beep.c

   1 #include <stdio.h>
   2 #include <math.h>
   3
   4 #include <AL/al.h>
   5 #include <AL/alc.h>
   6
   7 #include <errno.h>
   8 #include <time.h>
   9 int msleep(long millisecs) {
  10         struct timespec req, rem;
  11         req.tv_sec = millisecs / 1000;
  12         req.tv_nsec = (millisecs % 1000) * 1000 * 1000;
  13         int ret;
  14         while((ret = nanosleep(&req, &rem)) == -1 && errno == EINTR) req = rem;
  15         return ret;
  16 }
  17
  18 int main() {
  19
  20         ALuint buffer;
  21         ALuint source;
  22         ALCdevice*  device;
  23         ALCcontext* context;
  24         int numsamples = 1000;
  25         int samplerate = 11025;
  26         unsigned char samples[numsamples];
  27         int i;
  28         for(i = 0; i < numsamples; i++) {
  29                 samples[i] = round(120*sin(i*(2*M_PI)/30.0)+128);
  30         }
  31         device = alcOpenDevice(NULL);
  32         context = alcCreateContext(device, NULL);
  33         alcMakeContextCurrent(context);
  34
  35         alGenBuffers(1, &buffer);
  36         alBufferData(buffer, AL_FORMAT_MONO8, samples, numsamples, samplerate);
  37         if (alGetError()) return 1;
  38
  39         alGenSources(1, &source);
  40
  41         alSourcef(source, AL_PITCH, 1.0);
  42         alSourcef(source, AL_GAIN, 1.0);
  43         alSourcei(source, AL_BUFFER, buffer);
  44         alSourcei(source, AL_LOOPING, AL_FALSE);
  45         alSourcei(source, AL_BUFFER, buffer);
  46         if (alGetError()) return 1;
  47
  48         alSourcePlay(source);
  49         if (alGetError()) return 1;
  50
  51         float delay = ((float)numsamples/(float)samplerate) * 1000.f;
  52
  53         msleep(((long)(delay))*2);
  54         ALint state;
  55         do {
  56                 msleep(1);
  57                 alGetSourcei(source, AL_SOURCE_STATE, &state);
  58         } while(alGetError()==AL_NO_ERROR && state==AL_PLAYING);
  59
  60         alSourceStop(source);
  61
  62         alDeleteSources(1, &source);
  63         alDeleteBuffers(1, &buffer);
  64
  65         alcMakeContextCurrent(NULL);
  66
  67         alcDestroyContext(context);
  68         alcCloseDevice(device);
  69
  70         return 0;
  71
  72 }