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| author | Mohamed Tarek <mt@rockbox.org> | 2010-04-30 11:11:56 +0000 |
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| committer | Mohamed Tarek <mt@rockbox.org> | 2010-04-30 11:11:56 +0000 |
| commit | cf43e5083b9e0f87de262ea31fd8067225ebfcda (patch) | |
| tree | 073e6f4cd9561564d85e410a35432e1f4ead5b11 /apps/codecs/libwmapro/fft.c | |
| parent | bc3c5c16571487bf71fed8c22b30ee40481e156e (diff) | |
| download | rockbox-cf43e5083b9e0f87de262ea31fd8067225ebfcda.zip rockbox-cf43e5083b9e0f87de262ea31fd8067225ebfcda.tar.gz rockbox-cf43e5083b9e0f87de262ea31fd8067225ebfcda.tar.bz2 rockbox-cf43e5083b9e0f87de262ea31fd8067225ebfcda.tar.xz | |
Add libwmapro to apps/codecs. These files comprise a set of unmodified files needed from ffmpeg's libavcodec and libavutil to compile and use the wma pro decoder standalone. The files were taken from ffmpeg's svn r22886 dated 15 April 2010.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@25763 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'apps/codecs/libwmapro/fft.c')
| -rw-r--r-- | apps/codecs/libwmapro/fft.c | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/apps/codecs/libwmapro/fft.c b/apps/codecs/libwmapro/fft.c new file mode 100644 index 0000000..7275d98 --- /dev/null +++ b/apps/codecs/libwmapro/fft.c @@ -0,0 +1,368 @@ +/* + * FFT/IFFT transforms + * 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. + */ + +#include <stdlib.h> +#include <string.h> +#include "libavutil/mathematics.h" +#include "fft.h" + +/* cos(2*pi*x/n) for 0<=x<=n/4, followed by its reverse */ +#if !CONFIG_HARDCODED_TABLES +COSTABLE(16); +COSTABLE(32); +COSTABLE(64); +COSTABLE(128); +COSTABLE(256); +COSTABLE(512); +COSTABLE(1024); +COSTABLE(2048); +COSTABLE(4096); +COSTABLE(8192); +COSTABLE(16384); +COSTABLE(32768); +COSTABLE(65536); +#endif +COSTABLE_CONST FFTSample * const ff_cos_tabs[] = { + NULL, NULL, NULL, NULL, + ff_cos_16, ff_cos_32, ff_cos_64, ff_cos_128, ff_cos_256, ff_cos_512, ff_cos_1024, + ff_cos_2048, ff_cos_4096, ff_cos_8192, ff_cos_16384, ff_cos_32768, ff_cos_65536, +}; + +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; +} + +av_cold void ff_init_ff_cos_tabs(int index) +{ +#if !CONFIG_HARDCODED_TABLES + int i; + int m = 1<<index; + double freq = 2*M_PI/m; + FFTSample *tab = ff_cos_tabs[index]; + for(i=0; i<=m/4; i++) + tab[i] = cos(i*freq); + for(i=1; i<m/4; i++) + tab[m/2-i] = tab[i]; +#endif +} + +av_cold int ff_fft_init(FFTContext *s, int nbits, int inverse) +{ + int i, j, m, n; + float alpha, c1, s1, s2; + int av_unused has_vectors; + + if (nbits < 2 || nbits > 16) + goto fail; + s->nbits = nbits; + n = 1 << nbits; + + s->tmp_buf = NULL; + s->exptab = av_malloc((n / 2) * sizeof(FFTComplex)); + if (!s->exptab) + goto fail; + s->revtab = av_malloc(n * sizeof(uint16_t)); + if (!s->revtab) + goto fail; + s->inverse = inverse; + + s2 = inverse ? 1.0 : -1.0; + + s->fft_permute = ff_fft_permute_c; + s->fft_calc = ff_fft_calc_c; +#if CONFIG_MDCT + s->imdct_calc = ff_imdct_calc_c; + s->imdct_half = ff_imdct_half_c; + s->mdct_calc = ff_mdct_calc_c; +#endif + s->exptab1 = NULL; + s->split_radix = 1; + + if (ARCH_ARM) ff_fft_init_arm(s); + if (HAVE_ALTIVEC) ff_fft_init_altivec(s); + if (HAVE_MMX) ff_fft_init_mmx(s); + + if (s->split_radix) { + for(j=4; j<=nbits; j++) { + ff_init_ff_cos_tabs(j); + } + for(i=0; i<n; i++) + s->revtab[-split_radix_permutation(i, n, s->inverse) & (n-1)] = i; + s->tmp_buf = av_malloc(n * sizeof(FFTComplex)); + } else { + int np, nblocks, np2, l; + FFTComplex *q; + + for(i=0; i<(n/2); i++) { + alpha = 2 * M_PI * (float)i / (float)n; + c1 = cos(alpha); + s1 = sin(alpha) * s2; + s->exptab[i].re = c1; + s->exptab[i].im = s1; + } + + np = 1 << nbits; + nblocks = np >> 3; + np2 = np >> 1; + s->exptab1 = av_malloc(np * 2 * sizeof(FFTComplex)); + if (!s->exptab1) + goto fail; + q = s->exptab1; + do { + for(l = 0; l < np2; l += 2 * nblocks) { + *q++ = s->exptab[l]; + *q++ = s->exptab[l + nblocks]; + + q->re = -s->exptab[l].im; + q->im = s->exptab[l].re; + q++; + q->re = -s->exptab[l + nblocks].im; + q->im = s->exptab[l + nblocks].re; + q++; + } + nblocks = nblocks >> 1; + } while (nblocks != 0); + av_freep(&s->exptab); + + /* compute bit reverse table */ + for(i=0;i<n;i++) { + m=0; + for(j=0;j<nbits;j++) { + m |= ((i >> j) & 1) << (nbits-j-1); + } + s->revtab[i]=m; + } + } + + return 0; + fail: + av_freep(&s->revtab); + av_freep(&s->exptab); + av_freep(&s->exptab1); + av_freep(&s->tmp_buf); + return -1; +} + +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; + + if (s->tmp_buf) { + /* TODO: handle split-radix permute in a more optimal way, probably in-place */ + for(j=0;j<np;j++) s->tmp_buf[revtab[j]] = z[j]; + memcpy(z, s->tmp_buf, np * sizeof(FFTComplex)); + return; + } + + /* reverse */ + for(j=0;j<np;j++) { + k = revtab[j]; + if (k < j) { + tmp = z[k]; + z[k] = z[j]; + z[j] = tmp; + } + } +} + +av_cold void ff_fft_end(FFTContext *s) +{ + av_freep(&s->revtab); + av_freep(&s->exptab); + av_freep(&s->exptab1); + av_freep(&s->tmp_buf); +} + +#define sqrthalf (float)M_SQRT1_2 + +#define BF(x,y,a,b) {\ + x = a - b;\ + y = a + b;\ +} + +#define BUTTERFLIES(a0,a1,a2,a3) {\ + BF(t3, t5, t5, t1);\ + BF(a2.re, a0.re, a0.re, t5);\ + BF(a3.im, a1.im, a1.im, t3);\ + BF(t4, t6, t2, t6);\ + BF(a3.re, a1.re, a1.re, t4);\ + BF(a2.im, a0.im, a0.im, t6);\ +} + +// 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;\ + BF(t3, t5, t5, t1);\ + BF(a2.re, a0.re, r0, t5);\ + BF(a3.im, a1.im, i1, t3);\ + BF(t4, t6, t2, t6);\ + BF(a3.re, a1.re, r1, t4);\ + BF(a2.im, a0.im, i0, t6);\ +} + +#define TRANSFORM(a0,a1,a2,a3,wre,wim) {\ + t1 = a2.re * wre + a2.im * wim;\ + t2 = a2.im * wre - a2.re * wim;\ + t5 = a3.re * wre - a3.im * wim;\ + t6 = a3.im * wre + a3.re * wim;\ + BUTTERFLIES(a0,a1,a2,a3)\ +} + +#define TRANSFORM_ZERO(a0,a1,a2,a3) {\ + t1 = a2.re;\ + t2 = a2.im;\ + t5 = a3.re;\ + t6 = a3.im;\ + BUTTERFLIES(a0,a1,a2,a3)\ +} + +/* z[0...8n-1], w[1...2n-1] */ +#define PASS(name)\ +static void name(FFTComplex *z, const FFTSample *wre, unsigned int n)\ +{\ + FFTSample t1, t2, t3, t4, t5, t6;\ + int o1 = 2*n;\ + int o2 = 4*n;\ + int o3 = 6*n;\ + const FFTSample *wim = wre+o1;\ + n--;\ +\ + TRANSFORM_ZERO(z[0],z[o1],z[o2],z[o3]);\ + TRANSFORM(z[1],z[o1+1],z[o2+1],z[o3+1],wre[1],wim[-1]);\ + do {\ + z += 2;\ + wre += 2;\ + wim -= 2;\ + TRANSFORM(z[0],z[o1],z[o2],z[o3],wre[0],wim[0]);\ + TRANSFORM(z[1],z[o1+1],z[o2+1],z[o3+1],wre[1],wim[-1]);\ + } while(--n);\ +} + +PASS(pass) +#undef BUTTERFLIES +#define BUTTERFLIES BUTTERFLIES_BIG +PASS(pass_big) + +#define DECL_FFT(n,n2,n4)\ +static void fft##n(FFTComplex *z)\ +{\ + fft##n2(z);\ + fft##n4(z+n4*2);\ + fft##n4(z+n4*3);\ + pass(z,ff_cos_##n,n4/2);\ +} + +static void fft4(FFTComplex *z) +{ + FFTSample t1, t2, t3, t4, t5, t6, t7, t8; + + BF(t3, t1, z[0].re, z[1].re); + BF(t8, t6, z[3].re, z[2].re); + BF(z[2].re, z[0].re, t1, t6); + BF(t4, t2, z[0].im, z[1].im); + BF(t7, t5, z[2].im, z[3].im); + BF(z[3].im, z[1].im, t4, t8); + BF(z[3].re, z[1].re, t3, t7); + BF(z[2].im, z[0].im, t2, t5); +} + +static void fft8(FFTComplex *z) +{ + FFTSample t1, t2, t3, t4, t5, t6, t7, t8; + + fft4(z); + + 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); + + TRANSFORM(z[1],z[3],z[5],z[7],sqrthalf,sqrthalf); +} + +#if !CONFIG_SMALL +static void fft16(FFTComplex *z) +{ + FFTSample t1, t2, t3, t4, t5, t6; + + fft8(z); + fft4(z+8); + fft4(z+12); + + TRANSFORM_ZERO(z[0],z[4],z[8],z[12]); + TRANSFORM(z[2],z[6],z[10],z[14],sqrthalf,sqrthalf); + TRANSFORM(z[1],z[5],z[9],z[13],ff_cos_16[1],ff_cos_16[3]); + TRANSFORM(z[3],z[7],z[11],z[15],ff_cos_16[3],ff_cos_16[1]); +} +#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) +#if !CONFIG_SMALL +#define pass pass_big +#endif +DECL_FFT(1024,512,256) +DECL_FFT(2048,1024,512) +DECL_FFT(4096,2048,1024) +DECL_FFT(8192,4096,2048) +DECL_FFT(16384,8192,4096) +DECL_FFT(32768,16384,8192) +DECL_FFT(65536,32768,16384) + +static void (* const fft_dispatch[])(FFTComplex*) = { + fft4, fft8, fft16, fft32, fft64, fft128, fft256, fft512, fft1024, + fft2048, fft4096, fft8192, fft16384, fft32768, fft65536, +}; + +void ff_fft_calc_c(FFTContext *s, FFTComplex *z) +{ + fft_dispatch[s->nbits-2](z); +} + |