sndtools.c

实现在s3c2440平台上进行音频采集与回放

#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <string.h>
#define VAR_STATIC
int devfd = 0;
#include "sndtools.h"
/*

 * 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);
}