash.py

   1 import time
   2 import urllib.parse
   3
   4 from . import get_suitable_downloader
   5 from .fragment import FragmentFD
   6 from ..utils import update_url_query, urljoin
   7
   8
   9 class DashSegmentsFD(FragmentFD):
  10     """
  11     Download segments in a DASH manifest. External downloaders can take over
  12     the fragment downloads by supporting the 'dash_frag_urls' protocol
  13     """
  14
  15     FD_NAME = 'dashsegments'
  16
  17     def real_download(self, filename, info_dict):
  18         if 'http_dash_segments_generator' in info_dict['protocol'].split('+'):
  19             real_downloader = None  # No external FD can support --live-from-start
  20         else:
  21             if info_dict.get('is_live'):
  22                 self.report_error('Live DASH videos are not supported')
  23             real_downloader = get_suitable_downloader(
  24                 info_dict, self.params, None, protocol='dash_frag_urls', to_stdout=(filename == '-'))
  25
  26         real_start = time.time()
  27
  28         requested_formats = [{**info_dict, **fmt} for fmt in info_dict.get('requested_formats', [])]
  29         args = []
  30         for fmt in requested_formats or [info_dict]:
  31             try:
  32                 fragment_count = 1 if self.params.get('test') else len(fmt['fragments'])
  33             except TypeError:
  34                 fragment_count = None
  35             ctx = {
  36                 'filename': fmt.get('filepath') or filename,
  37                 'live': 'is_from_start' if fmt.get('is_from_start') else fmt.get('is_live'),
  38                 'total_frags': fragment_count,
  39             }
  40
  41             if real_downloader:
  42                 self._prepare_external_frag_download(ctx)
  43             else:
  44                 self._prepare_and_start_frag_download(ctx, fmt)
  45             ctx['start'] = real_start
  46
  47             extra_query = None
  48             extra_param_to_segment_url = info_dict.get('extra_param_to_segment_url')
  49             if extra_param_to_segment_url:
  50                 extra_query = urllib.parse.parse_qs(extra_param_to_segment_url)
  51
  52             fragments_to_download = self._get_fragments(fmt, ctx, extra_query)
  53
  54             if real_downloader:
  55                 self.to_screen(
  56                     f'[{self.FD_NAME}] Fragment downloads will be delegated to {real_downloader.get_basename()}')
  57                 info_dict['fragments'] = list(fragments_to_download)
  58                 fd = real_downloader(self.ydl, self.params)
  59                 return fd.real_download(filename, info_dict)
  60
  61             args.append([ctx, fragments_to_download, fmt])
  62
  63         return self.download_and_append_fragments_multiple(*args, is_fatal=lambda idx: idx == 0)
  64
  65     def _resolve_fragments(self, fragments, ctx):
  66         fragments = fragments(ctx) if callable(fragments) else fragments
  67         return [next(iter(fragments))] if self.params.get('test') else fragments
  68
  69     def _get_fragments(self, fmt, ctx, extra_query):
  70         fragment_base_url = fmt.get('fragment_base_url')
  71         fragments = self._resolve_fragments(fmt['fragments'], ctx)
  72
  73         frag_index = 0
  74         for i, fragment in enumerate(fragments):
  75             frag_index += 1
  76             if frag_index <= ctx['fragment_index']:
  77                 continue
  78             fragment_url = fragment.get('url')
  79             if not fragment_url:
  80                 assert fragment_base_url
  81                 fragment_url = urljoin(fragment_base_url, fragment['path'])
  82             if extra_query:
  83                 fragment_url = update_url_query(fragment_url, extra_query)
  84
  85             yield {
  86                 'frag_index': frag_index,
  87                 'fragment_count': fragment.get('fragment_count'),
  88                 'index': i,
  89                 'url': fragment_url,
  90             }