PCM文件播放器

1. 测试环境

  OK210开发板
  测试方式：./pcmplayer  test.pcm

2. 源代码

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

#define LENGTH 1 /* 存储秒数 */
#define RATE 16000 /* 采样频率 */
#define SIZE 8 /* 量化位数 */
#define CHANNELS 1 /* 声道数目 */
#define RSIZE 8 /*buf的大小 */



void dspInit(int fd,int rate,int sample_size , int sample_channel);
int rdOpen();
int wrOpen();
int pcmPlay(const char * pcmfilename);


int main(int argc, char *argv[])
{
    char * filepath;

    if(argc != 2)
    {
 printf("Usage: ./pcmplayer [your file'path]\n");
 printf("Example: ./pcmplayer test.pcm\n");
 return 0;
    }

    filepath =  argv[1];

    printf("filepath=%s\n",filepath);
    pcmPlay(filepath);

    return 0;
}


void dspInit(int fd,int rate,int sample_size , int sample_channel)
{
    /* 设置采样时的量化位数 */
    int arg;                        /* 用于ioctl调用的参数 */
    int status;                     /* 系统调用的返回值 */

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

    /* 设置采样时的声道数目 */
    arg = sample_channel;
    status = ioctl(fd, SOUND_PCM_WRITE_CHANNELS, &arg);
    if (status == -1)
        perror("SOUND_PCM_WRITE_CHANNELS ioctl failed");
    if (arg != sample_channel)
        perror("unable to set number of channels");
    /* 设置采样时的采样频率 */
    arg = rate;
    status = ioctl(fd, SOUND_PCM_WRITE_RATE, &arg);
    if (status == -1)
        perror("SOUND_PCM_WRITE_WRITE ioctl failed");
    status = ioctl(fd, SOUND_PCM_SYNC, 0);
    if (status == -1)
        perror("SOUND_PCM_SYNC ioctl failed");
}

int rdOpen()
{
    int fd;
    fd = open("/dev/dsp", O_RDONLY);
    if (fd < 0)
    {
      perror("open of /dev/dsp failed");
      return -1;
    }
    printf("[rdOpen]fd_dsprd =%d\n",fd);
    dspInit(fd ,RATE, (SIZE*2) , CHANNELS);
    return fd;
}

int wrOpen()
{
    int fd;
    fd = open("/dev/dsp", O_WRONLY);
    if (fd < 0)
    {
        perror("[write]open of /dev/dsp failed");
        return -1;
    }
    printf("[wrOpen]fd_dspwr =%d\n",fd);
    dspInit(fd ,(RATE/2), (SIZE*2) , CHANNELS);
    return fd;
}


int pcmPlay(const char * pcmfilename)
{
    int fd_f;
    unsigned int i ;
    unsigned char buf[RSIZE];
    unsigned long filesize = -1;
    int     fDspwr;
    struct stat statbuff;

    if(NULL == pcmfilename)return -1;

    printf("pcmfilename=%s\n",pcmfilename);
    if(stat(pcmfilename, &statbuff) < 0){
        printf("Get pcmfilesize failed,please check!\n");
        return -1;
    }else{
        filesize = statbuff.st_size;
    }

    if((fDspwr = wrOpen()) < 0)return -1;

    printf("PlayPCM...filesize=%ld\n",filesize);

    if(( fd_f = open(pcmfilename, O_RDONLY,0777))==-1)
    {
        perror("cannot open the sound file");
        return -1;
    }
    lseek(fd_f,0,SEEK_SET);
    for(i=0;i<(filesize)/RSIZE;i++)
    {
     if (read(fd_f, buf, sizeof(buf)) != sizeof(buf))
        perror("pcmfile read wrong number of bytes");
     if (write(fDspwr, buf, sizeof(buf)) != sizeof(buf))
        perror("pcm write wrong number of bytes");
    }
    close(fd_f);
    ioctl(fDspwr, SOUND_PCM_SYNC, 0);

    close(fDspwr);
    return 0;
}