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Toward minimising MovingMedian a bit

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This commit is contained in:
Chris Cannam
2022-06-06 21:53:54 +01:00
parent ef2d39b3af
commit 7519ef47cc
1 changed files with 36 additions and 22 deletions
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58
src/common/MovingMedian.h
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@@ -41,15 +41,14 @@ class MovingMedian : public SampleFilter<T>
public:
MovingMedian(int size, float percentile = 50.f) :
SampleFilter<T>(size),
m_frame(allocate_and_zero<T>(size)),
m_sorted(allocate_and_zero<T>(size)),
m_sortend(m_sorted + P::m_size - 1) {
m_frame(allocate_and_zero<T>(size * 2)),
m_sorted(m_frame + size)
{
setPercentile(percentile);
}
~MovingMedian() {
deallocate(m_frame);
deallocate(m_sorted);
}
void setPercentile(float p) {
@@ -63,10 +62,10 @@ public:
std::cerr << "WARNING: MovingMedian: NaN encountered" << std::endl;
value = T();
}
drop(m_frame[0]);
T toDrop = m_frame[0];
v_move(m_frame, m_frame+1, P::m_size-1);
m_frame[P::m_size-1] = value;
put(value);
dropAndPut(toDrop, value);
}
T get() const {
@@ -102,24 +101,39 @@ public:
private:
T *const m_frame;
T *const m_sorted;
T *const m_sortend;
int m_index;
void put(T value) {
// precondition: m_sorted contains m_size-1 values, packed at start
// postcondition: m_sorted contains m_size values, one of which is value
T *index = std::lower_bound(m_sorted, m_sortend, value);
v_move(index + 1, index, m_sortend - index);
*index = value;
}
void drop(T value) {
// precondition: m_sorted contains m_size values, one of which is value
// postcondition: m_sorted contains m_size-1 values, packed at start
T *index = std::lower_bound(m_sorted, m_sortend + 1, value);
assert(*index == value);
v_move(index, index + 1, m_sortend - index);
*m_sortend = T(0);
void dropAndPut(const T &toDrop, const T &toPut) {
// precondition: m_sorted contains m_size values, one of which is toDrop
// postcondition: m_sorted contains m_size values, one of which is toPut
// (and one instance of toDrop has been removed)
int n = P::m_size;
int dropIx = std::lower_bound(m_sorted, m_sorted + n, toDrop) - m_sorted;
// if (m_sorted[dropIx] != toDrop) {
// throw std::runtime_error("not found");
// }
int putIx;
if (toPut > toDrop) {
putIx = std::lower_bound(m_sorted + dropIx, m_sorted + n, toPut) - m_sorted;
} else if (toPut < toDrop) {
putIx = std::lower_bound(m_sorted, m_sorted + dropIx, toPut) - m_sorted;
} else {
m_sorted[dropIx] = toPut;
return;
}
if (putIx > dropIx) {
for (int i = dropIx; i+1 < putIx; ++i) {
m_sorted[i] = m_sorted[i+1];
}
m_sorted[putIx-1] = toPut;
} else if (putIx < dropIx) {
for (int i = dropIx; i > putIx; --i) {
m_sorted[i] = m_sorted[i-1];
}
m_sorted[putIx] = toPut;
} else {
m_sorted[putIx] = toPut;
}
}
MovingMedian(const MovingMedian &) =delete;