latest libac3 from walken

CVS patchset: 265
CVS date: 2001/07/10 21:50:31

1 files changed, 34 insertions, 84 deletions

diff --git a/src/libac3/imdct.c b/src/libac3/imdct.c
index a2e83d423..030026a54 100644
--- a/src/libac3/imdct.c
+++ b/src/libac3/imdct.c
@@ -24,32 +24,23 @@
 
 #include "config.h"
 
+#include <inttypes.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <math.h>
 #include "ac3.h"
 #include "ac3_internal.h"
 
-
-#include "decode.h"
-#include "imdct.h"
-
-void imdct_do_256(float data[],float delay[]);
-void imdct_do_512(float data[],float delay[]);
-
-void imdct_do_256_mlib(float data[],float delay[]);
-void imdct_do_512_mlib(float data[],float delay[]);
+void (* imdct_256) (float data[], float delay[]);
+void (* imdct_512) (float data[], float delay[]);
 
 typedef struct complex_s
 {
-	float real;
-	float imag;
+    float real;
+    float imag;
 } complex_t;
 
 
-#define N 512
-
-
 /* 128 point bit-reverse LUT */
 static uint8_t bit_reverse_512[] = {
 	0x00, 0x40, 0x20, 0x60, 0x10, 0x50, 0x30, 0x70, 
@@ -82,7 +73,6 @@ static uint8_t bit_reverse_256[] = {
 static complex_t buf[128];
 
 /* Twiddle factor LUT */
-static complex_t *w[7];
 static complex_t w_1[1];
 static complex_t w_2[2];
 static complex_t w_4[4];
@@ -90,6 +80,7 @@ static complex_t w_8[8];
 static complex_t w_16[16];
 static complex_t w_32[32];
 static complex_t w_64[64];
+static complex_t * w[7] = {w_1, w_2, w_4, w_8, w_16, w_32, w_64};
 
 /* Twiddle factors for IMDCT */
 static float xcos1[128];
@@ -97,9 +88,6 @@ static float xsin1[128];
 static float xcos2[64];
 static float xsin2[64];
 
-/* Delay buffer for time domain interleaving */
-static float delay[6][256];
-
 /* Windowing function for Modified DCT - Thank you acroread */
 float imdct_window[] = {
 	0.00014, 0.00024, 0.00037, 0.00051, 0.00067, 0.00086, 0.00107, 0.00130,
@@ -157,51 +145,6 @@ static inline complex_t cmplx_mult(complex_t a, complex_t b)
     return ret;
 }
 
-void imdct_init(void)
-{
-    int i,k;
-    complex_t angle_step;
-    complex_t current_angle;
-
-#ifdef LIBAC3_MLIB
-    return;
-#endif
-
-    /* Twiddle factors to turn IFFT into IMDCT */
-    for( i=0; i < 128; i++) {
-	xcos1[i] = -cos(2.0f * M_PI * (8*i+1)/(8*N)) ; 
-	xsin1[i] = -sin(2.0f * M_PI * (8*i+1)/(8*N)) ;
-    }
-	
-    /* More twiddle factors to turn IFFT into IMDCT */
-    for( i=0; i < 64; i++) {
-	xcos2[i] = -cos(2.0f * M_PI * (8*i+1)/(4*N)) ; 
-	xsin2[i] = -sin(2.0f * M_PI * (8*i+1)/(4*N)) ;
-    }
-
-    /* Canonical twiddle factors for FFT */
-    w[0] = w_1;
-    w[1] = w_2;
-    w[2] = w_4;
-    w[3] = w_8;
-    w[4] = w_16;
-    w[5] = w_32;
-    w[6] = w_64;
-
-    for( i = 0; i < 7; i++) {
-	angle_step.real = cos(-2.0 * M_PI / (1 << (i+1)));
-	angle_step.imag = sin(-2.0 * M_PI / (1 << (i+1)));
-
-	current_angle.real = 1.0;
-	current_angle.imag = 0.0;
-
-	for (k = 0; k < 1 << i; k++) {
-	    w[i][k] = current_angle;
-	    current_angle = cmplx_mult(current_angle,angle_step);
-	}
-    }
-}
-
 void
 imdct_do_512(float data[],float delay[])
 {
@@ -429,30 +372,37 @@ imdct_do_256(float data[],float delay[])
     }
 }
 
-void 
-imdct(ac3_state_t *state,audblk_t *audblk, stream_samples_t samples) {
-    int i;
-
+void imdct_init (void)
+{
 #ifdef LIBAC3_MLIB
-    for(i=0; i<state->nfchans;i++) {
-	if(audblk->blksw[i])
-	    imdct_do_256_mlib(samples[i],delay[i]);
-	else
-	    imdct_do_512_mlib(samples[i],delay[i]);
+    void imdct_do_256_mlib(float data[],float delay[]);
+    void imdct_do_512_mlib(float data[],float delay[]);
+
+    imdct_512 = imdct_do_512_mlib;
+    imdct_256 = imdct_do_256_mlib;
+#else
+    int i, j, k;
+
+    /* Twiddle factors to turn IFFT into IMDCT */
+    for (i = 0; i < 128; i++) {
+	xcos1[i] = -cos ((M_PI / 2048) * (8 * i + 1));
+	xsin1[i] = -sin ((M_PI / 2048) * (8 * i + 1));
     }
-    return;
-#endif
 
-    for(i=0; i<state->nfchans;i++) {
-	if(audblk->blksw[i])
-	    imdct_do_256(samples[i],delay[i]);
-	else
-	    imdct_do_512(samples[i],delay[i]);
+    /* More twiddle factors to turn IFFT into IMDCT */
+    for (i = 0; i < 64; i++) {
+	xcos2[i] = -cos ((M_PI / 1024) * (8 * i + 1));
+	xsin2[i] = -sin ((M_PI / 1024) * (8 * i + 1));
     }
 
-    //XXX We don't bother with the IMDCT for the LFE as it's currently
-    //unused.
-    //if (state->lfeon)
-    //	imdct_do_512(coeffs->lfe,samples->channel[5],delay[5]);
-    //	
+    for (i = 0; i < 7; i++) {
+	j = 1 << i;
+	for (k = 0; k < j; k++) {
+	    w[i][k].real = cos (-M_PI * k / j);
+	    w[i][k].imag = sin (-M_PI * k / j);
+	}
+    }
+    imdct_512 = imdct_do_512;
+    imdct_256 = imdct_do_256;
+#endif
 }