Mercurial > hg > audiostuff
comparison spandsp-0.0.3/spandsp-0.0.3/src/g711.c @ 5:f762bf195c4b
import spandsp-0.0.3
| author | Peter Meerwald <pmeerw@cosy.sbg.ac.at> |
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| date | Fri, 25 Jun 2010 16:00:21 +0200 |
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| 4:26cd8f1ef0b1 | 5:f762bf195c4b |
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| 1 /* | |
| 2 * SpanDSP - a series of DSP components for telephony | |
| 3 * | |
| 4 * g711.c - A-law and u-law transcoding routines | |
| 5 * | |
| 6 * Written by Steve Underwood <steveu@coppice.org> | |
| 7 * | |
| 8 * Copyright (C) 2006 Steve Underwood | |
| 9 * | |
| 10 * All rights reserved. | |
| 11 * | |
| 12 * This program is free software; you can redistribute it and/or modify | |
| 13 * it under the terms of the GNU General Public License version 2, as | |
| 14 * published by the Free Software Foundation. | |
| 15 * | |
| 16 * This program is distributed in the hope that it will be useful, | |
| 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 19 * GNU General Public License for more details. | |
| 20 * | |
| 21 * You should have received a copy of the GNU General Public License | |
| 22 * along with this program; if not, write to the Free Software | |
| 23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
| 24 * | |
| 25 * $Id: g711.c,v 1.4 2006/11/19 14:07:24 steveu Exp $ | |
| 26 */ | |
| 27 | |
| 28 /*! \file */ | |
| 29 | |
| 30 #ifdef HAVE_CONFIG_H | |
| 31 #include <config.h> | |
| 32 #endif | |
| 33 | |
| 34 #include <inttypes.h> | |
| 35 #include <stdlib.h> | |
| 36 #include <string.h> | |
| 37 #if defined(HAVE_TGMATH_H) | |
| 38 #include <tgmath.h> | |
| 39 #endif | |
| 40 #if defined(HAVE_MATH_H) | |
| 41 #include <math.h> | |
| 42 #endif | |
| 43 #include <assert.h> | |
| 44 | |
| 45 #include "spandsp/telephony.h" | |
| 46 #include "spandsp/logging.h" | |
| 47 #include "spandsp/bit_operations.h" | |
| 48 #include "spandsp/g711.h" | |
| 49 | |
| 50 /* Copied from the CCITT G.711 specification */ | |
| 51 static const uint8_t ulaw_to_alaw_table[256] = | |
| 52 { | |
| 53 42, 43, 40, 41, 46, 47, 44, 45, 34, 35, 32, 33, 38, 39, 36, 37, | |
| 54 58, 59, 56, 57, 62, 63, 60, 61, 50, 51, 48, 49, 54, 55, 52, 53, | |
| 55 10, 11, 8, 9, 14, 15, 12, 13, 2, 3, 0, 1, 6, 7, 4, 26, | |
| 56 27, 24, 25, 30, 31, 28, 29, 18, 19, 16, 17, 22, 23, 20, 21, 106, | |
| 57 104, 105, 110, 111, 108, 109, 98, 99, 96, 97, 102, 103, 100, 101, 122, 120, | |
| 58 126, 127, 124, 125, 114, 115, 112, 113, 118, 119, 116, 117, 75, 73, 79, 77, | |
| 59 66, 67, 64, 65, 70, 71, 68, 69, 90, 91, 88, 89, 94, 95, 92, 93, | |
| 60 82, 82, 83, 83, 80, 80, 81, 81, 86, 86, 87, 87, 84, 84, 85, 85, | |
| 61 170, 171, 168, 169, 174, 175, 172, 173, 162, 163, 160, 161, 166, 167, 164, 165, | |
| 62 186, 187, 184, 185, 190, 191, 188, 189, 178, 179, 176, 177, 182, 183, 180, 181, | |
| 63 138, 139, 136, 137, 142, 143, 140, 141, 130, 131, 128, 129, 134, 135, 132, 154, | |
| 64 155, 152, 153, 158, 159, 156, 157, 146, 147, 144, 145, 150, 151, 148, 149, 234, | |
| 65 232, 233, 238, 239, 236, 237, 226, 227, 224, 225, 230, 231, 228, 229, 250, 248, | |
| 66 254, 255, 252, 253, 242, 243, 240, 241, 246, 247, 244, 245, 203, 201, 207, 205, | |
| 67 194, 195, 192, 193, 198, 199, 196, 197, 218, 219, 216, 217, 222, 223, 220, 221, | |
| 68 210, 210, 211, 211, 208, 208, 209, 209, 214, 214, 215, 215, 212, 212, 213, 213 | |
| 69 }; | |
| 70 | |
| 71 /* These transcoding tables are copied from the CCITT G.711 specification. To achieve | |
| 72 optimal results, do not change them. */ | |
| 73 | |
| 74 static const uint8_t alaw_to_ulaw_table[256] = | |
| 75 { | |
| 76 42, 43, 40, 41, 46, 47, 44, 45, 34, 35, 32, 33, 38, 39, 36, 37, | |
| 77 57, 58, 55, 56, 61, 62, 59, 60, 49, 50, 47, 48, 53, 54, 51, 52, | |
| 78 10, 11, 8, 9, 14, 15, 12, 13, 2, 3, 0, 1, 6, 7, 4, 5, | |
| 79 26, 27, 24, 25, 30, 31, 28, 29, 18, 19, 16, 17, 22, 23, 20, 21, | |
| 80 98, 99, 96, 97, 102, 103, 100, 101, 93, 93, 92, 92, 95, 95, 94, 94, | |
| 81 116, 118, 112, 114, 124, 126, 120, 122, 106, 107, 104, 105, 110, 111, 108, 109, | |
| 82 72, 73, 70, 71, 76, 77, 74, 75, 64, 65, 63, 63, 68, 69, 66, 67, | |
| 83 86, 87, 84, 85, 90, 91, 88, 89, 79, 79, 78, 78, 82, 83, 80, 81, | |
| 84 170, 171, 168, 169, 174, 175, 172, 173, 162, 163, 160, 161, 166, 167, 164, 165, | |
| 85 185, 186, 183, 184, 189, 190, 187, 188, 177, 178, 175, 176, 181, 182, 179, 180, | |
| 86 138, 139, 136, 137, 142, 143, 140, 141, 130, 131, 128, 129, 134, 135, 132, 133, | |
| 87 154, 155, 152, 153, 158, 159, 156, 157, 146, 147, 144, 145, 150, 151, 148, 149, | |
| 88 226, 227, 224, 225, 230, 231, 228, 229, 221, 221, 220, 220, 223, 223, 222, 222, | |
| 89 244, 246, 240, 242, 252, 254, 248, 250, 234, 235, 232, 233, 238, 239, 236, 237, | |
| 90 200, 201, 198, 199, 204, 205, 202, 203, 192, 193, 191, 191, 196, 197, 194, 195, | |
| 91 214, 215, 212, 213, 218, 219, 216, 217, 207, 207, 206, 206, 210, 211, 208, 209 | |
| 92 }; | |
| 93 | |
| 94 uint8_t alaw_to_ulaw(uint8_t alaw) | |
| 95 { | |
| 96 return alaw_to_ulaw_table[alaw]; | |
| 97 } | |
| 98 /*- End of function --------------------------------------------------------*/ | |
| 99 | |
| 100 uint8_t ulaw_to_alaw(uint8_t ulaw) | |
| 101 { | |
| 102 return ulaw_to_alaw_table[ulaw]; | |
| 103 } | |
| 104 /*- End of function --------------------------------------------------------*/ | |
| 105 /*- End of file ------------------------------------------------------------*/ |