mirror of https://git.ffmpeg.org/ffmpeg.git
Fixed-point FFT and MDCT
This commit is contained in:
Mans Rullgard
parent
2f97b12eaf
commit
7087ce08c8
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@ -31,15 +31,16 @@ OBJS-$(CONFIG_ENCODERS) += faandct.o jfdctfst.o jfdctint.o
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OBJS-$(CONFIG_DCT) += dct.o
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OBJS-$(CONFIG_DWT) += dwt.o
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OBJS-$(CONFIG_DXVA2) += dxva2.o
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FFT-OBJS-$(CONFIG_HARDCODED_TABLES) += cos_tables.o
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OBJS-$(CONFIG_FFT) += avfft.o fft.o $(FFT-OBJS-yes)
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FFT-OBJS-$(CONFIG_HARDCODED_TABLES) += cos_tables.o cos_fixed_tables.o
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OBJS-$(CONFIG_FFT) += avfft.o fft_fixed.o fft_float.o \
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$(FFT-OBJS-yes)
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OBJS-$(CONFIG_GOLOMB) += golomb.o
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OBJS-$(CONFIG_H264DSP) += h264dsp.o h264idct.o
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OBJS-$(CONFIG_H264PRED) += h264pred.o
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OBJS-$(CONFIG_HUFFMAN) += huffman.o
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OBJS-$(CONFIG_LPC) += lpc.o
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OBJS-$(CONFIG_LSP) += lsp.o
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OBJS-$(CONFIG_MDCT) += mdct.o
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OBJS-$(CONFIG_MDCT) += mdct_fixed.o mdct_float.o
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RDFT-OBJS-$(CONFIG_HARDCODED_TABLES) += sin_tables.o
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OBJS-$(CONFIG_RDFT) += rdft.o $(RDFT-OBJS-yes)
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OBJS-$(CONFIG_SINEWIN) += sinewin.o
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@ -672,6 +673,9 @@ $(SUBDIR)dct-test$(EXESUF): $(SUBDIR)dctref.o
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$(SUBDIR)cos_tables.c: $(SUBDIR)costablegen$(HOSTEXESUF)
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$(M)./$< > $@
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$(SUBDIR)cos_fixed_tables.c: $(SUBDIR)costablegen$(HOSTEXESUF)
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$(M)./$< cos fixed > $@
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$(SUBDIR)sin_tables.c: $(SUBDIR)costablegen$(HOSTEXESUF)
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$(M)./$< sin > $@
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@ -29,14 +29,33 @@
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#endif
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#define BITS 16
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#define FLOATFMT "%.18e"
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#define FIXEDFMT "%6d"
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static int clip_f15(int v)
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{
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return v < -32767 ? -32767 :
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v > 32767 ? 32767 :
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v;
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}
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static void printval(double val, int fixed)
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{
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if (fixed)
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printf(" "FIXEDFMT",", clip_f15(lrint(val * (double)(1<<15))));
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else
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printf(" "FLOATFMT",", val);
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}
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int main(int argc, char *argv[])
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{
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int i, j;
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int do_sin = argc == 2 && !strcmp(argv[1], "sin");
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int do_sin = argc > 1 && !strcmp(argv[1], "sin");
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int fixed = argc > 2 && !strcmp(argv[2], "fixed");
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double (*func)(double) = do_sin ? sin : cos;
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printf("/* This file was generated by libavcodec/costablegen */\n");
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printf("#define CONFIG_FFT_FLOAT %d\n", !fixed);
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printf("#include \"libavcodec/%s\"\n", do_sin ? "rdft.h" : "fft.h");
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for (i = 4; i <= BITS; i++) {
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int m = 1 << i;
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@ -46,11 +65,12 @@ int main(int argc, char *argv[])
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int idx = j > m/4 ? m/2 - j : j;
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if (do_sin && j >= m/4)
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idx = m/4 - j;
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printf(" "FLOATFMT",", func(idx*freq));
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printval(func(idx*freq), fixed);
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if ((j & 3) == 3)
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printf("\n ");
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}
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printf(" "FLOATFMT"\n};\n", func(do_sin ? -(m/4 - 1)*freq : freq));
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printval(func(do_sin ? -(m/4 - 1)*freq : freq), fixed);
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printf("\n};\n");
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}
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return 0;
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}
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@ -0,0 +1,67 @@
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/*
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* This file is part of Libav.
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*
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* Libav 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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* Libav 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 Libav; 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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#ifndef AVCODEC_FFT_INTERNAL_H
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#define AVCODEC_FFT_INTERNAL_H
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#if CONFIG_FFT_FLOAT
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#define FIX15(v) (v)
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#define sqrthalf (float)M_SQRT1_2
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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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#else
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#include "libavutil/intmath.h"
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#include "mathops.h"
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#define SCALE_FLOAT(a, bits) lrint((a) * (double)(1 << (bits)))
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#define FIX15(a) av_clip(SCALE_FLOAT(a, 15), -32767, 32767)
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#define sqrthalf ((int16_t)((1<<15)*M_SQRT1_2))
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#define BF(x, y, a, b) do { \
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x = (a - b) >> 1; \
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y = (a + b) >> 1; \
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} while (0)
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#define CMUL(dre, dim, are, aim, bre, bim) do { \
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(dre) = (MUL16(are, bre) - MUL16(aim, bim)) >> 15; \
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(dim) = (MUL16(are, bim) + MUL16(aim, bre)) >> 15; \
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} while (0)
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#endif /* CONFIG_FFT_FLOAT */
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#define ff_imdct_calc_c FFT_NAME(ff_imdct_calc_c)
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#define ff_imdct_half_c FFT_NAME(ff_imdct_half_c)
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#define ff_mdct_calc_c FFT_NAME(ff_mdct_calc_c)
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void ff_imdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
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void ff_imdct_half_c(FFTContext *s, FFTSample *output, const FFTSample *input);
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void ff_mdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
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#endif /* AVCODEC_FFT_INTERNAL_H */
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@ -30,6 +30,7 @@
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#include <string.h>
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#include "libavutil/mathematics.h"
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#include "fft.h"
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#include "fft-internal.h"
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/* cos(2*pi*x/n) for 0<=x<=n/4, followed by its reverse */
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#if !CONFIG_HARDCODED_TABLES
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@ -47,10 +48,21 @@ COSTABLE(16384);
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COSTABLE(32768);
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COSTABLE(65536);
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#endif
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COSTABLE_CONST FFTSample * const ff_cos_tabs[] = {
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COSTABLE_CONST FFTSample * const FFT_NAME(ff_cos_tabs)[] = {
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NULL, NULL, NULL, NULL,
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ff_cos_16, ff_cos_32, ff_cos_64, ff_cos_128, ff_cos_256, ff_cos_512, ff_cos_1024,
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ff_cos_2048, ff_cos_4096, ff_cos_8192, ff_cos_16384, ff_cos_32768, ff_cos_65536,
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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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};
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static void ff_fft_permute_c(FFTContext *s, FFTComplex *z);
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@ -73,9 +85,9 @@ av_cold void ff_init_ff_cos_tabs(int index)
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int i;
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int m = 1<<index;
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double freq = 2*M_PI/m;
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FFTSample *tab = ff_cos_tabs[index];
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FFTSample *tab = FFT_NAME(ff_cos_tabs)[index];
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for(i=0; i<=m/4; i++)
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tab[i] = cos(i*freq);
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tab[i] = FIX15(cos(i*freq));
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for(i=1; i<m/4; i++)
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tab[m/2-i] = tab[i];
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#endif
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@ -107,9 +119,11 @@ av_cold int ff_fft_init(FFTContext *s, int nbits, int inverse)
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s->mdct_calc = ff_mdct_calc_c;
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#endif
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#if CONFIG_FFT_FLOAT
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if (ARCH_ARM) ff_fft_init_arm(s);
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if (HAVE_ALTIVEC) ff_fft_init_altivec(s);
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if (HAVE_MMX) ff_fft_init_mmx(s);
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#endif
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for(j=4; j<=nbits; j++) {
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ff_init_ff_cos_tabs(j);
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@ -144,13 +158,6 @@ av_cold void ff_fft_end(FFTContext *s)
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av_freep(&s->tmp_buf);
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}
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#define sqrthalf (float)M_SQRT1_2
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#define BF(x,y,a,b) {\
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x = a - b;\
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y = a + b;\
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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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@ -174,10 +181,8 @@ av_cold void ff_fft_end(FFTContext *s)
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}
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#define TRANSFORM(a0,a1,a2,a3,wre,wim) {\
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t1 = a2.re * wre + a2.im * wim;\
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t2 = a2.im * wre - a2.re * wim;\
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t5 = a3.re * wre - a3.im * wim;\
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t6 = a3.im * wre + a3.re * 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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@ -193,7 +198,7 @@ av_cold void ff_fft_end(FFTContext *s)
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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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FFTDouble 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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@ -222,12 +227,12 @@ static void fft##n(FFTComplex *z)\
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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,ff_cos_##n,n4/2);\
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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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FFTDouble 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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@ -241,7 +246,7 @@ static void fft4(FFTComplex *z)
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static void fft8(FFTComplex *z)
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{
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FFTSample t1, t2, t3, t4, t5, t6, t7, t8;
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FFTDouble t1, t2, t3, t4, t5, t6, t7, t8;
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fft4(z);
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@ -262,7 +267,9 @@ static void fft8(FFTComplex *z)
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#if !CONFIG_SMALL
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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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FFTDouble 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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@ -270,8 +277,8 @@ static void fft16(FFTComplex *z)
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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],sqrthalf,sqrthalf);
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TRANSFORM(z[1],z[5],z[9],z[13],ff_cos_16[1],ff_cos_16[3]);
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TRANSFORM(z[3],z[7],z[11],z[15],ff_cos_16[3],ff_cos_16[1]);
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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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#else
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DECL_FFT(16,8,4)
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@ -22,11 +22,37 @@
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#ifndef AVCODEC_FFT_H
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#define AVCODEC_FFT_H
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#ifndef CONFIG_FFT_FLOAT
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#define CONFIG_FFT_FLOAT 1
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#endif
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#include <stdint.h>
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#include "config.h"
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#include "libavutil/mem.h"
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#if CONFIG_FFT_FLOAT
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#include "avfft.h"
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#define FFT_NAME(x) x
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typedef float FFTDouble;
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#else
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#define FFT_NAME(x) x ## _fixed
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typedef int16_t FFTSample;
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typedef int FFTDouble;
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typedef struct FFTComplex {
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int16_t re, im;
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} FFTComplex;
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typedef struct FFTContext FFTContext;
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#endif /* CONFIG_FFT_FLOAT */
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/* FFT computation */
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struct FFTContext {
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@ -66,7 +92,7 @@ struct FFTContext {
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#endif
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#define COSTABLE(size) \
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COSTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_cos_##size)[size/2]
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COSTABLE_CONST DECLARE_ALIGNED(16, FFTSample, FFT_NAME(ff_cos_##size))[size/2]
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extern COSTABLE(16);
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extern COSTABLE(32);
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@ -81,7 +107,9 @@ extern COSTABLE(8192);
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extern COSTABLE(16384);
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extern COSTABLE(32768);
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extern COSTABLE(65536);
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extern COSTABLE_CONST FFTSample* const ff_cos_tabs[17];
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extern COSTABLE_CONST FFTSample* const FFT_NAME(ff_cos_tabs)[17];
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#define ff_init_ff_cos_tabs FFT_NAME(ff_init_ff_cos_tabs)
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/**
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* Initialize the cosine table in ff_cos_tabs[index]
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@ -89,6 +117,9 @@ extern COSTABLE_CONST FFTSample* const ff_cos_tabs[17];
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*/
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void ff_init_ff_cos_tabs(int index);
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#define ff_fft_init FFT_NAME(ff_fft_init)
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#define ff_fft_end FFT_NAME(ff_fft_end)
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/**
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* Set up a complex FFT.
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* @param nbits log2 of the length of the input array
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@ -102,10 +133,10 @@ void ff_fft_init_arm(FFTContext *s);
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void ff_fft_end(FFTContext *s);
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#define ff_mdct_init FFT_NAME(ff_mdct_init)
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#define ff_mdct_end FFT_NAME(ff_mdct_end)
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int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale);
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void ff_imdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
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void ff_imdct_half_c(FFTContext *s, FFTSample *output, const FFTSample *input);
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void ff_mdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
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void ff_mdct_end(FFTContext *s);
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#endif /* AVCODEC_FFT_H */
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@ -0,0 +1,20 @@
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/*
|
||||
* This file is part of Libav.
|
||||
*
|
||||
* Libav 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.
|
||||
*
|
||||
* Libav 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 Libav; if not, write to the Free Software
|
||||
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
||||
*/
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||||
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#define CONFIG_FFT_FLOAT 0
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#include "fft.c"
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@ -0,0 +1,20 @@
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/*
|
||||
* This file is part of Libav.
|
||||
*
|
||||
* Libav 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.
|
||||
*
|
||||
* Libav 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 Libav; if not, write to the Free Software
|
||||
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
||||
*/
|
||||
|
||||
#define CONFIG_FFT_FLOAT 1
|
||||
#include "fft.c"
|
||||
|
|
@ -24,12 +24,19 @@
|
|||
#include "libavutil/common.h"
|
||||
#include "libavutil/mathematics.h"
|
||||
#include "fft.h"
|
||||
#include "fft-internal.h"
|
||||
|
||||
/**
|
||||
* @file
|
||||
* MDCT/IMDCT transforms.
|
||||
*/
|
||||
|
||||
#if CONFIG_FFT_FLOAT
|
||||
# define RSCALE(x) (x)
|
||||
#else
|
||||
# define RSCALE(x) ((x) >> 1)
|
||||
#endif
|
||||
|
||||
/**
|
||||
* init MDCT or IMDCT computation.
|
||||
*/
|
||||
|
|
@ -70,8 +77,8 @@ av_cold int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale)
|
|||
scale = sqrt(fabs(scale));
|
||||
for(i=0;i<n4;i++) {
|
||||
alpha = 2 * M_PI * (i + theta) / n;
|
||||
s->tcos[i*tstep] = -cos(alpha) * scale;
|
||||
s->tsin[i*tstep] = -sin(alpha) * scale;
|
||||
s->tcos[i*tstep] = FIX15(-cos(alpha) * scale);
|
||||
s->tsin[i*tstep] = FIX15(-sin(alpha) * scale);
|
||||
}
|
||||
return 0;
|
||||
fail:
|
||||
|
|
@ -79,17 +86,6 @@ av_cold int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale)
|
|||
return -1;
|
||||
}
|
||||
|
||||
/* complex multiplication: p = a * b */
|
||||
#define CMUL(pre, pim, are, aim, bre, bim) \
|
||||
{\
|
||||
FFTSample _are = (are);\
|
||||
FFTSample _aim = (aim);\
|
||||
FFTSample _bre = (bre);\
|
||||
FFTSample _bim = (bim);\
|
||||
(pre) = _are * _bre - _aim * _bim;\
|
||||
(pim) = _are * _bim + _aim * _bre;\
|
||||
}
|
||||
|
||||
/**
|
||||
* Compute the middle half of the inverse MDCT of size N = 2^nbits,
|
||||
* thus excluding the parts that can be derived by symmetry
|
||||
|
|
@ -161,7 +157,7 @@ void ff_imdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input)
|
|||
void ff_mdct_calc_c(FFTContext *s, FFTSample *out, const FFTSample *input)
|
||||
{
|
||||
int i, j, n, n8, n4, n2, n3;
|
||||
FFTSample re, im;
|
||||
FFTDouble re, im;
|
||||
const uint16_t *revtab = s->revtab;
|
||||
const FFTSample *tcos = s->tcos;
|
||||
const FFTSample *tsin = s->tsin;
|
||||
|
|
@ -175,13 +171,13 @@ void ff_mdct_calc_c(FFTContext *s, FFTSample *out, const FFTSample *input)
|
|||
|
||||
/* pre rotation */
|
||||
for(i=0;i<n8;i++) {
|
||||
re = -input[2*i+n3] - input[n3-1-2*i];
|
||||
im = -input[n4+2*i] + input[n4-1-2*i];
|
||||
re = RSCALE(-input[2*i+n3] - input[n3-1-2*i]);
|
||||
im = RSCALE(-input[n4+2*i] + input[n4-1-2*i]);
|
||||
j = revtab[i];
|
||||
CMUL(x[j].re, x[j].im, re, im, -tcos[i], tsin[i]);
|
||||
|
||||
re = input[2*i] - input[n2-1-2*i];
|
||||
im = -(input[n2+2*i] + input[n-1-2*i]);
|
||||
re = RSCALE( input[2*i] - input[n2-1-2*i]);
|
||||
im = RSCALE(-input[n2+2*i] - input[ n-1-2*i]);
|
||||
j = revtab[n8 + i];
|
||||
CMUL(x[j].re, x[j].im, re, im, -tcos[n8 + i], tsin[n8 + i]);
|
||||
}
|
||||
|
|
|
|||
|
|
@ -0,0 +1,20 @@
|
|||
/*
|
||||
* This file is part of Libav.
|
||||
*
|
||||
* Libav 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.
|
||||
*
|
||||
* Libav 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 Libav; if not, write to the Free Software
|
||||
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
||||
*/
|
||||
|
||||
#define CONFIG_FFT_FLOAT 0
|
||||
#include "mdct.c"
|
||||
|
|
@ -0,0 +1,20 @@
|
|||
/*
|
||||
* This file is part of Libav.
|
||||
*
|
||||
* Libav 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.
|
||||
*
|
||||
* Libav 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 Libav; if not, write to the Free Software
|
||||
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
||||
*/
|
||||
|
||||
#define CONFIG_FFT_FLOAT 1
|
||||
#include "mdct.c"
|
||||
Loading…
Reference in New Issue