From d69c1cb37c0b88febe74656feeaa067cc09f9add Mon Sep 17 00:00:00 2001
From: Jean-Marc Valin <jean-marc.valin@usherbrooke.ca>
Date: Mon, 28 Dec 2009 00:34:29 -0500
Subject: [PATCH] Making new PLC code work in fixed-point even though it's
still using float arithmetic.
---
libcelt/celt.c | 52 ++++++++++++++++++++++-----------------------
libcelt/plc.c | 57 ++++++++++++++++++++++++--------------------------
2 files changed, 53 insertions(+), 56 deletions(-)
diff --git a/libcelt/celt.c b/libcelt/celt.c
index 642099ff6..41effc4c0 100644
--- a/libcelt/celt.c
+++ b/libcelt/celt.c
@@ -55,6 +55,9 @@
#include <stdarg.h>
#define LPC_ORDER 24
+#if !defined(FIXED_POINT) || defined(NEW_PLC)
+#include "plc.c"
+#endif
static const celt_word16 preemph = QCONST16(0.8f,15);
@@ -1092,8 +1095,8 @@ struct CELTDecoder {
celt_word16 *oldBandE;
-#ifndef FIXED_POINT
- celt_word16 *lpc;
+#ifdef NEW_PLC
+ float *lpc;
#endif
int last_pitch_index;
@@ -1170,14 +1173,14 @@ CELTDecoder *celt_decoder_create(const CELTMode *mode, int channels, int *error)
st->preemph_memD = (celt_sig*)celt_alloc(C*sizeof(celt_sig));
-#ifndef FIXED_POINT
- st->lpc = (celt_word16*)celt_alloc(C*LPC_ORDER*sizeof(celt_word16));
+#ifdef NEW_PLC
+ st->lpc = (float*)celt_alloc(C*LPC_ORDER*sizeof(float));
#endif
st->loss_count = 0;
if ((st->decode_mem!=NULL) && (st->out_mem!=NULL) && (st->oldBandE!=NULL) &&
-#ifndef FIXED_POINT
+#ifdef NEW_PLC
(st->lpc!=NULL) &&
#endif
(st->preemph_memD!=NULL))
@@ -1223,7 +1226,7 @@ void celt_decoder_destroy(CELTDecoder *st)
celt_free(st->oldBandE);
celt_free(st->preemph_memD);
-#ifndef FIXED_POINT
+#ifdef NEW_PLC
celt_free(st->lpc);
#endif
@@ -1232,9 +1235,6 @@ void celt_decoder_destroy(CELTDecoder *st)
celt_free(st);
}
-#ifndef FIXED_POINT
-#include "plc.c"
-#endif
static void celt_decode_lost(CELTDecoder * restrict st, celt_word16 * restrict pcm)
{
int c, N;
@@ -1270,7 +1270,7 @@ static void celt_decode_lost(CELTDecoder * restrict st, celt_word16 * restrict p
fade = 0;
}
-#ifdef FIXED_POINT
+#ifndef NEW_PLC
offset = MAX_PERIOD-pitch_index;
ALLOC(freq,C*N, celt_sig); /**< Interleaved signal MDCTs */
while (offset+len >= MAX_PERIOD)
@@ -1285,12 +1285,12 @@ static void celt_decode_lost(CELTDecoder * restrict st, celt_word16 * restrict p
#else
for (c=0;c<C;c++)
{
- float e[MAX_PERIOD];
+ celt_word32 e[MAX_PERIOD];
float exc[MAX_PERIOD];
float ac[LPC_ORDER+1];
float decay = 1;
float S1=0;
- celt_word32 mem[LPC_ORDER]={0};
+ float mem[LPC_ORDER]={0};
offset = MAX_PERIOD-pitch_index;
for (i=0;i<MAX_PERIOD;i++)
@@ -1341,7 +1341,7 @@ static void celt_decode_lost(CELTDecoder * restrict st, celt_word16 * restrict p
decay *= decay;
}
e[i] = decay*exc[offset+i];
- S1 += st->out_mem[offset+i]*st->out_mem[offset+i];
+ S1 += st->out_mem[offset+i]*1.*st->out_mem[offset+i];
}
iir(e, st->lpc, e, len+st->mode->overlap, LPC_ORDER, mem);
@@ -1349,7 +1349,7 @@ static void celt_decode_lost(CELTDecoder * restrict st, celt_word16 * restrict p
{
float ratio, S2=0;
for (i=0;i<len+overlap;i++)
- S2 += e[i]*e[i];
+ S2 += e[i]*1.*e[i];
ratio = sqrt((S1+1)/(S2+1));
if (ratio < 1)
for (i=0;i<len+overlap;i++)
@@ -1363,20 +1363,20 @@ static void celt_decode_lost(CELTDecoder * restrict st, celt_word16 * restrict p
previous and next frames */
for (i=0;i<overlap/2;i++)
{
- float tmp1, tmp2;
- tmp1 = e[i ]*st->mode->window[i ] -
- e[overlap-i-1]*st->mode->window[overlap-i-1];
- tmp2 = e[N+overlap-1-i]*st->mode->window[i] +
- e[N+i ]*st->mode->window[overlap-i-1];
- tmp1 *= fade;
- tmp2 *= fade;
- st->out_mem[C*(MAX_PERIOD+i)+c] = tmp2*st->mode->window[overlap-i-1];
- st->out_mem[C*(MAX_PERIOD+overlap-i-1)+c] = tmp2*st->mode->window[i];
- st->out_mem[C*(MAX_PERIOD-N+i)+c] += tmp1*st->mode->window[i];
- st->out_mem[C*(MAX_PERIOD-N+overlap-i-1)+c] -= tmp1*st->mode->window[overlap-i-1];
+ celt_word32 tmp1, tmp2;
+ tmp1 = MULT16_32_Q15(st->mode->window[i ], e[i ]) -
+ MULT16_32_Q15(st->mode->window[overlap-i-1], e[overlap-i-1]);
+ tmp2 = MULT16_32_Q15(st->mode->window[i], e[N+overlap-1-i]) +
+ MULT16_32_Q15(st->mode->window[overlap-i-1], e[N+i ]);
+ tmp1 = MULT16_32_Q15(fade, tmp1);
+ tmp2 = MULT16_32_Q15(fade, tmp2);
+ st->out_mem[C*(MAX_PERIOD+i)+c] = MULT16_32_Q15(st->mode->window[overlap-i-1], tmp2);
+ st->out_mem[C*(MAX_PERIOD+overlap-i-1)+c] = MULT16_32_Q15(st->mode->window[i], tmp2);
+ st->out_mem[C*(MAX_PERIOD-N+i)+c] += MULT16_32_Q15(st->mode->window[i], tmp1);
+ st->out_mem[C*(MAX_PERIOD-N+overlap-i-1)+c] -= MULT16_32_Q15(st->mode->window[overlap-i-1], tmp1);
}
for (i=0;i<N-overlap;i++)
- st->out_mem[C*(MAX_PERIOD-N+overlap+i)+c] = fade*e[overlap+i];
+ st->out_mem[C*(MAX_PERIOD-N+overlap+i)+c] = MULT16_32_Q15(fade, e[overlap+i]);
}
#endif
diff --git a/libcelt/plc.c b/libcelt/plc.c
index 8f5100c5d..8eb12d54c 100644
--- a/libcelt/plc.c
+++ b/libcelt/plc.c
@@ -1,16 +1,17 @@
+#ifndef NEW_PLC
+#define NEW_PLC
+#endif
-
-
-celt_word32 _celt_lpc(
-celt_word16 *lpc, /* out: [0...p-1] LPC coefficients */
-const celt_word16 *ac, /* in: [0...p] autocorrelation values */
+float _celt_lpc(
+ float *lpc, /* out: [0...p-1] LPC coefficients */
+const float *ac, /* in: [0...p] autocorrelation values */
int p
)
{
int i, j;
- celt_word16 r;
- celt_word16 error = ac[0];
+ float r;
+ float error = ac[0];
if (ac[0] == 0)
{
@@ -22,38 +23,34 @@ int p
for (i = 0; i < p; i++) {
/* Sum up this iteration's reflection coefficient */
- celt_word32 rr = NEG32(SHL32(EXTEND32(ac[i + 1]),13));
+ float rr = -ac[i + 1];
for (j = 0; j < i; j++)
- rr = SUB32(rr,MULT16_16(lpc[j],ac[i - j]));
-#ifdef FIXED_POINT
- r = DIV32_16(rr+PSHR32(error,1),ADD16(error,1));
-#else
+ rr = rr - lpc[j]*ac[i - j];
r = rr/(error+1e-15);
-#endif
/* Update LPC coefficients and total error */
lpc[i] = r;
for (j = 0; j < i>>1; j++)
{
- celt_word16 tmp = lpc[j];
- lpc[j] = MAC16_16_P13(lpc[j],r,lpc[i-1-j]);
- lpc[i-1-j] = MAC16_16_P13(lpc[i-1-j],r,tmp);
+ float tmp = lpc[j];
+ lpc[j] = lpc[j ] + r*lpc[i-1-j];
+ lpc[i-1-j] = lpc[i-1-j] + r*tmp;
}
if (i & 1)
- lpc[j] = MAC16_16_P13(lpc[j],lpc[j],r);
+ lpc[j] = lpc[j] + lpc[j]*r;
- error = SUB16(error,MULT16_16_Q13(r,MULT16_16_Q13(error,r)));
+ error = error - r*r*error;
if (error<.00001*ac[0])
break;
}
return error;
}
-void fir(const celt_word16 *x,
- const celt_word16 *num,
- celt_word16 *y,
+void fir(const float *x,
+ const float *num,
+ float *y,
int N,
int ord,
- celt_word32 *mem)
+ float *mem)
{
int i,j;
@@ -73,12 +70,12 @@ void fir(const celt_word16 *x,
}
}
-void iir(const celt_word16 *x,
- const celt_word16 *den,
- celt_word16 *y,
+void iir(const celt_word32 *x,
+ const float *den,
+ celt_word32 *y,
int N,
int ord,
- celt_word32 *mem)
+ float *mem)
{
int i,j;
for (i=0;i<N;i++)
@@ -98,9 +95,9 @@ void iir(const celt_word16 *x,
}
void _celt_autocorr(
- const celt_word16 *x, /* in: [0...n-1] samples x */
+ const float *x, /* in: [0...n-1] samples x */
float *ac, /* out: [0...lag-1] ac values */
- const float *window,
+ const celt_word16 *window,
int overlap,
int lag,
int n
@@ -115,8 +112,8 @@ void _celt_autocorr(
xx[i] = x[i];
for (i=0;i<overlap;i++)
{
- xx[i] *= window[i];
- xx[n-i-1] *= window[i];
+ xx[i] *= (1./Q15ONE)*window[i];
+ xx[n-i-1] *= (1./Q15ONE)*window[i];
}
while (lag>=0)
{
--
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