misc/tremor/misc.h
branchhedgeroid
changeset 6043 9bd2d6b1ba52
parent 5170 f7e49eff3708
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/tremor/misc.h	Sun Oct 09 15:17:21 2011 +0200
@@ -0,0 +1,244 @@
+/********************************************************************
+ *                                                                  *
+ * THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE.   *
+ *                                                                  *
+ * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
+ * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
+ * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
+ *                                                                  *
+ * THE OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2002    *
+ * BY THE Xiph.Org FOUNDATION http://www.xiph.org/                  *
+ *                                                                  *
+ ********************************************************************
+
+ function: miscellaneous math and prototypes
+
+ ********************************************************************/
+
+#ifndef _V_RANDOM_H_
+#define _V_RANDOM_H_
+#include "ivorbiscodec.h"
+#include "os.h"
+
+#include "asm_arm.h"
+#include <stdlib.h> /* for abs() */
+  
+#ifndef _V_WIDE_MATH
+#define _V_WIDE_MATH
+  
+#ifndef  _LOW_ACCURACY_
+/* 64 bit multiply */
+
+#if !(defined WIN32 && defined WINCE)
+#include <sys/types.h>
+#endif
+
+#if BYTE_ORDER==LITTLE_ENDIAN
+union magic {
+  struct {
+    ogg_int32_t lo;
+    ogg_int32_t hi;
+  } halves;
+  ogg_int64_t whole;
+};
+#endif 
+
+#if BYTE_ORDER==BIG_ENDIAN
+/*union magic {
+  struct {
+    ogg_int32_t hi;
+    ogg_int32_t lo;
+  } halves;
+  ogg_int64_t whole;
+};*/
+#endif
+
+STIN ogg_int32_t MULT32(ogg_int32_t x, ogg_int32_t y) {
+  union magic magic;
+  magic.whole = (ogg_int64_t)x * y;
+  return magic.halves.hi;
+}
+
+STIN ogg_int32_t MULT31(ogg_int32_t x, ogg_int32_t y) {
+  return MULT32(x,y)<<1;
+}
+
+STIN ogg_int32_t MULT31_SHIFT15(ogg_int32_t x, ogg_int32_t y) {
+  union magic magic;
+  magic.whole  = (ogg_int64_t)x * y;
+  return ((ogg_uint32_t)(magic.halves.lo)>>15) | ((magic.halves.hi)<<17);
+}
+
+#else
+/* 32 bit multiply, more portable but less accurate */
+
+/*
+ * Note: Precision is biased towards the first argument therefore ordering
+ * is important.  Shift values were chosen for the best sound quality after
+ * many listening tests.
+ */
+
+/*
+ * For MULT32 and MULT31: The second argument is always a lookup table
+ * value already preshifted from 31 to 8 bits.  We therefore take the 
+ * opportunity to save on text space and use unsigned char for those
+ * tables in this case.
+ */
+
+STIN ogg_int32_t MULT32(ogg_int32_t x, ogg_int32_t y) {
+  return (x >> 9) * y;  /* y preshifted >>23 */
+}
+
+STIN ogg_int32_t MULT31(ogg_int32_t x, ogg_int32_t y) {
+  return (x >> 8) * y;  /* y preshifted >>23 */
+}
+
+STIN ogg_int32_t MULT31_SHIFT15(ogg_int32_t x, ogg_int32_t y) {
+  return (x >> 6) * y;  /* y preshifted >>9 */
+}
+
+#endif
+
+/*
+ * This should be used as a memory barrier, forcing all cached values in
+ * registers to wr writen back to memory.  Might or might not be beneficial
+ * depending on the architecture and compiler.
+ */
+#define MB()
+
+/*
+ * The XPROD functions are meant to optimize the cross products found all
+ * over the place in mdct.c by forcing memory operation ordering to avoid
+ * unnecessary register reloads as soon as memory is being written to.
+ * However this is only beneficial on CPUs with a sane number of general
+ * purpose registers which exclude the Intel x86.  On Intel, better let the
+ * compiler actually reload registers directly from original memory by using
+ * macros.
+ */
+
+#ifdef __i386__
+
+#define XPROD32(_a, _b, _t, _v, _x, _y)		\
+  { *(_x)=MULT32(_a,_t)+MULT32(_b,_v);		\
+    *(_y)=MULT32(_b,_t)-MULT32(_a,_v); }
+#define XPROD31(_a, _b, _t, _v, _x, _y)		\
+  { *(_x)=MULT31(_a,_t)+MULT31(_b,_v);		\
+    *(_y)=MULT31(_b,_t)-MULT31(_a,_v); }
+#define XNPROD31(_a, _b, _t, _v, _x, _y)	\
+  { *(_x)=MULT31(_a,_t)-MULT31(_b,_v);		\
+    *(_y)=MULT31(_b,_t)+MULT31(_a,_v); }
+
+#else
+
+STIN void XPROD32(ogg_int32_t  a, ogg_int32_t  b,
+			   ogg_int32_t  t, ogg_int32_t  v,
+			   ogg_int32_t *x, ogg_int32_t *y)
+{
+  *x = MULT32(a, t) + MULT32(b, v);
+  *y = MULT32(b, t) - MULT32(a, v);
+}
+
+STIN void XPROD31(ogg_int32_t  a, ogg_int32_t  b,
+			   ogg_int32_t  t, ogg_int32_t  v,
+			   ogg_int32_t *x, ogg_int32_t *y)
+{
+  *x = MULT31(a, t) + MULT31(b, v);
+  *y = MULT31(b, t) - MULT31(a, v);
+}
+
+STIN void XNPROD31(ogg_int32_t  a, ogg_int32_t  b,
+			    ogg_int32_t  t, ogg_int32_t  v,
+			    ogg_int32_t *x, ogg_int32_t *y)
+{
+  *x = MULT31(a, t) - MULT31(b, v);
+  *y = MULT31(b, t) + MULT31(a, v);
+}
+
+#endif
+
+#endif
+
+#ifndef _V_CLIP_MATH
+#define _V_CLIP_MATH
+
+STIN ogg_int32_t CLIP_TO_15(ogg_int32_t x) {
+  int ret=x;
+  ret-= ((x<=32767)-1)&(x-32767);
+  ret-= ((x>=-32768)-1)&(x+32768);
+  return(ret);
+}
+
+#endif
+
+STIN ogg_int32_t VFLOAT_MULT(ogg_int32_t a,ogg_int32_t ap,
+				      ogg_int32_t b,ogg_int32_t bp,
+				      ogg_int32_t *p){
+  if(a && b){
+#ifndef _LOW_ACCURACY_
+    *p=ap+bp+32;
+    return MULT32(a,b);
+#else
+    *p=ap+bp+31;
+    return (a>>15)*(b>>16); 
+#endif
+  }else
+    return 0;
+}
+
+int _ilog(unsigned int);
+
+STIN ogg_int32_t VFLOAT_MULTI(ogg_int32_t a,ogg_int32_t ap,
+				      ogg_int32_t i,
+				      ogg_int32_t *p){
+
+  int ip=_ilog(abs(i))-31;
+  return VFLOAT_MULT(a,ap,i<<-ip,ip,p);
+}
+
+STIN ogg_int32_t VFLOAT_ADD(ogg_int32_t a,ogg_int32_t ap,
+				      ogg_int32_t b,ogg_int32_t bp,
+				      ogg_int32_t *p){
+
+  if(!a){
+    *p=bp;
+    return b;
+  }else if(!b){
+    *p=ap;
+    return a;
+  }
+
+  /* yes, this can leak a bit. */
+  if(ap>bp){
+    int shift=ap-bp+1;
+    *p=ap+1;
+    a>>=1;
+    if(shift<32){
+      b=(b+(1<<(shift-1)))>>shift;
+    }else{
+      b=0;
+    }
+  }else{
+    int shift=bp-ap+1;
+    *p=bp+1;
+    b>>=1;
+    if(shift<32){
+      a=(a+(1<<(shift-1)))>>shift;
+    }else{
+      a=0;
+    }
+  }
+
+  a+=b;
+  if((a&0xc0000000)==0xc0000000 || 
+     (a&0xc0000000)==0){
+    a<<=1;
+    (*p)--;
+  }
+  return(a);
+}
+
+#endif
+
+
+
+