2012-01-31

Linux环境下用c语言写的播放wav文件的小程序 (2009-12-31 11:32)转载

分类： 音频专题

#include
#include
#include
#include
#include
#include
#include
/* 下面的三个参数是跟具体文件相关的，文件什么样，就要设置成什么样 */

#define RATE 11025   
#define SIZE 16     
#define CHANNELS 2  // 1表示单声道，2为立体声
/* ................ */
unsigned char buf[RATE*SIZE/8]; //buf里面正好放一秒钟的音频，下面的计时还要用

int main()
{
    int fd; 
    int wavfd; //wav文件的描述符

    int arg;        /* ..ioctl..... */
    int status;   /* ........ */
                /* ...... */
    fd = open("/dev/dsp", O_RDWR);      

    if (fd < 0) {
        printf("open of /dev/dsp failed");
        exit(1);
}
    wavfd = open("a.wav",O_RDONLY);//有的系统只允许O_RDONLY,O_WRONLY
    if (wavfd < 0) {
        printf("open of wav failed");
        exit(1);
  }
 

/* .......... */
    arg = SIZE;
    status = ioctl(fd, SOUND_PCM_WRITE_BITS, &arg);
    if (status == -1)
         perror("SOUND_PCM_WRITE_BITS ioctl failed");
    if (arg != SIZE)
         perror("unable to set sample size");
 

/* .......... */
    arg = CHANNELS;
    status = ioctl(fd, SOUND_PCM_WRITE_CHANNELS, &arg);
    if (status == -1)
        perror("SOUND_PCM_WRITE_CHANNELS ioctl failed");
    if (arg != CHANNELS)
        perror("unable to set number of channels");
 

/* .......... */
     arg = RATE;
         status = ioctl(fd, SOUND_PCM_WRITE_RATE, &arg);
     if (status == -1)
         perror("SOUND_PCM_WRITE_WRITE ioctl failed");
 

    /* 从wav文件中读buf大小的内容，然后写入/etc/dsp中，直到文件结束 */

     int time = 0; //动态显示播放时间用

 

     while (status = read(wavfd, buf, sizeof(buf)) > 0) {
         write(fd, buf, sizeof(buf));
         printf("%ds, enjoy ...\n",time++); 

 

          /* 以下三句，用于在更改播放文件的参数时，播放掉缓冲区内的内容，可以用，更保险*/    

         status = ioctl(fd, SOUND_PCM_SYNC, 0);

           if (status == -1)
               perror("SOUND_PCM_SYNC ioctl failed");
                 

        }
}