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

annotate libgsmfr2/lpc.c @ 282:9ee8ad3d4d30

frtest: rm gsmfr-hand-test and gsmfr-max-out utils These hack programs were never properly documented and were written only as part of a debug chase, in pursuit of a bug that ultimately turned out to be in our then-hacky patch to osmo-bts-sysmo, before beginning of proper patches in Osmocom. These hack programs need to be dropped from the present sw package because they depend on old libgsm, and we are eliminating that dependency.

author	Mychaela Falconia <falcon@freecalypso.org>
date	Sun, 14 Apr 2024 05:44:47 +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 @ 282:9ee8ad3d4d30