1 /* 2 * Copyright (c) 2014 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #ifndef WEBRTC_COMMON_AUDIO_WAV_HEADER_H_ 12 #define WEBRTC_COMMON_AUDIO_WAV_HEADER_H_ 13 14 #include <stddef.h> 15 #include <stdint.h> 16 17 namespace webrtc { 18 19 static const size_t kWavHeaderSize = 44; 20 21 class ReadableWav { 22 public: 23 // Returns the number of bytes read. 24 size_t virtual Read(void* buf, size_t num_bytes) = 0; 25 virtual ~ReadableWav() {} 26 }; 27 28 enum WavFormat { 29 kWavFormatPcm = 1, // PCM, each sample of size bytes_per_sample 30 kWavFormatALaw = 6, // 8-bit ITU-T G.711 A-law 31 kWavFormatMuLaw = 7, // 8-bit ITU-T G.711 mu-law 32 }; 33 34 // Return true if the given parameters will make a well-formed WAV header. 35 bool CheckWavParameters(size_t num_channels, 36 int sample_rate, 37 WavFormat format, 38 size_t bytes_per_sample, 39 size_t num_samples); 40 41 // Write a kWavHeaderSize bytes long WAV header to buf. The payload that 42 // follows the header is supposed to have the specified number of interleaved 43 // channels and contain the specified total number of samples of the specified 44 // type. CHECKs the input parameters for validity. 45 void WriteWavHeader(uint8_t* buf, 46 size_t num_channels, 47 int sample_rate, 48 WavFormat format, 49 size_t bytes_per_sample, 50 size_t num_samples); 51 52 // Read a WAV header from an implemented ReadableWav and parse the values into 53 // the provided output parameters. ReadableWav is used because the header can 54 // be variably sized. Returns false if the header is invalid. 55 bool ReadWavHeader(ReadableWav* readable, 56 size_t* num_channels, 57 int* sample_rate, 58 WavFormat* format, 59 size_t* bytes_per_sample, 60 size_t* num_samples); 61 62 } // namespace webrtc 63 64 #endif // WEBRTC_COMMON_AUDIO_WAV_HEADER_H_ 65
