diff options
Diffstat (limited to 'libavformat/timefilter.c')
| -rw-r--r-- | libavformat/timefilter.c | 151 |
1 files changed, 0 insertions, 151 deletions
diff --git a/libavformat/timefilter.c b/libavformat/timefilter.c deleted file mode 100644 index 4860a4ff70..0000000000 --- a/libavformat/timefilter.c +++ /dev/null @@ -1,151 +0,0 @@ -/* - * Delay Locked Loop based time filter - * Copyright (c) 2009 Samalyse - * Copyright (c) 2009 Michael Niedermayer - * Author: Olivier Guilyardi <olivier samalyse com> - * Michael Niedermayer <michaelni gmx at> - * - * 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 - */ - - -#include "config.h" -#include "avformat.h" -#include "timefilter.h" - -struct TimeFilter { - /// Delay Locked Loop data. These variables refer to mathematical - /// concepts described in: http://www.kokkinizita.net/papers/usingdll.pdf - double cycle_time; - double feedback2_factor; - double feedback3_factor; - double clock_period; - int count; -}; - -TimeFilter * ff_timefilter_new(double clock_period, double feedback2_factor, double feedback3_factor) -{ - TimeFilter *self = av_mallocz(sizeof(TimeFilter)); - self->clock_period = clock_period; - self->feedback2_factor = feedback2_factor; - self->feedback3_factor = feedback3_factor; - return self; -} - -void ff_timefilter_destroy(TimeFilter *self) -{ - av_freep(&self); -} - -void ff_timefilter_reset(TimeFilter *self) -{ - self->count = 0; -} - -double ff_timefilter_update(TimeFilter *self, double system_time, double period) -{ - self->count++; - if (self->count==1) { - /// init loop - self->cycle_time = system_time; - } else { - double loop_error; - self->cycle_time += self->clock_period * period; - /// calculate loop error - loop_error = system_time - self->cycle_time; - - /// update loop - self->cycle_time += FFMAX(self->feedback2_factor, 1.0/(self->count)) * loop_error; - self->clock_period += self->feedback3_factor * loop_error / period; - } - return self->cycle_time; -} - -#ifdef TEST -#include "libavutil/lfg.h" -#define LFG_MAX ((1LL << 32) - 1) - -#undef printf - -int main(void) -{ - AVLFG prng; - double n0,n1; -#define SAMPLES 1000 - double ideal[SAMPLES]; - double samples[SAMPLES]; -#if 1 - for(n0= 0; n0<40; n0=2*n0+1){ - for(n1= 0; n1<10; n1=2*n1+1){ -#else - {{ - n0=7; - n1=1; -#endif - double best_error= 1000000000; - double bestpar0=1; - double bestpar1=0.001; - int better, i; - - av_lfg_init(&prng, 123); - for(i=0; i<SAMPLES; i++){ - ideal[i] = 10 + i + n1*i/(1000); - samples[i] = ideal[i] + n0 * (av_lfg_get(&prng) - LFG_MAX / 2) - / (LFG_MAX * 10LL); - } - - 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); - for(i=0; i<SAMPLES; i++){ - double filtered; - filtered= ff_timefilter_update(tf, samples[i], 1); - 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(" [%f %f %9f]", bestpar0, bestpar1, best_error); -#endif - } - printf("\n"); - } - return 0; -} -#endif |