new feature entropy filter to ignore gray frame without iframe

opencv-motion-detect/evdaemon.cpp

@@ -14,6 +14,7 @@ update: 2019/08/30
 #include "inc/zmqhelper.hpp"
 #include "inc/database.h"
 #include "inc/json.hpp"
+#include <cstdlib>
 
 using namespace std;
 using namespace httplib;
@@ -24,6 +25,7 @@ class HttpSrv{
     Server svr;
     json config;
     json info;
+    int port = 8088;
 
     void setMonitorThread() {
 
@@ -75,7 +77,10 @@ class HttpSrv{
     }
 
     HttpSrv(){
-
+        char* strPort = getenv("PORT");
+        if(strPort != NULL) {
+            port = stoi(strPort);
+        }
     };
     ~HttpSrv(){};
 };

opencv-motion-detect/evmlmotion.cpp

@@ -37,7 +37,7 @@ using namespace std;
 using namespace zmqhelper;
 
 #define URLOUT_DEFAULT "frames"
-#define NUM_PKT_IGNORE 18*10
+#define NUM_PKT_IGNORE 18*5
 #define FRAME_SIZE 500
 
 #define DEBUG
@@ -56,6 +56,7 @@ struct DetectParam {
     int fpsProc;
     int pre;
     int post;
+    float entropy;
 };
 
 enum EventState {
@@ -74,7 +75,7 @@ private:
     AVFormatContext *pAVFormatInput = NULL;
     AVCodecContext *pCodecCtx = NULL;
     AVDictionary *pOptsRemux = NULL;
-    DetectParam detPara = {25,200,-1,10,3,30};
+    DetectParam detPara = {25,200,-1,10,3,30, 0.3};
     EventState evtState = EventState::NONE;
     chrono::system_clock::time_point evtStartTm, evtStartTmLast;
     queue<string> *evtQueue;
@@ -210,6 +211,13 @@ private:
                     detPara.post = evmlmotion["post"];
                 }
 
+                if(evmlmotion.count("entropy") == 0||evmlmotion["entropy"] < 0 || evmlmotion["entropy"] >= 10) {
+                    spdlog::warn("evmlmotion {} invalid entropy value. should be in (0, 10), default to 0.3", selfId);
+                    detPara.entropy = 0.3;
+                }else{
+                    detPara.entropy = evmlmotion["entropy"];
+                }
+
                 // setup sub
                 pSubCtx = zmq_ctx_new();
                 pSub = zmq_socket(pSubCtx, ZMQ_SUB);
@@ -423,16 +431,14 @@ private:
                     pFrame->coded_picture_number
                 );
                 // string name = urlOut + "/"+ to_string(chrono::duration_cast<chrono::seconds>(chrono::system_clock::now().time_since_epoch()).count()) + ".pgm";
-                if(detect) {
-                    detectMotion(pCodecContext->pix_fmt,pFrame);
-                }
+                detectMotion(pCodecContext->pix_fmt, pFrame, detect);
                 break;
             }
         }
         return 0;
     }
 
-    void detectMotion(AVPixelFormat format,AVFrame *pFrame)
+    void detectMotion(AVPixelFormat format,AVFrame *pFrame, bool detect = true)
     {
         static bool first = true;
         static cv::Mat avg;
@@ -441,6 +447,7 @@ private:
         avcvhelpers::frame2mat(format, pFrame, origin);
         cv::resize(origin, gray, cv::Size(FRAME_SIZE,FRAME_SIZE));
         cv::cvtColor(gray, thresh, cv::COLOR_BGR2GRAY);
+        float fent = avcvhelpers::getEntropy(thresh);
         cv::GaussianBlur(thresh, gray, cv::Size(21, 21), cv::THRESH_BINARY);
         if(first) {
             // avg = cv::Mat::zeros(gray.size(), CV_32FC3);
@@ -455,10 +462,12 @@ private:
         // TODO: AVG
         // cv::accumulateWeighted(gray, avg, 0.5);
         cv::absdiff(gray, avg, thresh);
-
 #ifdef DEBUG
         avg = gray.clone();
 #endif
+        if(!detect || fent < detPara.entropy){
+            return;
+        }
 
         // TODO:
         cv::threshold(thresh, gray, detPara.thre, 255, cv::THRESH_BINARY);

opencv-motion-detect/inc/avcvhelpers.hpp

@@ -89,6 +89,28 @@ void frame2mat(AVPixelFormat format, const AVFrame * frame, cv::Mat& image)
     sws_scale(conversion, frame->data, frame->linesize, 0, height, &image.data, cvLinesizes);
     sws_freeContext(conversion);
 }
+
+float getEntropy(cv::Mat &frame){
+    int histSize = 256;
+    /// Set the ranges ( for B,G,R) )
+    float range[] = { 0, 256 } ;
+    const float* histRange = { range };
+    bool uniform = true; 
+    bool accumulate = false;
+    /// Compute the histograms:
+    cv::Mat hist;
+    cv::calcHist( &frame, 1, 0, cv::Mat(), hist, 1, &histSize, &histRange, true, false );
+    hist /= frame.total();
+    hist += 1e-4; //prevent 0
+
+    cv::Mat logP;
+    cv::log(hist,logP);
+
+    float entropy = -1*sum(hist.mul(logP)).val[0];
+    spdlog::debug("entropy: {}", entropy);
+    return entropy;
+}
+
 }
 
 #endif