Fix red by moving fsincos back to libwma

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@25036 a1c6a512-1295-4272-9138-f99709370657

2 files changed, 103 insertions, 1 deletions

diff --git a/apps/codecs/libwma/wmafixed.c b/apps/codecs/libwma/wmafixed.c
index 1472ed081c..649025b53a 100644
--- a/apps/codecs/libwma/wmafixed.c
+++ b/apps/codecs/libwma/wmafixed.c
@@ -250,3 +250,104 @@ fixed64 fixdiv64(fixed64 x, fixed64 y)
 
     return (fixed32)(r << (PRECISION / 2));
 }
+
+
+     static const long cordic_circular_gain = 0xb2458939; /* 0.607252929 */  
+     
+ /* Table of values of atan(2^-i) in 0.32 format fractions of pi where pi = 0xffffffff / 2 */    
+ static const unsigned long atan_table[] = {     
+     0x1fffffff, /* +0.785398163 (or pi/4) */    
+     0x12e4051d, /* +0.463647609 */  
+     0x09fb385b, /* +0.244978663 */  
+     0x051111d4, /* +0.124354995 */  
+     0x028b0d43, /* +0.062418810 */  
+     0x0145d7e1, /* +0.031239833 */  
+     0x00a2f61e, /* +0.015623729 */  
+     0x00517c55, /* +0.007812341 */  
+     0x0028be53, /* +0.003906230 */  
+     0x00145f2e, /* +0.001953123 */  
+     0x000a2f98, /* +0.000976562 */  
+     0x000517cc, /* +0.000488281 */  
+     0x00028be6, /* +0.000244141 */  
+     0x000145f3, /* +0.000122070 */  
+     0x0000a2f9, /* +0.000061035 */  
+     0x0000517c, /* +0.000030518 */  
+     0x000028be, /* +0.000015259 */  
+     0x0000145f, /* +0.000007629 */  
+     0x00000a2f, /* +0.000003815 */  
+     0x00000517, /* +0.000001907 */  
+     0x0000028b, /* +0.000000954 */  
+     0x00000145, /* +0.000000477 */  
+     0x000000a2, /* +0.000000238 */  
+     0x00000051, /* +0.000000119 */  
+     0x00000028, /* +0.000000060 */  
+     0x00000014, /* +0.000000030 */  
+     0x0000000a, /* +0.000000015 */  
+     0x00000005, /* +0.000000007 */  
+     0x00000002, /* +0.000000004 */  
+     0x00000001, /* +0.000000002 */  
+     0x00000000, /* +0.000000001 */  
+     0x00000000, /* +0.000000000 */  
+ };  
+     
+ /**     
+  * Implements sin and cos using CORDIC rotation.    
+  *  
+  * @param phase has range from 0 to 0xffffffff, representing 0 and  
+  *        2*pi respectively.    
+  * @param cos return address for cos    
+  * @return sin of phase, value is a signed value from LONG_MIN to LONG_MAX,     
+  *         representing -1 and 1 respectively.  
+  *  
+  *        Gives at least 24 bits precision (last 2-8 bits or so are probably off)   
+  */     
+     
+ long fsincos(unsigned long phase, fixed32 *cos)     
+ {   
+     int32_t x, x1, y, y1;   
+     unsigned long z, z1;    
+     int i;  
+     
+     /* Setup initial vector */  
+     x = cordic_circular_gain;   
+     y = 0;  
+     z = phase;  
+     
+     /* The phase has to be somewhere between 0..pi for this to work right */    
+     if (z < 0xffffffff / 4) {   
+         /* z in first quadrant, z += pi/2 to correct */     
+         x = -x;     
+         z += 0xffffffff / 4;    
+     } else if (z < 3 * (0xffffffff / 4)) {  
+         /* z in third quadrant, z -= pi/2 to correct */     
+         z -= 0xffffffff / 4;    
+     } else {    
+         /* z in fourth quadrant, z -= 3pi/2 to correct */   
+         x = -x;     
+         z -= 3 * (0xffffffff / 4);  
+     }   
+     
+     /* Each iteration adds roughly 1-bit of extra precision */  
+     for (i = 0; i < 31; i++) {  
+         x1 = x >> i;    
+         y1 = y >> i;    
+         z1 = atan_table[i];     
+     
+         /* Decided which direction to rotate vector. Pivot point is pi/2 */     
+         if (z >= 0xffffffff / 4) {  
+             x -= y1;    
+             y += x1;    
+             z -= z1;    
+         } else {    
+             x += y1;    
+             y -= x1;    
+             z += z1;    
+         }   
+     }   
+     
+     if (cos)    
+         *cos = x;   
+     
+     return y;   
+ }
+ 
\ No newline at end of file
diff --git a/apps/codecs/libwma/wmafixed.h b/apps/codecs/libwma/wmafixed.h
index 0ecdc5cfbc..d07acb3c6c 100644
--- a/apps/codecs/libwma/wmafixed.h
+++ b/apps/codecs/libwma/wmafixed.h
@@ -107,4 +107,5 @@ static inline fixed32 fixmul32(fixed32 x, fixed32 y)
 #endif
 
 
-/* get fixmul32b from codeclib */
+/* Inverse gain of circular cordic rotation in s0.31 format. */     
+long fsincos(unsigned long phase, fixed32 *cos);