Selftest code.

[ffmpeg] / libavformat / timefilter.c

diff --git a/libavformat/timefilter.c b/libavformat/timefilter.c
index 26d57c0617f05f3c2febfa05254cb714b670166c..809dbc60ce01f4346ffdc3fecd037ecf5ba932b3 100644 (file)
--- a/libavformat/timefilter.c
+++ b/libavformat/timefilter.c
@@ -32,6 +32,7 @@ struct TimeFilter {
     double feedback2_factor;
     double feedback3_factor;
     double integrator2_state;
+    int count;
 };
 
 TimeFilter * ff_timefilter_new(double feedback2_factor, double feedback3_factor)
@@ -50,12 +51,13 @@ void ff_timefilter_destroy(TimeFilter *self)
 
 void ff_timefilter_reset(TimeFilter *self)
 {
-    self->cycle_time = 0;
+    self->count      = 0;
 }
 
-void ff_timefilter_update(TimeFilter *self, double system_time, double period)
+double ff_timefilter_update(TimeFilter *self, double system_time, double period)
 {
-    if (!self->cycle_time) {
+    self->count++;
+    if (self->count==1) {
         /// init loop
         self->cycle_time        = system_time;
     } else {
@@ -65,12 +67,56 @@ void ff_timefilter_update(TimeFilter *self, double system_time, double period)
         loop_error = system_time - self->cycle_time;
 
         /// update loop
-        self->cycle_time        += self->feedback2_factor * loop_error;
+        self->cycle_time        += FFMAX(self->feedback2_factor, 1.0/(self->count)) * loop_error;
         self->integrator2_state += self->feedback3_factor * loop_error / period;
     }
+    return self->cycle_time;
 }
 
-double ff_timefilter_read(TimeFilter *self)
-{
-    return self->cycle_time;
+#ifdef TEST
+main(){
+    double n0,n1;
+#define SAMPLES 1000
+    double ideal[SAMPLES];
+    double samples[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=1;
+            double bestpar1=0.001;
+            int better, i;
+
+            srandom(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);
+            }
+
+            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(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);
+            printf(" [%f %f %f]", bestpar0, bestpar1, best_error);
+        }
+        printf("\n");
+    }
 }
+#endif