view dev/xmaxc-tables.c @ 282:9ee8ad3d4d30

frtest: rm gsmfr-hand-test and gsmfr-max-out utils These hack programs were never properly documented and were written only as part of a debug chase, in pursuit of a bug that ultimately turned out to be in our then-hacky patch to osmo-bts-sysmo, before beginning of proper patches in Osmocom. These hack programs need to be dropped from the present sw package because they depend on old libgsm, and we are eliminating that dependency.
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 14 Apr 2024 05:44:47 +0000
parents 56d3fbacd115
children
line wrap: on
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/*
 * For libgsmfrp: if we are going to initiate comfort noise generation
 * upon receiving an invalid SID, and if we are going to harvest the
 * needed LARc and Xmaxc parameters from the last speech frame, we'll
 * need a way to compute a single mean Xmaxc from the 4 subframe Xmaxc
 * parameters of that last speech frame.
 *
 * This program generates Xmaxc dequantization and requantization tables
 * that are specifically optimized for performing this mean manipulation.
 */

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>

static uint16_t dequant_table[64];
static uint8_t requant_table[1024];

static void
compute_dequant()
{
	unsigned xmaxc, dequant, step;

	dequant = 0;
	step = 1;
	for (xmaxc = 0; xmaxc < 64; xmaxc++) {
		dequant_table[xmaxc] = dequant;
		dequant += step;
		if ((xmaxc & 7) == 7 && xmaxc != 7)
			step <<= 1;
	}
}

static void
compute_requant()
{
	unsigned x, c;

	for (x = 0; x < 1024; x++) {
		for (c = 0; c < 63; c++) {
			if (x < dequant_table[c+1])
				break;
		}
		requant_table[x] = c;
	}
}

static void
print_dequant()
{
	unsigned c, r;

	puts("const uint16_t dequant_table[64] = {");
	for (c = 0; c < 64; c++) {
		r = c & 7;
		if (!r)
			putchar('\t');
		printf("%3u,", dequant_table[c]);
		if (r == 7)
			putchar('\n');
		else
			putchar(' ');
	}
	fputs("};\n\n", stdout);
}

static void
print_requant()
{
	unsigned x, r;

	puts("const uint8_t requant_table[1024] = {");
	for (x = 0; x < 1024; x++) {
		r = x & 15;
		if (!r)
			putchar('\t');
		printf("%2u,", requant_table[x]);
		if (r == 15)
			putchar('\n');
		else
			putchar(' ');
	}
	fputs("};\n", stdout);
}

main(argc, argv)
	char **argv;
{
	compute_dequant();
	compute_requant();
	print_dequant();
	print_requant();
	exit(0);
}