The Tor Browser: comparison media/libvorbis/lib/vorbis

--1:000000000000
+:0ba46966068b
+/********************************************************************
+*                                                                  *
+* THIS FILE IS PART OF THE OggVorbis SOFTWARE 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 SOURCE CODE IS (C) COPYRIGHT 1994-2009             *
+* by the Xiph.Org Foundation http://www.xiph.org/                  *
+*                                                                  *
+********************************************************************
+function: LSP (also called LSF) conversion routines
+last mod: $Id: lsp.c 17538 2010-10-15 02:52:29Z tterribe $
+The LSP generation code is taken (with minimal modification and a
+few bugfixes) from "On the Computation of the LSP Frequencies" by
+Joseph Rothweiler (see http://www.rothweiler.us for contact info).
+The paper is available at:
+http://www.myown1.com/joe/lsf
+********************************************************************/
+/* Note that the lpc-lsp conversion finds the roots of polynomial with
+an iterative root polisher (CACM algorithm 283).  It *is* possible
+to confuse this algorithm into not converging; that should only
+happen with absurdly closely spaced roots (very sharp peaks in the
+LPC f response) which in turn should be impossible in our use of
+the code.  If this *does* happen anyway, it's a bug in the floor
+finder; find the cause of the confusion (probably a single bin
+spike or accidental near-float-limit resolution problems) and
+correct it. */
+#include <math.h>
+#include <string.h>
+#include <stdlib.h>
+#include "lsp.h"
+#include "os.h"
+#include "misc.h"
+#include "lookup.h"
+#include "scales.h"
+/* three possible LSP to f curve functions; the exact computation
+(float), a lookup based float implementation, and an integer
+implementation.  The float lookup is likely the optimal choice on
+any machine with an FPU.  The integer implementation is *not* fixed
+point (due to the need for a large dynamic range and thus a
+separately tracked exponent) and thus much more complex than the
+relatively simple float implementations. It's mostly for future
+work on a fully fixed point implementation for processors like the
+ARM family. */
+/* define either of these (preferably FLOAT_LOOKUP) to have faster
+but less precise implementation. */
+#undef FLOAT_LOOKUP
+#undef INT_LOOKUP
+#ifdef FLOAT_LOOKUP
+#include "vorbis_lookup.c" /* catch this in the build system; we #include for
+compilers (like gcc) that can't inline across
+modules */
+/* side effect: changes *lsp to cosines of lsp */
+void vorbis_lsp_to_curve(float *curve,int *map,int n,int ln,float *lsp,int m,
+float amp,float ampoffset){
+int i;
+float wdel=M_PI/ln;
+vorbis_fpu_control fpu;
+vorbis_fpu_setround(&fpu);
+for(i=0;i<m;i++)lsp[i]=vorbis_coslook(lsp[i]);
+i=0;
+while(i<n){
+int k=map[i];
+int qexp;
+float p=.7071067812f;
+float q=.7071067812f;
+float w=vorbis_coslook(wdel*k);
+float *ftmp=lsp;
+int c=m>>1;
+while(c--){
+q*=ftmp[0]-w;
+p*=ftmp[1]-w;
+ftmp+=2;
+}
+if(m&1){
+/* odd order filter; slightly assymetric */
+/* the last coefficient */
+q*=ftmp[0]-w;
+q*=q;
+p*=p*(1.f-w*w);
+}else{
+/* even order filter; still symmetric */
+q*=q*(1.f+w);
+p*=p*(1.f-w);
+}
+q=frexp(p+q,&qexp);
+q=vorbis_fromdBlook(amp*
+vorbis_invsqlook(q)*
+vorbis_invsq2explook(qexp+m)-
+ampoffset);
+do{
+curve[i++]*=q;
+}while(map[i]==k);
+}
+vorbis_fpu_restore(fpu);
+}
+#else
+#ifdef INT_LOOKUP
+#include "vorbis_lookup.c" /* catch this in the build system; we #include for
+compilers (like gcc) that can't inline across
+modules */
+static const int MLOOP_1[64]={
+0,10,11,11, 12,12,12,12, 13,13,13,13, 13,13,13,13,
+14,14,14,14, 14,14,14,14, 14,14,14,14, 14,14,14,14,
+15,15,15,15, 15,15,15,15, 15,15,15,15, 15,15,15,15,
+15,15,15,15, 15,15,15,15, 15,15,15,15, 15,15,15,15,
+};
+static const int MLOOP_2[64]={
+0,4,5,5, 6,6,6,6, 7,7,7,7, 7,7,7,7,
+8,8,8,8, 8,8,8,8, 8,8,8,8, 8,8,8,8,
+9,9,9,9, 9,9,9,9, 9,9,9,9, 9,9,9,9,
+9,9,9,9, 9,9,9,9, 9,9,9,9, 9,9,9,9,
+};
+static const int MLOOP_3[8]={0,1,2,2,3,3,3,3};
+/* side effect: changes *lsp to cosines of lsp */
+void vorbis_lsp_to_curve(float *curve,int *map,int n,int ln,float *lsp,int m,
+float amp,float ampoffset){
+/* 0 <= m < 256 */
+/* set up for using all int later */
+int i;
+int ampoffseti=rint(ampoffset*4096.f);
+int ampi=rint(amp*16.f);
+long *ilsp=alloca(m*sizeof(*ilsp));
+for(i=0;i<m;i++)ilsp[i]=vorbis_coslook_i(lsp[i]/M_PI*65536.f+.5f);
+i=0;
+while(i<n){
+int j,k=map[i];
+unsigned long pi=46341; /* 2**-.5 in 0.16 */
+unsigned long qi=46341;
+int qexp=0,shift;
+long wi=vorbis_coslook_i(k*65536/ln);
+qi*=labs(ilsp[0]-wi);
+pi*=labs(ilsp[1]-wi);
+for(j=3;j<m;j+=2){
+if(!(shift=MLOOP_1[(pi|qi)>>25]))
+if(!(shift=MLOOP_2[(pi|qi)>>19]))
+shift=MLOOP_3[(pi|qi)>>16];
+qi=(qi>>shift)*labs(ilsp[j-1]-wi);
+pi=(pi>>shift)*labs(ilsp[j]-wi);
+qexp+=shift;
+}
+if(!(shift=MLOOP_1[(pi|qi)>>25]))
+if(!(shift=MLOOP_2[(pi|qi)>>19]))
+shift=MLOOP_3[(pi|qi)>>16];
+/* pi,qi normalized collectively, both tracked using qexp */
+if(m&1){
+/* odd order filter; slightly assymetric */
+/* the last coefficient */
+qi=(qi>>shift)*labs(ilsp[j-1]-wi);
+pi=(pi>>shift)<<14;
+qexp+=shift;
+if(!(shift=MLOOP_1[(pi|qi)>>25]))
+if(!(shift=MLOOP_2[(pi|qi)>>19]))
+shift=MLOOP_3[(pi|qi)>>16];
+pi>>=shift;
+qi>>=shift;
+qexp+=shift-14*((m+1)>>1);
+pi=((pi*pi)>>16);
+qi=((qi*qi)>>16);
+qexp=qexp*2+m;
+pi*=(1<<14)-((wi*wi)>>14);
+qi+=pi>>14;
+}else{
+/* even order filter; still symmetric */
+/* p*=p(1-w), q*=q(1+w), let normalization drift because it isn't
+worth tracking step by step */
+pi>>=shift;
+qi>>=shift;
+qexp+=shift-7*m;
+pi=((pi*pi)>>16);
+qi=((qi*qi)>>16);
+qexp=qexp*2+m;
+pi*=(1<<14)-wi;
+qi*=(1<<14)+wi;
+qi=(qi+pi)>>14;
+}
+/* we've let the normalization drift because it wasn't important;
+however, for the lookup, things must be normalized again.  We
+need at most one right shift or a number of left shifts */
+if(qi&0xffff0000){ /* checks for 1.xxxxxxxxxxxxxxxx */
+qi>>=1; qexp++;
+}else
+while(qi && !(qi&0x8000)){ /* checks for 0.0xxxxxxxxxxxxxxx or less*/
+qi<<=1; qexp--;
+}
+amp=vorbis_fromdBlook_i(ampi*                     /*  n.4         */
+vorbis_invsqlook_i(qi,qexp)-
+/*  m.8, m+n<=8 */
+ampoffseti);              /*  8.12[0]     */
+curve[i]*=amp;
+while(map[++i]==k)curve[i]*=amp;
+}
+}
+#else
+/* old, nonoptimized but simple version for any poor sap who needs to
+figure out what the hell this code does, or wants the other
+fraction of a dB precision */
+/* side effect: changes *lsp to cosines of lsp */
+void vorbis_lsp_to_curve(float *curve,int *map,int n,int ln,float *lsp,int m,
+float amp,float ampoffset){
+int i;
+float wdel=M_PI/ln;
+for(i=0;i<m;i++)lsp[i]=2.f*cos(lsp[i]);
+i=0;
+while(i<n){
+int j,k=map[i];
+float p=.5f;
+float q=.5f;
+float w=2.f*cos(wdel*k);
+for(j=1;j<m;j+=2){
+q *= w-lsp[j-1];
+p *= w-lsp[j];
+}
+if(j==m){
+/* odd order filter; slightly assymetric */
+/* the last coefficient */
+q*=w-lsp[j-1];
+p*=p*(4.f-w*w);
+q*=q;
+}else{
+/* even order filter; still symmetric */
+p*=p*(2.f-w);
+q*=q*(2.f+w);
+}
+q=fromdB(amp/sqrt(p+q)-ampoffset);
+curve[i]*=q;
+while(map[++i]==k)curve[i]*=q;
+}
+}
+#endif
+#endif
+static void cheby(float *g, int ord) {
+int i, j;
+g[0] *= .5f;
+for(i=2; i<= ord; i++) {
+for(j=ord; j >= i; j--) {
+g[j-2] -= g[j];
+g[j] += g[j];
+}
+}
+}
+static int comp(const void *a,const void *b){
+return (*(float *)a<*(float *)b)-(*(float *)a>*(float *)b);
+}
+/* Newton-Raphson-Maehly actually functioned as a decent root finder,
+but there are root sets for which it gets into limit cycles
+(exacerbated by zero suppression) and fails.  We can't afford to
+fail, even if the failure is 1 in 100,000,000, so we now use
+Laguerre and later polish with Newton-Raphson (which can then
+afford to fail) */
+#define EPSILON 10e-7
+static int Laguerre_With_Deflation(float *a,int ord,float *r){
+int i,m;
+double lastdelta=0.f;
+double *defl=alloca(sizeof(*defl)*(ord+1));
+for(i=0;i<=ord;i++)defl[i]=a[i];
+for(m=ord;m>0;m--){
+double new=0.f,delta;
+/* iterate a root */
+while(1){
+double p=defl[m],pp=0.f,ppp=0.f,denom;
+/* eval the polynomial and its first two derivatives */
+for(i=m;i>0;i--){
+ppp = new*ppp + pp;
+pp  = new*pp  + p;
+p   = new*p   + defl[i-1];
+}
+/* Laguerre's method */
+denom=(m-1) * ((m-1)*pp*pp - m*p*ppp);
+if(denom<0)
+return(-1);  /* complex root!  The LPC generator handed us a bad filter */
+if(pp>0){
+denom = pp + sqrt(denom);
+if(denom<EPSILON)denom=EPSILON;
+}else{
+denom = pp - sqrt(denom);
+if(denom>-(EPSILON))denom=-(EPSILON);
+}
+delta  = m*p/denom;
+new   -= delta;
+if(delta<0.f)delta*=-1;
+if(fabs(delta/new)<10e-12)break;
+lastdelta=delta;
+}
+r[m-1]=new;
+/* forward deflation */
+for(i=m;i>0;i--)
+defl[i-1]+=new*defl[i];
+defl++;
+}
+return(0);
+}
+/* for spit-and-polish only */
+static int Newton_Raphson(float *a,int ord,float *r){
+int i, k, count=0;
+double error=1.f;
+double *root=alloca(ord*sizeof(*root));
+for(i=0; i<ord;i++) root[i] = r[i];
+while(error>1e-20){
+error=0;
+for(i=0; i<ord; i++) { /* Update each point. */
+double pp=0.,delta;
+double rooti=root[i];
+double p=a[ord];
+for(k=ord-1; k>= 0; k--) {
+pp= pp* rooti + p;
+p = p * rooti + a[k];
+}
+delta = p/pp;
+root[i] -= delta;
+error+= delta*delta;
+}
+if(count>40)return(-1);
+count++;
+}
+/* Replaced the original bubble sort with a real sort.  With your
+help, we can eliminate the bubble sort in our lifetime. --Monty */
+for(i=0; i<ord;i++) r[i] = root[i];
+return(0);
+}
+/* Convert lpc coefficients to lsp coefficients */
+int vorbis_lpc_to_lsp(float *lpc,float *lsp,int m){
+int order2=(m+1)>>1;
+int g1_order,g2_order;
+float *g1=alloca(sizeof(*g1)*(order2+1));
+float *g2=alloca(sizeof(*g2)*(order2+1));
+float *g1r=alloca(sizeof(*g1r)*(order2+1));
+float *g2r=alloca(sizeof(*g2r)*(order2+1));
+int i;
+/* even and odd are slightly different base cases */
+g1_order=(m+1)>>1;
+g2_order=(m)  >>1;
+/* Compute the lengths of the x polynomials. */
+/* Compute the first half of K & R F1 & F2 polynomials. */
+/* Compute half of the symmetric and antisymmetric polynomials. */
+/* Remove the roots at +1 and -1. */
+g1[g1_order] = 1.f;
+for(i=1;i<=g1_order;i++) g1[g1_order-i] = lpc[i-1]+lpc[m-i];
+g2[g2_order] = 1.f;
+for(i=1;i<=g2_order;i++) g2[g2_order-i] = lpc[i-1]-lpc[m-i];
+if(g1_order>g2_order){
+for(i=2; i<=g2_order;i++) g2[g2_order-i] += g2[g2_order-i+2];
+}else{
+for(i=1; i<=g1_order;i++) g1[g1_order-i] -= g1[g1_order-i+1];
+for(i=1; i<=g2_order;i++) g2[g2_order-i] += g2[g2_order-i+1];
+}
+/* Convert into polynomials in cos(alpha) */
+cheby(g1,g1_order);
+cheby(g2,g2_order);
+/* Find the roots of the 2 even polynomials.*/
+if(Laguerre_With_Deflation(g1,g1_order,g1r) ||
+Laguerre_With_Deflation(g2,g2_order,g2r))
+return(-1);
+Newton_Raphson(g1,g1_order,g1r); /* if it fails, it leaves g1r alone */
+Newton_Raphson(g2,g2_order,g2r); /* if it fails, it leaves g2r alone */
+qsort(g1r,g1_order,sizeof(*g1r),comp);
+qsort(g2r,g2_order,sizeof(*g2r),comp);
+for(i=0;i<g1_order;i++)
+lsp[i*2] = acos(g1r[i]);
+for(i=0;i<g2_order;i++)
+lsp[i*2+1] = acos(g2r[i]);
+return(0);
+}

The Tor Browser / file comparison

comparison: media/libvorbis/lib/vorbis_lsp.c

media/libvorbis/lib/vorbis_lsp.c