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 // 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_