FreeCalypso > hg > gsm-codec-lib
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 |
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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); }
