ref: e4aeb472775c1875a89f130f2d636b7ac58351bb
parent: 528f4b8660a8eac7e24ca62ff048178f57da0b77
author: Jean-Marc Valin <[email protected]>
date: Sun Jun 29 08:06:05 EDT 2008
More fixed-point conversion of the time window.
--- a/libcelt/celt.c
+++ b/libcelt/celt.c
@@ -49,13 +49,10 @@
#include "psy.h"
#include "rate.h"
#include "stack_alloc.h"
+#include "mathops.h"
static const celt_word16_t preemph = QCONST16(0.8f,15);
-static const float gainWindow[16] = {- 0.0085135, 0.0337639, 0.0748914, 0.1304955, 0.1986827, 0.2771308, 0.3631685, 0.4538658,
- 0.5461342, 0.6368315, 0.7228692, 0.8013173, 0.8695045, 0.9251086, 0.9662361, 0.9914865};
-
#ifdef FIXED_POINT
static const celt_word16_t transientWindow[16] = {279, 1106, 2454, 4276, 6510, 9081, 11900, 14872,
@@ -298,22 +295,9 @@
/* Prevents problems from the imdct doing the overlap-add */
CELT_MEMSET(x+N4, 0, overlap);
mdct_backward(lookup, tmp, x, mode->window, overlap);
- if (transient_shift > 0)
- {-#ifdef FIXED_POINT
- for (j=0;j<16;j++)
- x[N4+transient_time+j-16] *= 1-gainWindow[j]+gainWindow[j]*(1<<transient_shift);
- for (j=transient_time;j<N+overlap;j++)
- x[N4+j] = SHL32(x[N4+j], transient_shift);
-#else
- for (j=0;j<16;j++)
- x[N4+transient_time+j-16] *= 1+gainWindow[j]*((1<<transient_shift)-1);
- for (j=transient_time;j<N+overlap;j++)
- x[N4+j] *= 1<<transient_shift;
-#endif
- }
+ celt_assert(transient_shift == 0)
/* The first and last part would need to be set to zero if we actually
- wanted to use them. */
+ wanted to use them. */
for (j=0;j<overlap;j++)
out_mem[C*(MAX_PERIOD-N)+C*j+c] += x[j+N4];
for (j=0;j<overlap;j++)
@@ -349,7 +333,7 @@
x[N4+j] = SHL32(x[N4+j], transient_shift);
#else
for (j=0;j<16;j++)
- x[N4+transient_time+j-16] *= 1+gainWindow[j]*((1<<transient_shift)-1);
+ x[N4+transient_time+j-16] *= 1+transientWindow[j]*((1<<transient_shift)-1);
for (j=transient_time;j<N+overlap;j++)
x[N4+j] *= 1<<transient_shift;
#endif
@@ -437,14 +421,17 @@
ec_enc_uint(&st->enc, transient_time, N+st->overlap);
if (transient_shift)
{+#ifdef FIXED_POINT
for (c=0;c<C;c++)
for (i=0;i<16;i++)
- in[C*(transient_time+i-16)+c] /= 1+gainWindow[i]*((1<<transient_shift)-1);
-#ifdef FIXED_POINT
+ in[C*(transient_time+i-16)+c] = MULT16_32_Q15(EXTRACT16(SHR32(celt_rcp(Q15ONE+MULT16_16(transientWindow[i],((1<<transient_shift)-1))),1)), in[C*(transient_time+i-16)+c]);
for (c=0;c<C;c++)
for (i=transient_time;i<N+st->overlap;i++)
in[C*i+c] = SHR32(in[C*i+c], transient_shift);
#else
+ for (c=0;c<C;c++)
+ for (i=0;i<16;i++)
+ in[C*(transient_time+i-16)+c] /= 1+transientWindow[i]*((1<<transient_shift)-1);
gain_1 = 1./(1<<transient_shift);
for (c=0;c<C;c++)
for (i=transient_time;i<N+st->overlap;i++)