Windows verwendet seine eigene und einzige Soundarchitektur, daher können Sie auf sound()
zugreifen Routine.
Verschiedene Linux-Rechner erfordern je nach installierten Paketen möglicherweise unterschiedliche Ansätze. Vielleicht das Dienstprogramm beep
(außerhalb dieser Frage zu Stackexchange) kann Sie in die richtige Richtung führen
Ich mag den obigen Tipp bezüglich libao - ich habe es gerade ausprobiert und es funktioniert gut. Hier ist ein ähnliches Maß an Komplexität, bei dem OpenAL verwendet wird, um einen Rohaudiopuffer im PCM-Format zu synthetisieren und dann als Audio zu rendern
// sudo apt-get install libopenal-dev
// gcc -o openal_play_monday openal_play_monday.c -lopenal -lm
#include <stdio.h>
#include <stdlib.h> // gives malloc
#include <math.h>
#ifdef __APPLE__
#include <OpenAL/al.h>
#include <OpenAL/alc.h>
#elif __linux
#include <AL/al.h>
#include <AL/alc.h>
#include <unistd.h>
#endif
ALCdevice * openal_output_device;
ALCcontext * openal_output_context;
ALuint internal_buffer;
ALuint streaming_source[1];
int al_check_error(const char * given_label) {
ALenum al_error;
al_error = alGetError();
if(AL_NO_ERROR != al_error) {
printf("ERROR - %s (%s)\n", alGetString(al_error), given_label);
return al_error;
}
return 0;
}
void MM_init_al() {
const char * defname = alcGetString(NULL, ALC_DEFAULT_DEVICE_SPECIFIER);
openal_output_device = alcOpenDevice(defname);
openal_output_context = alcCreateContext(openal_output_device, NULL);
alcMakeContextCurrent(openal_output_context);
// setup buffer and source
alGenBuffers(1, & internal_buffer);
al_check_error("failed call to alGenBuffers");
}
void MM_exit_al() {
ALenum errorCode = 0;
// Stop the sources
alSourceStopv(1, & streaming_source[0]); // streaming_source
int ii;
for (ii = 0; ii < 1; ++ii) {
alSourcei(streaming_source[ii], AL_BUFFER, 0);
}
// Clean-up
alDeleteSources(1, &streaming_source[0]);
alDeleteBuffers(16, &streaming_source[0]);
errorCode = alGetError();
alcMakeContextCurrent(NULL);
errorCode = alGetError();
alcDestroyContext(openal_output_context);
alcCloseDevice(openal_output_device);
}
void MM_render_one_buffer() {
/* Fill buffer with Sine-Wave */
// float freq = 440.f;
float freq = 100.f;
float incr_freq = 0.1f;
int seconds = 4;
// unsigned sample_rate = 22050;
unsigned sample_rate = 44100;
double my_pi = 3.14159;
size_t buf_size = seconds * sample_rate;
// allocate PCM audio buffer
short * samples = malloc(sizeof(short) * buf_size);
printf("\nhere is freq %f\n", freq);
int i=0;
for(; i<buf_size; ++i) {
samples[i] = 32760 * sin( (2.f * my_pi * freq)/sample_rate * i );
freq += incr_freq; // change freq just to make things interesting
if (100.0 > freq || freq > 5000.0) {
incr_freq *= -1.0f; // toggle direction of freq increment
}
}
/* upload buffer to OpenAL */
alBufferData( internal_buffer, AL_FORMAT_MONO16, samples, buf_size, sample_rate);
al_check_error("populating alBufferData");
free(samples);
/* Set-up sound source and play buffer */
// ALuint src = 0;
// alGenSources(1, &src);
// alSourcei(src, AL_BUFFER, internal_buffer);
alGenSources(1, & streaming_source[0]);
alSourcei(streaming_source[0], AL_BUFFER, internal_buffer);
// alSourcePlay(src);
alSourcePlay(streaming_source[0]);
// ---------------------
ALenum current_playing_state;
alGetSourcei(streaming_source[0], AL_SOURCE_STATE, & current_playing_state);
al_check_error("alGetSourcei AL_SOURCE_STATE");
while (AL_PLAYING == current_playing_state) {
printf("still playing ... so sleep\n");
sleep(1); // should use a thread sleep NOT sleep() for a more responsive finish
alGetSourcei(streaming_source[0], AL_SOURCE_STATE, & current_playing_state);
al_check_error("alGetSourcei AL_SOURCE_STATE");
}
printf("end of playing\n");
/* Dealloc OpenAL */
MM_exit_al();
} // MM_render_one_buffer
int main() {
MM_init_al();
MM_render_one_buffer();
}
Wenn Sie OpenAL weiterentwickeln möchten ... werfen Sie einen Blick darauf
https://github.com/scottstensland/render-audio-openal
Out of the Box spielt OpenAL einen Puffer von PCM-Audio ganz gut ab ... aber es lässt als Übung die Fähigkeit, einen Stream abzuspielen. In diesem Github-Repo habe ich einen Audioserver mit OpenAL geschrieben, der das Abspielen von Streaming-Audio implementiert ... viel Spaß