ref: fcfaf0f8232ca9f5d873e4f5101063efb0ea1c19
parent: 581dc7f90766d243af89f57d57711836c62a38b3
author: sur <sur>
date: Fri Feb 4 09:57:12 EST 2005
kiss-fft library v. 1.2.1 is added to faac source tree
--- /dev/null
+++ b/libfaac/kiss_fft/CHANGELOG
@@ -1,0 +1,58 @@
+1.2.1 (April 4, 2004)
+ compiles cleanly with just about every -W warning flag under the sun
+
+ reorganized kiss_fft_state so it could be read-only/const. This may be useful for embedded systems
+ that are willing to predeclare twiddle factors, factorization.
+
+ Fixed C_MUL,S_MUL on 16-bit platforms.
+
+ tmpbuf will only be allocated if input & output buffers are same
+ scratchbuf will only be allocated for ffts that are not multiples of 2,3,5
+
+ NOTE: The tmpbuf,scratchbuf changes may require synchronization code for multi-threaded apps.
+
+
+1.2 (Feb 23, 2004)
+ interface change -- cfg object is forward declaration of struct instead of void*
+ This maintains type saftey and lets the compiler warn/error about stupid mistakes.
+ (prompted by suggestion from Erik de Castro Lopo)
+
+ small speed improvements
+
+ added psdpng.c -- sample utility that will create png spectrum "waterfalls" from an input file
+ ( not terribly useful yet)
+
+1.1.1 (Feb 1, 2004 )
+ minor bug fix -- only affects odd rank, in-place, multi-dimensional FFTs
+
+1.1 : (Jan 30,2004)
+ split sample_code/ into test/ and tools/
+
+ Removed 2-D fft and added N-D fft (arbitrary)
+
+ modified fftutil.c to allow multi-d FFTs
+
+ Modified core fft routine to allow an input stride via kiss_fft_stride()
+ (eased support of multi-D ffts)
+
+ Added fast convolution filtering (FIR filtering using overlap-scrap method, with tail scrap)
+
+ Add kfc.[ch]: the KISS FFT Cache. It takes care of allocs for you ( suggested by Oscar Lesta ).
+
+1.0.1 (Dec 15, 2003)
+ fixed bug that occurred when nfft==1
+
+1.0 : (Dec 14, 2003)
+ changed kiss_fft function from using a single buffer, to two buffers.
+ If the same buffer pointer is supplied for both in and out, kiss will
+ manage the buffer copies.
+
+ added kiss_fft2d and kiss_fftr as separate source files (declarations in kiss_fft.h )
+
+0.4 :(Nov 4,2003) optimized for radix 2,3,4,5
+
+0.3 :(Oct 28, 2003) woops, version 2 didn't actually factor out any radices other than 2
+
+0.2 :(Oct 27, 2003) added mixed radix, only radix 2,4 optimized versions
+
+0.1 :(May 19 2003) initial release, radix 2 only
--- /dev/null
+++ b/libfaac/kiss_fft/COPYING
@@ -1,0 +1,11 @@
+Copyright (c) 2003-2004 Mark Borgerding
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
+ * Neither the author nor the names of any contributors may be used to endorse or promote products derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
--- /dev/null
+++ b/libfaac/kiss_fft/README
@@ -1,0 +1,109 @@
+KISS FFT - A mixed-radix Fast Fourier Transform based up on the principle,
+"Keep It Simple, Stupid."
+
+ There are many great fft libraries already around. Kiss FFT is not trying
+to be better than any of them. It only attempts to be a reasonably efficient,
+moderately useful FFT that can use fixed or floating data types and can be
+incorporated into someone's C program in a few minutes with trivial licensing.
+
+USAGE:
+
+ The basic usage for 1-d complex FFT is:
+
+ #include "kiss_fft.h"
+
+ kiss_fft_cfg cfg = kiss_fft_alloc( nfft ,inverse_fft );
+
+ while ...
+
+ ... // put kth sample in cx_in[k].r and cx_in[k].i
+
+ kiss_fft( cfg , cx_in , cx_out );
+
+ ... // transformed. DC is in cx_out[0].r and cx_out[0].i
+
+ free(cfg);
+
+ Note: frequency-domain data is stored from dc up to 2pi.
+ so cx_out[0] is the dc bin of the FFT
+ and cx_out[nfft/2] is the Nyquist bin (if exists)
+
+ Declarations are in "kiss_fft.h", along with a brief description of the
+functions you'll need to use.
+
+Code definitions for 1d complex FFTs are in kiss_fft.c.
+
+You can do other cool stuff with the extras you'll find in tools/
+
+ * arbitrary dimension complex FFTs
+ * 1-d real FFTs
+ * fast convolution FIR filtering
+ * spectrum image creation
+
+The core fft and most tools/ code can be compiled to use float, double
+or Q15 short samples. The default is float.
+
+
+BACKGROUND:
+
+ I started coding this because I couldn't find a fixed point FFT that didn't
+use assembly code. I started with floating point numbers so I could get the
+theory straight before working on fixed point issues. In the end, I had a
+little bit of code that could be recompiled easily to do ffts with short, float
+or double (other types should be easy too).
+
+ Once I got my FFT working, I was curious about the speed compared to
+a well respected and highly optimized fft library. I don't want to criticize
+this great library, so let's call it FFT_BRANDX.
+During this process, I learned:
+
+ 1. FFT_BRANDX has more than 100K lines of code. The core of kiss_fft is about 500 lines (cpx 1-d).
+ 2. It took me an embarrassingly long time to get FFT_BRANDX working.
+ 3. A simple program using FFT_BRANDX is 522KB. A similar program using kiss_fft is 18KB.
+ 4. FFT_BRANDX is roughly twice as fast as KISS FFT.
+
+ It is wonderful that free, highly optimized libraries like FFT_BRANDX exist.
+But such libraries carry a huge burden of complexity necessary to extract every
+last bit of performance.
+
+ Sometimes simpler is better, even if it's not better.
+
+PERFORMANCE:
+ (on Athlon XP 2100+, with gcc 2.96, float data type)
+
+ Kiss performed 10000 1024-pt cpx ffts in .63 s of cpu time.
+ For comparison, it took md5sum twice as long to process the same amount of data.
+
+ Transforming 5 minutes of CD quality audio takes less than a second (nfft=1024).
+
+DO NOT:
+ ... use Kiss if you need the Fastest Fourier Transform in the World
+ ... ask me to add features that will bloat the code
+
+UNDER THE HOOD:
+
+ Kiss FFT uses a time decimation, mixed-radix, out-of-place FFT.
+No scaling is done. Optimized butterflies are used for factors 2,3,4, and 5.
+
+ The real optimization code only works for even length ffts. It does two half-length
+ FFTs in parallel (packed into real&imag), and then combines them via twiddling.
+
+ The fast convolution filtering uses the overlap-scrap method, slightly
+ modified to put the scrap at the tail.
+
+LICENSE:
+ BSD, see COPYING for details. Basically, "free to use&change, give credit where due, no guarantees"
+
+TODO:
+ *) Add real optimization for odd length FFTs (DST?)
+ *) Add real optimization to the n-dimensional FFT
+ *) Add simple windowing function, e.g. Hamming : w(i)=.54-.46*cos(2pi*i/(n-1))
+ *) Make the fixed point scaling and bit shifts more easily configurable.
+ *) Document/revisit the input/output fft scaling
+ *) See if the fixed point code can be optimized a little without adding complexity.
+ *) Make doc describing the overlap (tail) scrap fast convolution filtering in kiss_fastfir.c
+ *) Test all the ./tools/ code with fixed point (kiss_fastfir.c doesn't work, maybe others)
+
+AUTHOR:
+ Mark Borgerding
+ Mark@Borgerding.net
--- a/libfaac/kiss_fft/README.kiss_fft
+++ b/libfaac/kiss_fft/README.kiss_fft
@@ -1,28 +1,6 @@
-To install kiss_fft library please visit http://kissfft.sourceforge.net
-and download latest kiss_fft package from there.
+See README and COPYING files for author and copyright information.
-Uncompress kiss_fft_v1_2_1.tar.gz in this catalog.
+kiss_fft.c is modified in order to eliminate static variables.
-Source tree shall be:
-
-/libfaac
- /kiss_fft <-- you are here
- /test
- /tools
- CHANGELOG
- COPYING
- kiss_fft.c
- kiss_fft.h
- Makefile
- README
- TIPS
- _kiss_fft_guts.h
-
-Copy kiss_fftr.c and kiss_fftr.h from ./tools catalog to kiss_fft catalog.
-
-kiss_fft library is distributed under its own license (non GPL), so I cannot
-include its sources here.
-
-See README and COPYING files from original package for author and copyright
-information.
+-- sur.
--- /dev/null
+++ b/libfaac/kiss_fft/TIPS
@@ -1,0 +1,23 @@
+Speed:
+ * experiment with compiler flags
+ Special thanks to Oscar Lesta. He suggested some compiler flags
+ for gcc that make a big difference. They shave 10-15% off
+ execution time on some systems. Try some combination of:
+ -march=pentiumpro
+ -ffast-math
+ -fomit-frame-pointer
+
+ * If the input data has no imaginary component, use the kiss_fftr code under tools/.
+ Real ffts are roughly twice as fast as complex.
+
+Reducing code size:
+ * remove some of the butterflies. There are currently butterflies optimized for radices
+ 2,3,4,5. It is worth mentioning that you can still use FFT sizes that contain
+ these factors, they just won't be quite as fast. You can decide for yourself
+ whether to keep radix 2 or 4. If you do some work in this area, let me
+ know what you find.
+
+ * For platforms where ROM/code space is more plentiful than RAM,
+ consider creating a hardcoded kiss_fft_state. In other words, decide which
+ FFT size(s) you want and make a structure with the correct factors and twiddles.
+
--- /dev/null
+++ b/libfaac/kiss_fft/_kiss_fft_guts.h
@@ -1,0 +1,97 @@
+/*
+Copyright (c) 2003-2004, Mark Borgerding
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
+ * Neither the author nor the names of any contributors may be used to endorse or promote products derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+/* kiss_fft.h
+ defines kiss_fft_scalar as either short or a float type
+ and defines
+ typedef struct { kiss_fft_scalar r; kiss_fft_scalar i; }kiss_fft_cpx; */+#include "kiss_fft.h"
+
+
+#define MAXFACTORS 32
+/* e.g. an fft of length 128 has 4 factors
+ as far as kissfft is concerned
+ 4*4*4*2
+ */
+
+struct kiss_fft_state{+ int nfft;
+ int inverse;
+ int factors[2*MAXFACTORS];
+ kiss_fft_cpx twiddles[1];
+};
+
+/*
+ Explanation of macros dealing with complex math:
+
+ C_MUL(m,a,b) : m = a*b
+ C_FIXDIV( c , div ) : if a fixed point impl., c /= div. noop otherwise
+ C_SUB( res, a,b) : res = a - b
+ C_SUBFROM( res , a) : res -= a
+ C_ADDTO( res , a) : res += a
+ * */
+#ifdef FIXED_POINT
+
+# define smul(a,b) ( (long)(a)*(b) )
+# define sround( x ) (short)( ( (x) + (1<<14) ) >>15 )
+
+# define S_MUL(a,b) sround( smul(a,b) )
+
+# define C_MUL(m,a,b) \
+ do{ (m).r = sround( smul((a).r,(b).r) - smul((a).i,(b).i) ); \+ (m).i = sround( smul((a).r,(b).i) + smul((a).i,(b).r) ); }while(0)
+
+# define C_FIXDIV(c,div) \
+ do{ (c).r /= div; (c).i /=div; }while(0)+
+# define C_MULBYSCALAR( c, s ) \
+ do{ (c).r = sround( smul( (c).r , s ) ) ;\+ (c).i = sround( smul( (c).i , s ) ) ; }while(0)
+
+#else /* not FIXED_POINT*/
+
+# define S_MUL(a,b) ( (a)*(b) )
+#define C_MUL(m,a,b) \
+ do{ (m).r = (a).r*(b).r - (a).i*(b).i;\+ (m).i = (a).r*(b).i + (a).i*(b).r; }while(0)
+# define C_FIXDIV(c,div) /* NOOP */
+# define C_MULBYSCALAR( c, s ) \
+ do{ (c).r *= (s);\+ (c).i *= (s); }while(0)
+#endif
+
+#define C_ADD( res, a,b)\
+ do { (res).r=(a).r+(b).r; (res).i=(a).i+(b).i; }while(0)+#define C_SUB( res, a,b)\
+ do { (res).r=(a).r-(b).r; (res).i=(a).i-(b).i; }while(0)+#define C_ADDTO( res , a)\
+ do { (res).r += (a).r; (res).i += (a).i; }while(0)+#define C_SUBFROM( res , a)\
+ do { (res).r -= (a).r; (res).i -= (a).i; }while(0)+
+static
+void kf_cexp(kiss_fft_cpx * x,double phase) /* returns e ** (j*phase) */
+{+#ifdef FIXED_POINT
+ x->r = (kiss_fft_scalar) (32767 * cos (phase));
+ x->i = (kiss_fft_scalar) (32767 * sin (phase));
+#else
+ x->r = cos (phase);
+ x->i = sin (phase);
+#endif
+}
+
+/* a debugging function */
+#define pcpx(c)\
+ fprintf(stderr,"%g + %gi\n",(double)((c)->r),(double)((c)->i) )
--- /dev/null
+++ b/libfaac/kiss_fft/kiss_fft.c
@@ -1,0 +1,362 @@
+/*
+Copyright (c) 2003-2004, Mark Borgerding
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
+ * Neither the author nor the names of any contributors may be used to endorse or promote products derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+
+#include "_kiss_fft_guts.h"
+/* The guts header contains all the multiplication and addition macros that are defined for
+ fixed or floating point complex numbers. It also delares the kf_ internal functions.
+ */
+
+static void kf_bfly2(
+ kiss_fft_cpx * Fout,
+ const size_t fstride,
+ const kiss_fft_cfg st,
+ int m
+ )
+{+ kiss_fft_cpx * Fout2;
+ kiss_fft_cpx * tw1 = st->twiddles;
+ kiss_fft_cpx t;
+ Fout2 = Fout + m;
+ do{+ C_FIXDIV(*Fout,2); C_FIXDIV(*Fout2,2);
+
+ C_MUL (t, *Fout2 , *tw1);
+ tw1 += fstride;
+ C_SUB( *Fout2 , *Fout , t );
+ C_ADDTO( *Fout , t );
+ ++Fout2;
+ ++Fout;
+ }while (--m);
+}
+
+static void kf_bfly4(
+ kiss_fft_cpx * Fout,
+ const size_t fstride,
+ const kiss_fft_cfg st,
+ const size_t m
+ )
+{+ kiss_fft_cpx *tw1,*tw2,*tw3;
+ kiss_fft_cpx scratch[6];
+ size_t k=m;
+ const size_t m2=2*m;
+ const size_t m3=3*m;
+
+ tw3 = tw2 = tw1 = st->twiddles;
+
+ do {+ C_FIXDIV(*Fout,4); C_FIXDIV(Fout[m],4); C_FIXDIV(Fout[m2],4); C_FIXDIV(Fout[m3],4);
+
+ C_MUL(scratch[0],Fout[m] , *tw1 );
+ C_MUL(scratch[1],Fout[m2] , *tw2 );
+ C_MUL(scratch[2],Fout[m3] , *tw3 );
+
+ C_SUB( scratch[5] , *Fout, scratch[1] );
+ C_ADDTO(*Fout, scratch[1]);
+ C_ADD( scratch[3] , scratch[0] , scratch[2] );
+ C_SUB( scratch[4] , scratch[0] , scratch[2] );
+ C_SUB( Fout[m2], *Fout, scratch[3] );
+ tw1 += fstride;
+ tw2 += fstride*2;
+ tw3 += fstride*3;
+ C_ADDTO( *Fout , scratch[3] );
+
+ if(st->inverse) {+ Fout[m].r = scratch[5].r - scratch[4].i;
+ Fout[m].i = scratch[5].i + scratch[4].r;
+ Fout[m3].r = scratch[5].r + scratch[4].i;
+ Fout[m3].i = scratch[5].i - scratch[4].r;
+ }else{+ Fout[m].r = scratch[5].r + scratch[4].i;
+ Fout[m].i = scratch[5].i - scratch[4].r;
+ Fout[m3].r = scratch[5].r - scratch[4].i;
+ Fout[m3].i = scratch[5].i + scratch[4].r;
+ }
+ ++Fout;
+ }while(--k);
+}
+
+static void kf_bfly3(
+ kiss_fft_cpx * Fout,
+ const size_t fstride,
+ const kiss_fft_cfg st,
+ size_t m
+ )
+{+ size_t k=m;
+ const size_t m2 = 2*m;
+ kiss_fft_cpx *tw1,*tw2;
+ kiss_fft_cpx scratch[5];
+ kiss_fft_cpx epi3;
+ epi3 = st->twiddles[fstride*m];
+
+ tw1=tw2=st->twiddles;
+
+ do{+ C_FIXDIV(*Fout,3); C_FIXDIV(Fout[m],3); C_FIXDIV(Fout[m2],3);
+
+ C_MUL(scratch[1],Fout[m] , *tw1);
+ C_MUL(scratch[2],Fout[m2] , *tw2);
+
+ C_ADD(scratch[3],scratch[1],scratch[2]);
+ C_SUB(scratch[0],scratch[1],scratch[2]);
+ tw1 += fstride;
+ tw2 += fstride*2;
+
+ Fout[m].r = Fout->r - scratch[3].r/2;
+ Fout[m].i = Fout->i - scratch[3].i/2;
+
+ C_MULBYSCALAR( scratch[0] , epi3.i );
+
+ C_ADDTO(*Fout,scratch[3]);
+
+ Fout[m2].r = Fout[m].r + scratch[0].i;
+ Fout[m2].i = Fout[m].i - scratch[0].r;
+
+ Fout[m].r -= scratch[0].i;
+ Fout[m].i += scratch[0].r;
+
+ ++Fout;
+ }while(--k);
+}
+
+static void kf_bfly5(
+ kiss_fft_cpx * Fout,
+ const size_t fstride,
+ const kiss_fft_cfg st,
+ int m
+ )
+{+ kiss_fft_cpx *Fout0,*Fout1,*Fout2,*Fout3,*Fout4;
+ int u;
+ kiss_fft_cpx scratch[13];
+ kiss_fft_cpx * twiddles = st->twiddles;
+ kiss_fft_cpx *tw;
+ kiss_fft_cpx ya,yb;
+ ya = twiddles[fstride*m];
+ yb = twiddles[fstride*2*m];
+
+ Fout0=Fout;
+ Fout1=Fout0+m;
+ Fout2=Fout0+2*m;
+ Fout3=Fout0+3*m;
+ Fout4=Fout0+4*m;
+
+ tw=st->twiddles;
+ for ( u=0; u<m; ++u ) {+ C_FIXDIV( *Fout0,5); C_FIXDIV( *Fout1,5); C_FIXDIV( *Fout2,5); C_FIXDIV( *Fout3,5); C_FIXDIV( *Fout4,5);
+ scratch[0] = *Fout0;
+
+ C_MUL(scratch[1] ,*Fout1, tw[u*fstride]);
+ C_MUL(scratch[2] ,*Fout2, tw[2*u*fstride]);
+ C_MUL(scratch[3] ,*Fout3, tw[3*u*fstride]);
+ C_MUL(scratch[4] ,*Fout4, tw[4*u*fstride]);
+
+ C_ADD( scratch[7],scratch[1],scratch[4]);
+ C_SUB( scratch[10],scratch[1],scratch[4]);
+ C_ADD( scratch[8],scratch[2],scratch[3]);
+ C_SUB( scratch[9],scratch[2],scratch[3]);
+
+ Fout0->r += scratch[7].r + scratch[8].r;
+ Fout0->i += scratch[7].i + scratch[8].i;
+
+ scratch[5].r = scratch[0].r + S_MUL(scratch[7].r,ya.r) + S_MUL(scratch[8].r,yb.r);
+ scratch[5].i = scratch[0].i + S_MUL(scratch[7].i,ya.r) + S_MUL(scratch[8].i,yb.r);
+
+ scratch[6].r = S_MUL(scratch[10].i,ya.i) + S_MUL(scratch[9].i,yb.i);
+ scratch[6].i = -S_MUL(scratch[10].r,ya.i) - S_MUL(scratch[9].r,yb.i);
+
+ C_SUB(*Fout1,scratch[5],scratch[6]);
+ C_ADD(*Fout4,scratch[5],scratch[6]);
+
+ scratch[11].r = scratch[0].r + S_MUL(scratch[7].r,yb.r) + S_MUL(scratch[8].r,ya.r);
+ scratch[11].i = scratch[0].i + S_MUL(scratch[7].i,yb.r) + S_MUL(scratch[8].i,ya.r);
+ scratch[12].r = - S_MUL(scratch[10].i,yb.i) + S_MUL(scratch[9].i,ya.i);
+ scratch[12].i = S_MUL(scratch[10].r,yb.i) - S_MUL(scratch[9].r,ya.i);
+
+ C_ADD(*Fout2,scratch[11],scratch[12]);
+ C_SUB(*Fout3,scratch[11],scratch[12]);
+
+ ++Fout0;++Fout1;++Fout2;++Fout3;++Fout4;
+ }
+}
+
+/* perform the butterfly for one stage of a mixed radix FFT */
+static void kf_bfly_generic(
+ kiss_fft_cpx * Fout,
+ const size_t fstride,
+ const kiss_fft_cfg st,
+ int m,
+ int p
+ )
+{+ int u,k,q1,q;
+ kiss_fft_cpx * twiddles = st->twiddles;
+ kiss_fft_cpx t;
+ int Norig = st->nfft;
+
+ kiss_fft_cpx *scratchbuf=(kiss_fft_cpx *)malloc( sizeof(kiss_fft_cpx) * p );
+
+ for ( u=0; u<m; ++u ) {+ k=u;
+ for ( q1=0 ; q1<p ; ++q1 ) {+ scratchbuf[q1] = Fout[ k ];
+ C_FIXDIV(scratchbuf[q1],p);
+ k += m;
+ }
+
+ k=u;
+ for ( q1=0 ; q1<p ; ++q1 ) {+ int twidx=0;
+ Fout[ k ] = scratchbuf[0];
+ for (q=1;q<p;++q ) {+ twidx += fstride * k;
+ if (twidx>=Norig) twidx-=Norig;
+ C_MUL(t,scratchbuf[q] , twiddles[twidx] );
+ C_ADDTO( Fout[ k ] ,t);
+ }
+ k += m;
+ }
+ }
+
+ free( scratchbuf );
+}
+
+static
+void kf_work(
+ kiss_fft_cpx * Fout,
+ const kiss_fft_cpx * f,
+ const size_t fstride,
+ int in_stride,
+ int * factors,
+ const kiss_fft_cfg st
+ )
+{+ kiss_fft_cpx * Fout_beg=Fout;
+ const int p=*factors++; /* the radix */
+ const int m=*factors++; /* stage's fft length/p */
+ const kiss_fft_cpx * Fout_end = Fout + p*m;
+
+ if (m==1) {+ do{+ *Fout = *f;
+ f += fstride*in_stride;
+ }while(++Fout != Fout_end );
+ }else{+ do{+ kf_work( Fout , f, fstride*p, in_stride, factors,st);
+ f += fstride*in_stride;
+ }while( (Fout += m) != Fout_end );
+ }
+
+ Fout=Fout_beg;
+
+ switch (p) {+ case 2: kf_bfly2(Fout,fstride,st,m); break;
+ case 3: kf_bfly3(Fout,fstride,st,m); break;
+ case 4: kf_bfly4(Fout,fstride,st,m); break;
+ case 5: kf_bfly5(Fout,fstride,st,m); break;
+ default: kf_bfly_generic(Fout,fstride,st,m,p); break;
+ }
+}
+
+/* facbuf is populated by p1,m1,p2,m2, ...
+ where
+ p[i] * m[i] = m[i-1]
+ m0 = n */
+static
+void kf_factor(int n,int * facbuf)
+{+ int p=4;
+ double floor_sqrt;
+ floor_sqrt = floor( sqrt((double)n) );
+
+ /*factor out powers of 4, powers of 2, then any remaining primes */
+ do {+ while (n % p) {+ switch (p) {+ case 4: p = 2; break;
+ case 2: p = 3; break;
+ default: p += 2; break;
+ }
+ if (p > floor_sqrt)
+ p = n; /* no more factors, skip to end */
+ }
+ n /= p;
+ *facbuf++ = p;
+ *facbuf++ = n;
+ } while (n > 1);
+}
+
+/*
+ *
+ * User-callable function to allocate all necessary storage space for the fft.
+ *
+ * The return value is a contiguous block of memory, allocated with malloc. As such,
+ * It can be freed with free(), rather than a kiss_fft-specific function.
+ * */
+kiss_fft_cfg kiss_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem )
+{+ kiss_fft_cfg st=NULL;
+ size_t memneeded = sizeof(struct kiss_fft_state)
+ + sizeof(kiss_fft_cpx)*(nfft-1); /* twiddle factors*/
+
+ if ( lenmem==NULL ) {+ st = ( kiss_fft_cfg)malloc( memneeded );
+ }else{+ if (*lenmem >= memneeded)
+ st = (kiss_fft_cfg)mem;
+ *lenmem = memneeded;
+ }
+ if (st) {+ int i;
+ const double pi=3.14159265358979323846264338327;
+ const double phase0 = -2.0 * pi / (double)( nfft );
+
+ st->nfft=nfft;
+ st->inverse = inverse_fft;
+
+ for (i=0;i<nfft;++i) {+ double phase = phase0 * i;
+ if (st->inverse)
+ phase *= -1;
+ kf_cexp(st->twiddles+i, phase );
+ }
+
+ kf_factor(nfft,st->factors);
+ }
+ return st;
+}
+
+
+
+
+void kiss_fft_stride(kiss_fft_cfg st,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int in_stride)
+{+ if (fin == fout) {+ kiss_fft_cpx *tmpbuf=(kiss_fft_cpx*)malloc( sizeof(kiss_fft_cpx) * st->nfft );
+ kf_work(tmpbuf,fin,1,in_stride, st->factors,st);
+ memcpy(fout,tmpbuf,sizeof(kiss_fft_cpx)*st->nfft);
+ free( tmpbuf );
+ }else{+ kf_work( fout, fin, 1,in_stride, st->factors,st );
+ }
+}
+
+void kiss_fft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout)
+{+ kiss_fft_stride(cfg,fin,fout,1);
+}
+
--- /dev/null
+++ b/libfaac/kiss_fft/kiss_fft.h
@@ -1,0 +1,88 @@
+#ifndef KISS_FFT_H
+#define KISS_FFT_H
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+#include <memory.h>
+
+#ifdef __cplusplus
+extern "C" {+#endif
+
+/*
+ ATTENTION!
+ If you would like a :
+ -- a utility that will handle the caching of fft objects
+ -- real-only FFT
+ -- a multi-dimensional FFT
+ -- a command-line utility to perform ffts
+ -- a command-line utility to perform fast-convolution filtering
+
+ then see tools/
+ */
+
+#ifdef FIXED_POINT
+# define kiss_fft_scalar short
+#else
+# ifndef kiss_fft_scalar
+/* default is float */
+# define kiss_fft_scalar float
+# endif
+#endif
+
+typedef struct {+ kiss_fft_scalar r;
+ kiss_fft_scalar i;
+}kiss_fft_cpx;
+
+typedef struct kiss_fft_state* kiss_fft_cfg;
+
+/*
+ * kiss_fft_alloc
+ *
+ * Initialize a FFT (or IFFT) algorithm's cfg/state buffer.
+ *
+ * typical usage: kiss_fft_cfg mycfg=kiss_fft_alloc(1024,0,NULL,NULL);
+ *
+ * The return value from fft_alloc is a cfg buffer used internally
+ * by the fft routine or NULL.
+ *
+ * If lenmem is NULL, then kiss_fft_alloc will allocate a cfg buffer using malloc.
+ * The returned value should be free()d when done to avoid memory leaks.
+ *
+ * The state can be placed in a user supplied buffer 'mem':
+ * If lenmem is not NULL and mem is not NULL and *lenmem is large enough,
+ * then the function places the cfg in mem and the size used in *lenmem
+ * and returns mem.
+ *
+ * If lenmem is not NULL and ( mem is NULL or *lenmem is not large enough),
+ * then the function returns NULL and places the minimum cfg
+ * buffer size in *lenmem.
+ * */
+
+kiss_fft_cfg kiss_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem);
+
+/*
+ * kiss_fft(cfg,in_out_buf)
+ *
+ * Perform an FFT on a complex input buffer.
+ * for a forward FFT,
+ * fin should be f[0] , f[1] , ... ,f[nfft-1]
+ * fout will be F[0] , F[1] , ... ,F[nfft-1]
+ * Note that each element is complex and can be accessed like
+ f[k].r and f[k].i
+ * */
+void kiss_fft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout);
+
+void kiss_fft_stride(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int fin_stride);
+
+/* If kiss_fft_alloc allocated a buffer, it is one contiguous
+ buffer and can be simply free()d when no longer needed*/
+#define kiss_fft_free free
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
--- /dev/null
+++ b/libfaac/kiss_fft/kiss_fftr.c
@@ -1,0 +1,137 @@
+/*
+Copyright (c) 2003-2004, Mark Borgerding
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
+ * Neither the author nor the names of any contributors may be used to endorse or promote products derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#include "kiss_fftr.h"
+#include "_kiss_fft_guts.h"
+
+struct kiss_fftr_state{+ kiss_fft_cfg substate;
+ kiss_fft_cpx * tmpbuf;
+ kiss_fft_cpx * super_twiddles;
+};
+
+kiss_fftr_cfg kiss_fftr_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem)
+{+ int i;
+ kiss_fftr_cfg st = NULL;
+ size_t subsize, memneeded;
+
+ if (nfft & 1) {+ fprintf(stderr,"Real FFT optimization must be even.\n");
+ return NULL;
+ }
+ nfft >>= 1;
+
+ kiss_fft_alloc (nfft, inverse_fft, NULL, &subsize);
+ memneeded = sizeof(struct kiss_fftr_state) + subsize + sizeof(kiss_fft_cpx) * ( nfft * 2);
+
+ if (lenmem == NULL) {+ st = (kiss_fftr_cfg) malloc (memneeded);
+ } else {+ if (*lenmem >= memneeded)
+ st = (kiss_fftr_cfg) mem;
+ *lenmem = memneeded;
+ }
+ if (!st)
+ return NULL;
+
+ st->substate = (kiss_fft_cfg) (st + 1); /*just beyond kiss_fftr_state struct */
+ st->tmpbuf = (kiss_fft_cpx *) (((char *) st->substate) + subsize);
+ st->super_twiddles = st->tmpbuf + nfft;
+ kiss_fft_alloc(nfft, inverse_fft, st->substate, &subsize);
+
+ for (i = 0; i < nfft; ++i) {+ double phase =
+ -3.14159265358979323846264338327 * ((double) i / nfft + .5);
+ if (inverse_fft)
+ phase *= -1;
+ kf_cexp (st->super_twiddles+i,phase);
+ }
+ return st;
+}
+
+void kiss_fftr(kiss_fftr_cfg st,const kiss_fft_scalar *timedata,kiss_fft_cpx *freqdata)
+{+ /* input buffer timedata is stored row-wise */
+ int k,N;
+
+ if ( st->substate->inverse) {+ fprintf(stderr,"kiss fft usage error: improper alloc\n");
+ exit(1);
+ }
+
+ N = st->substate->nfft;
+
+ /*perform the parallel fft of two real signals packed in real,imag*/
+ kiss_fft( st->substate , (const kiss_fft_cpx*)timedata, st->tmpbuf );
+
+ freqdata[0].r = st->tmpbuf[0].r + st->tmpbuf[0].i;
+ freqdata[0].i = 0;
+ C_FIXDIV(freqdata[0],2);
+
+ for (k=1;k <= N/2 ; ++k ) {+ kiss_fft_cpx fpnk,fpk,f1k,f2k,tw;
+
+ fpk = st->tmpbuf[k];
+ fpnk.r = st->tmpbuf[N-k].r;
+ fpnk.i = -st->tmpbuf[N-k].i;
+ C_FIXDIV(fpk,2);
+ C_FIXDIV(fpnk,2);
+
+ C_ADD( f1k, fpk , fpnk );
+ C_SUB( f2k, fpk , fpnk );
+ C_MUL( tw , f2k , st->super_twiddles[k]);
+
+ C_ADD( freqdata[k] , f1k ,tw);
+ freqdata[k].r = (f1k.r + tw.r) / 2;
+ freqdata[k].i = (f1k.i + tw.i) / 2;
+
+ freqdata[N-k].r = (f1k.r - tw.r)/2;
+ freqdata[N-k].i = - (f1k.i - tw.i)/2;
+ }
+ freqdata[N].r = st->tmpbuf[0].r - st->tmpbuf[0].i;
+ freqdata[N].i = 0;
+ C_FIXDIV(freqdata[N],2);
+}
+
+void kiss_fftri(kiss_fftr_cfg st,const kiss_fft_cpx *freqdata,kiss_fft_scalar *timedata)
+{+ /* input buffer timedata is stored row-wise */
+ int k, N;
+
+ if (st->substate->inverse == 0) {+ fprintf (stderr, "kiss fft usage error: improper alloc\n");
+ exit (1);
+ }
+
+ N = st->substate->nfft;
+
+ st->tmpbuf[0].r = freqdata[0].r + freqdata[N].r;
+ st->tmpbuf[0].i = freqdata[0].r - freqdata[N].r;
+
+ for (k = 1; k <= N / 2; ++k) {+ kiss_fft_cpx fk, fnkc, fek, fok, tmpbuf;
+ fk = freqdata[k];
+ fnkc.r = freqdata[N - k].r;
+ fnkc.i = -freqdata[N - k].i;
+
+ C_ADD (fek, fk, fnkc);
+ C_SUB (tmpbuf, fk, fnkc);
+ C_MUL (fok, tmpbuf, st->super_twiddles[k]);
+ C_ADD (st->tmpbuf[k], fek, fok);
+ C_SUB (st->tmpbuf[N - k], fek, fok);
+ st->tmpbuf[N - k].i *= -1;
+ }
+ kiss_fft (st->substate, st->tmpbuf, (kiss_fft_cpx *) timedata);
+}
--- /dev/null
+++ b/libfaac/kiss_fft/kiss_fftr.h
@@ -1,0 +1,46 @@
+#ifndef KISS_FTR_H
+#define KISS_FTR_H
+
+#include "kiss_fft.h"
+#ifdef __cplusplus
+extern "C" {+#endif
+
+
+/*
+
+ Real optimized version can save about 45% cpu time vs. complex fft of a real seq.
+
+
+
+ */
+
+typedef struct kiss_fftr_state *kiss_fftr_cfg;
+
+
+kiss_fftr_cfg kiss_fftr_alloc(int nfft,int inverse_fft,void * mem, size_t * lenmem);
+/*
+ nfft must be even
+
+ If you don't care to allocate space, use mem = lenmem = NULL
+*/
+
+
+void kiss_fftr(kiss_fftr_cfg cfg,const kiss_fft_scalar *timedata,kiss_fft_cpx *freqdata);
+/*
+ input timedata has nfft scalar points
+ output freqdata has nfft/2+1 complex points
+*/
+
+void kiss_fftri(kiss_fftr_cfg cfg,const kiss_fft_cpx *freqdata,kiss_fft_scalar *timedata);
+/*
+ input freqdata has nfft/2+1 complex points
+ output timedata has nfft scalar points
+*/
+
+#define kiss_fftr_free free
+
+#ifdef __cplusplus
+}
+#endif
+#endif