Merge pull request #8898 from dstftw/fragment-retries

Add --fragment-retries option (Fixes #8466)

youtube_dl/__init__.py

@@ -144,14 +144,20 @@ def _real_main(argv=None):
         if numeric_limit is None:
             parser.error('invalid max_filesize specified')
         opts.max_filesize = numeric_limit
-    if opts.retries is not None:
-        if opts.retries in ('inf', 'infinite'):
-            opts_retries = float('inf')
+
+    def parse_retries(retries):
+        if retries in ('inf', 'infinite'):
+            parsed_retries = float('inf')
         else:
             try:
-                opts_retries = int(opts.retries)
+                parsed_retries = int(retries)
             except (TypeError, ValueError):
                 parser.error('invalid retry count specified')
+        return parsed_retries
+    if opts.retries is not None:
+        opts.retries = parse_retries(opts.retries)
+    if opts.fragment_retries is not None:
+        opts.fragment_retries = parse_retries(opts.fragment_retries)
     if opts.buffersize is not None:
         numeric_buffersize = FileDownloader.parse_bytes(opts.buffersize)
         if numeric_buffersize is None:
@@ -299,7 +305,8 @@ def _real_main(argv=None):
         'force_generic_extractor': opts.force_generic_extractor,
         'ratelimit': opts.ratelimit,
         'nooverwrites': opts.nooverwrites,
-        'retries': opts_retries,
+        'retries': opts.retries,
+        'fragment_retries': opts.fragment_retries,
         'buffersize': opts.buffersize,
         'noresizebuffer': opts.noresizebuffer,
         'continuedl': opts.continue_dl,

youtube_dl/downloader/common.py

@@ -115,6 +115,10 @@ class FileDownloader(object):
             return '%10s' % '---b/s'
         return '%10s' % ('%s/s' % format_bytes(speed))
 
+    @staticmethod
+    def format_retries(retries):
+        return 'inf' if retries == float('inf') else '%.0f' % retries
+
     @staticmethod
     def best_block_size(elapsed_time, bytes):
         new_min = max(bytes / 2.0, 1.0)
@@ -297,7 +301,9 @@ class FileDownloader(object):
 
     def report_retry(self, count, retries):
         """Report retry in case of HTTP error 5xx"""
-        self.to_screen('[download] Got server HTTP error. Retrying (attempt %d of %.0f)...' % (count, retries))
+        self.to_screen(
+            '[download] Got server HTTP error. Retrying (attempt %d of %s)...'
+            % (count, self.format_retries(retries)))
 
     def report_file_already_downloaded(self, file_name):
         """Report file has already been fully downloaded."""

youtube_dl/downloader/dash.py

@@ -4,6 +4,7 @@ import os
 import re
 
 from .fragment import FragmentFD
+from ..compat import compat_urllib_error
 from ..utils import (
     sanitize_open,
     encodeFilename,
@@ -36,7 +37,13 @@ class DashSegmentsFD(FragmentFD):
 
         segments_filenames = []
 
-        def append_url_to_file(target_url, target_filename):
+        fragment_retries = self.params.get('fragment_retries', 0)
+
+        def append_url_to_file(target_url, tmp_filename, segment_name):
+            target_filename = '%s-%s' % (tmp_filename, segment_name)
+            count = 0
+            while count <= fragment_retries:
+                try:
                     success = ctx['dl'].download(target_filename, {'url': combine_url(base_url, target_url)})
                     if not success:
                         return False
@@ -44,12 +51,27 @@ class DashSegmentsFD(FragmentFD):
                     ctx['dest_stream'].write(down.read())
                     down.close()
                     segments_filenames.append(target_sanitized)
+                    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.
+                    # So, we will retry all fragments that fail with 404 HTTP error for now.
+                    if err.code != 404:
+                        raise
+                    # Retry fragment
+                    count += 1
+                    if count <= fragment_retries:
+                        self.report_retry_fragment(segment_name, count, fragment_retries)
+            if count > fragment_retries:
+                self.report_error('giving up after %s fragment retries' % fragment_retries)
+                return False
 
         if initialization_url:
-            append_url_to_file(initialization_url, ctx['tmpfilename'] + '-Init')
+            append_url_to_file(initialization_url, ctx['tmpfilename'], 'Init')
         for i, segment_url in enumerate(segment_urls):
-            segment_filename = '%s-Seg%d' % (ctx['tmpfilename'], i)
-            append_url_to_file(segment_url, segment_filename)
+            append_url_to_file(segment_url, ctx['tmpfilename'], 'Seg%d' % i)
 
         self._finish_frag_download(ctx)
 

youtube_dl/downloader/fragment.py

@@ -19,8 +19,17 @@ class HttpQuietDownloader(HttpFD):
 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 only)
     """
 
+    def report_retry_fragment(self, fragment_name, count, retries):
+        self.to_screen(
+            '[download] Got server HTTP error. Retrying fragment %s (attempt %d of %s)...'
+            % (fragment_name, count, self.format_retries(retries)))
+
     def _prepare_and_start_frag_download(self, ctx):
         self._prepare_frag_download(ctx)
         self._start_frag_download(ctx)

youtube_dl/options.py

@@ -399,6 +399,10 @@ def parseOpts(overrideArguments=None):
         '-R', '--retries',
         dest='retries', metavar='RETRIES', default=10,
         help='Number of retries (default is %default), or "infinite".')
+    downloader.add_option(
+        '--fragment-retries',
+        dest='fragment_retries', metavar='RETRIES', default=10,
+        help='Number of retries for a fragment (default is %default), or "infinite" (DASH only)')
     downloader.add_option(
         '--buffer-size',
         dest='buffersize', metavar='SIZE', default='1024',