/*
* 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 FFmpeg.
*
double cycle_time;
double feedback2_factor;
double feedback3_factor;
- double integrator2_state;
+ 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->integrator2_state = clock_period;
+ self->clock_period = clock_period;
self->feedback2_factor = feedback2_factor;
self->feedback3_factor = feedback3_factor;
return self;
self->count++;
if (self->count==1) {
/// init loop
- self->cycle_time = system_time;
+ self->cycle_time = system_time;
} else {
double loop_error;
- self->cycle_time+= self->integrator2_state * period;
+ self->cycle_time += self->clock_period * period;
/// calculate loop error
- loop_error = system_time - self->cycle_time;
+ loop_error = system_time - self->cycle_time;
/// update loop
- self->cycle_time += FFMAX(self->feedback2_factor, 1.0/(self->count)) * loop_error;
- self->integrator2_state += self->feedback3_factor * loop_error / period;
+ 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
-main(){
+#include "libavutil/lfg.h"
+#define LFG_MAX ((1LL << 32) - 1)
+
+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;
- srandom(123);
+ av_lfg_init(&prng, 123);
for(i=0; i<SAMPLES; i++){
ideal[i] = 10 + i + n1*i/(1000);
- samples[i]= ideal[i] + n0*(rand()-RAND_MAX/2)/(RAND_MAX*10LL);
+ samples[i] = ideal[i] + n0 * (av_lfg_get(&prng) - LFG_MAX / 2)
+ / (LFG_MAX * 10LL);
}
do{
}
}
}while(better);
- printf(" [%f %f %f]", bestpar0, bestpar1, best_error);
+#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