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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-10 20:34:10 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-10 20:34:10 +0000 |
commit | e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc (patch) | |
tree | 68cb5ef9081156392f1dd62a00c6ccc1451b93df /wsutil/g711.c | |
parent | Initial commit. (diff) | |
download | wireshark-e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc.tar.xz wireshark-e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc.zip |
Adding upstream version 4.2.2.upstream/4.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'wsutil/g711.c')
-rw-r--r-- | wsutil/g711.c | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/wsutil/g711.c b/wsutil/g711.c new file mode 100644 index 00000000..e6c3dcae --- /dev/null +++ b/wsutil/g711.c @@ -0,0 +1,300 @@ +/* + * This source code is a product of Sun Microsystems, Inc. and is provided + * for unrestricted use. Users may copy or modify this source code without + * charge. + * + * SUN SOURCE CODE IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING + * THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR + * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE. + * + * Sun source code is provided with no support and without any obligation on + * the part of Sun Microsystems, Inc. to assist in its use, correction, + * modification or enhancement. + * + * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE + * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY THIS SOFTWARE + * OR ANY PART THEREOF. + * + * In no event will Sun Microsystems, Inc. be liable for any lost revenue + * or profits or other special, indirect and consequential damages, even if + * Sun has been advised of the possibility of such damages. + * + * Sun Microsystems, Inc. + * 2550 Garcia Avenue + * Mountain View, California 94043 + */ + +#include "g711.h" + +/* + * g711.c + * + * u-law, A-law and linear PCM conversions. + */ +#define SIGN_BIT (0x80) /* Sign bit for a A-law byte. */ +#define QUANT_MASK (0xf) /* Quantization field mask. */ +#define NSEGS (8) /* Number of A-law segments. */ +#define SEG_SHIFT (4) /* Left shift for segment number. */ +#define SEG_MASK (0x70) /* Segment field mask. */ + +static short seg_end[8] = {0xFF, 0x1FF, 0x3FF, 0x7FF, + 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF}; + +/* copy from CCITT G.711 specifications */ +unsigned char _u2a[128] = { /* u- to A-law conversions */ + 1, 1, 2, 2, 3, 3, 4, 4, + 5, 5, 6, 6, 7, 7, 8, 8, + 9, 10, 11, 12, 13, 14, 15, 16, + 17, 18, 19, 20, 21, 22, 23, 24, + 25, 27, 29, 31, 33, 34, 35, 36, + 37, 38, 39, 40, 41, 42, 43, 44, + 46, 48, 49, 50, 51, 52, 53, 54, + 55, 56, 57, 58, 59, 60, 61, 62, + 64, 65, 66, 67, 68, 69, 70, 71, + 72, 73, 74, 75, 76, 77, 78, 79, + 81, 82, 83, 84, 85, 86, 87, 88, + 89, 90, 91, 92, 93, 94, 95, 96, + 97, 98, 99, 100, 101, 102, 103, 104, + 105, 106, 107, 108, 109, 110, 111, 112, + 113, 114, 115, 116, 117, 118, 119, 120, + 121, 122, 123, 124, 125, 126, 127, 128}; + +unsigned char _a2u[128] = { /* A- to u-law conversions */ + 1, 3, 5, 7, 9, 11, 13, 15, + 16, 17, 18, 19, 20, 21, 22, 23, + 24, 25, 26, 27, 28, 29, 30, 31, + 32, 32, 33, 33, 34, 34, 35, 35, + 36, 37, 38, 39, 40, 41, 42, 43, + 44, 45, 46, 47, 48, 48, 49, 49, + 50, 51, 52, 53, 54, 55, 56, 57, + 58, 59, 60, 61, 62, 63, 64, 64, + 65, 66, 67, 68, 69, 70, 71, 72, + 73, 74, 75, 76, 77, 78, 79, 79, + 80, 81, 82, 83, 84, 85, 86, 87, + 88, 89, 90, 91, 92, 93, 94, 95, + 96, 97, 98, 99, 100, 101, 102, 103, + 104, 105, 106, 107, 108, 109, 110, 111, + 112, 113, 114, 115, 116, 117, 118, 119, + 120, 121, 122, 123, 124, 125, 126, 127}; + +static int +search( + int val, + short *table, + int size) +{ + int i; + + for (i = 0; i < size; i++) { + if (val <= *table++) + return (i); + } + return (size); +} + +/* + * linear2alaw() - Convert a 16-bit linear PCM value to 8-bit A-law + * + * linear2alaw() accepts an 16-bit integer and encodes it as A-law data. + * + * Linear Input Code Compressed Code + * ------------------------ --------------- + * 0000000wxyza 000wxyz + * 0000001wxyza 001wxyz + * 000001wxyzab 010wxyz + * 00001wxyzabc 011wxyz + * 0001wxyzabcd 100wxyz + * 001wxyzabcde 101wxyz + * 01wxyzabcdef 110wxyz + * 1wxyzabcdefg 111wxyz + * + * For further information see John C. Bellamy's Digital Telephony, 1982, + * John Wiley & Sons, pps 98-111 and 472-476. + */ +unsigned char +linear2alaw( + int pcm_val) /* 2's complement (16-bit range) */ +{ + int mask; + int seg; + unsigned char aval; + if (pcm_val >= 0) { + mask = 0xD5; /* sign (7th) bit = 1 */ + } else { + mask = 0x55; /* sign bit = 0 */ + pcm_val = -pcm_val - 8; + } + + /* Convert the scaled magnitude to segment number. */ + seg = search(pcm_val, seg_end, 8); + + /* Combine the sign, segment, and quantization bits. */ + + if (seg >= 8) /* out of range, return maximum value. */ + return (0x7F ^ mask); + else { + aval = seg << SEG_SHIFT; + if (seg < 2) + aval |= (pcm_val >> 4) & QUANT_MASK; + else + aval |= (pcm_val >> (seg + 3)) & QUANT_MASK; + return (aval ^ mask); + } +} + +/* + * alaw2linear() - Convert an A-law value to 16-bit linear PCM + * + */ +int +alaw2linear( + unsigned char a_val) +{ + int t; + int seg; + /*printf(" vrednost a_val %X ", a_val);*/ + a_val ^= 0x55; + + t = (a_val & QUANT_MASK) << 4; + seg = ((unsigned)a_val & SEG_MASK) >> SEG_SHIFT; + switch (seg) { + case 0: + t += 8; + break; + case 1: + t += 0x108; + break; + default: + t += 0x108; + t <<= seg - 1; + } + /*printf("izracunan int %d in njegov hex %X \n", t,t);*/ + return ((a_val & SIGN_BIT) ? t : -t); +} + +#define BIAS (0x84) /* Bias for linear code. */ + +/* + * linear2ulaw() - Convert a linear PCM value to u-law + * + * In order to simplify the encoding process, the original linear magnitude + * is biased by adding 33 which shifts the encoding range from (0 - 8158) to + * (33 - 8191). The result can be seen in the following encoding table: + * + * Biased Linear Input Code Compressed Code + * ------------------------ --------------- + * 00000001wxyza 000wxyz + * 0000001wxyzab 001wxyz + * 000001wxyzabc 010wxyz + * 00001wxyzabcd 011wxyz + * 0001wxyzabcde 100wxyz + * 001wxyzabcdef 101wxyz + * 01wxyzabcdefg 110wxyz + * 1wxyzabcdefgh 111wxyz + * + * Each biased linear code has a leading 1 which identifies the segment + * number. The value of the segment number is equal to 7 minus the number + * of leading 0's. The quantization interval is directly available as the + * four bits wxyz. * The trailing bits (a - h) are ignored. + * + * Ordinarily the complement of the resulting code word is used for + * transmission, and so the code word is complemented before it is returned. + * + * For further information see John C. Bellamy's Digital Telephony, 1982, + * John Wiley & Sons, pps 98-111 and 472-476. + */ +unsigned char +linear2ulaw( + int pcm_val) /* 2's complement (16-bit range) */ +{ + int mask; + int seg; + unsigned char uval; + + /* Get the sign and the magnitude of the value. */ + if (pcm_val < 0) { + pcm_val = BIAS - pcm_val; + mask = 0x7F; + } else { + pcm_val += BIAS; + mask = 0xFF; + } + + /* Convert the scaled magnitude to segment number. */ + seg = search(pcm_val, seg_end, 8); + + /* + * Combine the sign, segment, quantization bits; + * and complement the code word. + */ + if (seg >= 8) /* out of range, return maximum value. */ + return (0x7F ^ mask); + else { + uval = (seg << 4) | ((pcm_val >> (seg + 3)) & 0xF); + return (uval ^ mask); + } + +} + +/* + * ulaw2linear() - Convert a u-law value to 16-bit linear PCM + * + * First, a biased linear code is derived from the code word. An unbiased + * output can then be obtained by subtracting 33 from the biased code. + * + * Note that this function expects to be passed the complement of the + * original code word. This is in keeping with ISDN conventions. + */ +int +ulaw2linear( + unsigned char u_val) +{ + int t; + + /* Complement to obtain normal u-law value. */ + u_val = ~u_val; + + /* + * Extract and bias the quantization bits. Then + * shift up by the segment number and subtract out the bias. + */ + t = ((u_val & QUANT_MASK) << 3) + BIAS; + t <<= ((unsigned)u_val & SEG_MASK) >> SEG_SHIFT; + + return ((u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS)); +} + +/* A-law to u-law conversion */ +/* unsigned char + * alaw2ulaw( + * unsigned char aval) + * { + * aval &= 0xff; + * return ((aval & 0x80) ? (0xFF ^ _a2u[aval ^ 0xD5]) : + * (0x7F ^ _a2u[aval ^ 0x55])); + * } + */ + +/* u-law to A-law conversion */ +/* unsigned char + * ulaw2alaw( + * unsigned char uval) + * { + * uval &= 0xff; + * return ((uval & 0x80) ? (0xD5 ^ (_u2a[0xFF ^ uval] - 1)) : + * (0x55 ^ (_u2a[0x7F ^ uval] - 1))); + * } + */ + +/* + * Editor modelines - https://www.wireshark.org/tools/modelines.html + * + * Local variables: + * c-basic-offset: 8 + * tab-width: 8 + * indent-tabs-mode: t + * End: + * + * vi: set shiftwidth=8 tabstop=8 noexpandtab: + * :indentSize=8:tabSize=8:noTabs=false: + */ |