Issue a parse error on unexpected negative timestamps.

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 480 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()) {
+    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 (fixup_negative_timestamps_ && is_audio &&
       stream_timestamp < base::TimeDelta() &&
       buffer->duration() != kNoTimestamp) {
     if (!audio_decoder_config().codec_delay()) {
       DCHECK_EQ(buffer->discard_padding().first, base::TimeDelta());
 
       if (stream_timestamp + buffer->duration() < base::TimeDelta()) {
         DCHECK_EQ(buffer->discard_padding().second, base::TimeDelta());
@@ skipping 34 matching lines @@
     // later.  See http://crbug.com/396864.
     if (fixup_negative_timestamps_ &&
         buffer->timestamp() < last_packet_timestamp_) {
       buffer->set_timestamp(last_packet_timestamp_ +
                             (last_packet_duration_ != kNoTimestamp
                                  ? last_packet_duration_
                                  : base::TimeDelta::FromMicroseconds(1)));
     }
 
     // The demuxer should always output positive timestamps.
-    DCHECK(buffer->timestamp() >= base::TimeDelta());
+    DCHECK_GE(buffer->timestamp(), base::TimeDelta());
 
     if (last_packet_timestamp_ < buffer->timestamp()) {
       buffered_ranges_.Add(last_packet_timestamp_, buffer->timestamp());
       demuxer_->NotifyBufferingChanged();
     }
   }
 
   if (packet.get()->flags & AV_PKT_FLAG_KEY)
     buffer->set_is_key_frame(true);
 
@@ skipping 1264 matching lines @@
 
 void FFmpegDemuxer::SetLiveness(DemuxerStream::Liveness liveness) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   for (const auto& stream : streams_) {
     if (stream)
       stream->SetLiveness(liveness);
   }
 }
 
 }  // namespace media