[xiph-commits] r10636 - trunk/speex/libspeex

[jm at svn.xiph.org]

Author: jm
Date: 2005-12-18 05:13:26 -0800 (Sun, 18 Dec 2005)
New Revision: 10636

Modified:
   trunk/speex/libspeex/lsp.c
   trunk/speex/libspeex/math_approx.c
   trunk/speex/libspeex/math_approx.h
   trunk/speex/libspeex/mdf.c
Log:
Moved spx_cos to math_approx.c and use it for initializing the mdf window.


Modified: trunk/speex/libspeex/lsp.c
===================================================================
--- trunk/speex/libspeex/lsp.c	2005-12-18 12:54:54 UTC (rev 10635)
+++ trunk/speex/libspeex/lsp.c	2005-12-18 13:13:26 UTC (rev 10636)
@@ -63,28 +63,8 @@
 
 #ifdef FIXED_POINT
 
-#define C1 8192
-#define C2 -4096
-#define C3 340
-#define C4 -10
 
-static spx_word16_t spx_cos(spx_word16_t x)
-{
-   spx_word16_t x2;
 
-   if (x<12868)
-   {
-      x2 = MULT16_16_P13(x,x);
-      return ADD32(C1, MULT16_16_P13(x2, ADD32(C2, MULT16_16_P13(x2, ADD32(C3, MULT16_16_P13(C4, x2))))));
-   } else {
-      x = SUB16(25736,x);
-      x2 = MULT16_16_P13(x,x);
-      return SUB32(-C1, MULT16_16_P13(x2, ADD32(C2, MULT16_16_P13(x2, ADD32(C3, MULT16_16_P13(C4, x2))))));
-      /*return SUB32(-C1, MULT16_16_Q13(x2, ADD32(C2, MULT16_16_Q13(C3, x2))));*/
-   }
-}
-
-
 #define FREQ_SCALE 16384
 
 /*#define ANGLE2X(a) (32768*cos(((a)/8192.)))*/
@@ -99,25 +79,6 @@
 #define C2 -0.49558072
 #define C3 0.03679168*/
 
-#define C1 0.9999932946f
-#define C2 -0.4999124376f
-#define C3 0.0414877472f
-#define C4 -0.0012712095f
-
-
-#define SPX_PI_2 1.5707963268
-static inline spx_word16_t spx_cos(spx_word16_t x)
-{
-   if (x<SPX_PI_2)
-   {
-      x *= x;
-      return C1 + x*(C2+x*(C3+C4*x));
-   } else {
-      x = M_PI-x;
-      x *= x;
-      return NEG16(C1 + x*(C2+x*(C3+C4*x)));
-   }
-}
 #define FREQ_SCALE 1.
 #define ANGLE2X(a) (spx_cos(a))
 #define X2ANGLE(x) (acos(x))

Modified: trunk/speex/libspeex/math_approx.c
===================================================================
--- trunk/speex/libspeex/math_approx.c	2005-12-18 12:54:54 UTC (rev 10635)
+++ trunk/speex/libspeex/math_approx.c	2005-12-18 13:13:26 UTC (rev 10636)
@@ -128,4 +128,48 @@
    return ret;
 }
 
+
+#define K1 8192
+#define K2 -4096
+#define K3 340
+#define K4 -10
+
+spx_word16_t spx_cos(spx_word16_t x)
+{
+   spx_word16_t x2;
+
+   if (x<12868)
+   {
+      x2 = MULT16_16_P13(x,x);
+      return ADD32(K1, MULT16_16_P13(x2, ADD32(K2, MULT16_16_P13(x2, ADD32(K3, MULT16_16_P13(K4, x2))))));
+   } else {
+      x = SUB16(25736,x);
+      x2 = MULT16_16_P13(x,x);
+      return SUB32(-K1, MULT16_16_P13(x2, ADD32(K2, MULT16_16_P13(x2, ADD32(K3, MULT16_16_P13(K4, x2))))));
+   }
+}
+
+#else
+
+#define C1 0.9999932946f
+#define C2 -0.4999124376f
+#define C3 0.0414877472f
+#define C4 -0.0012712095f
+
+
+#define SPX_PI_2 1.5707963268
+inline spx_word16_t spx_cos(spx_word16_t x)
+{
+   if (x<SPX_PI_2)
+   {
+      x *= x;
+      return C1 + x*(C2+x*(C3+C4*x));
+   } else {
+      x = M_PI-x;
+      x *= x;
+      return NEG16(C1 + x*(C2+x*(C3+C4*x)));
+   }
+}
+
+
 #endif

Modified: trunk/speex/libspeex/math_approx.h
===================================================================
--- trunk/speex/libspeex/math_approx.h	2005-12-18 12:54:54 UTC (rev 10635)
+++ trunk/speex/libspeex/math_approx.h	2005-12-18 13:13:26 UTC (rev 10636)
@@ -37,6 +37,8 @@
 
 #include "misc.h"
 
+spx_word16_t spx_cos(spx_word16_t x);
+
 #ifdef FIXED_POINT
 spx_word16_t spx_sqrt(spx_word32_t x);
 spx_word16_t spx_acos(spx_word16_t x);

Modified: trunk/speex/libspeex/mdf.c
===================================================================
--- trunk/speex/libspeex/mdf.c	2005-12-18 12:54:54 UTC (rev 10635)
+++ trunk/speex/libspeex/mdf.c	2005-12-18 13:13:26 UTC (rev 10636)
@@ -45,6 +45,7 @@
 #include "smallft.h"
 #include "fftwrap.h"
 #include "pseudofloat.h"
+#include "math_approx.h"
 
 #ifndef M_PI
 #define M_PI 3.14159265358979323846
@@ -239,8 +240,11 @@
    st->power_1 = (spx_float_t*)speex_alloc((frame_size+1)*sizeof(spx_float_t));
    st->window = (spx_word16_t*)speex_alloc(N*sizeof(spx_word16_t));
 #ifdef FIXED_POINT   
-   for (i=0;i<N;i++)
-      st->window[i] = 32767.*(.5-.5*cos(2*M_PI*i/N));
+   for (i=0;i<N>>1;i++)
+   {
+      st->window[i] = (16383-SHL16(spx_cos(DIV32_16(MULT16_16(25736,i<<1),N)),1));
+      st->window[N-i-1] = st->window[i];
+   }
 #else
    for (i=0;i<N;i++)
       st->window[i] = .5-.5*cos(2*M_PI*i/N);