playsound.c

一个linux 播放PCM数据程序

//gcc test2.c -O2 -I.. -L. ../libvo/aclib.c -lMP3 -lm -o test2

#include <stdio.h>
#include <stdlib.h>

#include <fcntl.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <sys/soundcard.h>

int audio_fd;
int r;
///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////

int playsound_init()
{
    printf( "playsound init\n" );

    audio_fd=open("/dev/dsp", O_WRONLY);
    if(audio_fd<0){  printf("Can't open audio device\n");exit(1); }

    //r=AFMT_S16_LE;
    r=AFMT_U8;
    ioctl (audio_fd, SNDCTL_DSP_SETFMT, &r);
    
    //r=MP3_channels-1;
    r = 0;
    ioctl (audio_fd, SNDCTL_DSP_STEREO, &r);
    
    r = 11025;
    ioctl (audio_fd, SNDCTL_DSP_SPEED, &r);
    
    return 1;
}

int playsound_close()
{
    printf( "playsound close\n" );
    close( audio_fd );
    return 1;
}

int playsound_play( char* buffer, int len )
{
    printf( "playsound play\n" );
    return write(audio_fd,buffer,len);
}