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FFmpeg/libavcodec/fft-test.c
Olivier Langlois 6fdf35fe35 lavc: Use av_gettime_relative 
Whenever av_gettime() is used to measure relative period of time,
av_gettime_relative() is prefered as it guarantee monotonic time
on supported platforms.

Signed-off-by: Martin Storsjö <martin@martin.st>
2014-10-24 09:53:42 +03:00

514 lines
14 KiB
C
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/*
* (c) 2002 Fabrice Bellard
*
* 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
*/
/**
* @file
* FFT and MDCT tests.
*/
#include "config.h"
#include <math.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "libavutil/cpu.h"
#include "libavutil/lfg.h"
#include "libavutil/log.h"
#include "libavutil/mathematics.h"
#include "libavutil/time.h"
#include "fft.h"
#if FFT_FLOAT
#include "dct.h"
#include "rdft.h"
#endif
/* reference fft */
#define MUL16(a, b) ((a) * (b))
#define CMAC(pre, pim, are, aim, bre, bim) \
{ \
pre += (MUL16(are, bre) - MUL16(aim, bim)); \
pim += (MUL16(are, bim) + MUL16(bre, aim)); \
}
#if FFT_FLOAT
#define RANGE 1.0
#define REF_SCALE(x, bits) (x)
#define FMT "%10.6f"
#else
#define RANGE 16384
#define REF_SCALE(x, bits) ((x) / (1 << (bits)))
#define FMT "%6d"
#endif
static struct {
float re, im;
} *exptab;
static int fft_ref_init(int nbits, int inverse)
{
int i, n = 1 << nbits;
exptab = av_malloc((n / 2) * sizeof(*exptab));
if (!exptab)
return AVERROR(ENOMEM);
for (i = 0; i < (n / 2); i++) {
double alpha = 2 * M_PI * (float) i / (float) n;
double c1 = cos(alpha), s1 = sin(alpha);
if (!inverse)
s1 = -s1;
exptab[i].re = c1;
exptab[i].im = s1;
}
return 0;
}
static void fft_ref(FFTComplex *tabr, FFTComplex *tab, int nbits)
{
int i, j;
int n = 1 << nbits;
int n2 = n >> 1;
for (i = 0; i < n; i++) {
double tmp_re = 0, tmp_im = 0;
FFTComplex *q = tab;
for (j = 0; j < n; j++) {
double s, c;
int k = (i * j) & (n - 1);
if (k >= n2) {
c = -exptab[k - n2].re;
s = -exptab[k - n2].im;
} else {
c = exptab[k].re;
s = exptab[k].im;
}
CMAC(tmp_re, tmp_im, c, s, q->re, q->im);
q++;
}
tabr[i].re = REF_SCALE(tmp_re, nbits);
tabr[i].im = REF_SCALE(tmp_im, nbits);
}
}
#if CONFIG_MDCT
static void imdct_ref(FFTSample *out, FFTSample *in, int nbits)
{
int i, k, n = 1 << nbits;
for (i = 0; i < n; i++) {
double sum = 0;
for (k = 0; k < n / 2; k++) {
int a = (2 * i + 1 + (n / 2)) * (2 * k + 1);
double f = cos(M_PI * a / (double) (2 * n));
sum += f * in[k];
}
out[i] = REF_SCALE(-sum, nbits - 2);
}
}
/* NOTE: no normalisation by 1 / N is done */
static void mdct_ref(FFTSample *output, FFTSample *input, int nbits)
{
int i, k, n = 1 << nbits;
/* do it by hand */
for (k = 0; k < n / 2; k++) {
double s = 0;
for (i = 0; i < n; i++) {
double a = (2 * M_PI * (2 * i + 1 + n / 2) * (2 * k + 1) / (4 * n));
s += input[i] * cos(a);
}
output[k] = REF_SCALE(s, nbits - 1);
}
}
#endif /* CONFIG_MDCT */
#if FFT_FLOAT
#if CONFIG_DCT
static void idct_ref(float *output, float *input, int nbits)
{
int i, k, n = 1 << nbits;
/* do it by hand */
for (i = 0; i < n; i++) {
double s = 0.5 * input[0];
for (k = 1; k < n; k++) {
double a = M_PI * k * (i + 0.5) / n;
s += input[k] * cos(a);
}
output[i] = 2 * s / n;
}
}
static void dct_ref(float *output, float *input, int nbits)
{
int i, k, n = 1 << nbits;
/* do it by hand */
for (k = 0; k < n; k++) {
double s = 0;
for (i = 0; i < n; i++) {
double a = M_PI * k * (i + 0.5) / n;
s += input[i] * cos(a);
}
output[k] = s;
}
}
#endif /* CONFIG_DCT */
#endif /* FFT_FLOAT */
static FFTSample frandom(AVLFG *prng)
{
return (int16_t) av_lfg_get(prng) / 32768.0 * RANGE;
}
static int check_diff(FFTSample *tab1, FFTSample *tab2, int n, double scale)
{
int i, err = 0;
double error = 0, max = 0;
for (i = 0; i < n; i++) {
double e = fabsf(tab1[i] - (tab2[i] / scale)) / RANGE;
if (e >= 1e-3) {
av_log(NULL, AV_LOG_ERROR, "ERROR %5d: "FMT" "FMT"\n",
i, tab1[i], tab2[i]);
err = 1;
}
error += e * e;
if (e > max)
max = e;
}
av_log(NULL, AV_LOG_INFO, "max:%f e:%g\n", max, sqrt(error) / n);
return err;
}
static void help(void)
{
av_log(NULL, AV_LOG_INFO,
"usage: fft-test [-h] [-s] [-i] [-n b]\n"
"-h print this help\n"
"-s speed test\n"
"-m (I)MDCT test\n"
"-d (I)DCT test\n"
"-r (I)RDFT test\n"
"-i inverse transform test\n"
"-n b set the transform size to 2^b\n"
"-f x set scale factor for output data of (I)MDCT to x\n");
}
enum tf_transform {
TRANSFORM_FFT,
TRANSFORM_MDCT,
TRANSFORM_RDFT,
TRANSFORM_DCT,
};
#if !HAVE_GETOPT
#include "compat/getopt.c"
#endif
int main(int argc, char **argv)
{
FFTComplex *tab, *tab1, *tab_ref;
FFTSample *tab2;
enum tf_transform transform = TRANSFORM_FFT;
FFTContext m, s;
#if FFT_FLOAT
RDFTContext r;
DCTContext d;
#endif /* FFT_FLOAT */
int it, i, err = 1;
int do_speed = 0, do_inverse = 0;
int fft_nbits = 9, fft_size;
double scale = 1.0;
AVLFG prng;
av_lfg_init(&prng, 1);
for (;;) {
int c = getopt(argc, argv, "hsimrdn:f:c:");
if (c == -1)
break;
switch (c) {
case 'h':
help();
return 1;
case 's':
do_speed = 1;
break;
case 'i':
do_inverse = 1;
break;
case 'm':
transform = TRANSFORM_MDCT;
break;
case 'r':
transform = TRANSFORM_RDFT;
break;
case 'd':
transform = TRANSFORM_DCT;
break;
case 'n':
fft_nbits = atoi(optarg);
break;
case 'f':
scale = atof(optarg);
break;
case 'c':
{
int cpuflags = av_parse_cpu_flags(optarg);
if (cpuflags < 0)
return 1;
av_set_cpu_flags_mask(cpuflags);
break;
}
}
}
fft_size = 1 << fft_nbits;
tab = av_malloc(fft_size * sizeof(FFTComplex));
tab1 = av_malloc(fft_size * sizeof(FFTComplex));
tab_ref = av_malloc(fft_size * sizeof(FFTComplex));
tab2 = av_malloc(fft_size * sizeof(FFTSample));
if (!(tab && tab1 && tab_ref && tab2))
goto cleanup;
switch (transform) {
#if CONFIG_MDCT
case TRANSFORM_MDCT:
av_log(NULL, AV_LOG_INFO, "Scale factor is set to %f\n", scale);
if (do_inverse)
av_log(NULL, AV_LOG_INFO, "IMDCT");
else
av_log(NULL, AV_LOG_INFO, "MDCT");
ff_mdct_init(&m, fft_nbits, do_inverse, scale);
break;
#endif /* CONFIG_MDCT */
case TRANSFORM_FFT:
if (do_inverse)
av_log(NULL, AV_LOG_INFO, "IFFT");
else
av_log(NULL, AV_LOG_INFO, "FFT");
ff_fft_init(&s, fft_nbits, do_inverse);
if (err = fft_ref_init(fft_nbits, do_inverse) < 0)
goto cleanup;
break;
#if FFT_FLOAT
#if CONFIG_RDFT
case TRANSFORM_RDFT:
if (do_inverse)
av_log(NULL, AV_LOG_INFO, "IDFT_C2R");
else
av_log(NULL, AV_LOG_INFO, "DFT_R2C");
ff_rdft_init(&r, fft_nbits, do_inverse ? IDFT_C2R : DFT_R2C);
if (err = fft_ref_init(fft_nbits, do_inverse) < 0)
goto cleanup;
break;
#endif /* CONFIG_RDFT */
#if CONFIG_DCT
case TRANSFORM_DCT:
if (do_inverse)
av_log(NULL, AV_LOG_INFO, "DCT_III");
else
av_log(NULL, AV_LOG_INFO, "DCT_II");
ff_dct_init(&d, fft_nbits, do_inverse ? DCT_III : DCT_II);
break;
#endif /* CONFIG_DCT */
#endif /* FFT_FLOAT */
default:
av_log(NULL, AV_LOG_ERROR, "Requested transform not supported\n");
goto cleanup;
}
av_log(NULL, AV_LOG_INFO, " %d test\n", fft_size);
/* generate random data */
for (i = 0; i < fft_size; i++) {
tab1[i].re = frandom(&prng);
tab1[i].im = frandom(&prng);
}
/* checking result */
av_log(NULL, AV_LOG_INFO, "Checking...\n");
switch (transform) {
#if CONFIG_MDCT
case TRANSFORM_MDCT:
if (do_inverse) {
imdct_ref(&tab_ref->re, &tab1->re, fft_nbits);
m.imdct_calc(&m, tab2, &tab1->re);
err = check_diff(&tab_ref->re, tab2, fft_size, scale);
} else {
mdct_ref(&tab_ref->re, &tab1->re, fft_nbits);
m.mdct_calc(&m, tab2, &tab1->re);
err = check_diff(&tab_ref->re, tab2, fft_size / 2, scale);
}
break;
#endif /* CONFIG_MDCT */
case TRANSFORM_FFT:
memcpy(tab, tab1, fft_size * sizeof(FFTComplex));
s.fft_permute(&s, tab);
s.fft_calc(&s, tab);
fft_ref(tab_ref, tab1, fft_nbits);
err = check_diff(&tab_ref->re, &tab->re, fft_size * 2, 1.0);
break;
#if FFT_FLOAT
#if CONFIG_RDFT
case TRANSFORM_RDFT:
{
int fft_size_2 = fft_size >> 1;
if (do_inverse) {
tab1[0].im = 0;
tab1[fft_size_2].im = 0;
for (i = 1; i < fft_size_2; i++) {
tab1[fft_size_2 + i].re = tab1[fft_size_2 - i].re;
tab1[fft_size_2 + i].im = -tab1[fft_size_2 - i].im;
}
memcpy(tab2, tab1, fft_size * sizeof(FFTSample));
tab2[1] = tab1[fft_size_2].re;
r.rdft_calc(&r, tab2);
fft_ref(tab_ref, tab1, fft_nbits);
for (i = 0; i < fft_size; i++) {
tab[i].re = tab2[i];
tab[i].im = 0;
}
err = check_diff(&tab_ref->re, &tab->re, fft_size * 2, 0.5);
} else {
for (i = 0; i < fft_size; i++) {
tab2[i] = tab1[i].re;
tab1[i].im = 0;
}
r.rdft_calc(&r, tab2);
fft_ref(tab_ref, tab1, fft_nbits);
tab_ref[0].im = tab_ref[fft_size_2].re;
err = check_diff(&tab_ref->re, tab2, fft_size, 1.0);
}
break;
}
#endif /* CONFIG_RDFT */
#if CONFIG_DCT
case TRANSFORM_DCT:
memcpy(tab, tab1, fft_size * sizeof(FFTComplex));
d.dct_calc(&d, &tab->re);
if (do_inverse)
idct_ref(&tab_ref->re, &tab1->re, fft_nbits);
else
dct_ref(&tab_ref->re, &tab1->re, fft_nbits);
err = check_diff(&tab_ref->re, &tab->re, fft_size, 1.0);
break;
#endif /* CONFIG_DCT */
#endif /* FFT_FLOAT */
}
/* do a speed test */
if (do_speed) {
int64_t time_start, duration;
int nb_its;
av_log(NULL, AV_LOG_INFO, "Speed test...\n");
/* we measure during about 1 seconds */
nb_its = 1;
for (;;) {
time_start = av_gettime_relative();
for (it = 0; it < nb_its; it++) {
switch (transform) {
case TRANSFORM_MDCT:
if (do_inverse)
m.imdct_calc(&m, &tab->re, &tab1->re);
else
m.mdct_calc(&m, &tab->re, &tab1->re);
break;
case TRANSFORM_FFT:
memcpy(tab, tab1, fft_size * sizeof(FFTComplex));
s.fft_calc(&s, tab);
break;
#if FFT_FLOAT
case TRANSFORM_RDFT:
memcpy(tab2, tab1, fft_size * sizeof(FFTSample));
r.rdft_calc(&r, tab2);
break;
case TRANSFORM_DCT:
memcpy(tab2, tab1, fft_size * sizeof(FFTSample));
d.dct_calc(&d, tab2);
break;
#endif /* FFT_FLOAT */
}
}
duration = av_gettime_relative() - time_start;
if (duration >= 1000000)
break;
nb_its *= 2;
}
av_log(NULL, AV_LOG_INFO,
"time: %0.1f us/transform [total time=%0.2f s its=%d]\n",
(double) duration / nb_its,
(double) duration / 1000000.0,
nb_its);
}
switch (transform) {
#if CONFIG_MDCT
case TRANSFORM_MDCT:
ff_mdct_end(&m);
break;
#endif /* CONFIG_MDCT */
case TRANSFORM_FFT:
ff_fft_end(&s);
break;
#if FFT_FLOAT
#if CONFIG_RDFT
case TRANSFORM_RDFT:
ff_rdft_end(&r);
break;
#endif /* CONFIG_RDFT */
#if CONFIG_DCT
case TRANSFORM_DCT:
ff_dct_end(&d);
break;
#endif /* CONFIG_DCT */
#endif /* FFT_FLOAT */
}
cleanup:
av_free(tab);
av_free(tab1);
av_free(tab2);
av_free(tab_ref);
av_free(exptab);
if (err)
printf("Error: %d.\n", err);
return !!err;
}
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