ref: e410d00c4821726accfbe1f825f2def6376e181f
dir: /libgsm/short_term.c/
/*
* Copyright 1992 by Jutta Degener and Carsten Bormann, Technische
* Universitaet Berlin. See the accompanying file "COPYRIGHT" for
* details. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE.
*/
/* $Header: /cvsroot/sox/sox/libgsm/short_term.c,v 1.1 2007/09/06 16:50:56 cbagwell Exp $ */
#include <stdio.h>
#include <assert.h>
#include "private.h"
#include "gsm.h"
/*
* SHORT TERM ANALYSIS FILTERING SECTION
*/
/* 4.2.8 */
static void Decoding_of_the_coded_Log_Area_Ratios (
word * LARc, /* coded log area ratio [0..7] IN */
word * LARpp) /* out: decoded .. */
{
register word temp1 /* , temp2 */;
register long ltmp; /* for GSM_ADD */
/* This procedure requires for efficient implementation
* two tables.
*
* INVA[1..8] = integer( (32768 * 8) / real_A[1..8])
* MIC[1..8] = minimum value of the LARc[1..8]
*/
/* Compute the LARpp[1..8]
*/
/* for (i = 1; i <= 8; i++, B++, MIC++, INVA++, LARc++, LARpp++) {
*
* temp1 = GSM_ADD( *LARc, *MIC ) << 10;
* temp2 = *B << 1;
* temp1 = GSM_SUB( temp1, temp2 );
*
* assert(*INVA != MIN_WORD);
*
* temp1 = GSM_MULT_R( *INVA, temp1 );
* *LARpp = GSM_ADD( temp1, temp1 );
* }
*/
#undef STEP
#define STEP( B, MIC, INVA ) \
temp1 = GSM_ADD( *LARc++, MIC ) << 10; \
temp1 = GSM_SUB( temp1, B << 1 ); \
temp1 = GSM_MULT_R( INVA, temp1 ); \
*LARpp++ = GSM_ADD( temp1, temp1 );
STEP( 0, -32, 13107 );
STEP( 0, -32, 13107 );
STEP( 2048, -16, 13107 );
STEP( -2560, -16, 13107 );
STEP( 94, -8, 19223 );
STEP( -1792, -8, 17476 );
STEP( -341, -4, 31454 );
STEP( -1144, -4, 29708 );
/* NOTE: the addition of *MIC is used to restore
* the sign of *LARc.
*/
}
/* 4.2.9 */
/* Computation of the quantized reflection coefficients
*/
/* 4.2.9.1 Interpolation of the LARpp[1..8] to get the LARp[1..8]
*/
/*
* Within each frame of 160 analyzed speech samples the short term
* analysis and synthesis filters operate with four different sets of
* coefficients, derived from the previous set of decoded LARs(LARpp(j-1))
* and the actual set of decoded LARs (LARpp(j))
*
* (Initial value: LARpp(j-1)[1..8] = 0.)
*/
static void Coefficients_0_12 (
register word * LARpp_j_1,
register word * LARpp_j,
register word * LARp)
{
register int i;
register longword ltmp;
for (i = 1; i <= 8; i++, LARp++, LARpp_j_1++, LARpp_j++) {
*LARp = GSM_ADD( SASR( *LARpp_j_1, 2 ), SASR( *LARpp_j, 2 ));
*LARp = GSM_ADD( *LARp, SASR( *LARpp_j_1, 1));
}
}
static void Coefficients_13_26 (
register word * LARpp_j_1,
register word * LARpp_j,
register word * LARp)
{
register int i;
register longword ltmp;
for (i = 1; i <= 8; i++, LARpp_j_1++, LARpp_j++, LARp++) {
*LARp = GSM_ADD( SASR( *LARpp_j_1, 1), SASR( *LARpp_j, 1 ));
}
}
static void Coefficients_27_39 (
register word * LARpp_j_1,
register word * LARpp_j,
register word * LARp)
{
register int i;
register longword ltmp;
for (i = 1; i <= 8; i++, LARpp_j_1++, LARpp_j++, LARp++) {
*LARp = GSM_ADD( SASR( *LARpp_j_1, 2 ), SASR( *LARpp_j, 2 ));
*LARp = GSM_ADD( *LARp, SASR( *LARpp_j, 1 ));
}
}
static void Coefficients_40_159 (
register word * LARpp_j,
register word * LARp)
{
register int i;
for (i = 1; i <= 8; i++, LARp++, LARpp_j++)
*LARp = *LARpp_j;
}
/* 4.2.9.2 */
static void LARp_to_rp (
register word * LARp) /* [0..7] IN/OUT */
/*
* The input of this procedure is the interpolated LARp[0..7] array.
* The reflection coefficients, rp[i], are used in the analysis
* filter and in the synthesis filter.
*/
{
register int i;
register word temp;
register longword ltmp;
for (i = 1; i <= 8; i++, LARp++) {
/* temp = GSM_ABS( *LARp );
*
* if (temp < 11059) temp <<= 1;
* else if (temp < 20070) temp += 11059;
* else temp = GSM_ADD( temp >> 2, 26112 );
*
* *LARp = *LARp < 0 ? -temp : temp;
*/
if (*LARp < 0) {
temp = *LARp == MIN_WORD ? MAX_WORD : -(*LARp);
*LARp = - ((temp < 11059) ? temp << 1
: ((temp < 20070) ? temp + 11059
: GSM_ADD( temp >> 2, 26112 )));
} else {
temp = *LARp;
*LARp = (temp < 11059) ? temp << 1
: ((temp < 20070) ? temp + 11059
: GSM_ADD( temp >> 2, 26112 ));
}
}
}
/* 4.2.10 */
static void Short_term_analysis_filtering (
struct gsm_state * S,
register word * rp, /* [0..7] IN */
register int k_n, /* k_end - k_start */
register word * s /* [0..n-1] IN/OUT */
)
/*
* This procedure computes the short term residual signal d[..] to be fed
* to the RPE-LTP loop from the s[..] signal and from the local rp[..]
* array (quantized reflection coefficients). As the call of this
* procedure can be done in many ways (see the interpolation of the LAR
* coefficient), it is assumed that the computation begins with index
* k_start (for arrays d[..] and s[..]) and stops with index k_end
* (k_start and k_end are defined in 4.2.9.1). This procedure also
* needs to keep the array u[0..7] in memory for each call.
*/
{
register word * u = S->u;
register int i;
register word di, zzz, ui, sav, rpi;
register longword ltmp;
for (; k_n--; s++) {
di = sav = *s;
for (i = 0; i < 8; i++) { /* YYY */
ui = u[i];
rpi = rp[i];
u[i] = sav;
zzz = GSM_MULT_R(rpi, di);
sav = GSM_ADD( ui, zzz);
zzz = GSM_MULT_R(rpi, ui);
di = GSM_ADD( di, zzz );
}
*s = di;
}
}
#if defined(USE_FLOAT_MUL) && defined(FAST)
static void Fast_Short_term_analysis_filtering (
struct gsm_state * S,
register word * rp, /* [0..7] IN */
register int k_n, /* k_end - k_start */
register word * s /* [0..n-1] IN/OUT */
)
{
register word * u = S->u;
register int i;
float uf[8],
rpf[8];
register float scalef = 3.0517578125e-5;
register float sav, di, temp;
for (i = 0; i < 8; ++i) {
uf[i] = u[i];
rpf[i] = rp[i] * scalef;
}
for (; k_n--; s++) {
sav = di = *s;
for (i = 0; i < 8; ++i) {
register float rpfi = rpf[i];
register float ufi = uf[i];
uf[i] = sav;
temp = rpfi * di + ufi;
di += rpfi * ufi;
sav = temp;
}
*s = di;
}
for (i = 0; i < 8; ++i) u[i] = uf[i];
}
#endif /* ! (defined (USE_FLOAT_MUL) && defined (FAST)) */
static void Short_term_synthesis_filtering (
struct gsm_state * S,
register word * rrp, /* [0..7] IN */
register int k, /* k_end - k_start */
register word * wt, /* [0..k-1] IN */
register word * sr /* [0..k-1] OUT */
)
{
register word * v = S->v;
register int i;
register word sri, tmp1, tmp2;
register longword ltmp; /* for GSM_ADD & GSM_SUB */
while (k--) {
sri = *wt++;
for (i = 8; i--;) {
/* sri = GSM_SUB( sri, gsm_mult_r( rrp[i], v[i] ) );
*/
tmp1 = rrp[i];
tmp2 = v[i];
tmp2 = ( tmp1 == MIN_WORD && tmp2 == MIN_WORD
? MAX_WORD
: 0x0FFFF & (( (longword)tmp1 * (longword)tmp2
+ 16384) >> 15)) ;
sri = GSM_SUB( sri, tmp2 );
/* v[i+1] = GSM_ADD( v[i], gsm_mult_r( rrp[i], sri ) );
*/
tmp1 = ( tmp1 == MIN_WORD && sri == MIN_WORD
? MAX_WORD
: 0x0FFFF & (( (longword)tmp1 * (longword)sri
+ 16384) >> 15)) ;
v[i+1] = GSM_ADD( v[i], tmp1);
}
*sr++ = v[0] = sri;
}
}
#if defined(FAST) && defined(USE_FLOAT_MUL)
static void Fast_Short_term_synthesis_filtering (
struct gsm_state * S,
register word * rrp, /* [0..7] IN */
register int k, /* k_end - k_start */
register word * wt, /* [0..k-1] IN */
register word * sr /* [0..k-1] OUT */
)
{
register word * v = S->v;
register int i;
float va[9], rrpa[8];
register float scalef = 3.0517578125e-5, temp;
for (i = 0; i < 8; ++i) {
va[i] = v[i];
rrpa[i] = (float)rrp[i] * scalef;
}
while (k--) {
register float sri = *wt++;
for (i = 8; i--;) {
sri -= rrpa[i] * va[i];
if (sri < -32768.) sri = -32768.;
else if (sri > 32767.) sri = 32767.;
temp = va[i] + rrpa[i] * sri;
if (temp < -32768.) temp = -32768.;
else if (temp > 32767.) temp = 32767.;
va[i+1] = temp;
}
*sr++ = va[0] = sri;
}
for (i = 0; i < 9; ++i) v[i] = va[i];
}
#endif /* defined(FAST) && defined(USE_FLOAT_MUL) */
void Gsm_Short_Term_Analysis_Filter (
struct gsm_state * S,
word * LARc, /* coded log area ratio [0..7] IN */
word * s /* signal [0..159] IN/OUT */
)
{
word * LARpp_j = S->LARpp[ S->j ];
word * LARpp_j_1 = S->LARpp[ S->j ^= 1 ];
word LARp[8];
#undef FILTER
#if defined(FAST) && defined(USE_FLOAT_MUL)
# define FILTER (* (S->fast \
? Fast_Short_term_analysis_filtering \
: Short_term_analysis_filtering ))
#else
# define FILTER Short_term_analysis_filtering
#endif
Decoding_of_the_coded_Log_Area_Ratios( LARc, LARpp_j );
Coefficients_0_12( LARpp_j_1, LARpp_j, LARp );
LARp_to_rp( LARp );
FILTER( S, LARp, 13, s);
Coefficients_13_26( LARpp_j_1, LARpp_j, LARp);
LARp_to_rp( LARp );
FILTER( S, LARp, 14, s + 13);
Coefficients_27_39( LARpp_j_1, LARpp_j, LARp);
LARp_to_rp( LARp );
FILTER( S, LARp, 13, s + 27);
Coefficients_40_159( LARpp_j, LARp);
LARp_to_rp( LARp );
FILTER( S, LARp, 120, s + 40);
}
void Gsm_Short_Term_Synthesis_Filter (
struct gsm_state * S,
word * LARcr, /* received log area ratios [0..7] IN */
word * wt, /* received d [0..159] IN */
word * s /* signal s [0..159] OUT */
)
{
word * LARpp_j = S->LARpp[ S->j ];
word * LARpp_j_1 = S->LARpp[ S->j ^=1 ];
word LARp[8];
#undef FILTER
#if defined(FAST) && defined(USE_FLOAT_MUL)
# define FILTER (* (S->fast \
? Fast_Short_term_synthesis_filtering \
: Short_term_synthesis_filtering ))
#else
# define FILTER Short_term_synthesis_filtering
#endif
Decoding_of_the_coded_Log_Area_Ratios( LARcr, LARpp_j );
Coefficients_0_12( LARpp_j_1, LARpp_j, LARp );
LARp_to_rp( LARp );
FILTER( S, LARp, 13, wt, s );
Coefficients_13_26( LARpp_j_1, LARpp_j, LARp);
LARp_to_rp( LARp );
FILTER( S, LARp, 14, wt + 13, s + 13 );
Coefficients_27_39( LARpp_j_1, LARpp_j, LARp);
LARp_to_rp( LARp );
FILTER( S, LARp, 13, wt + 27, s + 27 );
Coefficients_40_159( LARpp_j, LARp );
LARp_to_rp( LARp );
FILTER(S, LARp, 120, wt + 40, s + 40);
}