ref: f28062fe6a762a083797d57ade1a8eba0bd1bb2c
parent: 227ad2f82d77a91f9965096c3b063fec5dec7db2
author: Jean-Marc Valin <[email protected]>
date: Mon Mar 3 08:24:01 EST 2008
Don't bother multiplying when the window's value is one or zero
--- a/libcelt/celt.c
+++ b/libcelt/celt.c
@@ -161,13 +161,14 @@
}
/** Apply window and compute the MDCT for all sub-frames and all channels in a frame */
-static celt_word32_t compute_mdcts(const mdct_lookup *mdct_lookup, celt_word16_t *window, celt_sig_t *in, celt_sig_t *out, int N, int B, int C)
+static celt_word32_t compute_mdcts(const mdct_lookup *mdct_lookup, celt_word16_t *window, celt_sig_t *in, celt_sig_t *out, int N, int overlap, int B, int C)
{- int i, c;
+ int i, c, N4;
celt_word32_t E = 0;
VARDECL(celt_word32_t *x);
VARDECL(celt_word32_t *tmp);
SAVE_STACK;
+ N4 = (N-overlap)/2;
ALLOC(x, 2*N, celt_word32_t);
ALLOC(tmp, N, celt_word32_t);
for (c=0;c<C;c++)
@@ -176,10 +177,25 @@
{int j;
for (j=0;j<2*N;j++)
+ x[j] = in[C*i*N+C*j+c];
+#if 0
+ for (j=0;j<2*N;j++)
+ x[j] = MULT16_32_Q15(window[j],x[j]);
+#else
+ for (j=0;j<overlap;j++)
{- x[j] = MULT16_32_Q15(window[j],in[C*i*N+C*j+c]);
- E += MULT16_16(EXTRACT16(SHR32(x[j],SIG_SHIFT+4)),EXTRACT16(SHR32(x[j],SIG_SHIFT+4)));
+ x[j+N4] = MULT16_32_Q15(window[j+N4],x[j+N4]);
+ x[2*N-j-N4-1] = MULT16_32_Q15(window[j+N4],x[2*N-j-N4-1]);
}
+ for (j=0;j<N4;j++)
+ {+ x[j] = 0;
+ x[2*N-j-1] = 0;
+ }
+ //printf ("%d %d %d %d\n", window[N4-1], window[N4], window[N4+overlap-1], window[N4+overlap]);+#endif
+ for (j=0;j<2*N;j++)
+ E += MULT16_16(EXTRACT16(SHR32(x[j],SIG_SHIFT+4)),EXTRACT16(SHR32(x[j],SIG_SHIFT+4)));
mdct_forward(mdct_lookup, x, tmp);
/* Interleaving the sub-frames */
for (j=0;j<N;j++)
@@ -209,9 +225,19 @@
for (j=0;j<N;j++)
tmp[j] = X[C*B*j+C*i+c];
mdct_backward(mdct_lookup, tmp, x);
+#if 0
for (j=0;j<2*N;j++)
x[j] = MULT16_32_Q15(window[j],x[j]);
+#else
+ /* The first and last part would need to be set to zero if we actually
+ wanted to use them. */
for (j=0;j<overlap;j++)
+ {+ x[j+N4] = MULT16_32_Q15(window[j+N4],x[j+N4]);
+ x[2*N-j-N4-1] = MULT16_32_Q15(window[j+N4],x[2*N-j-N4-1]);
+ }
+#endif
+ for (j=0;j<overlap;j++)
out_mem[C*(MAX_PERIOD+(i-B)*N)+C*j+c] = 2*(x[N4+j]+mdct_overlap[C*j+c]);
for (j=0;j<2*N4;j++)
out_mem[C*(MAX_PERIOD+(i-B)*N)+C*(j+overlap)+c] = 2*x[j+N4+overlap];
@@ -268,7 +294,7 @@
}
/*for (i=0;i<(B+1)*C*N;i++) printf ("%f(%d) ", in[i], i); printf ("\n");*//* Compute MDCTs */
- curr_power = compute_mdcts(&st->mode->mdct, st->mode->window, in, freq, N, B, C);
+ curr_power = compute_mdcts(&st->mode->mdct, st->mode->window, in, freq, N, st->overlap, B, C);
#if 0 /* Mask disabled until it can be made to do something useful */
compute_mdct_masking(X, mask, B*C*N, st->Fs);
@@ -282,11 +308,16 @@
/* Pitch analysis */
for (c=0;c<C;c++)
{- for (i=0;i<N;i++)
+ for (i=0;i<N4;i++)
{- in[C*i+c] = MULT16_32_Q15(st->mode->window[i], in[C*i+c]);
- in[C*(B*N+i)+c] = MULT16_32_Q15(st->mode->window[N+i], in[C*(B*N+i)+c]);
+ in[C*i+c] = 0;
+ in[C*(B*N+N-i-1)+c] = 0;
}
+ for (i=0;i<st->overlap;i++)
+ {+ in[C*(i+N4)+c] = MULT16_32_Q15(st->mode->window[i+N4], in[C*(i+N4)+c]);
+ in[C*(B*N+N-i-N4-1)+c] = MULT16_32_Q15(st->mode->window[i+N4], in[C*(B*N+N-i-N4-1)+c]);
+ }
}
find_spectral_pitch(st->fft, &st->psy, in, st->out_mem, MAX_PERIOD, (B+1)*N, C, &pitch_index);
@@ -309,7 +340,7 @@
/*for (i=0;i<N*B*C;i++)printf("%f ", X[i]);printf("\n");*//* Compute MDCTs of the pitch part */
- pitch_power = compute_mdcts(&st->mode->mdct, st->mode->window, st->out_mem+pitch_index*C, freq, N, B, C);
+ pitch_power = compute_mdcts(&st->mode->mdct, st->mode->window, st->out_mem+pitch_index*C, freq, N, st->overlap, B, C);
quant_energy(st->mode, bandE, st->oldBandE, nbCompressedBytes*8/3, &st->enc);
@@ -524,7 +555,7 @@
pitch_index = st->last_pitch_index;
/* Use the pitch MDCT as the "guessed" signal */
- compute_mdcts(&st->mode->mdct, st->mode->window, st->out_mem+pitch_index*C, freq, N, B, C);
+ compute_mdcts(&st->mode->mdct, st->mode->window, st->out_mem+pitch_index*C, freq, N, st->overlap, B, C);
CELT_MOVE(st->out_mem, st->out_mem+C*B*N, C*(MAX_PERIOD-B*N));
/* Compute inverse MDCTs */
@@ -606,7 +637,7 @@
}
/* Pitch MDCT */
- compute_mdcts(&st->mode->mdct, st->mode->window, st->out_mem+pitch_index*C, freq, N, B, C);
+ compute_mdcts(&st->mode->mdct, st->mode->window, st->out_mem+pitch_index*C, freq, N, st->overlap, B, C);
{VARDECL(celt_ener_t *bandEp);
--- a/libcelt/modes.c
+++ b/libcelt/modes.c
@@ -274,9 +274,15 @@
for (i=0;i<2*N;i++)
mode->window[i] = 0;
+#ifndef FIXED_POINT
for (i=0;i<mode->overlap;i++)
mode->window[N4+i] = mode->window[2*N-N4-i-1]
= Q15ONE*sin(.5*M_PI* sin(.5*M_PI*(i+.5)/mode->overlap) * sin(.5*M_PI*(i+.5)/mode->overlap));
+#else
+ for (i=0;i<mode->overlap;i++)
+ mode->window[N4+i] = mode->window[2*N-N4-i-1]
+ = MIN32(32767,32768.*sin(.5*M_PI* sin(.5*M_PI*(i+.5)/mode->overlap) * sin(.5*M_PI*(i+.5)/mode->overlap)));
+#endif
for (i=0;i<N2;i++)
mode->window[N-N4+i] = Q15ONE;