Add MediaCodecAudioDecoder implementation

media/base/audio_decoder_config.h

 // 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.
 
 #ifndef MEDIA_BASE_AUDIO_DECODER_CONFIG_H_
 #define MEDIA_BASE_AUDIO_DECODER_CONFIG_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 93 matching lines @@
 
   // Optional byte data required to initialize audio decoders such as Vorbis
   // codebooks.
   const std::vector<uint8_t>& extra_data() const { return extra_data_; }
 
   // Whether the audio stream is potentially encrypted.
   // Note that in a potentially encrypted audio stream, individual buffers
   // can be encrypted or not encrypted.
   bool is_encrypted() const { return is_encrypted_; }
 
+  // Modifies sampling rate. Used by decoders based on Android MediaCodec.

[DaleCurtis, 2016/02/04 23:15:31]

We don't have setters for any other values; if possible we should avoid
introducing one just for sample rate. Can you just create a new config instead?

Also for audio we don't support unexpected sample rate changes (i.e. sample rate
changes are not supported with src=, only with MSE where a Flush and reconfigure
occur), so you might be able to simplify some code here.

[Tima Vaisburd, 2016/02/11 20:23:22]

Changed the code not to support sample rate changes on the fly. Thus the method
set_samples_per_second() is also gone. Will the pipeline destroy and recreate
the decoder in case of MSE sample rate change?

+  void set_samples_per_second(int value) { samples_per_second_ = value; }
+
  private:
   AudioCodec codec_;
   SampleFormat sample_format_;
   int bytes_per_channel_;
   ChannelLayout channel_layout_;
   int samples_per_second_;
   int bytes_per_frame_;
   std::vector<uint8_t> extra_data_;
   bool is_encrypted_;
 
   // |seek_preroll_| is the duration of the data that the decoder must decode
   // before the decoded data is valid.
   base::TimeDelta seek_preroll_;
 
   // |codec_delay_| is the number of frames the decoder should discard before
   // returning decoded data.  This value can include both decoder delay as well
   // as padding added during encoding.
   int codec_delay_;
 
   // Not using DISALLOW_COPY_AND_ASSIGN here intentionally to allow the compiler
   // generated copy constructor and assignment operator. Since the extra data is
   // typically small, the performance impact is minimal.
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_AUDIO_DECODER_CONFIG_H_