arm ubunutu下调用alsa声卡播放音频文件

这几天做linux下讯飞语音识别，用来播放，下篇讲解下怎么配科大讯飞

一，一般缺少一个库：

apt-get install libasound2-dev

二，链接到cmakelists下

最重要的代码：

#include //根据自己机器中的路径修改
#include 
#include 
#include 
#include 

//#include"tts-sample.h"
int play_sound(char *filename)
{
  long loops;
  int rc;
  int size;
  snd_pcm_t *handle;
  snd_pcm_hw_params_t *params;
  unsigned int val;
  int dir;
  snd_pcm_uframes_t frames;
  printf("222133\n");
 char buffer[20*2];/*size=frame*channles*byte persaple*/
 int fd,i;



if ( ( fd = open (filename,O_RDONLY))<0)
{
fprintf ( stderr, " Can't open sound file!\n");
exit (-1 );
}
  /* Open PCM device for playback. */
  rc = snd_pcm_open(&handle, "default",
                    SND_PCM_STREAM_PLAYBACK, 0);
  if (rc < 0) {
    fprintf(stderr,
            "unable to open pcm device: %s\n",
            snd_strerror(rc));
    exit(1);
  }




  /* Allocate a hardware parameters object. */
  snd_pcm_hw_params_alloca(¶ms);


  /* Fill it in with default values. */
  snd_pcm_hw_params_any(handle, params);


  /* Set the desired hardware parameters. */


  /* Interleaved mode */
  snd_pcm_hw_params_set_access(handle, params,
                      SND_PCM_ACCESS_RW_INTERLEAVED);


  /* Signed 16-bit little-endian format */
  snd_pcm_hw_params_set_format(handle, params,
                              SND_PCM_FORMAT_S16_LE);


  /* Two channels (stereo) */
  snd_pcm_hw_params_set_channels(handle, params, 1);


  /* 44100 bits/second sampling rate (CD quality) */
  val = 16000;
  snd_pcm_hw_params_set_rate_near(handle, params,
                                  &val, &dir);


  /* Set period size to 32 frames. */
  frames =20;/*一次送人的帧太少，会下溢冲（至少15帧)*/
 // snd_pcm_hw_params_set_period_size_near(handle,  params, &frames, &dir);


  /* Write the parameters to the driver */
  rc = snd_pcm_hw_params(handle, params);
  if (rc < 0) {
    fprintf(stderr,
            "unable to set hw parameters: %s\n",
            snd_strerror(rc));
    exit(1);
  }


  /* Use a buffer large enough to hold one period */
 
 // snd_pcm_hw_params_get_period_size(params, &frames,&dir);
  //size = frames * 4; /* 2 bytes/sample, 2 channels */
 // buffer = (char *) malloc(size);


long s=0;
 i =0;
  while(i = read(fd,buffer, sizeof(buffer))>0)
  {
  //s+=i;
  //printf("s=%ld\n",s);
    #if 0
    rc = read(0, buffer, size);
    if (rc == 0) {
      fprintf(stderr, "end of file on input\n");
      break;
    } else if (rc != size) {
      fprintf(stderr,
              "short read: read %d bytes\n", rc);
    }
#endif
     rc = snd_pcm_writei(handle, buffer, frames);
    if (rc==frames*2)
    {
     printf("read data oK\n");
    }
    if (rc == -EPIPE) {
      /* EPIPE means underrun */
      fprintf(stderr, "underrun occurred\n");
      snd_pcm_prepare(handle);
    } else if (rc < 0) {
      fprintf(stderr,
              "error from writei: %s\n",
              snd_strerror(rc));
    }  else if (rc != (int)frames) {
      fprintf(stderr,
              "short write, write %d frames\n", rc);
    }
  }
  snd_pcm_drain(handle);
  snd_pcm_close(handle);
  printf("play end \n");
//  free(buffer);
  close(fd);
  return 0;
}