#include "wmadec.h" #include "wmafixed.h" #include fixed64 IntTo64(int x){ fixed64 res = 0; unsigned char *p = (unsigned char *)&res; #ifdef ROCKBOX_BIG_ENDIAN p[5] = x & 0xff; p[4] = (x & 0xff00)>>8; p[3] = (x & 0xff0000)>>16; p[2] = (x & 0xff000000)>>24; #else p[2] = x & 0xff; p[3] = (x & 0xff00)>>8; p[4] = (x & 0xff0000)>>16; p[5] = (x & 0xff000000)>>24; #endif return res; } int IntFrom64(fixed64 x) { int res = 0; unsigned char *p = (unsigned char *)&x; #ifdef ROCKBOX_BIG_ENDIAN res = p[5] | (p[4]<<8) | (p[3]<<16) | (p[2]<<24); #else res = p[2] | (p[3]<<8) | (p[4]<<16) | (p[5]<<24); #endif return res; } fixed32 Fixed32From64(fixed64 x) { return x & 0xFFFFFFFF; } fixed64 Fixed32To64(fixed32 x) { return (fixed64)x; } /* Fixed precision multiply code. */ /*Sign-15.16 format */ #ifdef CPU_ARM /* these are defines in wmafixed.h*/ #elif defined(CPU_COLDFIRE) #else fixed32 fixmul32(fixed32 x, fixed32 y) { fixed64 temp; temp = x; temp *= y; temp >>= PRECISION; return (fixed32)temp; } #endif /* Special fixmul32 that does a 16.16 x 1.31 multiply that returns a 16.16 value. this is needed because the fft constants are all normalized to be less then 1 and can't fit into a 16 bit number without excessive rounding */ #ifndef CPU_ARM fixed32 fixmul32b(fixed32 x, fixed32 y) { fixed64 temp; temp = x; temp *= y; temp >>= 31; //16+31-16 = 31 bits return (fixed32)temp; } #endif /* Not performance senstitive code here */ fixed64 fixmul64byfixed(fixed64 x, fixed32 y) { //return x * y; return (x * y); // return (fixed64) fixmul32(Fixed32From64(x),y); } fixed32 fixdiv32(fixed32 x, fixed32 y) { fixed64 temp; if(x == 0) return 0; if(y == 0) return 0x7fffffff; temp = x; temp <<= PRECISION; return (fixed32)(temp / y); } fixed64 fixdiv64(fixed64 x, fixed64 y) { fixed64 temp; if(x == 0) return 0; if(y == 0) return 0x07ffffffffffffffLL; temp = x; temp <<= PRECISION64; return (fixed64)(temp / y); } fixed32 fixsqrt32(fixed32 x) { unsigned long r = 0, s, v = (unsigned long)x; #define STEP(k) s = r + (1 << k * 2); r >>= 1; \ if (s <= v) { v -= s; r |= (1 << k * 2); } STEP(15); STEP(14); STEP(13); STEP(12); STEP(11); STEP(10); STEP(9); STEP(8); STEP(7); STEP(6); STEP(5); STEP(4); STEP(3); STEP(2); STEP(1); STEP(0); return (fixed32)(r << (PRECISION / 2)); } /* Inverse gain of circular cordic rotation in s0.31 format. */ 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 */ }; /* Below here functions do not use standard fixed precision! */ /** * 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; } /* Old trig functions. Still used in 1 place each. */ fixed32 fixsin32(fixed32 x) { fixed64 x2, temp; int sign = 1; if(x < 0) { sign = -1; x = -x; } while (x > 0x19220) { x -= M_PI_F; sign = -sign; } if (x > 0x19220) { x = M_PI_F - x; } x2 = (fixed64)x * x; x2 >>= PRECISION; if(sign != 1) { x = -x; } /** temp = ftofix32(-.0000000239f) * x2; temp >>= PRECISION; **/ temp = 0; // PJJ //temp = (temp + 0x0) * x2; //MGG: this can't possibly do anything? //temp >>= PRECISION; temp = (temp - 0xd) * x2; temp >>= PRECISION; temp = (temp + 0x222) * x2; temp >>= PRECISION; temp = (temp - 0x2aab) * x2; temp >>= PRECISION; temp += 0x10000; temp = temp * x; temp >>= PRECISION; return (fixed32)(temp); } fixed32 fixcos32(fixed32 x) { return fixsin32(x - (M_PI_F>>1))*-1; }