Cleanup OPUS decoder. Remove extraneous transforms and copies.

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 <string>
 
 #include "base/base64.h"
@@ skipping 827 matching lines @@
       new_packet->dts = packet->dts;
       new_packet->pos = packet->pos;
       new_packet->duration = packet->duration;
       new_packet->convergence_duration = packet->convergence_duration;
       new_packet->flags = packet->flags;
       new_packet->stream_index = packet->stream_index;
 
       packet.swap(new_packet);
     }
 
+    // Special case for opus in ogg.  FFmpeg is pre-trimming the codec delay
+    // from the packet timestamp.  Chrome expects to handle this itself inside
+    // the decoder, so shift timestamps by the delay in this case.
+    if (strcmp(glue_->format_context()->iformat->name, "ogg") == 0) {
+      const AVCodecContext* codec_context =
+          glue_->format_context()->streams[packet->stream_index]->codec;
+      if (codec_context->codec_id == AV_CODEC_ID_OPUS &&
+          codec_context->delay > 0) {
+        packet->pts += codec_context->delay;
+      }
+    }
+
     FFmpegDemuxerStream* demuxer_stream = streams_[packet->stream_index];
     demuxer_stream->EnqueuePacket(packet.Pass());
   }
 
   // Keep reading until we've reached capacity.
   ReadFrameIfNeeded();
 }
 
 void FFmpegDemuxer::OnDataSourceStopped(const base::Closure& callback) {
   // This will block until all tasks complete. Note that after this returns it's
@@ skipping 63 matching lines @@
   }
   for (size_t i = 0; i < buffered.size(); ++i)
     host_->AddBufferedTimeRange(buffered.start(i), buffered.end(i));
 }
 
 void FFmpegDemuxer::OnDataSourceError() {
   host_->OnDemuxerError(PIPELINE_ERROR_READ);
 }
 
 }  // namespace media