Merge M50: "Fix audio glitch issue introduced by security fix for format changes."

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 <stdint.h>
 
 #include "base/callback_helpers.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 282 matching lines @@
     packet.data += result;
 
     scoped_refptr<AudioBuffer> output;
 
     bool config_changed = false;
     if (frame_decoded) {
       const int channels = DetermineChannels(av_frame_.get());
       ChannelLayout channel_layout = ChannelLayoutToChromeChannelLayout(
           codec_context_->channel_layout, codec_context_->channels);
 
+      bool is_sample_rate_change =
+          av_frame_->sample_rate != config_.samples_per_second();
       bool is_config_stale =
-          av_frame_->sample_rate != config_.samples_per_second() ||
+          is_sample_rate_change ||
           channels != ChannelLayoutToChannelCount(config_.channel_layout()) ||
           av_frame_->format != av_sample_format_;
 
       // Only consider channel layout changes for AAC.
       // TODO(tguilbert, dalecurtis): Due to http://crbug.com/600538 we need to
       // allow channel layout changes for the moment. See if ffmpeg is fixable.
       if (config_.codec() == kCodecAAC)
         is_config_stale |= channel_layout != config_.channel_layout();
 
       if (is_config_stale) {
         // Only allow midstream configuration changes for AAC. Sample format is
         // not expected to change between AAC profiles.
         if (config_.codec() == kCodecAAC &&
             av_frame_->format == av_sample_format_) {
           MEDIA_LOG(DEBUG, media_log_)
               << " Detected AAC midstream configuration change"
               << " PTS:" << buffer->timestamp().InMicroseconds()
               << " Sample Rate: " << av_frame_->sample_rate << " vs "
               << config_.samples_per_second()
               << ", ChannelLayout: " << channel_layout << " vs "
               << config_.channel_layout() << ", Channels: " << channels
               << " vs "
               << ChannelLayoutToChannelCount(config_.channel_layout());
           config_.Initialize(config_.codec(), config_.sample_format(),
                              channel_layout, av_frame_->sample_rate,
                              config_.extra_data(), config_.is_encrypted(),
                              config_.seek_preroll(), config_.codec_delay());
           config_changed = true;
-          if (av_frame_->sample_rate != config_.samples_per_second())
+          if (is_sample_rate_change)
             ResetTimestampState();
         } else {
           MEDIA_LOG(ERROR, media_log_)
               << "Unsupported midstream configuration change!"
               << " Sample Rate: " << av_frame_->sample_rate << " vs "
               << config_.samples_per_second() << ", Channels: " << channels
               << " vs " << ChannelLayoutToChannelCount(config_.channel_layout())
               << ", Sample Format: " << av_frame_->format << " vs "
               << av_sample_format_;
           // This is an unrecoverable error, so bail out.
@@ skipping 85 matching lines @@
   return true;
 }
 
 void FFmpegAudioDecoder::ResetTimestampState() {
   discard_helper_.reset(new AudioDiscardHelper(config_.samples_per_second(),
                                                config_.codec_delay()));
   discard_helper_->Reset(config_.codec_delay());
 }
 
 }  // namespace media