Improves post processing timestamp matching

EyeRecToo/src/post-processing/PostProcessingWidget.cpp

@@ -587,8 +587,11 @@ void PostProcessingWidget::present(const VideoFrame& videoFrame)
     updatePresentIdx(videoFrame.idx);
     ui->playbackSlider->setValue(presentIdx);
 
-    auto getTimestamp = [](const DataTuple& d) { return d.timestamp; };
-    size_t idx = ts2idx(playbackTuples, videoFrame.t, getTimestamp) + 1;
+    // Note that given a field frame, there might be more than one data tuple that contains it
+    // we simply pick one of them
+    auto getTimestamp = [](const DataTuple& d) { return d.field.timestamp; };
+    auto idx = findClosestIdx(playbackTuples, videoFrame.t, getTimestamp);
+
     DataTuple tuple;
     if (idx < playbackTuples.size())
         tuple = playbackTuples[idx];

EyeRecToo/src/post-processing/PostProcessingWidget.h

@@ -156,25 +156,6 @@ private:
     void updatePresentIdx(const int idx);
     void keyPressEvent(QKeyEvent* event) override;
 
-    template <typename T, typename Functor>
-    size_t ts2idx(const std::vector<T>& v, const double& t, Functor& functor) const
-    {
-        size_t s = 0;
-        size_t e = v.size();
-
-        while (true) {
-            size_t mid = round((e + s) / 2);
-            if (mid == s || mid == e)
-                return mid;
-            if (t < functor(v[mid]))
-                e = mid;
-            else
-                s = mid;
-        }
-
-        return -1;
-    }
-
     QStateMachine batchStateMachine;
 };
 

EyeRecToo/src/post-processing/VideoSource.h

@@ -80,20 +80,7 @@ private:
 
     size_t ts2idx(const Timestamp& t) const
     {
-        size_t s = 0;
-        size_t e = timestamps.size();
-
-        while (true) {
-            size_t mid = round((e + s) / 2);
-            if (mid == s || mid == e)
-                return mid;
-            if (t < timestamps[mid])
-                e = mid;
-            else
-                s = mid;
-        }
-
-        return -1;
+        return findClosestIdx(timestamps, t, [](const Timestamp& t) { return t; });
     }
 
 private slots:

EyeRecToo/src/utils.h

@@ -130,7 +130,7 @@ public:
     {
         total = 0;
     }
-    double average() const { return mean(values); }
+    double average() const { return total / values.size(); }
     void update(const T t)
     {
         values.emplace_back(t);
@@ -148,4 +148,16 @@ private:
     double total;
 };
 
+template <typename Vec, typename Val, typename Functor>
+size_t findClosestIdx(const Vec& vec, const Val& val, const Functor& f, size_t start = 0, size_t end = 0)
+{
+    if (start == 0 && end == 0)
+        return findClosestIdx(vec, val, f, 0, vec.size() - 1);
+
+    if (end - start <= 1)
+        return abs(f(vec[start]) - val) < abs(f(vec[end]) - val) ? start : end;
+    auto mid = (end + start) / 2;
+    return f(vec[mid]) > val ? findClosestIdx(vec, val, f, start, mid) : findClosestIdx(vec, val, f, mid, end);
+}
+
 #endif // UTILS_H