Using libfacedetection with video capture

libfacedetectcnn-example.cpp

/*
The MIT License (MIT)

Copyright (c) 2018-2019 Shiqi Yu
shiqi.yu@gmail.com

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

#include <stdio.h>
#include <opencv2/opencv.hpp>
#include "facedetectcnn.h"

//define the buffer size. Do not change the size!
#define DETECT_BUFFER_SIZE 0x20000
using namespace cv;

int main(int argc, char* argv[])
{
    if(argc != 2)
    {
        printf("Usage: %s <image_file_name>\n", argv[0]);
        return -1;
    }

    char *err = nullptr;
    VideoCapture cap;
    int camera = strtol(argv[1], &err, 10);

    if (err && *err)
        cap = VideoCapture(argv[1]);
    else
        cap = VideoCapture(camera);

    if (!cap.isOpened()) {
        fprintf(stderr, "Can not open VideoCapture.\n");
        return -1;
    }

    while (true)
    {
        int key = waitKey(1);
        if (key == 27)
            break;
        Mat frame;
        cap >> frame;

        if(frame.empty())
        {
            fprintf(stderr, "Can not load the frame %s.\n", argv[1]);
            continue;
        }

        float scale = 640.0 / (float)frame.size().width;
		Mat image(frame.size().height * scale, frame.size().width * scale, frame.type());
		resize(frame, image, image.size(), INTER_CUBIC);

        int * pResults = NULL; 
        //pBuffer is used in the detection functions.
        //If you call functions in multiple threads, please create one buffer for each thread!
        unsigned char * pBuffer = (unsigned char *)malloc(DETECT_BUFFER_SIZE);
        if(!pBuffer)
        {
            fprintf(stderr, "Can not alloc buffer.\n");
            return -1;
        }

        ///////////////////////////////////////////
        // CNN face detection 
        // Best detection rate
        //////////////////////////////////////////
        //!!! The input image must be a RGB one (three-channel)
        //!!! DO NOT RELEASE pResults !!!
        pResults = facedetect_cnn(pBuffer, (unsigned char*)(image.ptr(0)), image.cols, image.rows, (int)image.step);

        printf("%d faces detected.\n", (pResults ? *pResults : 0));
        Mat result_cnn = image.clone();
        //print the detection results
        for(int i = 0; i < (pResults ? *pResults : 0); i++)
        {
            short * p = ((short*)(pResults+1))+142*i;
            int x = p[0];
            int y = p[1];
            int w = p[2];
            int h = p[3];
            //int neighbors = p[4];
            //int angle = p[5];

            //printf("face_rect=[%d, %d, %d, %d], neighbors=%d, angle=%d\n", x,y,w,h,neighbors, angle);
            rectangle(result_cnn, Rect(x, y, w, h), Scalar(0, 255, 0), 2);
        }
        imshow("result_cnn", result_cnn);

        //release the buffer
        free(pBuffer);
    }
    destroyAllWindows();

    return 0;
}

Makefile

SRCS = \
	libfacedetectcnn-example.cpp \
	../src/facedetectcnn.cpp \
	../src/facedetectcnn-floatdata.cpp \
	../src/facedetectcnn-int8data.cpp \
	../src/facedetectcnn-model.cpp


OBJS = $(subst .cc,.o,$(subst .cxx,.o,$(subst .cpp,.o,$(SRCS))))

CXXFLAGS = -I../src $(shell pkg-config --cflags opencv4) -Wall -O5 -mavx -mfma -ffast-math
LIBS = $(shell pkg-config --libs opencv4)
TARGET = example
ifeq ($(OS),Windows_NT)
TARGET := $(TARGET).exe
endif

.SUFFIXES: .cpp .cxx .o

all : $(TARGET)

$(TARGET) : $(OBJS)
	g++ -std=c++14 -o $@ $(OBJS) $(LIBS)

.cxx.o :
	g++ -std=c++14 -c $(CXXFLAGS) -I. $< -o $@

.cpp.o :
	g++ -std=c++14 -c $(CXXFLAGS) -I. $< -o $@

clean :
	rm -f *.o $(TARGET)