md.c

void detectMotion(AVPixelFormat format, AVFrame *pFrame)
{
    static bool firstRun = true;
    static cv::Mat lastImage;
    static double _area = 0;
    static double area = 0;
    static int frameProcessed = 0;
    vector<vector<cv::Point> > cnts;
    cv::Mat origin;
    avcvhelpers::frame2mat(format, pFrame, origin);
    // check region
    auto w = origin.size().width;
    auto h = origin.size().height;

    // auto config
    if(detPara.resize == 0) {
        detPara.resize = detPara.size*1.0/h;
    }
    else {
        detPara.size = int(h * detPara.resize);
    }

    if(detPara.resize  > 0 && detPara.resize < 1) {
        // resize. new w, h caculated
        w = int(w * detPara.resize);
        h = int(h * detPara.resize);
        cv::resize(origin, origin, cv::Size(w,h));
    }
    else {
        detPara.resize = 1;
    }

    if(detPara.region[0].y == 0 || (detPara.region[0].x == 0 && detPara.region[0].y == 0 && detPara.region[1].x == 1 && detPara.region[1].y == 1)) {
        // do nothing
    }
    else {
        // crop
        auto x = (int)(w * detPara.region[0].x);
        auto y = (int)(h * detPara.region[0].y);
        w = w * (detPara.region[1].x - detPara.region[0].x);
        h = h * (detPara.region[1].y - detPara.region[0].y);
        cv::Rect crop(x,y,w,h);
        origin = origin(crop);
    }

    cv::Mat gray;
    cv::cvtColor(origin, gray, cv::COLOR_BGR2GRAY);
    // float fent = avcvhelpers::getEntropy(thresh);
    cv::GaussianBlur(gray, gray, cv::Size(21, 21), cv::THRESH_BINARY);
    if(firstRun) {
        // lastImage = cv::Mat::zeros(gray.size(), CV_32FC3);
        lastImage.release();
        lastImage = gray.clone();
        firstRun = false;
        area = detPara.area == 0 ? (AREA_1080P * detPara.size * detPara.size * 1.0/1080/1080) : detPara.area;
        spdlog::info("{} resize: {}, area: {}, origin area: {}", selfId, detPara.resize, area, detPara.area);
        return;
    }
    // packetTm = chrono::system_clock::now();
    packetTm = packetTs;
    // TODO: AVG
    // cv::accumulateWeighted(gray, lastImage, 0.5);
    cv::Mat diff;
    cv::absdiff(gray, lastImage, diff);

    cv::Mat thresh;
    cv::threshold(diff, thresh, detPara.thre, 255, cv::THRESH_BINARY);
    //cv::dilate(gray, thresh, cv::Mat(), cv::Point(-1,-1), 2);
    cv::findContours(thresh, cnts, cv::RETR_EXTERNAL, cv::CHAIN_APPROX_SIMPLE);
    bool hasEvent = false;
    static int evtCnt = 0;
    int i = 0;
    // avoid vage cases
    if(area < 5) {
        area = 5;
    }
    for(; i < cnts.size(); i++) {
        _area = cv::contourArea(cnts[i]);
        if(_area < area) {
            // nothing
        }
        else {
            hasEvent = true;
            evtCnt++;
            //spdlog::info("{} motion detected: idx {}, area: {}", selfId, i, _area);
            break;
        }
    } //end for
    lastImage.release();
    lastImage = gray.clone();

    frameProcessed++;
    spdlog::debug("{} contours {} area {}, thresh {} hasEvent {}", selfId, cnts.size(), hasEvent? cv::contourArea(cnts[i]):0, detPara.area, hasEvent);

    // business logic for event
    // auto dura = chrono::duration_cast<chrono::seconds>(packetTm - evtStartTmLast).count();
    long long dura = 0;
    if(evtStartTmLast != 0) {
        dura = packetTm - evtStartTmLast;
    }
    else {
        evtStartTmLast = packetTm;
        return;
    }

    static long long pktDelt = 0;
    if(pktCnt %18 == 0) {
        auto tmp =  chrono::duration_cast<chrono::seconds>(chrono::system_clock::now().time_since_epoch()).count();
        pktDelt = tmp - packetTm;
    }

    switch(evtState) {
    case NONE:
    case PRE:
        if(dura >= detPara.pre) {
            auto thr = frameProcessed/2;
            if(evtCnt <= thr) {
                spdlog::info("state: NONE->NONE ({}, {}, {}, {}, {}, {}, {})", pktDelt, this->fps, dura, frameProcessed, evtCnt, thr, _area);
            }
            else {
                json p;
                evtState = IN;
                evtStartTmOrig = packetTm - detPara.pre;
                spdlog::info("{} state: NONE->IN ({}, {}, {}, {}, {}, {}, {})", selfId, pktDelt, this->fps, dura, frameProcessed, evtCnt, thr, _area);
                makeEvent(EV_MSG_EVENT_MOTION_START, evtStartTmOrig);
            }
            evtCnt = 0;
            frameProcessed = 0;
            evtStartTmLast = packetTm;
        }
        break;
    case IN: {
        if( packetTm - evtStartTmOrig > 60 *detPara.maxDuration ) {
            evtStartTmOrig = packetTm;
            makeEvent(EV_MSG_EVENT_MOTION_END, packetTs);
            makeEvent(EV_MSG_EVENT_MOTION_START, packetTs);
            spdlog::warn("{} event video continued over {} minutes, force segmenting and continue", devSn, detPara.maxDuration);
            spdlog::debug("{} state: IN->IN ({}, {})",selfId, dura, evtCnt);
            evtCnt = 0;
            frameProcessed = 0;
            evtStartTmLast = packetTm;
        }
        else if(dura >= detPara.post/2) {
            auto thr = frameProcessed/5;
            if(evtCnt <= thr) {
                evtState = POST;
                spdlog::info("{} state: IN->POST ({}, {}, {}, {}, {}, {}, {})", selfId, pktDelt, this->fps, dura, frameProcessed, evtCnt, thr, _area);
            }
            else {
                spdlog::info("{} state: IN->IN ({}, {}, {}, {}, {}, {}, {})", selfId, pktDelt, this->fps, dura, frameProcessed, evtCnt, thr, _area);
            }
            evtCnt = 0;
            frameProcessed = 0;
            evtStartTmLast = packetTm;
        }
        break;
    }
    case POST: {
        if(dura >= detPara.post/2) {
            auto thr = frameProcessed/5;
            if(evtCnt <= thr) {
                spdlog::info("{} state: POST->NONE ({}, {}, {}, {}, {}, {}, {})",selfId, pktDelt, this->fps, dura, frameProcessed, evtCnt, thr, _area);
                evtState = NONE;
                makeEvent(EV_MSG_EVENT_MOTION_END, packetTs - detPara.post/2);
            }
            else {
                spdlog::info("{} state: POST->IN ({}, {}, {}, {}, {}, {}, {})",selfId, pktDelt, this->fps, dura, frameProcessed, evtCnt, thr, _area);
                evtState = IN;
            }
            evtCnt = 0;
            frameProcessed = 0;
            evtStartTmLast = packetTm;
        }
        break;
    }
    }
}