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      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef MEDIA_BASE_AUDIO_DECODER_CONFIG_H_
      6 #define MEDIA_BASE_AUDIO_DECODER_CONFIG_H_
      7 
      8 #include <vector>
      9 
     10 #include "base/basictypes.h"
     11 #include "media/base/channel_layout.h"
     12 #include "media/base/media_export.h"
     13 #include "media/base/sample_format.h"
     14 
     15 namespace media {
     16 
     17 enum AudioCodec {
     18   // These values are histogrammed over time; do not change their ordinal
     19   // values.  When deleting a codec replace it with a dummy value; when adding a
     20   // codec, do so at the bottom before kAudioCodecMax.
     21   kUnknownAudioCodec = 0,
     22   kCodecAAC,
     23   kCodecMP3,
     24   kCodecPCM,
     25   kCodecVorbis,
     26   kCodecFLAC,
     27   kCodecAMR_NB,
     28   kCodecAMR_WB,
     29   kCodecPCM_MULAW,
     30   kCodecGSM_MS,
     31   kCodecPCM_S16BE,
     32   kCodecPCM_S24BE,
     33   kCodecOpus,
     34   kCodecEAC3,
     35   // DO NOT ADD RANDOM AUDIO CODECS!
     36   //
     37   // The only acceptable time to add a new codec is if there is production code
     38   // that uses said codec in the same CL.
     39 
     40   // Must always be last!
     41   kAudioCodecMax
     42 };
     43 
     44 // TODO(dalecurtis): FFmpeg API uses |bytes_per_channel| instead of
     45 // |bits_per_channel|, we should switch over since bits are generally confusing
     46 // to work with.
     47 class MEDIA_EXPORT AudioDecoderConfig {
     48  public:
     49   // Constructs an uninitialized object. Clients should call Initialize() with
     50   // appropriate values before using.
     51   AudioDecoderConfig();
     52 
     53   // Constructs an initialized object. It is acceptable to pass in NULL for
     54   // |extra_data|, otherwise the memory is copied.
     55   AudioDecoderConfig(AudioCodec codec, SampleFormat sample_format,
     56                      ChannelLayout channel_layout, int samples_per_second,
     57                      const uint8* extra_data, size_t extra_data_size,
     58                      bool is_encrypted);
     59 
     60   ~AudioDecoderConfig();
     61 
     62   // Resets the internal state of this object.
     63   void Initialize(AudioCodec codec, SampleFormat sample_format,
     64                   ChannelLayout channel_layout, int samples_per_second,
     65                   const uint8* extra_data, size_t extra_data_size,
     66                   bool is_encrypted, bool record_stats);
     67 
     68   // Returns true if this object has appropriate configuration values, false
     69   // otherwise.
     70   bool IsValidConfig() const;
     71 
     72   // Returns true if all fields in |config| match this config.
     73   // Note: The contents of |extra_data_| are compared not the raw pointers.
     74   bool Matches(const AudioDecoderConfig& config) const;
     75 
     76   AudioCodec codec() const { return codec_; }
     77   int bits_per_channel() const { return bytes_per_channel_ * 8; }
     78   int bytes_per_channel() const { return bytes_per_channel_; }
     79   ChannelLayout channel_layout() const { return channel_layout_; }
     80   int samples_per_second() const { return samples_per_second_; }
     81   SampleFormat sample_format() const { return sample_format_; }
     82   int bytes_per_frame() const { return bytes_per_frame_; }
     83 
     84   // Optional byte data required to initialize audio decoders such as Vorbis
     85   // codebooks.
     86   const uint8* extra_data() const {
     87     return extra_data_.empty() ? NULL : &extra_data_[0];
     88   }
     89   size_t extra_data_size() const { return extra_data_.size(); }
     90 
     91   // Whether the audio stream is potentially encrypted.
     92   // Note that in a potentially encrypted audio stream, individual buffers
     93   // can be encrypted or not encrypted.
     94   bool is_encrypted() const { return is_encrypted_; }
     95 
     96  private:
     97   AudioCodec codec_;
     98   SampleFormat sample_format_;
     99   int bytes_per_channel_;
    100   ChannelLayout channel_layout_;
    101   int samples_per_second_;
    102   int bytes_per_frame_;
    103   std::vector<uint8> extra_data_;
    104   bool is_encrypted_;
    105 
    106   // Not using DISALLOW_COPY_AND_ASSIGN here intentionally to allow the compiler
    107   // generated copy constructor and assignment operator. Since the extra data is
    108   // typically small, the performance impact is minimal.
    109 };
    110 
    111 }  // namespace media
    112 
    113 #endif  // MEDIA_BASE_AUDIO_DECODER_CONFIG_H_
    114