youtube_dl/downloader/dash.py

   1 from __future__ import unicode_literals
   2
   3 import os
   4 import re
   5
   6 from .fragment import FragmentFD
   7 from ..compat import compat_urllib_error
   8 from ..utils import (
   9     sanitize_open,
  10     encodeFilename,
  11 )
  12
  13
  14 class DashSegmentsFD(FragmentFD):
  15     """
  16     Download segments in a DASH manifest
  17     """
  18
  19     FD_NAME = 'dashsegments'
  20
  21     def real_download(self, filename, info_dict):
  22         base_url = info_dict['url']
  23         segment_urls = [info_dict['segment_urls'][0]] if self.params.get('test', False) else info_dict['segment_urls']
  24         initialization_url = info_dict.get('initialization_url')
  25
  26         ctx = {
  27             'filename': filename,
  28             'total_frags': len(segment_urls) + (1 if initialization_url else 0),
  29         }
  30
  31         self._prepare_and_start_frag_download(ctx)
  32
  33         def combine_url(base_url, target_url):
  34             if re.match(r'^https?://', target_url):
  35                 return target_url
  36             return '%s%s%s' % (base_url, '' if base_url.endswith('/') else '/', target_url)
  37
  38         segments_filenames = []
  39
  40         fragment_retries = self.params.get('fragment_retries', 0)
  41
  42         def append_url_to_file(target_url, tmp_filename, segment_name):
  43             target_filename = '%s-%s' % (tmp_filename, segment_name)
  44             count = 0
  45             while count <= fragment_retries:
  46                 try:
  47                     success = ctx['dl'].download(target_filename, {'url': combine_url(base_url, target_url)})
  48                     if not success:
  49                         return False
  50                     down, target_sanitized = sanitize_open(target_filename, 'rb')
  51                     ctx['dest_stream'].write(down.read())
  52                     down.close()
  53                     segments_filenames.append(target_sanitized)
  54                     break
  55                 except (compat_urllib_error.HTTPError, ) as err:
  56                     # YouTube may often return 404 HTTP error for a fragment causing the
  57                     # whole download to fail. However if the same fragment is immediately
  58                     # retried with the same request data this usually succeeds (1-2 attemps
  59                     # is usually enough) thus allowing to download the whole file successfully.
  60                     # So, we will retry all fragments that fail with 404 HTTP error for now.
  61                     if err.code != 404:
  62                         raise
  63                     # Retry fragment
  64                     count += 1
  65                     if count <= fragment_retries:
  66                         self.report_retry_fragment(segment_name, count, fragment_retries)
  67             if count > fragment_retries:
  68                 self.report_error('giving up after %s fragment retries' % fragment_retries)
  69                 return False
  70
  71         if initialization_url:
  72             append_url_to_file(initialization_url, ctx['tmpfilename'], 'Init')
  73         for i, segment_url in enumerate(segment_urls):
  74             append_url_to_file(segment_url, ctx['tmpfilename'], 'Seg%d' % i)
  75
  76         self._finish_frag_download(ctx)
  77
  78         for segment_file in segments_filenames:
  79             os.remove(encodeFilename(segment_file))
  80
  81         return True