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 "base/time/time.h" 12 #include "media/base/channel_layout.h" 13 #include "media/base/media_export.h" 14 #include "media/base/sample_format.h" 15 16 namespace media { 17 18 enum AudioCodec { 19 // These values are histogrammed over time; do not change their ordinal 20 // values. When deleting a codec replace it with a dummy value; when adding a 21 // codec, do so at the bottom before kAudioCodecMax. 22 kUnknownAudioCodec = 0, 23 kCodecAAC, 24 kCodecMP3, 25 kCodecPCM, 26 kCodecVorbis, 27 kCodecFLAC, 28 kCodecAMR_NB, 29 kCodecAMR_WB, 30 kCodecPCM_MULAW, 31 kCodecGSM_MS, 32 kCodecPCM_S16BE, 33 kCodecPCM_S24BE, 34 kCodecOpus, 35 kCodecEAC3, 36 kCodecPCM_ALAW, 37 // DO NOT ADD RANDOM AUDIO CODECS! 38 // 39 // The only acceptable time to add a new codec is if there is production code 40 // that uses said codec in the same CL. 41 42 // Must always be last! 43 kAudioCodecMax 44 }; 45 46 // TODO(dalecurtis): FFmpeg API uses |bytes_per_channel| instead of 47 // |bits_per_channel|, we should switch over since bits are generally confusing 48 // to work with. 49 class MEDIA_EXPORT AudioDecoderConfig { 50 public: 51 // Constructs an uninitialized object. Clients should call Initialize() with 52 // appropriate values before using. 53 AudioDecoderConfig(); 54 55 // Constructs an initialized object. It is acceptable to pass in NULL for 56 // |extra_data|, otherwise the memory is copied. 57 AudioDecoderConfig(AudioCodec codec, SampleFormat sample_format, 58 ChannelLayout channel_layout, int samples_per_second, 59 const uint8* extra_data, size_t extra_data_size, 60 bool is_encrypted); 61 62 ~AudioDecoderConfig(); 63 64 // Resets the internal state of this object. 65 void Initialize(AudioCodec codec, SampleFormat sample_format, 66 ChannelLayout channel_layout, int samples_per_second, 67 const uint8* extra_data, size_t extra_data_size, 68 bool is_encrypted, bool record_stats, 69 base::TimeDelta seek_preroll, 70 base::TimeDelta codec_delay); 71 72 // Returns true if this object has appropriate configuration values, false 73 // otherwise. 74 bool IsValidConfig() const; 75 76 // Returns true if all fields in |config| match this config. 77 // Note: The contents of |extra_data_| are compared not the raw pointers. 78 bool Matches(const AudioDecoderConfig& config) const; 79 codec()80 AudioCodec codec() const { return codec_; } bits_per_channel()81 int bits_per_channel() const { return bytes_per_channel_ * 8; } bytes_per_channel()82 int bytes_per_channel() const { return bytes_per_channel_; } channel_layout()83 ChannelLayout channel_layout() const { return channel_layout_; } samples_per_second()84 int samples_per_second() const { return samples_per_second_; } sample_format()85 SampleFormat sample_format() const { return sample_format_; } bytes_per_frame()86 int bytes_per_frame() const { return bytes_per_frame_; } seek_preroll()87 base::TimeDelta seek_preroll() const { return seek_preroll_; } codec_delay()88 base::TimeDelta codec_delay() const { return codec_delay_; } 89 90 // Optional byte data required to initialize audio decoders such as Vorbis 91 // codebooks. extra_data()92 const uint8* extra_data() const { 93 return extra_data_.empty() ? NULL : &extra_data_[0]; 94 } extra_data_size()95 size_t extra_data_size() const { return extra_data_.size(); } 96 97 // Whether the audio stream is potentially encrypted. 98 // Note that in a potentially encrypted audio stream, individual buffers 99 // can be encrypted or not encrypted. is_encrypted()100 bool is_encrypted() const { return is_encrypted_; } 101 102 private: 103 AudioCodec codec_; 104 SampleFormat sample_format_; 105 int bytes_per_channel_; 106 ChannelLayout channel_layout_; 107 int samples_per_second_; 108 int bytes_per_frame_; 109 std::vector<uint8> extra_data_; 110 bool is_encrypted_; 111 112 // |seek_preroll_| is the duration of the data that the decoder must decode 113 // before the decoded data is valid. 114 base::TimeDelta seek_preroll_; 115 116 // |codec_delay_| is the overall delay overhead added by the codec while 117 // encoding. This value should be subtracted from each block's timestamp to 118 // get the actual timestamp. 119 base::TimeDelta codec_delay_; 120 121 // Not using DISALLOW_COPY_AND_ASSIGN here intentionally to allow the compiler 122 // generated copy constructor and assignment operator. Since the extra data is 123 // typically small, the performance impact is minimal. 124 }; 125 126 } // namespace media 127 128 #endif // MEDIA_BASE_AUDIO_DECODER_CONFIG_H_ 129