[xiph-cvs] cvs commit: speex/libspeex lsp.c

[Jean-Marc Valin]

jm          04/01/17 11:06:05

  Modified:    libspeex lsp.c
  Log:
  replaced cos by an approximation for the float version

Revision  Changes    Path
1.50      +23 -4     speex/libspeex/lsp.c

Index: lsp.c
===================================================================
RCS file: /usr/local/cvsroot/speex/libspeex/lsp.c,v
retrieving revision 1.49
retrieving revision 1.50
diff -u -r1.49 -r1.50
--- lsp.c	29 Nov 2003 19:25:48 -0000	1.49
+++ lsp.c	17 Jan 2004 16:06:04 -0000	1.50
@@ -90,12 +90,31 @@
 
 #else
 
-#define C1 0.99940307
+/*#define C1 0.99940307
 #define C2 -0.49558072
-#define C3 0.03679168
+#define C3 0.03679168*/
 
+#define C1 0.9999932946
+#define C2 -0.4999124376
+#define C3 0.0414877472
+#define C4 -0.0012712095
+
+
+#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 -(C1 + x*(C2+x*(C3+C4*x)));
+   }
+}
 #define FREQ_SCALE 1.
-#define ANGLE2X(a) (cos(a))
+#define ANGLE2X(a) (spx_cos(a))
 #define X2ANGLE(x) (acos(x))
 
 #endif
@@ -465,7 +484,7 @@
     float xout1,xout2,xin1,xin2;
     float *Wp;
     float *pw,*n1,*n2,*n3,*n4=NULL;
-    int m = lpcrdr/2;
+    int m = lpcrdr>>1;
 
     Wp = PUSH(stack, 4*m+2, float);
     pw = Wp;

<p><p>--- >8 ----
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