remove all stretch markers

void RemoveAllStretchMarkersAndAdjustLength(MediaItem* item) {
    auto take = GetActiveTake(item);
    int num_sm = GetTakeNumStretchMarkers(take);
    double item_length = GetMediaItemInfo_Value(item, "D_LENGTH");
    double take_playrate = GetMediaItemTakeInfo_Value(take, "D_PLAYRATE");

    double p1, p2, s1, s2, dss, dpp, disp;
    disp = 0.0;

    GetTakeStretchMarker(take, 0, &p1, &s1);
    for (int i = 1; i < num_sm; ++i) {
        GetTakeStretchMarker(take, i, &p2, &s2);
        dpp = p2 - p1;
        dss = s2 - s1;
        disp += dpp - dss;

        p1 = p2;
        s1 = s2;
    }

    auto TakeList = GetTakes(item);
    for (const auto& take : TakeList) DeleteTakeStretchMarkers(take, 0, &num_sm);

    SetMediaItemInfo_Value(item, "D_LENGTH", item_length - (disp / take_playrate));
}