Media: Reject negative initial video timestamps in FFmpegDemuxer.

media/filters/ffmpeg_demuxer.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/filters/ffmpeg_demuxer.h"
 
 #include <algorithm>
 #include <memory>
 #include <set>
 #include <utility>
@@ skipping 489 matching lines @@
   // Don't rebase timestamps for positive start times, the HTML Media Spec
   // details this in section "4.8.10.6 Offsets into the media resource." We
   // will still need to rebase timestamps before seeking with FFmpeg though.
   if (start_time > base::TimeDelta())
     start_time = base::TimeDelta();
 
   buffer->set_timestamp(stream_timestamp - start_time);
 
   // Only allow negative timestamps past if we know they'll be fixed up by the
   // code paths below; otherwise they should be treated as a parse error.
-  if (!fixup_negative_timestamps_ && buffer->timestamp() < base::TimeDelta()) {
+  if ((!fixup_negative_timestamps_ || last_packet_timestamp_ == kNoTimestamp) &&
+      buffer->timestamp() < base::TimeDelta()) {
     MEDIA_LOG(DEBUG, media_log_)
         << "FFmpegDemuxer: unfixable negative timestamp";
     demuxer_->NotifyDemuxerError(DEMUXER_ERROR_COULD_NOT_PARSE);
     return;
   }
 
   // If enabled, and no codec delay is present, mark audio packets with negative
   // timestamps for post-decode discard. If codec delay is present, discard is
   // handled by the decoder using that value.
   if (fixup_negative_timestamps_ && is_audio &&
@@ skipping 1346 matching lines @@
 
 void FFmpegDemuxer::SetLiveness(DemuxerStream::Liveness liveness) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   for (const auto& stream : streams_) {
     if (stream)
       stream->SetLiveness(liveness);
   }
 }
 
 }  // namespace media