D-Modem/pjproject-2.11.1/pjmedia/include/pjmedia/wave.h
2021-10-29 14:41:03 -04:00

184 lines
4.7 KiB
C

/* $Id$ */
/*
* Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)
* Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef __PJMEDIA_WAVE_H__
#define __PJMEDIA_WAVE_H__
/**
* @file wave.h
* @brief WAVE file manipulation.
*/
#include <pjmedia/types.h>
/**
* @defgroup PJMEDIA_FILE_FORMAT File Formats
* @brief Supported file formats
*/
/**
* @defgroup PJMEDIA_WAVE WAVE Header
* @ingroup PJMEDIA_FILE_FORMAT
* @brief Representation of RIFF/WAVE file format
* @{
*
* This the the low level representation of RIFF/WAVE file format. For
* higher abstraction, please see \ref PJMEDIA_FILE_PLAY and
* \ref PJMEDIA_FILE_REC.
*/
PJ_BEGIN_DECL
/**
* Standard RIFF tag to identify RIFF file format in the WAVE header.
*/
#define PJMEDIA_RIFF_TAG ('F'<<24|'F'<<16|'I'<<8|'R')
/**
* Standard WAVE tag to identify WAVE header.
*/
#define PJMEDIA_WAVE_TAG ('E'<<24|'V'<<16|'A'<<8|'W')
/**
* Standard FMT tag to identify format chunks.
*/
#define PJMEDIA_FMT_TAG (' '<<24|'t'<<16|'m'<<8|'f')
/**
* Standard DATA tag to identify data chunks.
*/
#define PJMEDIA_DATA_TAG ('a'<<24|'t'<<16|'a'<<8|'d')
/**
* Standard FACT tag to identify fact chunks.
*/
#define PJMEDIA_FACT_TAG ('t'<<24|'c'<<16|'a'<<8|'f')
/**
* Enumeration of format compression tag.
*/
typedef enum {
PJMEDIA_WAVE_FMT_TAG_PCM = 1,
PJMEDIA_WAVE_FMT_TAG_ALAW = 6,
PJMEDIA_WAVE_FMT_TAG_ULAW = 7
} pjmedia_wave_fmt_tag;
/**
* This file describes the simpler/canonical version of a WAVE file.
* It does not support the full RIFF format specification.
*/
#pragma pack(2)
struct pjmedia_wave_hdr
{
/** This structure describes RIFF WAVE file header */
struct {
pj_uint32_t riff; /**< "RIFF" ASCII tag. */
pj_uint32_t file_len; /**< File length minus 8 bytes */
pj_uint32_t wave; /**< "WAVE" ASCII tag. */
} riff_hdr;
/** This structure describes format chunks/header */
struct {
pj_uint32_t fmt; /**< "fmt " ASCII tag. */
pj_uint32_t len; /**< 16 for PCM. */
pj_uint16_t fmt_tag; /**< 1 for PCM */
pj_uint16_t nchan; /**< Number of channels. */
pj_uint32_t sample_rate; /**< Sampling rate. */
pj_uint32_t bytes_per_sec; /**< Average bytes per second. */
pj_uint16_t block_align; /**< nchannels * bits / 8 */
pj_uint16_t bits_per_sample; /**< Bits per sample. */
} fmt_hdr;
/** The data header preceeds the actual data in the file. */
struct {
pj_uint32_t data; /**< "data" ASCII tag. */
pj_uint32_t len; /**< Data length. */
} data_hdr;
};
#pragma pack()
/**
* @see pjmedia_wave_hdr
*/
typedef struct pjmedia_wave_hdr pjmedia_wave_hdr;
/**
* This structure describes generic RIFF subchunk header.
*/
typedef struct pjmedia_wave_subchunk
{
pj_uint32_t id; /**< Subchunk ASCII tag. */
pj_uint32_t len; /**< Length following this field */
} pjmedia_wave_subchunk;
/**
* Normalize subchunk header from little endian (the representation of
* RIFF file) into host's endian.
*/
#if defined(PJ_IS_BIG_ENDIAN) && PJ_IS_BIG_ENDIAN!=0
# define PJMEDIA_WAVE_NORMALIZE_SUBCHUNK(ch) \
do { \
(ch)->id = pj_swap32((ch)->id); \
(ch)->len = pj_swap32((ch)->len); \
} while (0)
#else
# define PJMEDIA_WAVE_NORMALIZE_SUBCHUNK(ch)
#endif
/**
* On big-endian hosts, this function swaps the byte order of the values
* in the WAVE header fields. On little-endian hosts, this function does
* nothing.
*
* Application SHOULD call this function after reading the WAVE header
* chunks from a file.
*
* @param hdr The WAVE header.
*/
PJ_DECL(void) pjmedia_wave_hdr_file_to_host( pjmedia_wave_hdr *hdr );
/**
* On big-endian hosts, this function swaps the byte order of the values
* in the WAVE header fields. On little-endian hosts, this function does
* nothing.
*
* Application SHOULD call this function before writing the WAVE header
* to a file.
*
* @param hdr The WAVE header.
*/
PJ_DECL(void) pjmedia_wave_hdr_host_to_file( pjmedia_wave_hdr *hdr );
PJ_END_DECL
/**
* @}
*/
#endif /* __PJMEDIA_WAVE_H__ */