codecCoeffConvert.c

#include <math.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>



// Compile with "gcc -std=c17 -O2 -fstrict-aliasing -ffunction-sections -Wall -Wl,--gc-sections codecCoeffConvert.c -o codecCoeffConvert -lm"
int main(int argc, char *argv[])
{
	if(argc != 4 && argc != 6)
	{
		fputs("Not enough arguments.\n", stderr);
		return 1;
	}

	const bool fixedIn = strchr(argv[1], '.') == NULL;
	double b0, b1, b2, a1, a2;
	if(argc == 4) // First order.
	{
		if(fixedIn) // Fixed point input.
		{
			b0 = (double)strtol(argv[1], NULL, 0) / 32768;
			b1 = (double)strtol(argv[2], NULL, 0) / 32768;
			b2 = 0.0;
			a1 = (double)strtol(argv[3], NULL, 0) / 32768 * (-1);
			a2 = 0.0;
		}
		else // Normalized input.
		{
			b0 = strtod(argv[1], NULL) * 32768;
			b1 = strtod(argv[2], NULL) * 32768;
			b2 = 0.0;
			a1 = strtod(argv[3], NULL) * 32768 * (-1);
			a2 = 0.0;
		}
	}
	else // Second order biquad.
	{
		if(fixedIn) // Fixed point input.
		{
			b0 = (double)strtol(argv[1], NULL, 0) / 32768;
			b1 = (double)strtol(argv[2], NULL, 0) * 2 / 32768;
			b2 = (double)strtol(argv[3], NULL, 0) / 32768;
			a1 = (double)strtol(argv[4], NULL, 0) * 2 / 32768 * (-1);
			a2 = (double)strtol(argv[5], NULL, 0) / 32768 * (-1);
		}
		else // Normalized input.
		{
			b0 = strtod(argv[1], NULL) * 32768;
			b1 = strtod(argv[2], NULL) * 32768 / 2;
			b2 = strtod(argv[3], NULL) * 32768;
			a1 = strtod(argv[4], NULL) * 32768 / 2 * (-1);
			a2 = strtod(argv[5], NULL) * 32768 * (-1);
		}
	}

	if(!fixedIn)
	{
		printf("b0 = %d\nb1 = %d\nb2 = %d\n"
		       "a1 = %d\na2 = %d\n",
		       (int)round(b0), (int)round(b1), (int)round(b2),
		       (int)round(a1), (int)round(a2));
	}
	else
	{
		printf("b0 = %.17g\nb1 = %.17g\nb2 = %.17g\n"
		       "a1 = %.17g\na2 = %.17g\n",
		       b0, b1, b2, a1, a2);
	}

	return 0;
}