1 files changed, 92 insertions, 0 deletions
diff --git a/libavdevice/timefilter-test.c b/libavdevice/timefilter-test.c
new file mode 100644
index 0000000000..5e93f3c8d3
--- /dev/null
+++ b/libavdevice/timefilter-test.c
@@ -0,0 +1,92 @@
+/*
+ * 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 <stdio.h>
+
+#include "libavutil/common.h"
+#include "libavutil/lfg.h"
+
+#include "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];
+    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;
+
+            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);
+                        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], 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;
+}