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Diffstat (limited to 'libavdevice/tests/timefilter.c')
| -rw-r--r-- | libavdevice/tests/timefilter.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/libavdevice/tests/timefilter.c b/libavdevice/tests/timefilter.c new file mode 100644 index 0000000000..7c1ed0a4b6 --- /dev/null +++ b/libavdevice/tests/timefilter.c @@ -0,0 +1,98 @@ +/* + * 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 + */ + +#include <stdio.h> + +#include "libavutil/common.h" +#include "libavutil/lfg.h" + +#include "libavdevice/timefilter.h" + +#define LFG_MAX ((1LL << 32) - 1) + +int main(void) +{ + AVLFG prng; + double n0, n1; +#define SAMPLES 1000 + double ideal[SAMPLES]; + double samples[SAMPLES]; + double samplet[SAMPLES]; + for (n0 = 0; n0 < 40; n0 = 2 * n0 + 1) { + for (n1 = 0; n1 < 10; n1 = 2 * n1 + 1) { + double best_error = 1000000000; + double bestpar0 = n0 ? 1 : 100000; + double bestpar1 = 1; + int better, i; + + av_lfg_init(&prng, 123); + for (i = 0; i < SAMPLES; i++) { + samplet[i] = 10 + i + (av_lfg_get(&prng) < LFG_MAX/2 ? 0 : 0.999); + ideal[i] = samplet[i] + n1 * i / (1000); + samples[i] = ideal[i] + n0 * (av_lfg_get(&prng) - LFG_MAX / 2) / (LFG_MAX * 10LL); + if(i && samples[i]<samples[i-1]) + samples[i]=samples[i-1]+0.001; + } + + do { + double par0, par1; + better = 0; + for (par0 = bestpar0 * 0.8; par0 <= bestpar0 * 1.21; par0 += bestpar0 * 0.05) { + for (par1 = bestpar1 * 0.8; par1 <= bestpar1 * 1.21; par1 += bestpar1 * 0.05) { + double error = 0; + TimeFilter *tf = ff_timefilter_new(1, par0, par1); + if (!tf) { + printf("Could not allocate memory for timefilter.\n"); + exit(1); + } + for (i = 0; i < SAMPLES; i++) { + double filtered; + filtered = ff_timefilter_update(tf, samples[i], i ? (samplet[i] - samplet[i-1]) : 1); + if(filtered < 0 || filtered > 1000000000) + printf("filter is unstable\n"); + error += (filtered - ideal[i]) * (filtered - ideal[i]); + } + ff_timefilter_destroy(tf); + if (error < best_error) { + best_error = error; + bestpar0 = par0; + bestpar1 = par1; + better = 1; + } + } + } + } while (better); +#if 0 + double lastfil = 9; + TimeFilter *tf = ff_timefilter_new(1, bestpar0, bestpar1); + for (i = 0; i < SAMPLES; i++) { + double filtered; + filtered = ff_timefilter_update(tf, samples[i], 1); + printf("%f %f %f %f\n", i - samples[i] + 10, filtered - samples[i], + samples[FFMAX(i, 1)] - samples[FFMAX(i - 1, 0)], filtered - lastfil); + lastfil = filtered; + } + ff_timefilter_destroy(tf); +#else + printf(" [%12f %11f %9f]", bestpar0, bestpar1, best_error); +#endif + } + printf("\n"); + } + return 0; +} |