作者: hotfire [文章出自: www.phpx.com]
以下假设你对ioctl已有一定的认识及了解
sndtools.h
代码:
#ifndef SNDTOOLS_H
#define SNDTOOLS_H
#include <linux/soundcard.h>
#define FMT8BITSAFMT_S8_LE
#define FMT16BITSAFMT_S16_LE
#define FMT8K8000
#define FMT16K16000
#define FMT22K22000
#define FMT44K44000
#define MONO1
#define STERO2
#ifndef VAR_STATIC
extern int devfd;
extern int CapMask;
#endif //ifndef VAR_STATIC
//Open sound device, return 1 if open success
//else return 0
int OpenSnd();
//Close sound device
int CloseSnd();
//Set record or playback format, return 1 if success
//else return 0
int SetFormat(int bits, int hz);
//Set record or playback channel, return 1 if success
//else return 1
int SetChannel(int chn);
//Record
int Record(char *buf, int size);
//Playback
int Play(char *buf, int size);
#endif //ifndef SNDTOOLS_H
sndtools.c
代码:
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <string.h>
#define VAR_STATIC
#include "sndtools.h"
int devfd = 0;
/*
* Open Sound device
* Return 1 if success, else return 0.
*/
int OpenSnd(/* add by new version */int nWhich)
{
if(devfd > 0)
close(devfd);
devfd = open("/dev/dsp", O_RDWR);
if(devfd < 0)
return 0;
return 1;
}
/*
* Close Sound device
* return 1 if success, else return 0.
*/
int CloseSnd(/* add by new version */int nWhich)
{
close(devfd);
devfd = 0;
return 1;
}
/*
* Set Record an Playback format
* return 1 if success, else return 0.
* bits -- FMT8BITS(8bits), FMT16BITS(16bits)
* hz -- FMT8K(8000HZ), FMT16K(16000HZ), FMT22K(22000HZ), FMT44K(44000HZ)
*/
int SetFormat(int bits, int hz)
{
int tmp = bits;
if( -1 == ioctl(devfd, SNDCTL_DSP_SETFMT, &tmp))
{
#ifdef DEBUG_WARN
printf("Set fmt to s16_little faile:%d\\n", nWhich);
#endif
return 0;
}
tmp = hz;
if( -1 == ioctl(devfd, SNDCTL_DSP_SPEED, &tmp))
{
#ifdef DEBUG_WARN
printf("Set speed to %d:%d\\n", hz, nWhich);
#endif
return 0;
}
return 1;
}
/*
* Set Sound Card Channel
* return 1 if success, else return 0.
* chn -- MONO, STERO
*/
int SetChannel(int chn)
{
int tmp = chn;
if(-1 == ioctl(devfd, SNDCTL_DSP_CHANNELS, &tmp))
{
#ifdef DEBUG_WARN
printf("Set Audio Channel faile:%d\\n", nWhich);
#endif
return 0;
}
return 1;
}
/*
* Record
* return numbers of byte for read.
*/
int Record(char *buf, int size)
{
return read(devfd, buf, size);
}
/*
* Playback
* return numbers of byte for write.
*/
int Play(char *buf, int size)
{
return write(devfd, buf, size);
}
test.c
代码:
// A sample to test record and playback.
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "sndtools.h"
int main()
{
char *buf;
int dwSize;
if(!OpenSnd())
{
printf("Open sound device error!\\n");
exit(-1);
}
SetFormat(FMT16BITS, FMT8K, WAVOUTDEV);
SetChannel(MONO, WAVOUTDEV);
buf = (char *)malloc(320);
if(buf == NULL)
exit(-1);
for(int i = 0; i <1000; i++)
{
dwSize = Record(buf, 640);
dwSize = Play(buf, dwSize);
}
exit 1;
}