X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=laserbrain_demo;a=blobdiff_plain;f=libs%2Fvorbis%2Fsmallft.c;fp=libs%2Fvorbis%2Fsmallft.c;h=ae2bc41b6b1f4a83b7962a488c17fa55ea133e2d;hp=0000000000000000000000000000000000000000;hb=f25228d21d10f8df4607384ddb879251d31ee40e;hpb=c48096383ed398a518e69070bfc9373537ab00bb diff --git a/libs/vorbis/smallft.c b/libs/vorbis/smallft.c new file mode 100644 index 0000000..ae2bc41 --- /dev/null +++ b/libs/vorbis/smallft.c @@ -0,0 +1,1255 @@ +/******************************************************************** + * * + * 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: *unnormalized* fft transform + last mod: $Id: smallft.c 16227 2009-07-08 06:58:46Z xiphmont $ + + ********************************************************************/ + +/* FFT implementation from OggSquish, minus cosine transforms, + * minus all but radix 2/4 case. In Vorbis we only need this + * cut-down version. + * + * To do more than just power-of-two sized vectors, see the full + * version I wrote for NetLib. + * + * Note that the packing is a little strange; rather than the FFT r/i + * packing following R_0, I_n, R_1, I_1, R_2, I_2 ... R_n-1, I_n-1, + * it follows R_0, R_1, I_1, R_2, I_2 ... R_n-1, I_n-1, I_n like the + * FORTRAN version + */ + +#include +#include +#include +#include "smallft.h" +#include "os.h" +#include "misc.h" + +static void drfti1(int n, float *wa, int *ifac){ + static int ntryh[4] = { 4,2,3,5 }; + static float tpi = 6.28318530717958648f; + float arg,argh,argld,fi; + int ntry=0,i,j=-1; + int k1, l1, l2, ib; + int ld, ii, ip, is, nq, nr; + int ido, ipm, nfm1; + int nl=n; + int nf=0; + + L101: + j++; + if (j < 4) + ntry=ntryh[j]; + else + ntry+=2; + + L104: + nq=nl/ntry; + nr=nl-ntry*nq; + if (nr!=0) goto L101; + + nf++; + ifac[nf+1]=ntry; + nl=nq; + if(ntry!=2)goto L107; + if(nf==1)goto L107; + + for (i=1;i>1; + ipp2=ip; + idp2=ido; + nbd=(ido-1)>>1; + t0=l1*ido; + t10=ip*ido; + + if(ido==1)goto L119; + for(ik=0;ikl1){ + for(j=1;j>1; + ipp2=ip; + ipph=(ip+1)>>1; + if(idol1)goto L139; + + is= -ido-1; + t1=0; + for(j=1;jn==1)return; + drftf1(l->n,data,l->trigcache,l->trigcache+l->n,l->splitcache); +} + +void drft_backward(drft_lookup *l,float *data){ + if (l->n==1)return; + drftb1(l->n,data,l->trigcache,l->trigcache+l->n,l->splitcache); +} + +void drft_init(drft_lookup *l,int n){ + l->n=n; + l->trigcache=_ogg_calloc(3*n,sizeof(*l->trigcache)); + l->splitcache=_ogg_calloc(32,sizeof(*l->splitcache)); + fdrffti(n, l->trigcache, l->splitcache); +} + +void drft_clear(drft_lookup *l){ + if(l){ + if(l->trigcache)_ogg_free(l->trigcache); + if(l->splitcache)_ogg_free(l->splitcache); + memset(l,0,sizeof(*l)); + } +}