youtube_dl/downloader/fragment.py

   1 from __future__ import division, unicode_literals
   2
   3 import os
   4 import time
   5
   6 from .common import FileDownloader
   7 from .http import HttpFD
   8 from ..utils import (
   9     encodeFilename,
  10     sanitize_open,
  11 )
  12
  13
  14 class HttpQuietDownloader(HttpFD):
  15     def to_screen(self, *args, **kargs):
  16         pass
  17
  18
  19 class FragmentFD(FileDownloader):
  20     """
  21     A base file downloader class for fragmented media (e.g. f4m/m3u8 manifests).
  22     """
  23
  24     def _prepare_and_start_frag_download(self, ctx):
  25         self._prepare_frag_download(ctx)
  26         self._start_frag_download(ctx)
  27
  28     def _prepare_frag_download(self, ctx):
  29         self.to_screen('[%s] Total fragments: %d' % (self.FD_NAME, ctx['total_frags']))
  30         self.report_destination(ctx['filename'])
  31         dl = HttpQuietDownloader(
  32             self.ydl,
  33             {
  34                 'continuedl': True,
  35                 'quiet': True,
  36                 'noprogress': True,
  37                 'ratelimit': self.params.get('ratelimit', None),
  38                 'retries': self.params.get('retries', 0),
  39                 'test': self.params.get('test', False),
  40             }
  41         )
  42         tmpfilename = self.temp_name(ctx['filename'])
  43         dest_stream, tmpfilename = sanitize_open(tmpfilename, 'wb')
  44         ctx.update({
  45             'dl': dl,
  46             'dest_stream': dest_stream,
  47             'tmpfilename': tmpfilename,
  48         })
  49
  50     def _start_frag_download(self, ctx):
  51         total_frags = ctx['total_frags']
  52         # This dict stores the download progress, it's updated by the progress
  53         # hook
  54         state = {
  55             'status': 'downloading',
  56             'downloaded_bytes': 0,
  57             'frag_index': 0,
  58             'frag_count': total_frags,
  59             'filename': ctx['filename'],
  60             'tmpfilename': ctx['tmpfilename'],
  61         }
  62
  63         start = time.time()
  64         ctx.update({
  65             'started': start,
  66             # Total complete fragments downloaded so far in bytes
  67             'complete_frags_downloaded_bytes': 0,
  68             # Amount of fragment's bytes downloaded by the time of the previous
  69             # frag progress hook invocation
  70             'prev_frag_downloaded_bytes': 0,
  71         })
  72
  73         def frag_progress_hook(s):
  74             if s['status'] not in ('downloading', 'finished'):
  75                 return
  76
  77             frag_total_bytes = s.get('total_bytes') or 0
  78
  79             estimated_size = (
  80                 (ctx['complete_frags_downloaded_bytes'] + frag_total_bytes) /
  81                 (state['frag_index'] + 1) * total_frags)
  82             time_now = time.time()
  83             state['total_bytes_estimate'] = estimated_size
  84             state['elapsed'] = time_now - start
  85
  86             if s['status'] == 'finished':
  87                 state['frag_index'] += 1
  88                 state['downloaded_bytes'] += frag_total_bytes - ctx['prev_frag_downloaded_bytes']
  89                 ctx['complete_frags_downloaded_bytes'] = state['downloaded_bytes']
  90                 ctx['prev_frag_downloaded_bytes'] = 0
  91             else:
  92                 frag_downloaded_bytes = s['downloaded_bytes']
  93                 state['downloaded_bytes'] += frag_downloaded_bytes - ctx['prev_frag_downloaded_bytes']
  94                 state['eta'] = self.calc_eta(
  95                     start, time_now, estimated_size,
  96                     state['downloaded_bytes'])
  97                 state['speed'] = s.get('speed')
  98                 ctx['prev_frag_downloaded_bytes'] = frag_downloaded_bytes
  99             self._hook_progress(state)
 100
 101         ctx['dl'].add_progress_hook(frag_progress_hook)
 102
 103         return start
 104
 105     def _finish_frag_download(self, ctx):
 106         ctx['dest_stream'].close()
 107         elapsed = time.time() - ctx['started']
 108         self.try_rename(ctx['tmpfilename'], ctx['filename'])
 109         fsize = os.path.getsize(encodeFilename(ctx['filename']))
 110
 111         self._hook_progress({
 112             'downloaded_bytes': fsize,
 113             'total_bytes': fsize,
 114             'filename': ctx['filename'],
 115             'status': 'finished',
 116             'elapsed': elapsed,
 117         })