diff options
Diffstat (limited to 'plugins/wma/libwma/fft-ffmpeg.c')
| -rw-r--r-- | plugins/wma/libwma/fft-ffmpeg.c | 481 |
1 files changed, 481 insertions, 0 deletions
diff --git a/plugins/wma/libwma/fft-ffmpeg.c b/plugins/wma/libwma/fft-ffmpeg.c new file mode 100644 index 00000000..e2d1777d --- /dev/null +++ b/plugins/wma/libwma/fft-ffmpeg.c @@ -0,0 +1,481 @@ +/* + * FFT/IFFT transforms converted to integer precision + * Copyright (c) 2010 Dave Hooper, Mohamed Tarek, Michael Giacomelli + * Copyright (c) 2008 Loren Merritt + * Copyright (c) 2002 Fabrice Bellard + * Partly based on libdjbfft by D. J. Bernstein + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file libavcodec/fft.c + * FFT/IFFT transforms. + */ + + +#ifdef CPU_ARM +// we definitely want CONFIG_SMALL undefined for ipod +// so we get the inlined version of fft16 (which is measurably faster) +#undef CONFIG_SMALL +#else +#undef CONFIG_SMALL +#endif + +#include "fft.h" +#include <string.h> +#include <stdlib.h> +#include <math.h> +#include <inttypes.h> +#include <time.h> + +#include "codeclib_misc.h" +#include "mdct_lookup.h" + +/* constants for fft_16 (same constants as in mdct_arm.S ... ) */ +#define cPI1_8 (0x7641af3d) /* cos(pi/8) s.31 */ +#define cPI2_8 (0x5a82799a) /* cos(2pi/8) = 1/sqrt(2) s.31 */ +#define cPI3_8 (0x30fbc54d) /* cos(3pi/8) s.31 */ + +/* asm-optimised functions and/or macros */ +#include "fft-ffmpeg_arm.h" + +#ifndef ICODE_ATTR_TREMOR_MDCT +#define ICODE_ATTR_TREMOR_MDCT ICODE_ATTR +#endif + +/* Use to give gcc hints on which branch is most likely taken */ +#if defined(__GNUC__) && __GNUC__ >= 3 +#define LIKELY(x) __builtin_expect(!!(x), 1) +#define UNLIKELY(x) __builtin_expect(!!(x), 0) +#else +#define LIKELY(x) (x) +#define UNLIKELY(x) (x) +#endif + +#if 0 +static int split_radix_permutation(int i, int n, int inverse) +{ + int m; + if(n <= 2) return i&1; + m = n >> 1; + if(!(i&m)) return split_radix_permutation(i, m, inverse)*2; + m >>= 1; + if(inverse == !(i&m)) return split_radix_permutation(i, m, inverse)*4 + 1; + else return split_radix_permutation(i, m, inverse)*4 - 1; +} + +static void ff_fft_permute_c(FFTContext *s, FFTComplex *z) +{ + int j, k, np; + FFTComplex tmp; + //const uint16_t *revtab = s->revtab; + np = 1 << s->nbits; + + const int revtab_shift = (12 - s->nbits); + + /* reverse */ + for(j=0;j<np;j++) { + k = revtab[j]>>revtab_shift; + if (k < j) { + tmp = z[k]; + z[k] = z[j]; + z[j] = tmp; + } + } +} +#endif + +#define BF(x,y,a,b) {\ + x = a - b;\ + y = a + b;\ +} + +#define BF_REV(x,y,a,b) {\ + x = a + b;\ + y = a - b;\ +} + +#ifndef FFT_FFMPEG_INCL_OPTIMISED_BUTTERFLIES +#define BUTTERFLIES(a0,a1,a2,a3) {\ + {\ + FFTSample temp1,temp2;\ + BF(temp1, temp2, t5, t1);\ + BF(a2.re, a0.re, a0.re, temp2);\ + BF(a3.im, a1.im, a1.im, temp1);\ + }\ + {\ + FFTSample temp1,temp2;\ + BF(temp1, temp2, t2, t6);\ + BF(a3.re, a1.re, a1.re, temp1);\ + BF(a2.im, a0.im, a0.im, temp2);\ + }\ +} + +// force loading all the inputs before storing any. +// this is slightly slower for small data, but avoids store->load aliasing +// for addresses separated by large powers of 2. +#define BUTTERFLIES_BIG(a0,a1,a2,a3) {\ + FFTSample r0=a0.re, i0=a0.im, r1=a1.re, i1=a1.im;\ + {\ + FFTSample temp1, temp2;\ + BF(temp1, temp2, t5, t1);\ + BF(a2.re, a0.re, r0, temp2);\ + BF(a3.im, a1.im, i1, temp1);\ + }\ + {\ + FFTSample temp1, temp2;\ + BF(temp1, temp2, t2, t6);\ + BF(a3.re, a1.re, r1, temp1);\ + BF(a2.im, a0.im, i0, temp2);\ + }\ +} +#endif + +/* + see conjugate pair description in + http://www.fftw.org/newsplit.pdf + + a0 = z[k] + a1 = z[k+N/4] + a2 = z[k+2N/4] + a3 = z[k+3N/4] + + result: + y[k] = z[k]+w(z[k+2N/4])+w'(z[k+3N/4]) + y[k+N/4] = z[k+N/4]-iw(z[k+2N/4])+iw'(z[k+3N/4]) + y[k+2N/4] = z[k]-w(z[k+2N/4])-w'(z[k+3N/4]) + y[k+3N/4] = z[k+N/4]+iw(z[k+2N/4])-iw'(z[k+3N/4]) + + i.e. + + a0 = a0 + (w.a2 + w'.a3) + a1 = a1 - i(w.a2 - w'.a3) + a2 = a0 - (w.a2 + w'.a3) + a3 = a1 + i(w.a2 - w'.a3) + + note re(w') = re(w) and im(w') = -im(w) + + so therefore + + re(a0) = re(a0) + re(w.a2) + re(w.a3) + im(a0) = im(a0) + im(w.a2) - im(w.a3) etc + + and remember also that + Re([s+it][u+iv]) = su-tv + Im([s+it][u+iv]) = sv+tu + + so + Re(w'.(s+it)) = Re(w').s - Im(w').t = Re(w).s + Im(w).t + Im(w'.(s+it)) = Re(w').t + Im(w').s = Re(w).t - Im(w).s + + For inverse dft we take the complex conjugate of all twiddle factors. + Hence + + a0 = a0 + (w'.a2 + w.a3) + a1 = a1 - i(w'.a2 - w.a3) + a2 = a0 - (w'.a2 + w.a3) + a3 = a1 + i(w'.a2 - w.a3) + + Define t1 = Re(w'.a2) = Re(w)*Re(a2) + Im(w)*Im(a2) + t2 = Im(w'.a2) = Re(w)*Im(a2) - Im(w)*Re(a2) + t5 = Re(w.a3) = Re(w)*Re(a3) - Im(w)*Im(a3) + t6 = Im(w.a3) = Re(w)*Im(a3) + Im(w)*Re(a3) + + Then we just output: + a0.re = a0.re + ( t1 + t5 ) + a0.im = a0.im + ( t2 + t6 ) + a1.re = a1.re + ( t2 - t6 ) // since we multiply by -i and i(-i) = 1 + a1.im = a1.im - ( t1 - t5 ) // since we multiply by -i and 1(-i) = -i + a2.re = a0.re - ( t1 + t5 ) + a2.im = a0.im - ( t1 + t5 ) + a3.re = a1.re - ( t2 - t6 ) // since we multiply by +i and i(+i) = -1 + a3.im = a1.im + ( t1 - t5 ) // since we multiply by +i and 1(+i) = i + + +*/ + +#ifndef FFT_FFMPEG_INCL_OPTIMISED_TRANSFORM +static inline FFTComplex* TRANSFORM(FFTComplex * z, unsigned int n, FFTSample wre, FFTSample wim) +{ + register FFTSample t1,t2,t5,t6,r_re,r_im; + r_re = z[n*2].re; + r_im = z[n*2].im; + XPROD31_R(r_re, r_im, wre, wim, t1,t2); + r_re = z[n*3].re; + r_im = z[n*3].im; + XNPROD31_R(r_re, r_im, wre, wim, t5,t6); + BUTTERFLIES(z[0],z[n],z[n*2],z[n*3]); + return z+1; +} + +static inline FFTComplex* TRANSFORM_W01(FFTComplex * z, unsigned int n, const FFTSample * w) +{ + register const FFTSample wre=w[0],wim=w[1]; + register FFTSample t1,t2,t5,t6,r_re,r_im; + r_re = z[n*2].re; + r_im = z[n*2].im; + XPROD31_R(r_re, r_im, wre, wim, t1,t2); + r_re = z[n*3].re; + r_im = z[n*3].im; + XNPROD31_R(r_re, r_im, wre, wim, t5,t6); + BUTTERFLIES(z[0],z[n],z[n*2],z[n*3]); + return z+1; +} + +static inline FFTComplex* TRANSFORM_W10(FFTComplex * z, unsigned int n, const FFTSample * w) +{ + register const FFTSample wim=w[0],wre=w[1]; + register FFTSample t1,t2,t5,t6,r_re,r_im; + r_re = z[n*2].re; + r_im = z[n*2].im; + XPROD31_R(r_re, r_im, wre, wim, t1,t2); + r_re = z[n*3].re; + r_im = z[n*3].im; + XNPROD31_R(r_re, r_im, wre, wim, t5,t6); + BUTTERFLIES(z[0],z[n],z[n*2],z[n*3]); + return z+1; +} + +static inline FFTComplex* TRANSFORM_EQUAL(FFTComplex * z, unsigned int n) +{ + register FFTSample t1,t2,t5,t6,temp1,temp2; + register FFTSample * my_z = (FFTSample *)(z); + my_z += n*4; + t2 = MULT31(my_z[0], cPI2_8); + temp1 = MULT31(my_z[1], cPI2_8); + my_z += n*2; + temp2 = MULT31(my_z[0], cPI2_8); + t5 = MULT31(my_z[1], cPI2_8); + t1 = ( temp1 + t2 ); + t2 = ( temp1 - t2 ); + t6 = ( temp2 + t5 ); + t5 = ( temp2 - t5 ); + my_z -= n*6; + BUTTERFLIES(z[0],z[n],z[n*2],z[n*3]); + return z+1; +} + +static inline FFTComplex* TRANSFORM_ZERO(FFTComplex * z, unsigned int n) +{ + FFTSample t1,t2,t5,t6; + t1 = z[n*2].re; + t2 = z[n*2].im; + t5 = z[n*3].re; + t6 = z[n*3].im; + BUTTERFLIES(z[0],z[n],z[n*2],z[n*3]); + return z+1; +} +#endif + +/* z[0...8n-1], w[1...2n-1] */ +#define ICODE_ATTR +static void pass(FFTComplex *z_arg, unsigned int STEP_arg, unsigned int n_arg) ICODE_ATTR_TREMOR_MDCT; +static void pass(FFTComplex *z_arg, unsigned int STEP_arg, unsigned int n_arg) +{ + register FFTComplex * z = z_arg; + register unsigned int STEP = STEP_arg; + register unsigned int n = n_arg; + + register const FFTSample *w = sincos_lookup0+STEP; + /* wre = *(wim+1) . ordering is sin,cos */ + register const FFTSample *w_end = sincos_lookup0+1024; + + /* first two are special (well, first one is special, but we need to do pairs) */ + z = TRANSFORM_ZERO(z,n); + z = TRANSFORM_W10(z,n,w); + w += STEP; + /* first pass forwards through sincos_lookup0*/ + do { + z = TRANSFORM_W10(z,n,w); + w += STEP; + z = TRANSFORM_W10(z,n,w); + w += STEP; + } while(LIKELY(w < w_end)); + /* second half: pass backwards through sincos_lookup0*/ + /* wim and wre are now in opposite places so ordering now [0],[1] */ + w_end=sincos_lookup0; + while(LIKELY(w>w_end)) + { + z = TRANSFORM_W01(z,n,w); + w -= STEP; + z = TRANSFORM_W01(z,n,w); + w -= STEP; + } +} + +/* what is STEP? + sincos_lookup0 has sin,cos pairs for 1/4 cycle, in 1024 points + so half cycle would be 2048 points + ff_cos_16 has 8 elements corresponding to 4 cos points and 4 sin points + so each of the 4 points pairs corresponds to a 256*2-byte jump in sincos_lookup0 + 8192/16 (from "ff_cos_16") is 512 bytes. + i.e. for fft16, STEP = 8192/16 */ +#define DECL_FFT(n,n2,n4)\ +static void fft##n(FFTComplex *z) ICODE_ATTR_TREMOR_MDCT;\ +static void fft##n(FFTComplex *z)\ +{\ + fft##n2(z);\ + fft##n4(z+n4*2);\ + fft##n4(z+n4*3);\ + pass(z,8192/n,n4);\ +} + +#ifndef FFT_FFMPEG_INCL_OPTIMISED_FFT4 +static inline void fft4(FFTComplex *z) +{ + FFTSample t1, t2, t3, t4, t5, t6, t7, t8; + + BF(t3, t1, z[0].re, z[1].re); // t3=r1-r3 ; t1 = r1+r3 + BF(t8, t6, z[3].re, z[2].re); // t8=r7-r5 ; t6 = r7+r5 + + BF(z[2].re, z[0].re, t1, t6); // r5=t1-t6 ; r1 = t1+t6 + + BF(t4, t2, z[0].im, z[1].im); // t4=r2-r4 ; t2 = r2+r4 + BF(t7, t5, z[2].im, z[3].im); // t7=r6-r8 ; t5 = r6+r8 + + BF(z[3].im, z[1].im, t4, t8); // r8=t4-t8 ; r4 = t4+t8 + BF(z[3].re, z[1].re, t3, t7); // r7=t3-t7 ; r3 = t3+t7 + BF(z[2].im, z[0].im, t2, t5); // r6=t2-t5 ; r2 = t2+t5 +} +#endif + +static void fft4_dispatch(FFTComplex *z) +{ + fft4(z); +} + +#ifndef FFT_FFMPEG_INCL_OPTIMISED_FFT8 +static inline void fft8(FFTComplex *z) +{ + fft4(z); + FFTSample t1,t2,t3,t4,t7,t8; + + BF(t1, z[5].re, z[4].re, -z[5].re); + BF(t2, z[5].im, z[4].im, -z[5].im); + BF(t3, z[7].re, z[6].re, -z[7].re); + BF(t4, z[7].im, z[6].im, -z[7].im); + BF(t8, t1, t3, t1); + BF(t7, t2, t2, t4); + BF(z[4].re, z[0].re, z[0].re, t1); + BF(z[4].im, z[0].im, z[0].im, t2); + BF(z[6].re, z[2].re, z[2].re, t7); + BF(z[6].im, z[2].im, z[2].im, t8); + + z++; + TRANSFORM_EQUAL(z,2); +} +#endif + +static void fft8_dispatch(FFTComplex *z) +{ + fft8(z); +} + +#ifndef CONFIG_SMALL +static void fft16(FFTComplex *z) ICODE_ATTR_TREMOR_MDCT; +static void fft16(FFTComplex *z) +{ + fft8(z); + fft4(z+8); + fft4(z+12); + + TRANSFORM_ZERO(z,4); + z+=2; + TRANSFORM_EQUAL(z,4); + z-=1; + TRANSFORM(z,4,cPI1_8,cPI3_8); + z+=2; + TRANSFORM(z,4,cPI3_8,cPI1_8); +} +#else +DECL_FFT(16,8,4) +#endif +DECL_FFT(32,16,8) +DECL_FFT(64,32,16) +DECL_FFT(128,64,32) +DECL_FFT(256,128,64) +DECL_FFT(512,256,128) +DECL_FFT(1024,512,256) +DECL_FFT(2048,1024,512) +DECL_FFT(4096,2048,1024) + +static void (*fft_dispatch[])(FFTComplex*) = { + fft4_dispatch, fft8_dispatch, fft16, fft32, fft64, fft128, fft256, fft512, fft1024, + fft2048, fft4096 +}; + +void ff_fft_calc_c(int nbits, FFTComplex *z) +{ + fft_dispatch[nbits-2](z); +} + +#if 0 +int main (void) +{ +#define PRECISION 16 +#define FFT_SIZE 1024 +#define ftofix32(x) ((fixed32)((x) * (float)(1 << PRECISION) + ((x) < 0 ? -0.5 : 0.5))) +#define itofix32(x) ((x) << PRECISION) +#define fixtoi32(x) ((x) >> PRECISION) + + int j; + const long N = FFT_SIZE; + double r[FFT_SIZE] = {0.0}, i[FFT_SIZE] = {0.0}; + long n; + double t; + double amp, phase; + clock_t start, end; + double exec_time = 0; + FFTContext s; + FFTComplex z[FFT_SIZE]; + memset(z, 0, 64*sizeof(FFTComplex)); + + /* Generate saw-tooth test data */ + for (n = 0; n < FFT_SIZE; n++) + { + t = (2 * M_PI * n)/N; + /*z[n].re = 1.1 + sin( t) + + 0.5 * sin(2.0 * t) + + (1.0/3.0) * sin(3.0 * t) + + 0.25 * sin(4.0 * t) + + 0.2 * sin(5.0 * t) + + (1.0/6.0) * sin(6.0 * t) + + (1.0/7.0) * sin(7.0 * t) ;*/ + z[n].re = ftofix32(cos(2*M_PI*n/64)); + //printf("z[%d] = %f\n", n, z[n].re); + //getchar(); + } + + ff_fft_init(&s, 10, 1); +//start = clock(); +//for(n = 0; n < 1000000; n++) + ff_fft_permute_c(&s, z); + ff_fft_calc_c(&s, z); +//end = clock(); +//exec_time = (((double)end-(double)start)/CLOCKS_PER_SEC); + for(j = 0; j < FFT_SIZE; j++) + { + printf("%8.4f\n", sqrt(pow(fixtof32(z[j].re),2)+ pow(fixtof32(z[j].im), 2))); + //getchar(); + } + printf("muls = %d, adds = %d\n", muls, adds); +//printf(" Time elapsed = %f\n", exec_time); + //ff_fft_end(&s); + +} +#endif |