dsp音频播放程序 playsound

/* Linux
* --Mao
*
* 播放音频文件要用ioctl函数设置使播放参数与音频文件相同
* 设置声卡采样频率 arg = 16; ioctl(handler,SOUND_PCM_WRITE_BITS,&arg);
*
*
*
*/

#include <stdio.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <unistd.h>
#include <linux/soundcard.h>

#define Audio_Device "/dev/dsp"

    /*
    不同的声音有不同的播放参数，这些参数可以使用file命令获得
    */

#define Sample_Size 16
#define Sample_Rate 44100

int play_sound(char *filename)
{
    struct stat stat_buf;
    unsigned char *buf = NULL;
    int handler,fd;
    int result;
    int arg,status;
    //打开声音文件，将文件读入内存
    fd = open(filename,O_RDONLY);
    if(fd < 0)
        return -1;
    if(fstat(fd,&stat_buf))
    {
        close(fd);
        return -1;
    }
    if(!stat_buf.st_size)
    {
        close(fd);
        return -1;
    }

    buf = malloc(stat_buf.st_size);
    if(!buf)
    {
        close(fd);
        return -1;
    }
    if(read(fd,buf,stat_buf.st_size) < 0)
    {
        free(buf);
        close(fd);
        return -1;
    }

    /*
    打开声卡设备，并设置声卡播放参数，这些参数必须与声音文件参数一致
    */

    handler = open(Audio_Device,O_WRONLY);
    if(handler == -1)
    {
        perror("Cannot open the Audio_Device");
        return -1;
    }

    arg = Sample_Rate;
    status = ioctl(handler,SOUND_PCM_WRITE_RATE,&arg);
    if(status == -1)
    {
        perror("error from SOUND_PCM_WRITE_RATE ioctl");
        return -1;
    }

    arg = Sample_Size;
    status = ioctl(handler,SOUND_PCM_WRITE_BITS,&arg);
    if(status == -1)
    {
        perror("error from SOUND_PCM_WRITE_BITS ioctl");
        return -1;
    }

    result = write(handler,buf,stat_buf.st_size);
    if(result == -1)
    {
        perror("Fail to play the sound");
        return -1;
    }
    free(buf);
    close(fd);
    close(handler);
    return result;
}

void main(void)
{
    play_sound("windowXp.wav");
}