diff options
Diffstat (limited to 'plugins/shn/sulawalaw.c')
| -rw-r--r-- | plugins/shn/sulawalaw.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/plugins/shn/sulawalaw.c b/plugins/shn/sulawalaw.c new file mode 100644 index 00000000..61b417b8 --- /dev/null +++ b/plugins/shn/sulawalaw.c @@ -0,0 +1,192 @@ +/* + * $Id: sulawalaw.c,v 1.5 2001/12/30 05:12:04 jason Exp $ + */ + +#include <stdio.h> +#include <stdlib.h> +#include <stddef.h> +#include <math.h> +#include "shorten.h" + +int Sulaw2lineartab[] = {-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, + 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}; + +#ifndef Sulaw2linear +#ifdef __STDC__ +int Sulaw2linear(uchar ulaw) { +#else +int Sulaw2linear(ulaw) uchar ulaw; { +#endif + return(Sulaw2lineartab[ulaw]); +} +#endif + +/* adapted by ajr for int input */ +#ifdef __STDC__ +uchar Slinear2ulaw(int sample) { +#else +uchar Slinear2ulaw(sample) int sample; { +#endif +/* +** This routine converts from linear to ulaw. +** +** Craig Reese: IDA/Supercomputing Research Center +** Joe Campbell: Department of Defense +** 29 September 1989 +** +** References: +** 1) CCITT Recommendation G.711 (very difficult to follow) +** 2) "A New Digital Technique for Implementation of Any +** Continuous PCM Companding Law," Villeret, Michel, +** et al. 1973 IEEE Int. Conf. on Communications, Vol 1, +** 1973, pg. 11.12-11.17 +** 3) MIL-STD-188-113,"Interoperability and Performance Standards +** for Analog-to_Digital Conversion Techniques," +** 17 February 1987 +** +** Input: Signed 16 bit linear sample +** Output: 8 bit ulaw sample +*/ + +#define BIAS 0x84 /* define the add-in bias for 16 bit samples */ +#define CLIP 32635 + + static int exp_lut[256] = {0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3, + 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, + 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5, + 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5, + 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, + 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, + 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, + 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, + 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, + 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, + 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, + 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, + 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, + 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, + 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, + 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7}; + int sign, exponent, mantissa; + uchar ulawbyte; + + /* Get the sample into sign-magnitude. */ + if(sample < 0) { + sign = 0x80; + sample = -sample; + } + else + sign = 0; + + /* clip the magnitude */ + if(sample > CLIP) sample = CLIP; + + /* Convert from 16 bit linear to ulaw. */ + sample = sample + BIAS; + exponent = exp_lut[( sample >> 7 ) & 0xFF]; + mantissa = (sample >> (exponent + 3)) & 0x0F; + ulawbyte = ~(sign | (exponent << 4) | mantissa); + + return(ulawbyte); +} + + +/****************** + * ALAW starts here + */ + +int Salaw2lineartab[] = {-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, 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}; + +#ifndef Salaw2linear +#ifdef __STDC__ +int Salaw2linear(uchar alaw) { +#else +int Salaw2linear(alaw) uchar alaw; { +#endif + return(Salaw2lineartab[alaw]); +} +#endif + +/* this is derived from the Sun code - it is a bit simpler and has int input */ +#define QUANT_MASK (0xf) /* Quantization field mask. */ +#define NSEGS (8) /* Number of A-law segments. */ +#define SEG_SHIFT (4) /* Left shift for segment number. */ +#ifdef __STDC__ +uchar Slinear2alaw(int linear) { +#else +uchar Slinear2alaw(linear) int linear; { +#endif + int seg; + uchar aval, mask; + static sshort seg_aend[NSEGS] = {0x1f,0x3f,0x7f,0xff,0x1ff,0x3ff,0x7ff,0xfff}; + + linear = linear >> 3; + + if(linear >= 0) { + mask = 0xd5; /* sign (7th) bit = 1 */ + } else { + mask = 0x55; /* sign bit = 0 */ + linear = -linear - 1; + } + + /* Convert the scaled magnitude to segment number. */ + for(seg = 0; seg < NSEGS && linear > seg_aend[seg]; seg++); + + /* Combine the sign, segment, and quantization bits. */ + if(seg >= NSEGS) /* out of range, return maximum value. */ + return (uchar) (0x7F ^ mask); + else { + aval = (uchar) seg << SEG_SHIFT; + if (seg < 2) + aval |= (linear >> 1) & QUANT_MASK; + else + aval |= (linear >> seg) & QUANT_MASK; + return (aval ^ mask); + } +} |