FreeCalypso > hg > gsm-codec-lib
view miscutil/pcm8-to-pcm16.c @ 242:f081a6850fb5
libgsmfrp: new refined implementation
The previous implementation exhibited the following defects,
which are now fixed:
1) The last received valid SID was cached forever for the purpose of
handling future invalid SIDs - we could have received some valid
SID ages ago, then lots of speech or NO_DATA, and if we then get
an invalid SID, we would resurrect the last valid SID from ancient
history - a bad design. In our new design, we handle invalid SID
based on the current state, much like BFI.
2) GSM 06.11 spec says clearly that after the second lost SID
(received BFI=1 && TAF=1 in CN state) we need to gradually decrease
the output level, rather than jump directly to emitting silence
frames - we previously failed to implement such logic.
3) Per GSM 06.12 section 5.2, Xmaxc should be the same in all 4 subframes
in a SID frame. What should we do if we receive an otherwise valid
SID frame with different Xmaxc? Our previous approach would
replicate this Xmaxc oddity in every subsequent generated CN frame,
which is rather bad. In our new design, the very first CN frame
(which can be seen as a transformation of the SID frame itself)
retains the original 4 distinct Xmaxc, but all subsequent CN frames
are based on the Xmaxc from the last subframe of the most recent SID.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Tue, 09 May 2023 05:16:31 +0000 |
parents | 8710c94df334 |
children |
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/* * This program reads an 8-bit PCM recording in either A-law or mu-law * encoding (needs to be specified on the command line) and converts it * to 16-bit linear PCM. Both input and output file formats are raw binary; * the output format is robe by default or can be changed to LE via * an additional command line argument. * * The expansion tables for A-law and mu-law have been generated by * developer aid programs in the ../dev directory. */ #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include <string.h> #include <strings.h> uint16_t pcma_decode_table[256] = { 60032, 60288, 59520, 59776, 61056, 61312, 60544, 60800, 57984, 58240, 57472, 57728, 59008, 59264, 58496, 58752, 62784, 62912, 62528, 62656, 63296, 63424, 63040, 63168, 61760, 61888, 61504, 61632, 62272, 62400, 62016, 62144, 43520, 44544, 41472, 42496, 47616, 48640, 45568, 46592, 35328, 36352, 33280, 34304, 39424, 40448, 37376, 38400, 54528, 55040, 53504, 54016, 56576, 57088, 55552, 56064, 50432, 50944, 49408, 49920, 52480, 52992, 51456, 51968, 65192, 65208, 65160, 65176, 65256, 65272, 65224, 65240, 65064, 65080, 65032, 65048, 65128, 65144, 65096, 65112, 65448, 65464, 65416, 65432, 65512, 65528, 65480, 65496, 65320, 65336, 65288, 65304, 65384, 65400, 65352, 65368, 64160, 64224, 64032, 64096, 64416, 64480, 64288, 64352, 63648, 63712, 63520, 63584, 63904, 63968, 63776, 63840, 64848, 64880, 64784, 64816, 64976, 65008, 64912, 64944, 64592, 64624, 64528, 64560, 64720, 64752, 64656, 64688, 5504, 5248, 6016, 5760, 4480, 4224, 4992, 4736, 7552, 7296, 8064, 7808, 6528, 6272, 7040, 6784, 2752, 2624, 3008, 2880, 2240, 2112, 2496, 2368, 3776, 3648, 4032, 3904, 3264, 3136, 3520, 3392, 22016, 20992, 24064, 23040, 17920, 16896, 19968, 18944, 30208, 29184, 32256, 31232, 26112, 25088, 28160, 27136, 11008, 10496, 12032, 11520, 8960, 8448, 9984, 9472, 15104, 14592, 16128, 15616, 13056, 12544, 14080, 13568, 344, 328, 376, 360, 280, 264, 312, 296, 472, 456, 504, 488, 408, 392, 440, 424, 88, 72, 120, 104, 24, 8, 56, 40, 216, 200, 248, 232, 152, 136, 184, 168, 1376, 1312, 1504, 1440, 1120, 1056, 1248, 1184, 1888, 1824, 2016, 1952, 1632, 1568, 1760, 1696, 688, 656, 752, 720, 560, 528, 624, 592, 944, 912, 1008, 976, 816, 784, 880, 848, }; uint16_t pcmu_decode_table[256] = { 33412, 34436, 35460, 36484, 37508, 38532, 39556, 40580, 41604, 42628, 43652, 44676, 45700, 46724, 47748, 48772, 49540, 50052, 50564, 51076, 51588, 52100, 52612, 53124, 53636, 54148, 54660, 55172, 55684, 56196, 56708, 57220, 57604, 57860, 58116, 58372, 58628, 58884, 59140, 59396, 59652, 59908, 60164, 60420, 60676, 60932, 61188, 61444, 61636, 61764, 61892, 62020, 62148, 62276, 62404, 62532, 62660, 62788, 62916, 63044, 63172, 63300, 63428, 63556, 63652, 63716, 63780, 63844, 63908, 63972, 64036, 64100, 64164, 64228, 64292, 64356, 64420, 64484, 64548, 64612, 64660, 64692, 64724, 64756, 64788, 64820, 64852, 64884, 64916, 64948, 64980, 65012, 65044, 65076, 65108, 65140, 65164, 65180, 65196, 65212, 65228, 65244, 65260, 65276, 65292, 65308, 65324, 65340, 65356, 65372, 65388, 65404, 65416, 65424, 65432, 65440, 65448, 65456, 65464, 65472, 65480, 65488, 65496, 65504, 65512, 65520, 65528, 0, 32124, 31100, 30076, 29052, 28028, 27004, 25980, 24956, 23932, 22908, 21884, 20860, 19836, 18812, 17788, 16764, 15996, 15484, 14972, 14460, 13948, 13436, 12924, 12412, 11900, 11388, 10876, 10364, 9852, 9340, 8828, 8316, 7932, 7676, 7420, 7164, 6908, 6652, 6396, 6140, 5884, 5628, 5372, 5116, 4860, 4604, 4348, 4092, 3900, 3772, 3644, 3516, 3388, 3260, 3132, 3004, 2876, 2748, 2620, 2492, 2364, 2236, 2108, 1980, 1884, 1820, 1756, 1692, 1628, 1564, 1500, 1436, 1372, 1308, 1244, 1180, 1116, 1052, 988, 924, 876, 844, 812, 780, 748, 716, 684, 652, 620, 588, 556, 524, 492, 460, 428, 396, 372, 356, 340, 324, 308, 292, 276, 260, 244, 228, 212, 196, 180, 164, 148, 132, 120, 112, 104, 96, 88, 80, 72, 64, 56, 48, 40, 32, 24, 16, 8, 0, }; main(argc, argv) char **argv; { uint16_t *exp_table; int little_endian; FILE *inf, *outf; int inp; unsigned out; if (argc < 4 || argc > 5) { usage: fprintf(stderr, "usage: %s alaw|ulaw input.pcm8 output.pcm16 [le]\n", argv[0]); exit(1); } if (!strcmp(argv[1], "alaw")) exp_table = pcma_decode_table; else if (!strcmp(argv[1], "ulaw")) exp_table = pcmu_decode_table; else goto usage; if (argc == 4) little_endian = 0; else { if (strcmp(argv[4], "le")) goto usage; little_endian = 1; } inf = fopen(argv[2], "r"); if (!inf) { perror(argv[2]); exit(1); } outf = fopen(argv[3], "w"); if (!outf) { perror(argv[3]); exit(1); } for (;;) { inp = getc(inf); if (inp == EOF) break; out = exp_table[inp]; if (little_endian) { putc(out & 0xFF, outf); putc((out >> 8) & 0xFF, outf); } else { putc((out >> 8) & 0xFF, outf); putc(out & 0xFF, outf); } } fclose(outf); exit(0); }