X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavformat%2Ftimefilter.c;h=5c780c8d90fe4ee8131d131017d58a39b34eb72b;hb=3c3daf4d198306295e3342631f19422bdc258dbb;hp=6873ad7b5502010871bedb9edb210e00a67c33f6;hpb=32284910277308ea3236edf5bf523cffc857cb12;p=ffmpeg

diff --git a/libavformat/timefilter.c b/libavformat/timefilter.c
index 6873ad7b550..5c780c8d90f 100644
--- a/libavformat/timefilter.c
+++ b/libavformat/timefilter.c
@@ -1,7 +1,9 @@
 /*
  * 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.
  *
@@ -31,14 +33,14 @@ struct TimeFilter {
     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;
@@ -59,37 +61,51 @@ double ff_timefilter_update(TimeFilter *self, double system_time, double period)
     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)
+
+#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;
 
-            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{
@@ -114,9 +130,22 @@ main(){
                     }
                 }
             }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