| niklase@google.com | 470e71d | 2011-07-07 08:21:25 +0000 | [diff] [blame] | 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 | * Despite my general liking of the GPL, I place this code in the |
| 11 | * public domain for the benefit of all mankind - even the slimy |
| 12 | * ones who might try to proprietize my work and use it to my |
| 13 | * detriment. |
| 14 | * |
| 15 | * $Id: g711.c,v 1.1 2006/06/07 15:46:39 steveu Exp $ |
| 16 | * |
| 17 | * Modifications for WebRtc, 2011/04/28, by tlegrand: |
| 18 | * -Removed unused include files |
| 19 | * -Changed to use WebRtc types |
| 20 | * -Added option to run encoder bitexact with ITU-T reference implementation |
| 21 | */ |
| 22 | |
| 23 | /*! \file */ |
| 24 | |
| 25 | #include "g711.h" |
| 26 | #include "typedefs.h" |
| 27 | |
| 28 | /* Copied from the CCITT G.711 specification */ |
| 29 | static const WebRtc_UWord8 ulaw_to_alaw_table[256] = |
| 30 | { |
| 31 | 42, 43, 40, 41, 46, 47, 44, 45, 34, 35, 32, 33, 38, 39, 36, 37, |
| 32 | 58, 59, 56, 57, 62, 63, 60, 61, 50, 51, 48, 49, 54, 55, 52, 53, |
| 33 | 10, 11, 8, 9, 14, 15, 12, 13, 2, 3, 0, 1, 6, 7, 4, 26, |
| 34 | 27, 24, 25, 30, 31, 28, 29, 18, 19, 16, 17, 22, 23, 20, 21, 106, |
| 35 | 104, 105, 110, 111, 108, 109, 98, 99, 96, 97, 102, 103, 100, 101, 122, 120, |
| 36 | 126, 127, 124, 125, 114, 115, 112, 113, 118, 119, 116, 117, 75, 73, 79, 77, |
| 37 | 66, 67, 64, 65, 70, 71, 68, 69, 90, 91, 88, 89, 94, 95, 92, 93, |
| 38 | 82, 82, 83, 83, 80, 80, 81, 81, 86, 86, 87, 87, 84, 84, 85, 85, |
| 39 | 170, 171, 168, 169, 174, 175, 172, 173, 162, 163, 160, 161, 166, 167, 164, 165, |
| 40 | 186, 187, 184, 185, 190, 191, 188, 189, 178, 179, 176, 177, 182, 183, 180, 181, |
| 41 | 138, 139, 136, 137, 142, 143, 140, 141, 130, 131, 128, 129, 134, 135, 132, 154, |
| 42 | 155, 152, 153, 158, 159, 156, 157, 146, 147, 144, 145, 150, 151, 148, 149, 234, |
| 43 | 232, 233, 238, 239, 236, 237, 226, 227, 224, 225, 230, 231, 228, 229, 250, 248, |
| 44 | 254, 255, 252, 253, 242, 243, 240, 241, 246, 247, 244, 245, 203, 201, 207, 205, |
| 45 | 194, 195, 192, 193, 198, 199, 196, 197, 218, 219, 216, 217, 222, 223, 220, 221, |
| 46 | 210, 210, 211, 211, 208, 208, 209, 209, 214, 214, 215, 215, 212, 212, 213, 213 |
| 47 | }; |
| 48 | |
| 49 | /* These transcoding tables are copied from the CCITT G.711 specification. To achieve |
| 50 | optimal results, do not change them. */ |
| 51 | |
| 52 | static const WebRtc_UWord8 alaw_to_ulaw_table[256] = |
| 53 | { |
| 54 | 42, 43, 40, 41, 46, 47, 44, 45, 34, 35, 32, 33, 38, 39, 36, 37, |
| 55 | 57, 58, 55, 56, 61, 62, 59, 60, 49, 50, 47, 48, 53, 54, 51, 52, |
| 56 | 10, 11, 8, 9, 14, 15, 12, 13, 2, 3, 0, 1, 6, 7, 4, 5, |
| 57 | 26, 27, 24, 25, 30, 31, 28, 29, 18, 19, 16, 17, 22, 23, 20, 21, |
| 58 | 98, 99, 96, 97, 102, 103, 100, 101, 93, 93, 92, 92, 95, 95, 94, 94, |
| 59 | 116, 118, 112, 114, 124, 126, 120, 122, 106, 107, 104, 105, 110, 111, 108, 109, |
| 60 | 72, 73, 70, 71, 76, 77, 74, 75, 64, 65, 63, 63, 68, 69, 66, 67, |
| 61 | 86, 87, 84, 85, 90, 91, 88, 89, 79, 79, 78, 78, 82, 83, 80, 81, |
| 62 | 170, 171, 168, 169, 174, 175, 172, 173, 162, 163, 160, 161, 166, 167, 164, 165, |
| 63 | 185, 186, 183, 184, 189, 190, 187, 188, 177, 178, 175, 176, 181, 182, 179, 180, |
| 64 | 138, 139, 136, 137, 142, 143, 140, 141, 130, 131, 128, 129, 134, 135, 132, 133, |
| 65 | 154, 155, 152, 153, 158, 159, 156, 157, 146, 147, 144, 145, 150, 151, 148, 149, |
| 66 | 226, 227, 224, 225, 230, 231, 228, 229, 221, 221, 220, 220, 223, 223, 222, 222, |
| 67 | 244, 246, 240, 242, 252, 254, 248, 250, 234, 235, 232, 233, 238, 239, 236, 237, |
| 68 | 200, 201, 198, 199, 204, 205, 202, 203, 192, 193, 191, 191, 196, 197, 194, 195, |
| 69 | 214, 215, 212, 213, 218, 219, 216, 217, 207, 207, 206, 206, 210, 211, 208, 209 |
| 70 | }; |
| 71 | |
| 72 | WebRtc_UWord8 alaw_to_ulaw(WebRtc_UWord8 alaw) |
| 73 | { |
| 74 | return alaw_to_ulaw_table[alaw]; |
| 75 | } |
| 76 | /*- End of function --------------------------------------------------------*/ |
| 77 | |
| 78 | WebRtc_UWord8 ulaw_to_alaw(WebRtc_UWord8 ulaw) |
| 79 | { |
| 80 | return ulaw_to_alaw_table[ulaw]; |
| 81 | } |
| 82 | /*- End of function --------------------------------------------------------*/ |
| 83 | /*- End of file ------------------------------------------------------------*/ |