A Simple Sine wave frequency generator

sine_freq.c

/*
* Freq Generator
* A Simple Sine wave frequency generator
*
* Developed by - DuskyElf
* MIT Licence @duskyelf 2023
*
* compile command - 
* `cc -o sine_freq sine_freq.c -lm`
*
* requirements -
* ffmpeg (ffplay)
*/

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

#define FREQ 440
#define VOLUME 0.01f
#define DURATION 5
#define SAMPLE_RATE 44100
const char *output_file = "output.bin";

#define Arr_Len(arr) (sizeof(arr) / sizeof(arr[0]))
float wave[SAMPLE_RATE * DURATION];

int main(void) {
    printf("Generating %s...\n", output_file);

    FILE *output = fopen(output_file, "wb");
    assert(output_file != NULL && "Could not open file");

    for (int i = 0; i < Arr_Len(wave); ++i) {
        wave[i] = sinf((float)i / (float)SAMPLE_RATE * 2 * M_PI * FREQ) * VOLUME;
    }

    fwrite(wave, sizeof(float), Arr_Len(wave), output);

    char buff[1024] = {0};
    sprintf(buff, "ffplay -f f32le -ar %d %s", SAMPLE_RATE, output_file);
    system(buff);

    fclose(output);
    return 0;
}