73 lines
3.7 KiB
C
73 lines
3.7 KiB
C
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/*
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* SpanDSP - a series of DSP components for telephony
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*
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* g711.c - A-law and u-law transcoding routines
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*
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* Written by Steve Underwood <steveu@coppice.org>
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*
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* Copyright (C) 2006 Steve Underwood
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*
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* Despite my general liking of the GPL, I place this code in the
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* public domain for the benefit of all mankind - even the slimy
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* ones who might try to proprietize my work and use it to my
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* detriment.
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*
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* $Id: g711.c,v 1.1 2006/06/07 15:46:39 steveu Exp $
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*
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* Modifications for WebRtc, 2011/04/28, by tlegrand:
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* -Removed unused include files
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* -Changed to use WebRtc types
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* -Added option to run encoder bitexact with ITU-T reference implementation
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*/
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#include "modules/third_party/g711/g711.h"
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/* Copied from the CCITT G.711 specification */
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static const uint8_t ulaw_to_alaw_table[256] = {
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42, 43, 40, 41, 46, 47, 44, 45, 34, 35, 32, 33, 38, 39, 36,
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37, 58, 59, 56, 57, 62, 63, 60, 61, 50, 51, 48, 49, 54, 55,
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52, 53, 10, 11, 8, 9, 14, 15, 12, 13, 2, 3, 0, 1, 6,
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7, 4, 26, 27, 24, 25, 30, 31, 28, 29, 18, 19, 16, 17, 22,
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23, 20, 21, 106, 104, 105, 110, 111, 108, 109, 98, 99, 96, 97, 102,
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103, 100, 101, 122, 120, 126, 127, 124, 125, 114, 115, 112, 113, 118, 119,
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116, 117, 75, 73, 79, 77, 66, 67, 64, 65, 70, 71, 68, 69, 90,
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91, 88, 89, 94, 95, 92, 93, 82, 82, 83, 83, 80, 80, 81, 81,
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86, 86, 87, 87, 84, 84, 85, 85, 170, 171, 168, 169, 174, 175, 172,
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173, 162, 163, 160, 161, 166, 167, 164, 165, 186, 187, 184, 185, 190, 191,
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188, 189, 178, 179, 176, 177, 182, 183, 180, 181, 138, 139, 136, 137, 142,
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143, 140, 141, 130, 131, 128, 129, 134, 135, 132, 154, 155, 152, 153, 158,
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159, 156, 157, 146, 147, 144, 145, 150, 151, 148, 149, 234, 232, 233, 238,
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239, 236, 237, 226, 227, 224, 225, 230, 231, 228, 229, 250, 248, 254, 255,
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252, 253, 242, 243, 240, 241, 246, 247, 244, 245, 203, 201, 207, 205, 194,
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195, 192, 193, 198, 199, 196, 197, 218, 219, 216, 217, 222, 223, 220, 221,
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210, 210, 211, 211, 208, 208, 209, 209, 214, 214, 215, 215, 212, 212, 213,
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213
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};
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/* These transcoding tables are copied from the CCITT G.711 specification. To
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achieve optimal results, do not change them. */
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static const uint8_t alaw_to_ulaw_table[256] = {
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42, 43, 40, 41, 46, 47, 44, 45, 34, 35, 32, 33, 38, 39, 36,
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37, 57, 58, 55, 56, 61, 62, 59, 60, 49, 50, 47, 48, 53, 54,
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51, 52, 10, 11, 8, 9, 14, 15, 12, 13, 2, 3, 0, 1, 6,
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7, 4, 5, 26, 27, 24, 25, 30, 31, 28, 29, 18, 19, 16, 17,
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22, 23, 20, 21, 98, 99, 96, 97, 102, 103, 100, 101, 93, 93, 92,
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92, 95, 95, 94, 94, 116, 118, 112, 114, 124, 126, 120, 122, 106, 107,
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104, 105, 110, 111, 108, 109, 72, 73, 70, 71, 76, 77, 74, 75, 64,
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65, 63, 63, 68, 69, 66, 67, 86, 87, 84, 85, 90, 91, 88, 89,
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79, 79, 78, 78, 82, 83, 80, 81, 170, 171, 168, 169, 174, 175, 172,
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173, 162, 163, 160, 161, 166, 167, 164, 165, 185, 186, 183, 184, 189, 190,
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187, 188, 177, 178, 175, 176, 181, 182, 179, 180, 138, 139, 136, 137, 142,
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143, 140, 141, 130, 131, 128, 129, 134, 135, 132, 133, 154, 155, 152, 153,
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158, 159, 156, 157, 146, 147, 144, 145, 150, 151, 148, 149, 226, 227, 224,
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225, 230, 231, 228, 229, 221, 221, 220, 220, 223, 223, 222, 222, 244, 246,
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240, 242, 252, 254, 248, 250, 234, 235, 232, 233, 238, 239, 236, 237, 200,
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201, 198, 199, 204, 205, 202, 203, 192, 193, 191, 191, 196, 197, 194, 195,
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214, 215, 212, 213, 218, 219, 216, 217, 207, 207, 206, 206, 210, 211, 208,
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209
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};
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uint8_t alaw_to_ulaw(uint8_t alaw) { return alaw_to_ulaw_table[alaw]; }
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uint8_t ulaw_to_alaw(uint8_t ulaw) { return ulaw_to_alaw_table[ulaw]; }
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