mirror of
https://git.ffmpeg.org/ffmpeg.git
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804 lines
30 KiB
C
804 lines
30 KiB
C
/*
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* Copyright (c) 2019 Lynne <dev@lynne.ee>
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* Power of two FFT:
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* Copyright (c) 2008 Loren Merritt
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* Copyright (c) 2002 Fabrice Bellard
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* Partly based on libdjbfft by D. J. Bernstein
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <stddef.h>
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#include "tx.h"
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#include "thread.h"
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#include "mem.h"
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#include "avassert.h"
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typedef float FFTSample;
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typedef AVComplexFloat FFTComplex;
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struct AVTXContext {
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int n; /* Nptwo part */
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int m; /* Ptwo part */
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FFTComplex *exptab; /* MDCT exptab */
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FFTComplex *tmp; /* Temporary buffer needed for all compound transforms */
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int *pfatab; /* Input/Output mapping for compound transforms */
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int *revtab; /* Input mapping for power of two transforms */
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};
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#define FFT_NAME(x) x
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#define COSTABLE(size) \
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static DECLARE_ALIGNED(32, FFTSample, FFT_NAME(ff_cos_##size))[size/2]
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static FFTSample * const FFT_NAME(ff_cos_tabs)[18];
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COSTABLE(16);
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COSTABLE(32);
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COSTABLE(64);
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COSTABLE(128);
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COSTABLE(256);
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COSTABLE(512);
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COSTABLE(1024);
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COSTABLE(2048);
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COSTABLE(4096);
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COSTABLE(8192);
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COSTABLE(16384);
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COSTABLE(32768);
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COSTABLE(65536);
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COSTABLE(131072);
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static av_cold void init_ff_cos_tabs(int index)
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{
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int m = 1 << index;
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double freq = 2*M_PI/m;
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FFTSample *tab = FFT_NAME(ff_cos_tabs)[index];
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for(int i = 0; i <= m/4; i++)
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tab[i] = cos(i*freq);
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for(int i = 1; i < m/4; i++)
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tab[m/2 - i] = tab[i];
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}
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typedef struct CosTabsInitOnce {
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void (*func)(void);
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AVOnce control;
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} CosTabsInitOnce;
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#define INIT_FF_COS_TABS_FUNC(index, size) \
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static av_cold void init_ff_cos_tabs_ ## size (void) \
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{ \
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init_ff_cos_tabs(index); \
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}
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INIT_FF_COS_TABS_FUNC(4, 16)
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INIT_FF_COS_TABS_FUNC(5, 32)
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INIT_FF_COS_TABS_FUNC(6, 64)
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INIT_FF_COS_TABS_FUNC(7, 128)
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INIT_FF_COS_TABS_FUNC(8, 256)
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INIT_FF_COS_TABS_FUNC(9, 512)
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INIT_FF_COS_TABS_FUNC(10, 1024)
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INIT_FF_COS_TABS_FUNC(11, 2048)
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INIT_FF_COS_TABS_FUNC(12, 4096)
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INIT_FF_COS_TABS_FUNC(13, 8192)
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INIT_FF_COS_TABS_FUNC(14, 16384)
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INIT_FF_COS_TABS_FUNC(15, 32768)
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INIT_FF_COS_TABS_FUNC(16, 65536)
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INIT_FF_COS_TABS_FUNC(17, 131072)
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static CosTabsInitOnce cos_tabs_init_once[] = {
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{ NULL },
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{ NULL },
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{ NULL },
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{ NULL },
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{ init_ff_cos_tabs_16, AV_ONCE_INIT },
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{ init_ff_cos_tabs_32, AV_ONCE_INIT },
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{ init_ff_cos_tabs_64, AV_ONCE_INIT },
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{ init_ff_cos_tabs_128, AV_ONCE_INIT },
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{ init_ff_cos_tabs_256, AV_ONCE_INIT },
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{ init_ff_cos_tabs_512, AV_ONCE_INIT },
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{ init_ff_cos_tabs_1024, AV_ONCE_INIT },
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{ init_ff_cos_tabs_2048, AV_ONCE_INIT },
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{ init_ff_cos_tabs_4096, AV_ONCE_INIT },
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{ init_ff_cos_tabs_8192, AV_ONCE_INIT },
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{ init_ff_cos_tabs_16384, AV_ONCE_INIT },
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{ init_ff_cos_tabs_32768, AV_ONCE_INIT },
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{ init_ff_cos_tabs_65536, AV_ONCE_INIT },
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{ init_ff_cos_tabs_131072, AV_ONCE_INIT },
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};
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static FFTSample * const FFT_NAME(ff_cos_tabs)[] = {
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NULL, NULL, NULL, NULL,
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FFT_NAME(ff_cos_16),
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FFT_NAME(ff_cos_32),
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FFT_NAME(ff_cos_64),
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FFT_NAME(ff_cos_128),
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FFT_NAME(ff_cos_256),
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FFT_NAME(ff_cos_512),
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FFT_NAME(ff_cos_1024),
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FFT_NAME(ff_cos_2048),
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FFT_NAME(ff_cos_4096),
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FFT_NAME(ff_cos_8192),
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FFT_NAME(ff_cos_16384),
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FFT_NAME(ff_cos_32768),
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FFT_NAME(ff_cos_65536),
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FFT_NAME(ff_cos_131072),
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};
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static av_cold void ff_init_ff_cos_tabs(int index)
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{
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ff_thread_once(&cos_tabs_init_once[index].control,
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cos_tabs_init_once[index].func);
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}
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static AVOnce tabs_53_once = AV_ONCE_INIT;
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static DECLARE_ALIGNED(32, FFTComplex, FFT_NAME(ff_53_tabs))[4];
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static av_cold void ff_init_53_tabs(void)
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{
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ff_53_tabs[0] = (FFTComplex){ cos(2 * M_PI / 12), cos(2 * M_PI / 12) };
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ff_53_tabs[1] = (FFTComplex){ 0.5, 0.5 };
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ff_53_tabs[2] = (FFTComplex){ cos(2 * M_PI / 5), sin(2 * M_PI / 5) };
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ff_53_tabs[3] = (FFTComplex){ cos(2 * M_PI / 10), sin(2 * M_PI / 10) };
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}
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#define BF(x, y, a, b) do { \
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x = (a) - (b); \
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y = (a) + (b); \
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} while (0)
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#define CMUL(dre, dim, are, aim, bre, bim) do { \
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(dre) = (are) * (bre) - (aim) * (bim); \
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(dim) = (are) * (bim) + (aim) * (bre); \
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} while (0)
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#define CMUL3(c, a, b) CMUL((c).re, (c).im, (a).re, (a).im, (b).re, (b).im)
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static av_always_inline void fft3(FFTComplex *out, FFTComplex *in,
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ptrdiff_t stride)
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{
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FFTComplex tmp[2];
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tmp[0].re = in[1].im - in[2].im;
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tmp[0].im = in[1].re - in[2].re;
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tmp[1].re = in[1].re + in[2].re;
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tmp[1].im = in[1].im + in[2].im;
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out[0*stride].re = in[0].re + tmp[1].re;
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out[0*stride].im = in[0].im + tmp[1].im;
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tmp[0].re *= ff_53_tabs[0].re;
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tmp[0].im *= ff_53_tabs[0].im;
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tmp[1].re *= ff_53_tabs[1].re;
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tmp[1].im *= ff_53_tabs[1].re;
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out[1*stride].re = in[0].re - tmp[1].re + tmp[0].re;
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out[1*stride].im = in[0].im - tmp[1].im - tmp[0].im;
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out[2*stride].re = in[0].re - tmp[1].re - tmp[0].re;
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out[2*stride].im = in[0].im - tmp[1].im + tmp[0].im;
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}
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#define DECL_FFT5(NAME, D0, D1, D2, D3, D4) \
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static av_always_inline void NAME(FFTComplex *out, FFTComplex *in, \
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ptrdiff_t stride) \
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{ \
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FFTComplex z0[4], t[6]; \
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\
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t[0].re = in[1].re + in[4].re; \
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t[0].im = in[1].im + in[4].im; \
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t[1].im = in[1].re - in[4].re; \
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t[1].re = in[1].im - in[4].im; \
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t[2].re = in[2].re + in[3].re; \
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t[2].im = in[2].im + in[3].im; \
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t[3].im = in[2].re - in[3].re; \
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t[3].re = in[2].im - in[3].im; \
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\
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out[D0*stride].re = in[0].re + in[1].re + in[2].re + \
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in[3].re + in[4].re; \
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out[D0*stride].im = in[0].im + in[1].im + in[2].im + \
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in[3].im + in[4].im; \
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\
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t[4].re = ff_53_tabs[2].re * t[2].re - ff_53_tabs[3].re * t[0].re; \
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t[4].im = ff_53_tabs[2].re * t[2].im - ff_53_tabs[3].re * t[0].im; \
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t[0].re = ff_53_tabs[2].re * t[0].re - ff_53_tabs[3].re * t[2].re; \
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t[0].im = ff_53_tabs[2].re * t[0].im - ff_53_tabs[3].re * t[2].im; \
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t[5].re = ff_53_tabs[2].im * t[3].re - ff_53_tabs[3].im * t[1].re; \
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t[5].im = ff_53_tabs[2].im * t[3].im - ff_53_tabs[3].im * t[1].im; \
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t[1].re = ff_53_tabs[2].im * t[1].re + ff_53_tabs[3].im * t[3].re; \
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t[1].im = ff_53_tabs[2].im * t[1].im + ff_53_tabs[3].im * t[3].im; \
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\
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z0[0].re = t[0].re - t[1].re; \
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z0[0].im = t[0].im - t[1].im; \
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z0[1].re = t[4].re + t[5].re; \
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z0[1].im = t[4].im + t[5].im; \
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\
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z0[2].re = t[4].re - t[5].re; \
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z0[2].im = t[4].im - t[5].im; \
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z0[3].re = t[0].re + t[1].re; \
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z0[3].im = t[0].im + t[1].im; \
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\
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out[D1*stride].re = in[0].re + z0[3].re; \
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out[D1*stride].im = in[0].im + z0[0].im; \
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out[D2*stride].re = in[0].re + z0[2].re; \
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out[D2*stride].im = in[0].im + z0[1].im; \
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out[D3*stride].re = in[0].re + z0[1].re; \
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out[D3*stride].im = in[0].im + z0[2].im; \
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out[D4*stride].re = in[0].re + z0[0].re; \
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out[D4*stride].im = in[0].im + z0[3].im; \
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}
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DECL_FFT5(fft5, 0, 1, 2, 3, 4)
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DECL_FFT5(fft5_m1, 0, 6, 12, 3, 9)
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DECL_FFT5(fft5_m2, 10, 1, 7, 13, 4)
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DECL_FFT5(fft5_m3, 5, 11, 2, 8, 14)
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static av_always_inline void fft15(FFTComplex *out, FFTComplex *in,
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ptrdiff_t stride)
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{
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FFTComplex tmp[15];
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for (int i = 0; i < 5; i++)
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fft3(tmp + i, in + i*3, 5);
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fft5_m1(out, tmp + 0, stride);
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fft5_m2(out, tmp + 5, stride);
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fft5_m3(out, tmp + 10, stride);
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}
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#define BUTTERFLIES(a0,a1,a2,a3) {\
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BF(t3, t5, t5, t1);\
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BF(a2.re, a0.re, a0.re, t5);\
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BF(a3.im, a1.im, a1.im, t3);\
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BF(t4, t6, t2, t6);\
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BF(a3.re, a1.re, a1.re, t4);\
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BF(a2.im, a0.im, a0.im, t6);\
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}
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// force loading all the inputs before storing any.
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// this is slightly slower for small data, but avoids store->load aliasing
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// for addresses separated by large powers of 2.
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#define BUTTERFLIES_BIG(a0,a1,a2,a3) {\
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FFTSample r0=a0.re, i0=a0.im, r1=a1.re, i1=a1.im;\
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BF(t3, t5, t5, t1);\
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BF(a2.re, a0.re, r0, t5);\
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BF(a3.im, a1.im, i1, t3);\
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BF(t4, t6, t2, t6);\
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BF(a3.re, a1.re, r1, t4);\
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BF(a2.im, a0.im, i0, t6);\
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}
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#define TRANSFORM(a0,a1,a2,a3,wre,wim) {\
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CMUL(t1, t2, a2.re, a2.im, wre, -wim);\
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CMUL(t5, t6, a3.re, a3.im, wre, wim);\
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BUTTERFLIES(a0,a1,a2,a3)\
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}
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#define TRANSFORM_ZERO(a0,a1,a2,a3) {\
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t1 = a2.re;\
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t2 = a2.im;\
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t5 = a3.re;\
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t6 = a3.im;\
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BUTTERFLIES(a0,a1,a2,a3)\
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}
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/* z[0...8n-1], w[1...2n-1] */
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#define PASS(name)\
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static void name(FFTComplex *z, const FFTSample *wre, unsigned int n)\
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{\
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FFTSample t1, t2, t3, t4, t5, t6;\
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int o1 = 2*n;\
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int o2 = 4*n;\
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int o3 = 6*n;\
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const FFTSample *wim = wre+o1;\
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n--;\
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\
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TRANSFORM_ZERO(z[0],z[o1],z[o2],z[o3]);\
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TRANSFORM(z[1],z[o1+1],z[o2+1],z[o3+1],wre[1],wim[-1]);\
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do {\
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z += 2;\
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wre += 2;\
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wim -= 2;\
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TRANSFORM(z[0],z[o1],z[o2],z[o3],wre[0],wim[0]);\
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TRANSFORM(z[1],z[o1+1],z[o2+1],z[o3+1],wre[1],wim[-1]);\
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} while(--n);\
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}
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PASS(pass)
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#undef BUTTERFLIES
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#define BUTTERFLIES BUTTERFLIES_BIG
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PASS(pass_big)
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#define DECL_FFT(n,n2,n4)\
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static void fft##n(FFTComplex *z)\
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{\
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fft##n2(z);\
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fft##n4(z+n4*2);\
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fft##n4(z+n4*3);\
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pass(z,FFT_NAME(ff_cos_##n),n4/2);\
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}
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static void fft4(FFTComplex *z)
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{
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FFTSample t1, t2, t3, t4, t5, t6, t7, t8;
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BF(t3, t1, z[0].re, z[1].re);
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BF(t8, t6, z[3].re, z[2].re);
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BF(z[2].re, z[0].re, t1, t6);
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BF(t4, t2, z[0].im, z[1].im);
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BF(t7, t5, z[2].im, z[3].im);
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BF(z[3].im, z[1].im, t4, t8);
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BF(z[3].re, z[1].re, t3, t7);
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BF(z[2].im, z[0].im, t2, t5);
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}
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static void fft8(FFTComplex *z)
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{
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FFTSample t1, t2, t3, t4, t5, t6;
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fft4(z);
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BF(t1, z[5].re, z[4].re, -z[5].re);
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BF(t2, z[5].im, z[4].im, -z[5].im);
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BF(t5, z[7].re, z[6].re, -z[7].re);
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BF(t6, z[7].im, z[6].im, -z[7].im);
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BUTTERFLIES(z[0],z[2],z[4],z[6]);
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TRANSFORM(z[1],z[3],z[5],z[7],M_SQRT1_2,M_SQRT1_2);
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}
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static void fft16(FFTComplex *z)
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{
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FFTSample t1, t2, t3, t4, t5, t6;
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FFTSample cos_16_1 = FFT_NAME(ff_cos_16)[1];
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FFTSample cos_16_3 = FFT_NAME(ff_cos_16)[3];
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fft8(z);
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fft4(z+8);
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fft4(z+12);
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TRANSFORM_ZERO(z[0],z[4],z[8],z[12]);
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TRANSFORM(z[2],z[6],z[10],z[14],M_SQRT1_2,M_SQRT1_2);
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TRANSFORM(z[1],z[5],z[9],z[13],cos_16_1,cos_16_3);
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TRANSFORM(z[3],z[7],z[11],z[15],cos_16_3,cos_16_1);
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}
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DECL_FFT(32,16,8)
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DECL_FFT(64,32,16)
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DECL_FFT(128,64,32)
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DECL_FFT(256,128,64)
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DECL_FFT(512,256,128)
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#define pass pass_big
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DECL_FFT(1024,512,256)
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DECL_FFT(2048,1024,512)
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DECL_FFT(4096,2048,1024)
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DECL_FFT(8192,4096,2048)
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DECL_FFT(16384,8192,4096)
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DECL_FFT(32768,16384,8192)
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DECL_FFT(65536,32768,16384)
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DECL_FFT(131072,65536,32768)
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static void (* const fft_dispatch[])(FFTComplex*) = {
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fft4, fft8, fft16, fft32, fft64, fft128, fft256, fft512, fft1024,
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fft2048, fft4096, fft8192, fft16384, fft32768, fft65536, fft131072
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|
};
|
|
|
|
#define DECL_COMP_FFT(N) \
|
|
static void compound_fft_##N##xM(AVTXContext *s, void *_out, \
|
|
void *_in, ptrdiff_t stride) \
|
|
{ \
|
|
const int m = s->m, *in_map = s->pfatab, *out_map = in_map + N*m; \
|
|
FFTComplex *in = _in; \
|
|
FFTComplex *out = _out; \
|
|
FFTComplex fft##N##in[N]; \
|
|
void (*fftp)(FFTComplex *z) = fft_dispatch[av_log2(m) - 2]; \
|
|
\
|
|
for (int i = 0; i < m; i++) { \
|
|
for (int j = 0; j < N; j++) \
|
|
fft##N##in[j] = in[in_map[i*N + j]]; \
|
|
fft##N(s->tmp + s->revtab[i], fft##N##in, m); \
|
|
} \
|
|
\
|
|
for (int i = 0; i < N; i++) \
|
|
fftp(s->tmp + m*i); \
|
|
\
|
|
for (int i = 0; i < N*m; i++) \
|
|
out[i] = s->tmp[out_map[i]]; \
|
|
}
|
|
|
|
DECL_COMP_FFT(3)
|
|
DECL_COMP_FFT(5)
|
|
DECL_COMP_FFT(15)
|
|
|
|
static void monolithic_fft(AVTXContext *s, void *_out, void *_in,
|
|
ptrdiff_t stride)
|
|
{
|
|
FFTComplex *in = _in;
|
|
FFTComplex *out = _out;
|
|
int m = s->m, mb = av_log2(m) - 2;
|
|
for (int i = 0; i < m; i++)
|
|
out[s->revtab[i]] = in[i];
|
|
fft_dispatch[mb](out);
|
|
}
|
|
|
|
#define DECL_COMP_IMDCT(N) \
|
|
static void compound_imdct_##N##xM(AVTXContext *s, void *_dst, void *_src, \
|
|
ptrdiff_t stride) \
|
|
{ \
|
|
FFTComplex fft##N##in[N]; \
|
|
FFTComplex *z = _dst, *exp = s->exptab; \
|
|
const int m = s->m, len8 = N*m >> 1; \
|
|
const int *in_map = s->pfatab, *out_map = in_map + N*m; \
|
|
const float *src = _src, *in1, *in2; \
|
|
void (*fftp)(FFTComplex *) = fft_dispatch[av_log2(m) - 2]; \
|
|
\
|
|
stride /= sizeof(*src); /* To convert it from bytes */ \
|
|
in1 = src; \
|
|
in2 = src + ((N*m*2) - 1) * stride; \
|
|
\
|
|
for (int i = 0; i < m; i++) { \
|
|
for (int j = 0; j < N; j++) { \
|
|
const int k = in_map[i*N + j]; \
|
|
FFTComplex tmp = { in2[-k*stride], in1[k*stride] }; \
|
|
CMUL3(fft##N##in[j], tmp, exp[k >> 1]); \
|
|
} \
|
|
fft##N(s->tmp + s->revtab[i], fft##N##in, m); \
|
|
} \
|
|
\
|
|
for (int i = 0; i < N; i++) \
|
|
fftp(s->tmp + m*i); \
|
|
\
|
|
for (int i = 0; i < len8; i++) { \
|
|
const int i0 = len8 + i, i1 = len8 - i - 1; \
|
|
const int s0 = out_map[i0], s1 = out_map[i1]; \
|
|
FFTComplex src1 = { s->tmp[s1].im, s->tmp[s1].re }; \
|
|
FFTComplex src0 = { s->tmp[s0].im, s->tmp[s0].re }; \
|
|
\
|
|
CMUL(z[i1].re, z[i0].im, src1.re, src1.im, exp[i1].im, exp[i1].re); \
|
|
CMUL(z[i0].re, z[i1].im, src0.re, src0.im, exp[i0].im, exp[i0].re); \
|
|
} \
|
|
}
|
|
|
|
DECL_COMP_IMDCT(3)
|
|
DECL_COMP_IMDCT(5)
|
|
DECL_COMP_IMDCT(15)
|
|
|
|
#define DECL_COMP_MDCT(N) \
|
|
static void compound_mdct_##N##xM(AVTXContext *s, void *_dst, void *_src, \
|
|
ptrdiff_t stride) \
|
|
{ \
|
|
float *src = _src, *dst = _dst; \
|
|
FFTComplex *exp = s->exptab, tmp, fft##N##in[N]; \
|
|
const int m = s->m, len4 = N*m, len3 = len4 * 3, len8 = len4 >> 1; \
|
|
const int *in_map = s->pfatab, *out_map = in_map + N*m; \
|
|
void (*fftp)(FFTComplex *) = fft_dispatch[av_log2(m) - 2]; \
|
|
\
|
|
stride /= sizeof(*dst); \
|
|
\
|
|
for (int i = 0; i < m; i++) { /* Folding and pre-reindexing */ \
|
|
for (int j = 0; j < N; j++) { \
|
|
const int k = in_map[i*N + j]; \
|
|
if (k < len4) { \
|
|
tmp.re = -src[ len4 + k] + src[1*len4 - 1 - k]; \
|
|
tmp.im = -src[ len3 + k] - src[1*len3 - 1 - k]; \
|
|
} else { \
|
|
tmp.re = -src[ len4 + k] - src[5*len4 - 1 - k]; \
|
|
tmp.im = src[-len4 + k] - src[1*len3 - 1 - k]; \
|
|
} \
|
|
CMUL(fft##N##in[j].im, fft##N##in[j].re, tmp.re, tmp.im, \
|
|
exp[k >> 1].re, exp[k >> 1].im); \
|
|
} \
|
|
fft##N(s->tmp + s->revtab[i], fft##N##in, m); \
|
|
} \
|
|
\
|
|
for (int i = 0; i < N; i++) \
|
|
fftp(s->tmp + m*i); \
|
|
\
|
|
for (int i = 0; i < len8; i++) { \
|
|
const int i0 = len8 + i, i1 = len8 - i - 1; \
|
|
const int s0 = out_map[i0], s1 = out_map[i1]; \
|
|
FFTComplex src1 = { s->tmp[s1].re, s->tmp[s1].im }; \
|
|
FFTComplex src0 = { s->tmp[s0].re, s->tmp[s0].im }; \
|
|
\
|
|
CMUL(dst[2*i1*stride + stride], dst[2*i0*stride], src0.re, src0.im, \
|
|
exp[i0].im, exp[i0].re); \
|
|
CMUL(dst[2*i0*stride + stride], dst[2*i1*stride], src1.re, src1.im, \
|
|
exp[i1].im, exp[i1].re); \
|
|
} \
|
|
}
|
|
|
|
DECL_COMP_MDCT(3)
|
|
DECL_COMP_MDCT(5)
|
|
DECL_COMP_MDCT(15)
|
|
|
|
static void monolithic_imdct(AVTXContext *s, void *_dst, void *_src,
|
|
ptrdiff_t stride)
|
|
{
|
|
FFTComplex *z = _dst, *exp = s->exptab;
|
|
const int m = s->m, len8 = m >> 1;
|
|
const float *src = _src, *in1, *in2;
|
|
void (*fftp)(FFTComplex *) = fft_dispatch[av_log2(m) - 2];
|
|
|
|
stride /= sizeof(*src);
|
|
in1 = src;
|
|
in2 = src + ((m*2) - 1) * stride;
|
|
|
|
for (int i = 0; i < m; i++) {
|
|
FFTComplex tmp = { in2[-2*i*stride], in1[2*i*stride] };
|
|
CMUL3(z[s->revtab[i]], tmp, exp[i]);
|
|
}
|
|
|
|
fftp(z);
|
|
|
|
for (int i = 0; i < len8; i++) {
|
|
const int i0 = len8 + i, i1 = len8 - i - 1;
|
|
FFTComplex src1 = { z[i1].im, z[i1].re };
|
|
FFTComplex src0 = { z[i0].im, z[i0].re };
|
|
|
|
CMUL(z[i1].re, z[i0].im, src1.re, src1.im, exp[i1].im, exp[i1].re);
|
|
CMUL(z[i0].re, z[i1].im, src0.re, src0.im, exp[i0].im, exp[i0].re);
|
|
}
|
|
}
|
|
|
|
static void monolithic_mdct(AVTXContext *s, void *_dst, void *_src,
|
|
ptrdiff_t stride)
|
|
{
|
|
float *src = _src, *dst = _dst;
|
|
FFTComplex *exp = s->exptab, tmp, *z = _dst;
|
|
const int m = s->m, len4 = m, len3 = len4 * 3, len8 = len4 >> 1;
|
|
void (*fftp)(FFTComplex *) = fft_dispatch[av_log2(m) - 2];
|
|
|
|
stride /= sizeof(*dst);
|
|
|
|
for (int i = 0; i < m; i++) { /* Folding and pre-reindexing */
|
|
const int k = 2*i;
|
|
if (k < len4) {
|
|
tmp.re = -src[ len4 + k] + src[1*len4 - 1 - k];
|
|
tmp.im = -src[ len3 + k] - src[1*len3 - 1 - k];
|
|
} else {
|
|
tmp.re = -src[ len4 + k] - src[5*len4 - 1 - k];
|
|
tmp.im = src[-len4 + k] - src[1*len3 - 1 - k];
|
|
}
|
|
CMUL(z[s->revtab[i]].im, z[s->revtab[i]].re, tmp.re, tmp.im,
|
|
exp[i].re, exp[i].im);
|
|
}
|
|
|
|
fftp(z);
|
|
|
|
for (int i = 0; i < len8; i++) {
|
|
const int i0 = len8 + i, i1 = len8 - i - 1;
|
|
FFTComplex src1 = { z[i1].re, z[i1].im };
|
|
FFTComplex src0 = { z[i0].re, z[i0].im };
|
|
|
|
CMUL(dst[2*i1*stride + stride], dst[2*i0*stride], src0.re, src0.im,
|
|
exp[i0].im, exp[i0].re);
|
|
CMUL(dst[2*i0*stride + stride], dst[2*i1*stride], src1.re, src1.im,
|
|
exp[i1].im, exp[i1].re);
|
|
}
|
|
}
|
|
|
|
/* Calculates the modular multiplicative inverse, not fast, replace */
|
|
static int mulinv(int n, int m)
|
|
{
|
|
n = n % m;
|
|
for (int x = 1; x < m; x++)
|
|
if (((n * x) % m) == 1)
|
|
return x;
|
|
av_assert0(0); /* Never reached */
|
|
}
|
|
|
|
/* Guaranteed to work for any n, m where gcd(n, m) == 1 */
|
|
static int gen_compound_mapping(AVTXContext *s, int n, int m, int inv,
|
|
enum AVTXType type)
|
|
{
|
|
int *in_map, *out_map;
|
|
const int len = n*m;
|
|
const int m_inv = mulinv(m, n);
|
|
const int n_inv = mulinv(n, m);
|
|
const int mdct = type == AV_TX_FLOAT_MDCT;
|
|
|
|
if (!(s->pfatab = av_malloc(2*len*sizeof(*s->pfatab))))
|
|
return AVERROR(ENOMEM);
|
|
|
|
in_map = s->pfatab;
|
|
out_map = s->pfatab + n*m;
|
|
|
|
/* Ruritanian map for input, CRT map for output, can be swapped */
|
|
for (int j = 0; j < m; j++) {
|
|
for (int i = 0; i < n; i++) {
|
|
/* Shifted by 1 to simplify forward MDCTs */
|
|
in_map[j*n + i] = ((i*m + j*n) % len) << mdct;
|
|
out_map[(i*m*m_inv + j*n*n_inv) % len] = i*m + j;
|
|
}
|
|
}
|
|
|
|
/* Change transform direction by reversing all ACs */
|
|
if (inv) {
|
|
for (int i = 0; i < m; i++) {
|
|
int *in = &in_map[i*n + 1]; /* Skip the DC */
|
|
for (int j = 0; j < ((n - 1) >> 1); j++)
|
|
FFSWAP(int, in[j], in[n - j - 2]);
|
|
}
|
|
}
|
|
|
|
/* Our 15-point transform is also a compound one, so embed its input map */
|
|
if (n == 15) {
|
|
for (int k = 0; k < m; k++) {
|
|
int tmp[15];
|
|
memcpy(tmp, &in_map[k*15], 15*sizeof(*tmp));
|
|
for (int i = 0; i < 5; i++) {
|
|
for (int j = 0; j < 3; j++)
|
|
in_map[k*15 + i*3 + j] = tmp[(i*3 + j*5) % 15];
|
|
}
|
|
}
|
|
}
|
|
|
|
return 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 int get_ptwo_revtab(AVTXContext *s, int m, int inv)
|
|
{
|
|
if (!(s->revtab = av_malloc(m*sizeof(*s->revtab))))
|
|
return AVERROR(ENOMEM);
|
|
|
|
/* Default */
|
|
for (int i = 0; i < m; i++) {
|
|
int k = -split_radix_permutation(i, m, inv) & (m - 1);
|
|
s->revtab[k] = i;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int gen_mdct_exptab(AVTXContext *s, int len4, double scale)
|
|
{
|
|
const double theta = (scale < 0 ? len4 : 0) + 1.0/8.0;
|
|
|
|
if (!(s->exptab = av_malloc_array(len4, sizeof(*s->exptab))))
|
|
return AVERROR(ENOMEM);
|
|
|
|
scale = sqrt(fabs(scale));
|
|
for (int i = 0; i < len4; i++) {
|
|
const double alpha = M_PI_2 * (i + theta) / len4;
|
|
s->exptab[i].re = cos(alpha) * scale;
|
|
s->exptab[i].im = sin(alpha) * scale;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
av_cold void av_tx_uninit(AVTXContext **ctx)
|
|
{
|
|
if (!(*ctx))
|
|
return;
|
|
|
|
av_free((*ctx)->pfatab);
|
|
av_free((*ctx)->exptab);
|
|
av_free((*ctx)->revtab);
|
|
av_free((*ctx)->tmp);
|
|
|
|
av_freep(ctx);
|
|
}
|
|
|
|
static int init_mdct_fft(AVTXContext *s, av_tx_fn *tx, enum AVTXType type,
|
|
int inv, int len, const void *scale, uint64_t flags)
|
|
{
|
|
int err, n = 1, m = 1, max_ptwo = 1 << (FF_ARRAY_ELEMS(fft_dispatch) + 1);
|
|
|
|
if (type == AV_TX_FLOAT_MDCT)
|
|
len >>= 1;
|
|
|
|
#define CHECK_FACTOR(DST, FACTOR, SRC) \
|
|
if (DST == 1 && !(SRC % FACTOR)) { \
|
|
DST = FACTOR; \
|
|
SRC /= FACTOR; \
|
|
}
|
|
CHECK_FACTOR(n, 15, len)
|
|
CHECK_FACTOR(n, 5, len)
|
|
CHECK_FACTOR(n, 3, len)
|
|
#undef CHECK_NPTWO_FACTOR
|
|
|
|
/* len must be a power of two now */
|
|
if (!(len & (len - 1)) && len >= 4 && len <= max_ptwo) {
|
|
m = len;
|
|
len = 1;
|
|
}
|
|
|
|
/* Filter out direct 3, 5 and 15 transforms, too niche */
|
|
if (len > 1 || m == 1) {
|
|
av_log(NULL, AV_LOG_ERROR, "Unsupported transform size: n = %i, "
|
|
"m = %i, residual = %i!\n", n, m, len);
|
|
return AVERROR(EINVAL);
|
|
} else if (n > 1 && m > 1) { /* 2D transform case */
|
|
if ((err = gen_compound_mapping(s, n, m, inv, type)))
|
|
return err;
|
|
if (!(s->tmp = av_malloc(n*m*sizeof(*s->tmp))))
|
|
return AVERROR(ENOMEM);
|
|
*tx = n == 3 ? compound_fft_3xM :
|
|
n == 5 ? compound_fft_5xM :
|
|
compound_fft_15xM;
|
|
if (type == AV_TX_FLOAT_MDCT)
|
|
*tx = n == 3 ? inv ? compound_imdct_3xM : compound_mdct_3xM :
|
|
n == 5 ? inv ? compound_imdct_5xM : compound_mdct_5xM :
|
|
inv ? compound_imdct_15xM : compound_mdct_15xM;
|
|
} else { /* Direct transform case */
|
|
*tx = monolithic_fft;
|
|
if (type == AV_TX_FLOAT_MDCT)
|
|
*tx = inv ? monolithic_imdct : monolithic_mdct;
|
|
}
|
|
|
|
if (n != 1)
|
|
ff_thread_once(&tabs_53_once, ff_init_53_tabs);
|
|
if (m != 1) {
|
|
get_ptwo_revtab(s, m, inv);
|
|
for (int i = 4; i <= av_log2(m); i++)
|
|
ff_init_ff_cos_tabs(i);
|
|
}
|
|
|
|
if (type == AV_TX_FLOAT_MDCT)
|
|
if ((err = gen_mdct_exptab(s, n*m, *((float *)scale))))
|
|
return err;
|
|
|
|
s->n = n;
|
|
s->m = m;
|
|
|
|
return 0;
|
|
}
|
|
|
|
av_cold int av_tx_init(AVTXContext **ctx, av_tx_fn *tx, enum AVTXType type,
|
|
int inv, int len, const void *scale, uint64_t flags)
|
|
{
|
|
int err;
|
|
AVTXContext *s = av_mallocz(sizeof(*s));
|
|
if (!s)
|
|
return AVERROR(ENOMEM);
|
|
|
|
switch (type) {
|
|
case AV_TX_FLOAT_FFT:
|
|
case AV_TX_FLOAT_MDCT:
|
|
if ((err = init_mdct_fft(s, tx, type, inv, len, scale, flags)))
|
|
goto fail;
|
|
break;
|
|
default:
|
|
err = AVERROR(EINVAL);
|
|
goto fail;
|
|
}
|
|
|
|
*ctx = s;
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
av_tx_uninit(&s);
|
|
*tx = NULL;
|
|
return err;
|
|
}
|