diff -r 000000000000 -r 6474c204b198 content/media/fmp4/demuxer/audio_decoder_config.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/content/media/fmp4/demuxer/audio_decoder_config.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,127 @@
+// 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 <vector>
+
+#include "mp4_demuxer/basictypes.h"
+#include "mp4_demuxer/channel_layout.h"
+
+namespace mp4_demuxer {
+
+enum AudioCodec {
+  // These values are histogrammed over time; do not change their ordinal
+  // values.  When deleting a codec replace it with a dummy value; when adding a
+  // codec, do so at the bottom before kAudioCodecMax.
+  kUnknownAudioCodec = 0,
+  kCodecAAC,
+  kCodecMP3,
+  kCodecPCM,
+  kCodecVorbis,
+  kCodecFLAC,
+  kCodecAMR_NB,
+  kCodecAMR_WB,
+  kCodecPCM_MULAW,
+  kCodecGSM_MS,
+  kCodecPCM_S16BE,
+  kCodecPCM_S24BE,
+  kCodecOpus,
+  // DO NOT ADD RANDOM AUDIO CODECS!
+  //
+  // The only acceptable time to add a new codec is if there is production code
+  // that uses said codec in the same CL.
+
+  // Must always be last!
+  kAudioCodecMax
+};
+
+enum SampleFormat {
+  // These values are histogrammed over time; do not change their ordinal
+  // values.  When deleting a sample format replace it with a dummy value; when
+  // adding a sample format, do so at the bottom before kSampleFormatMax.
+  kUnknownSampleFormat = 0,
+  kSampleFormatU8,         // Unsigned 8-bit w/ bias of 128.
+  kSampleFormatS16,        // Signed 16-bit.
+  kSampleFormatS32,        // Signed 32-bit.
+  kSampleFormatF32,        // Float 32-bit.
+  kSampleFormatPlanarS16,  // Signed 16-bit planar.
+  kSampleFormatPlanarF32,  // Float 32-bit planar.
+
+  // Must always be last!
+  kSampleFormatMax
+};
+
+// TODO(dalecurtis): FFmpeg API uses |bytes_per_channel| instead of
+// |bits_per_channel|, we should switch over since bits are generally confusing
+// to work with.
+class AudioDecoderConfig {
+ public:
+  // Constructs an uninitialized object. Clients should call Initialize() with
+  // appropriate values before using.
+  AudioDecoderConfig();
+
+  // Constructs an initialized object. It is acceptable to pass in NULL for
+  // |extra_data|, otherwise the memory is copied.
+  AudioDecoderConfig(AudioCodec codec, SampleFormat sample_format,
+                     ChannelLayout channel_layout, int samples_per_second,
+                     const uint8_t* extra_data, size_t extra_data_size,
+                     bool is_encrypted);
+
+  ~AudioDecoderConfig();
+
+  // Resets the internal state of this object.
+  void Initialize(AudioCodec codec, SampleFormat sample_format,
+                  ChannelLayout channel_layout, int samples_per_second,
+                  const uint8_t* extra_data, size_t extra_data_size,
+                  bool is_encrypted);
+
+  // Returns true if this object has appropriate configuration values, false
+  // otherwise.
+  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;
+
+  AudioCodec codec() const { return codec_; }
+  int bits_per_channel() const { return bits_per_channel_; }
+  ChannelLayout channel_layout() const { return channel_layout_; }
+  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_; }
+
+  // Optional byte data required to initialize audio decoders such as Vorbis
+  // codebooks.
+  const uint8_t* extra_data() const {
+    return extra_data_.empty() ? NULL : &extra_data_[0];
+  }
+  size_t extra_data_size() const { return extra_data_.size(); }
+
+  // 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_; }
+
+  std::string AsHumanReadableString() const;
+
+ private:
+  AudioCodec codec_;
+  SampleFormat sample_format_;
+  int bits_per_channel_;
+  ChannelLayout channel_layout_;
+  int samples_per_second_;
+  int bytes_per_frame_;
+  std::vector<uint8_t> extra_data_;
+  bool is_encrypted_;
+
+  // 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 mp4_demuxer
+
+#endif  // MEDIA_BASE_AUDIO_DECODER_CONFIG_H_