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/*
* Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef WEBRTC_COMMON_AUDIO_WAV_HEADER_H_
#define WEBRTC_COMMON_AUDIO_WAV_HEADER_H_
#include <stddef.h>
#include <stdint.h>
namespace webrtc {
static const size_t kWavHeaderSize = 44;
class ReadableWav {
public:
// Returns the number of bytes read.
size_t virtual Read(void* buf, size_t num_bytes) = 0;
virtual ~ReadableWav() {}
};
enum WavFormat {
kWavFormatPcm = 1, // PCM, each sample of size bytes_per_sample
kWavFormatALaw = 6, // 8-bit ITU-T G.711 A-law
kWavFormatMuLaw = 7, // 8-bit ITU-T G.711 mu-law
};
// Return true if the given parameters will make a well-formed WAV header.
bool CheckWavParameters(int num_channels,
int sample_rate,
WavFormat format,
int bytes_per_sample,
uint32_t num_samples);
// Write a kWavHeaderSize bytes long WAV header to buf. The payload that
// follows the header is supposed to have the specified number of interleaved
// channels and contain the specified total number of samples of the specified
// type. CHECKs the input parameters for validity.
void WriteWavHeader(uint8_t* buf,
int num_channels,
int sample_rate,
WavFormat format,
int bytes_per_sample,
uint32_t num_samples);
// Read a WAV header from an implemented ReadableWav and parse the values into
// the provided output parameters. ReadableWav is used because the header can
// be variably sized. Returns false if the header is invalid.
bool ReadWavHeader(ReadableWav* readable,
int* num_channels,
int* sample_rate,
WavFormat* format,
int* bytes_per_sample,
uint32_t* num_samples);
} // namespace webrtc
#endif // WEBRTC_COMMON_AUDIO_WAV_HEADER_H_
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