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-rw-r--r--lib/rbcodec/codecs/libwma/wmafixed.c223
1 files changed, 223 insertions, 0 deletions
diff --git a/lib/rbcodec/codecs/libwma/wmafixed.c b/lib/rbcodec/codecs/libwma/wmafixed.c
new file mode 100644
index 0000000000..bdf87a548b
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+++ b/lib/rbcodec/codecs/libwma/wmafixed.c
@@ -0,0 +1,223 @@
+/****************************************************************************
+ * __________ __ ___.
+ * Open \______ \ ____ ____ | | _\_ |__ _______ ___
+ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
+ * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
+ * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
+ * \/ \/ \/ \/ \/
+ *
+ * Copyright (C) 2007 Michael Giacomelli
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+#include "wmadec.h"
+#include "wmafixed.h"
+#include <codecs.h>
+
+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;
+}
+
+/*
+ Not performance senstitive code here
+
+*/
+
+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));
+}
+
+
+ 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;
+ }