+
−/*
+
− * 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);
+
−}