+ 'total_frags': len(segments),
+ }
+
+ self._prepare_and_start_frag_download(ctx)
+
+ fragment_retries = self.params.get('fragment_retries', 0)
+ skip_unavailable_fragments = self.params.get('skip_unavailable_fragments', True)
+
+ frag_index = 0
+ for i, segment in enumerate(segments):
+ frag_index += 1
+ if frag_index <= ctx['fragment_index']:
+ continue
+ # In DASH, the first segment contains necessary headers to
+ # generate a valid MP4 file, so always abort for the first segment
+ fatal = i == 0 or not skip_unavailable_fragments
+ count = 0
+ while count <= fragment_retries:
+ try:
+ success, frag_content = self._download_fragment(ctx, segment['url'], info_dict)
+ if not success:
+ return False
+ self._append_fragment(ctx, frag_content)
+ break
+ except compat_urllib_error.HTTPError as err:
+ # YouTube may often return 404 HTTP error for a fragment causing the
+ # whole download to fail. However if the same fragment is immediately
+ # retried with the same request data this usually succeeds (1-2 attemps
+ # is usually enough) thus allowing to download the whole file successfully.
+ # To be future-proof we will retry all fragments that fail with any
+ # HTTP error.
+ count += 1
+ if count <= fragment_retries:
+ self.report_retry_fragment(err, frag_index, count, fragment_retries)
+ if count > fragment_retries:
+ if not fatal:
+ self.report_skip_fragment(frag_index)
+ continue
+ self.report_error('giving up after %s fragment retries' % fragment_retries)
+ return False
+
+ self._finish_frag_download(ctx)