gsm-codec-lib: libgsmfr2/lpc.c annotate

annotate libgsmfr2/lpc.c @ 508:c275e57132f8

libgsmhr1/{pack,unpack}_frame.c: comment fix there is only one unvoiced mode, hence it should be singular

author	Mychaela Falconia <falcon@freecalypso.org>
date	Sat, 17 Aug 2024 21:45:34 +0000
parents	0cfb7c95cce2
children

rev	line source
268 0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	1 /*
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	2 * This C source file has been adapted from TU-Berlin libgsm source,
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	3 * original notice follows:
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	4 *
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	5 * Copyright 1992 by Jutta Degener and Carsten Bormann, Technische
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	6 * Universitaet Berlin. See the accompanying file "COPYRIGHT" for
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	7 * details. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE.
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	8 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	9
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	10 #include <stdint.h>
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	11 #include <assert.h>
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	12 #include "tw_gsmfr.h"
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	13 #include "typedef.h"
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	14 #include "ed_state.h"
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	15 #include "ed_internal.h"
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	16
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	17 /*
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	18 * 4.2.4 .. 4.2.7 LPC ANALYSIS SECTION
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	19 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	20
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	21 /* 4.2.4 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	22
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	23 static void Autocorrelation (
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	24 word * s, /* [0..159] IN/OUT */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	25 longword * L_ACF) /* [0..8] OUT */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	26 /*
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	27 * The goal is to compute the array L_ACF[k]. The signal s[i] must
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	28 * be scaled in order to avoid an overflow situation.
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	29 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	30 {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	31 register int k, i;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	32
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	33 word temp, smax, scalauto;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	34
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	35 /* Dynamic scaling of the array s[0..159]
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	36 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	37
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	38 /* Search for the maximum.
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	39 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	40 smax = 0;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	41 for (k = 0; k <= 159; k++) {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	42 temp = GSM_ABS( s[k] );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	43 if (temp > smax) smax = temp;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	44 }
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	45
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	46 /* Computation of the scaling factor.
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	47 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	48 if (smax == 0) scalauto = 0;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	49 else {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	50 assert(smax > 0);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	51 scalauto = 4 - gsm_norm( (longword)smax << 16 );/* sub(4,..) */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	52 }
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	53
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	54 /* Scaling of the array s[0...159]
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	55 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	56
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	57 if (scalauto > 0) {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	58
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	59 # define SCALE(n) \
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	60 case n: for (k = 0; k <= 159; k++) \
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	61 s[k] = GSM_MULT_R( s[k], 16384 >> (n-1) );\
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	62 break;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	63
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	64 switch (scalauto) {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	65 SCALE(1)
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	66 SCALE(2)
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	67 SCALE(3)
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	68 SCALE(4)
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	69 }
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	70 # undef SCALE
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	71 }
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	72
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	73 /* Compute the L_ACF[..].
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	74 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	75 {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	76 word * sp = s;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	77 word sl = *sp;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	78
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	79 # define STEP(k) L_ACF[k] += ((longword)sl * sp[ -(k) ]);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	80
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	81 # define NEXTI sl = *++sp
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	82
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	83
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	84 for (k = 9; k--; L_ACF[k] = 0) ;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	85
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	86 STEP (0);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	87 NEXTI;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	88 STEP(0); STEP(1);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	89 NEXTI;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	90 STEP(0); STEP(1); STEP(2);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	91 NEXTI;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	92 STEP(0); STEP(1); STEP(2); STEP(3);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	93 NEXTI;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	94 STEP(0); STEP(1); STEP(2); STEP(3); STEP(4);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	95 NEXTI;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	96 STEP(0); STEP(1); STEP(2); STEP(3); STEP(4); STEP(5);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	97 NEXTI;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	98 STEP(0); STEP(1); STEP(2); STEP(3); STEP(4); STEP(5); STEP(6);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	99 NEXTI;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	100 STEP(0); STEP(1); STEP(2); STEP(3); STEP(4); STEP(5); STEP(6); STEP(7);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	101
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	102 for (i = 8; i <= 159; i++) {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	103
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	104 NEXTI;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	105
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	106 STEP(0);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	107 STEP(1); STEP(2); STEP(3); STEP(4);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	108 STEP(5); STEP(6); STEP(7); STEP(8);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	109 }
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	110
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	111 for (k = 9; k--; L_ACF[k] <<= 1) ;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	112
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	113 }
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	114 /* Rescaling of the array s[0..159]
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	115 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	116 if (scalauto > 0) {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	117 assert(scalauto <= 4);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	118 for (k = 160; k--; *s++ <<= scalauto) ;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	119 }
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	120 }
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	121
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	122 /* 4.2.5 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	123
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	124 static void Reflection_coefficients (
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	125 longword * L_ACF, /* 0...8 IN */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	126 register word * r /* 0...7 OUT */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	127 )
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	128 {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	129 register int i, m, n;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	130 register word temp;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	131 register longword ltmp;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	132 word ACF[9]; /* 0..8 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	133 word P[ 9]; /* 0..8 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	134 word K[ 9]; /* 2..8 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	135
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	136 /* Schur recursion with 16 bits arithmetic.
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	137 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	138
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	139 if (L_ACF[0] == 0) {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	140 for (i = 8; i--; *r++ = 0) ;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	141 return;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	142 }
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	143
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	144 assert( L_ACF[0] != 0 );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	145 temp = gsm_norm( L_ACF[0] );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	146
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	147 assert(temp >= 0 && temp < 32);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	148
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	149 /* ? overflow ? */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	150 for (i = 0; i <= 8; i++) ACF[i] = SASR( L_ACF[i] << temp, 16 );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	151
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	152 /* Initialize array P[..] and K[..] for the recursion.
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	153 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	154
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	155 for (i = 1; i <= 7; i++) K[ i ] = ACF[ i ];
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	156 for (i = 0; i <= 8; i++) P[ i ] = ACF[ i ];
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	157
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	158 /* Compute reflection coefficients
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	159 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	160 for (n = 1; n <= 8; n++, r++) {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	161
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	162 temp = P[1];
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	163 temp = GSM_ABS(temp);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	164 if (P[0] < temp) {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	165 for (i = n; i <= 8; i++) *r++ = 0;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	166 return;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	167 }
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	168
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	169 *r = gsm_div( temp, P[0] );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	170
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	171 assert(*r >= 0);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	172 if (P[1] > 0) r = -r; /* r[n] = sub(0, r[n]) */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	173 assert (*r != MIN_WORD);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	174 if (n == 8) return;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	175
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	176 /* Schur recursion
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	177 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	178 temp = GSM_MULT_R( P[1], *r );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	179 P[0] = GSM_ADD( P[0], temp );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	180
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	181 for (m = 1; m <= 8 - n; m++) {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	182 temp = GSM_MULT_R( K[ m ], *r );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	183 P[m] = GSM_ADD( P[ m+1 ], temp );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	184
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	185 temp = GSM_MULT_R( P[ m+1 ], *r );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	186 K[m] = GSM_ADD( K[ m ], temp );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	187 }
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	188 }
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	189 }
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	190
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	191 /* 4.2.6 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	192
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	193 static void Transformation_to_Log_Area_Ratios (
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	194 register word * r /* 0..7 IN/OUT */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	195 )
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	196 /*
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	197 * The following scaling for r[..] and LAR[..] has been used:
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	198 *
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	199 * r[..] = integer( real_r[..]*32768. ); -1 <= real_r < 1.
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	200 * LAR[..] = integer( real_LAR[..] * 16384 );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	201 * with -1.625 <= real_LAR <= 1.625
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	202 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	203 {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	204 register word temp;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	205 register int i;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	206
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	207 /* Computation of the LAR[0..7] from the r[0..7]
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	208 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	209 for (i = 1; i <= 8; i++, r++) {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	210
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	211 temp = *r;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	212 temp = GSM_ABS(temp);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	213 assert(temp >= 0);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	214
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	215 if (temp < 22118) {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	216 temp >>= 1;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	217 } else if (temp < 31130) {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	218 assert( temp >= 11059 );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	219 temp -= 11059;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	220 } else {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	221 assert( temp >= 26112 );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	222 temp -= 26112;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	223 temp <<= 2;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	224 }
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	225
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	226 r = r < 0 ? -temp : temp;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	227 assert( *r != MIN_WORD );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	228 }
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	229 }
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	230
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	231 /* 4.2.7 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	232
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	233 static void Quantization_and_coding (
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	234 register word * LAR /* [0..7] IN/OUT */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	235 )
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	236 {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	237 register word temp;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	238 longword ltmp;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	239
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	240 /* This procedure needs four tables; the following equations
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	241 * give the optimum scaling for the constants:
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	242 *
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	243 * A[0..7] = integer( real_A[0..7] * 1024 )
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	244 * B[0..7] = integer( real_B[0..7] * 512 )
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	245 * MAC[0..7] = maximum of the LARc[0..7]
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	246 * MIC[0..7] = minimum of the LARc[0..7]
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	247 */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	248
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	249 # undef STEP
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	250 # define STEP( A, B, MAC, MIC ) \
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	251 temp = GSM_MULT( A, *LAR ); \
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	252 temp = GSM_ADD( temp, B ); \
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	253 temp = GSM_ADD( temp, 256 ); \
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	254 temp = SASR( temp, 9 ); \
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	255 *LAR = temp>MAC ? MAC - MIC : (temp<MIC ? 0 : temp - MIC); \
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	256 LAR++;
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	257
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	258 STEP( 20480, 0, 31, -32 );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	259 STEP( 20480, 0, 31, -32 );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	260 STEP( 20480, 2048, 15, -16 );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	261 STEP( 20480, -2560, 15, -16 );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	262
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	263 STEP( 13964, 94, 7, -8 );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	264 STEP( 15360, -1792, 7, -8 );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	265 STEP( 8534, -341, 3, -4 );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	266 STEP( 9036, -1144, 3, -4 );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	267
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	268 # undef STEP
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	269 }
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	270
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	271 void Gsm_LPC_Analysis (
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	272 struct gsmfr_0610_state *S,
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	273 word * s, /* 0..159 signals IN/OUT */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	274 word * LARc) /* 0..7 LARc's OUT */
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	275 {
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	276 longword L_ACF[9];
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	277
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	278 Autocorrelation (s, L_ACF );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	279 Reflection_coefficients (L_ACF, LARc );
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	280 Transformation_to_Log_Area_Ratios (LARc);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	281 Quantization_and_coding (LARc);
0cfb7c95cce2 libgsmfr2: integrate lpc.c from libgsm Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	282 }

FreeCalypso > hg > gsm-codec-lib

annotate libgsmfr2/lpc.c @ 508:c275e57132f8