Line data    Source code

       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           0 : class ReadableWav {
      22             :  public:
      23             :   // Returns the number of bytes read.
      24             :   size_t virtual Read(void* buf, size_t num_bytes) = 0;
      25           0 :   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_