1 // Copyright 2013 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_AUDIO_SOUNDS_WAV_AUDIO_HANDLER_H_ 6 #define MEDIA_AUDIO_SOUNDS_WAV_AUDIO_HANDLER_H_ 7 8 #include "base/strings/string_piece.h" 9 #include "media/base/media_export.h" 10 11 namespace media { 12 13 class AudioBus; 14 15 // This class provides the input from wav file format. See 16 // https://ccrma.stanford.edu/courses/422/projects/WaveFormat/ 17 class MEDIA_EXPORT WavAudioHandler { 18 public: 19 explicit WavAudioHandler(const base::StringPiece& wav_data); 20 virtual ~WavAudioHandler(); 21 22 // Returns true when cursor points to the end of the track. 23 bool AtEnd(size_t cursor) const; 24 25 // Copies the audio data to |bus| starting from the |cursor| and in 26 // the case of success stores the number of written bytes in 27 // |bytes_written|. |bytes_written| should not be NULL. 28 bool CopyTo(AudioBus* bus, size_t cursor, size_t* bytes_written) const; 29 size()30 int size() const { return data_.size(); } num_channels()31 uint16 num_channels() const { return num_channels_; } sample_rate()32 uint32 sample_rate() const { return sample_rate_; } byte_rate()33 uint32 byte_rate() const { return byte_rate_; } bits_per_sample()34 uint16 bits_per_sample() const { return bits_per_sample_; } 35 36 private: 37 // Parses a chunk of wav format data. Returns the length of the chunk. 38 int ParseSubChunk(const base::StringPiece& data); 39 40 // Parses the 'fmt' section chunk and stores |params_|. 41 bool ParseFmtChunk(const base::StringPiece& data); 42 43 // Parses the 'data' section chunk and stores |data_|. 44 bool ParseDataChunk(const base::StringPiece& data); 45 46 // Data part of the |wav_data_|. 47 base::StringPiece data_; 48 49 uint16 num_channels_; 50 uint32 sample_rate_; 51 uint32 byte_rate_; 52 uint16 bits_per_sample_; 53 int bytes_per_sample_; 54 int bytes_per_frame_; 55 }; 56 57 } // namespace media 58 59 #endif // MEDIA_AUDIO_SOUNDS_WAV_AUDIO_HANDLER_H_ 60