Merge branch 'bilibili' of https://github.com/PeterDing/youtube-dl into PeterDing...

[youtube-dl] / youtube_dl / downloader / dash.py

diff --git a/youtube_dl/downloader/dash.py b/youtube_dl/downloader/dash.py
index 4f3eeb3861549a2551070d1cac0e7567363baf1a..41fc9cfc2b6b301bc09261c4b79668ca2395d544 100644 (file)
--- a/youtube_dl/downloader/dash.py
+++ b/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,
@@ -35,20 +36,53 @@ class DashSegmentsFD(FragmentFD):
             return '%s%s%s' % (base_url, '' if base_url.endswith('/') else '/', target_url)
 
         segments_filenames = []
-        def append_url_to_file(target_url, target_filename):
-            success = ctx['dl'].download(target_filename, {'url': combine_url(base_url, target_url)})
-            if not success:
+
+        fragment_retries = self.params.get('fragment_retries', 0)
+        skip_unavailable_fragments = self.params.get('skip_unavailable_fragments', True)
+
+        def process_segment(segment, tmp_filename, fatal):
+            target_url, segment_name = segment
+            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
+                    down, target_sanitized = sanitize_open(target_filename, 'rb')
+                    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.
+                    # 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, segment_name, count, fragment_retries)
+            if count > fragment_retries:
+                if not fatal:
+                    self.report_skip_fragment(segment_name)
+                    return True
+                self.report_error('giving up after %s fragment retries' % fragment_retries)
+                return False
+            return True
+
+        segments_to_download = [(initialization_url, 'Init')] if initialization_url else []
+        segments_to_download.extend([
+            (segment_url, 'Seg%d' % i)
+            for i, segment_url in enumerate(segment_urls)])
+
+        for i, segment in enumerate(segments_to_download):
+            # 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
+            if not process_segment(segment, ctx['tmpfilename'], fatal):
                 return False
-            down, target_sanitized = sanitize_open(target_filename, 'rb')
-            ctx['dest_stream'].write(down.read())
-            down.close()
-            segments_filenames.append(target_sanitized)
-
-        if initialization_url:
-            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)
 
         self._finish_frag_download(ctx)