yt-dlp/youtube_dl/downloader/fragment.py
Remita Amine 75a2485407 [fragment,hls,f4m,dash,ism] improve fragment downloading
- resume immediately
- no need to concatenate segments and decrypt them on every resume
- no need to save temp files for segments

and for hls downloader:
- no need to download keys for segments that already downloaded
2017-04-19 11:46:07 +01:00

182 lines
6.7 KiB
Python

from __future__ import division, unicode_literals
import os
import time
import io
from .common import FileDownloader
from .http import HttpFD
from ..utils import (
error_to_compat_str,
encodeFilename,
sanitize_open,
sanitized_Request,
compat_str,
)
class HttpQuietDownloader(HttpFD):
def to_screen(self, *args, **kargs):
pass
class FragmentFD(FileDownloader):
"""
A base file downloader class for fragmented media (e.g. f4m/m3u8 manifests).
Available options:
fragment_retries: Number of times to retry a fragment for HTTP error (DASH
and hlsnative only)
skip_unavailable_fragments:
Skip unavailable fragments (DASH and hlsnative only)
"""
def report_retry_fragment(self, err, frag_index, count, retries):
self.to_screen(
'[download] Got server HTTP error: %s. Retrying fragment %d (attempt %d of %s)...'
% (error_to_compat_str(err), frag_index, count, self.format_retries(retries)))
def report_skip_fragment(self, frag_index):
self.to_screen('[download] Skipping fragment %d...' % frag_index)
def _prepare_url(self, info_dict, url):
headers = info_dict.get('http_headers')
return sanitized_Request(url, None, headers) if headers else url
def _prepare_and_start_frag_download(self, ctx):
self._prepare_frag_download(ctx)
self._start_frag_download(ctx)
def _download_fragment(self, ctx, frag_url, info_dict, headers=None):
down = io.BytesIO()
success = ctx['dl'].download(down, {
'url': frag_url,
'http_headers': headers or info_dict.get('http_headers'),
})
if not success:
return False, None
frag_content = down.getvalue()
down.close()
return True, frag_content
def _append_fragment(self, ctx, frag_content):
ctx['dest_stream'].write(frag_content)
if not (ctx.get('live') or ctx['tmpfilename'] == '-'):
frag_index_stream, _ = sanitize_open(ctx['tmpfilename'] + '.fragindex', 'w')
frag_index_stream.write(compat_str(ctx['frag_index']))
frag_index_stream.close()
def _prepare_frag_download(self, ctx):
if 'live' not in ctx:
ctx['live'] = False
self.to_screen(
'[%s] Total fragments: %s'
% (self.FD_NAME, ctx['total_frags'] if not ctx['live'] else 'unknown (live)'))
self.report_destination(ctx['filename'])
dl = HttpQuietDownloader(
self.ydl,
{
'continuedl': True,
'quiet': True,
'noprogress': True,
'ratelimit': self.params.get('ratelimit'),
'retries': self.params.get('retries', 0),
'nopart': self.params.get('nopart', False),
'test': self.params.get('test', False),
}
)
tmpfilename = self.temp_name(ctx['filename'])
open_mode = 'wb'
resume_len = 0
frag_index = 0
# Establish possible resume length
if os.path.isfile(encodeFilename(tmpfilename)):
open_mode = 'ab'
resume_len = os.path.getsize(encodeFilename(tmpfilename))
if os.path.isfile(encodeFilename(tmpfilename + '.fragindex')):
frag_index_stream, _ = sanitize_open(tmpfilename + '.fragindex', 'r')
frag_index = int(frag_index_stream.read())
frag_index_stream.close()
dest_stream, tmpfilename = sanitize_open(tmpfilename, open_mode)
ctx.update({
'dl': dl,
'dest_stream': dest_stream,
'tmpfilename': tmpfilename,
'frag_index': frag_index,
# Total complete fragments downloaded so far in bytes
'complete_frags_downloaded_bytes': resume_len,
})
def _start_frag_download(self, ctx):
total_frags = ctx['total_frags']
# This dict stores the download progress, it's updated by the progress
# hook
state = {
'status': 'downloading',
'downloaded_bytes': ctx['complete_frags_downloaded_bytes'],
'frag_index': ctx['frag_index'],
'frag_count': total_frags,
'filename': ctx['filename'],
'tmpfilename': ctx['tmpfilename'],
}
start = time.time()
ctx.update({
'started': start,
# Amount of fragment's bytes downloaded by the time of the previous
# frag progress hook invocation
'prev_frag_downloaded_bytes': 0,
})
def frag_progress_hook(s):
if s['status'] not in ('downloading', 'finished'):
return
time_now = time.time()
state['elapsed'] = time_now - start
frag_total_bytes = s.get('total_bytes') or 0
if not ctx['live']:
estimated_size = (
(ctx['complete_frags_downloaded_bytes'] + frag_total_bytes) /
(state['frag_index'] + 1) * total_frags)
state['total_bytes_estimate'] = estimated_size
if s['status'] == 'finished':
state['frag_index'] += 1
ctx['frag_index'] = state['frag_index']
state['downloaded_bytes'] += frag_total_bytes - ctx['prev_frag_downloaded_bytes']
ctx['complete_frags_downloaded_bytes'] = state['downloaded_bytes']
ctx['prev_frag_downloaded_bytes'] = 0
else:
frag_downloaded_bytes = s['downloaded_bytes']
state['downloaded_bytes'] += frag_downloaded_bytes - ctx['prev_frag_downloaded_bytes']
if not ctx['live']:
state['eta'] = self.calc_eta(
start, time_now, estimated_size,
state['downloaded_bytes'])
state['speed'] = s.get('speed') or ctx.get('speed')
ctx['speed'] = state['speed']
ctx['prev_frag_downloaded_bytes'] = frag_downloaded_bytes
self._hook_progress(state)
ctx['dl'].add_progress_hook(frag_progress_hook)
return start
def _finish_frag_download(self, ctx):
ctx['dest_stream'].close()
if os.path.isfile(encodeFilename(ctx['tmpfilename'] + '.fragindex')):
os.remove(encodeFilename(ctx['tmpfilename'] + '.fragindex'))
elapsed = time.time() - ctx['started']
self.try_rename(ctx['tmpfilename'], ctx['filename'])
fsize = os.path.getsize(encodeFilename(ctx['filename']))
self._hook_progress({
'downloaded_bytes': fsize,
'total_bytes': fsize,
'filename': ctx['filename'],
'status': 'finished',
'elapsed': elapsed,
})