feed.c

This example shows how to feed a stream with a callback function.

/*
 * Feed stream example.
 */
 
#include <math.h>
#include <stdio.h>
#ifdef _WIN32
#include <windows.h>
#define sleep(sec)  Sleep((sec)*1000)
#else
#include <unistd.h>
#endif
#include "faun.h"
 
typedef struct {
    float wform, pan;
} Clocks;
 
int feedAudio(float* samples, int frames, void* user)
{
    Clocks* clocks = (Clocks*) user;
    const float winc = 3.141592653f * 0.01f;
    const float pinc = 3.141592653f * 0.00001f;
    float v, p;
 
    //printf("feedAudio %d\n", frames);
 
    for (int i = 0; i < frames; ++i) {
        v = sinf(clocks->wform) * 0.5f;
        clocks->wform += winc;
 
        p = cosf(clocks->pan);
        clocks->pan += pinc;
 
        *samples++ = v * p;
        *samples++ = v * (1.0f - p);
    }
    return 0;
}
 
int main(int argc, char** argv)
{
    Clocks clocks;
    const int sourceCount = 0;
    const int st0 = sourceCount;
    const char* error;
    uint32_t pid;
    int rc = 0;
 
    if ((error = faun_startup(0, sourceCount, 2, 0, "Faun Test"))) {
        fprintf(stderr, "faun_startup: %s\n", error);
        return 1;
    }
 
    clocks.wform = clocks.pan = 0.0f;
 
    pid = faun_feedStream(st0, feedAudio, &clocks);
    if (pid) {
        sleep(10);
        faun_control(FAUN_PID_SOURCE(pid), 1, FC_STOP);
        sleep(1);
    } else {
        fprintf(stderr, "faun_feedStream failed\n");
        rc = 1;
    }
 
    faun_shutdown();
    return rc;
}