Support Opus Ambisonics playback

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 45 matching lines @@
   bool IsValidConfig() const;
 
   // Returns true if all fields in |config| match this config.
   // Note: The contents of |extra_data_| are compared not the raw pointers.
   bool Matches(const AudioDecoderConfig& config) const;
 
   // Returns a human-readable string describing |*this|.  For debugging & test
   // output only.
   std::string AsHumanReadableString() const;
 
+  void set_channels_for_discrete(int channels) {

[DaleCurtis, 2017/03/20 17:38:58]

Should be SetChannelsForDiscrete(), since hacker_style() is only allowed for
simple (single-value, no dcheck) setters.

[flim-chromium, 2017/03/22 06:20:50]

Done.

+    DCHECK(channel_layout_ == CHANNEL_LAYOUT_DISCRETE ||
+           channels == ChannelLayoutToChannelCount(channel_layout_));
+    channels_ = channels;
+    bytes_per_frame_= channels_ * bytes_per_channel_;
+  }
+
   AudioCodec codec() const { return codec_; }
   int bits_per_channel() const { return bytes_per_channel_ * 8; }
   int bytes_per_channel() const { return bytes_per_channel_; }
   ChannelLayout channel_layout() const { return channel_layout_; }
+  int channels() const { return channels_; }
   int samples_per_second() const { return samples_per_second_; }
   SampleFormat sample_format() const { return sample_format_; }
   int bytes_per_frame() const { return bytes_per_frame_; }
   base::TimeDelta seek_preroll() const { return seek_preroll_; }
   int codec_delay() const { return codec_delay_; }
 
   // 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 encryption_scheme_.is_encrypted(); }
 
   // Encryption scheme used for encrypted buffers.
   const EncryptionScheme& encryption_scheme() const {
     return encryption_scheme_;
   }
 
  private:
   AudioCodec codec_;
   SampleFormat sample_format_;
   int bytes_per_channel_;
   ChannelLayout channel_layout_;
+  int channels_;
   int samples_per_second_;
   int bytes_per_frame_;
   std::vector<uint8_t> extra_data_;
   EncryptionScheme encryption_scheme_;
 
   // |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_