DSP

linux下声音的录制与播放 /dev/dsp

2019-07-13 10:22发布

#include
#include
#include
#include
#include
#include
#include
#define LENGTH 3    /* 存储秒数 */
#define RATE 8000   /* 采样频率 */
#define SIZE 8      /* 量化位数 */
#define CHANNELS 1  /* 声道数目 */
/* 用于保存数字音频数据的内存缓冲区 */
unsigned char buf[LENGTH*RATE*SIZE*CHANNELS/8];
int main()
{
  int fd; /* 声音设备的文件描述符 */
  int arg; /* 用于ioctl调用的参数 */
  int status;   /* 系统调用的返回值 */
  /* 打开声音设备 */
  fd = open("/dev/dsp", O_RDWR);
  if (fd < 0) {
    perror("open of /dev/dsp failed");
    exit(1);
  }
  /* 设置采样时的量化位数 */
  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");
  /* 设置采样时的声道数目 */
  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");
  /* 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");
  /* 循环,直到按下Control-C */
  while (1) {
    printf("Say something: ");
    status = read(fd, buf, sizeof(buf)); /* 录音 */
    if (status != sizeof(buf))
      perror("read wrong number of bytes");
    printf("You said: ");
    status = write(fd, buf, sizeof(buf)); /* 回放 */
    if (status != sizeof(buf))
      perror("wrote wrong number of bytes");
    /* 在继续录音前等待回放结束 */
    status = ioctl(fd, SOUND_PCM_SYNC, 0);
    if (status == -1)
      perror("SOUND_PCM_SYNC ioctl failed");
  }
}
还有其余的这种一边录制一边播放等各种版本,欢迎留言进行交流。。。