Wire up codec_delay() to MP3StreamParser and FFmpegAudioDecoder.

media/filters/ffmpeg_audio_decoder.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_audio_decoder.h"
 
 #include "base/callback_helpers.h"
 #include "base/single_thread_task_runner.h"
 #include "media/base/audio_buffer.h"
 #include "media/base/audio_bus.h"
@@ skipping 249 matching lines @@
     decode_cb.Run(kDecodeError, NULL);
     return;
   }
 
   if (!buffer->end_of_stream()) {
     if (last_input_timestamp_ == kNoTimestamp() &&
         codec_context_->codec_id == AV_CODEC_ID_VORBIS &&
         buffer->timestamp() < base::TimeDelta()) {
       // Dropping frames for negative timestamps as outlined in section A.2
       // in the Vorbis spec. http://xiph.org/vorbis/doc/Vorbis_I_spec.html
-      output_frames_to_drop_ = floor(0.5 + -buffer->timestamp().InSecondsF() *

[acolwell GONE FROM CHROMIUM, 2014/04/17 21:11:24]

Why is this change needed?

[DaleCurtis, 2014/04/17 21:42:49]

It's a cleanup from an earlier patch set.  I kept it since the floor() is
unnecessary for n >= 0.

-                                               config_.samples_per_second());
+      output_frames_to_drop_ = 0.5 + -buffer->timestamp().InSecondsF() *
+                                         config_.samples_per_second();
     } else {
       if (last_input_timestamp_ != kNoTimestamp() &&
           buffer->timestamp() < last_input_timestamp_) {
         const base::TimeDelta diff =
             buffer->timestamp() - last_input_timestamp_;
         DLOG(WARNING)
             << "Input timestamps are not monotonically increasing! "
             << " ts " << buffer->timestamp().InMicroseconds() << " us"
             << " diff " << diff.InMicroseconds() << " us";
       }
@@ skipping 69 matching lines @@
     }
 
     // Update packet size and data pointer in case we need to call the decoder
     // with the remaining bytes from this packet.
     packet.size -= result;
     packet.data += result;
 
     if (output_timestamp_helper_->base_timestamp() == kNoTimestamp() &&
         !buffer->end_of_stream()) {
       DCHECK(buffer->timestamp() != kNoTimestamp());
-      if (output_frames_to_drop_ > 0) {
-        // Currently Vorbis is the only codec that causes us to drop samples.
-        // If we have to drop samples it always means the timeline starts at 0.
-        DCHECK_EQ(codec_context_->codec_id, AV_CODEC_ID_VORBIS);
+      if (output_frames_to_drop_ > 0 &&
+          codec_context_->codec_id == AV_CODEC_ID_VORBIS) {
+        // If we are dropping samples for Vorbis, it always means the timeline
+        // starts at 0.
         output_timestamp_helper_->SetBaseTimestamp(base::TimeDelta());

[acolwell GONE FROM CHROMIUM, 2014/04/17 21:11:24]

Can we move this up into DecodeBuffer() next to the code that sets
output_frames_to_drop_? It seems like that would be cleaner by setting all the
state up in one place.

[DaleCurtis, 2014/04/17 21:42:49]

Done.

       } else {
         output_timestamp_helper_->SetBaseTimestamp(buffer->timestamp());
       }
     }
 
     scoped_refptr<AudioBuffer> output;
     int decoded_frames = 0;
     int original_frames = 0;
     int channels = DetermineChannels(av_frame_.get());
     if (frame_decoded) {
@@ skipping 113 matching lines @@
   if (codec_context_->channels !=
       ChannelLayoutToChannelCount(config_.channel_layout())) {
     DLOG(ERROR) << "Audio configuration specified "
                 << ChannelLayoutToChannelCount(config_.channel_layout())
                 << " channels, but FFmpeg thinks the file contains "
                 << codec_context_->channels << " channels";
     ReleaseFFmpegResources();
     state_ = kUninitialized;
     return false;
   }
+
+  output_frames_to_drop_ = config_.codec_delay();
   return true;
 }
 
 void FFmpegAudioDecoder::ResetTimestampState() {
   output_timestamp_helper_->SetBaseTimestamp(kNoTimestamp());
   last_input_timestamp_ = kNoTimestamp();
   output_frames_to_drop_ = 0;
 }
 
 }  // namespace media