DirectShow_Graph_OpenCV.cpp

DirectShow_Graph_OpenCV.cpp

/*
  DirectShow_Graph_OpenCV.cpp

  see also DirectShow_Graph_trap_OpenCV.cpp
*/

#define UNICODE
#define _UNICODE
#include <wchar.h>

#define WIN32_LEAN_AND_MEAN
#define _WIN32_DCOM
#define _CRT_SECURE_NO_DEPRECATE
#include <windows.h>
#include <dshow.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

// download qedit.h and edit it
#include <qedit.h> // CLSID_SampleGrabber ISampleGrabber IID_ISampleGrabber

// use CV_PI instead of M_PI
// #define _USE_MATH_DEFINES
#include <opencv2/opencv.hpp>

int main(int ac, char **av)
{
  HRESULT hr = CoInitialize(NULL);
  if(FAILED(hr)){
    fprintf(stderr, "CoInitialize Failed\n");
    return 1;
  }
  ICreateDevEnum *pDevEnum = NULL;
  CoCreateInstance(CLSID_SystemDeviceEnum, NULL, CLSCTX_INPROC,
    IID_ICreateDevEnum, (void **)&pDevEnum);
  IEnumMoniker *pClassEnum = NULL;
  pDevEnum->CreateClassEnumerator(CLSID_VideoInputDeviceCategory, &pClassEnum, 0);
  if(!pClassEnum){
    fprintf(stderr, "Device does not exist\n");
    pDevEnum->Release();
    CoUninitialize();
    return 2;
  }
  // find Nth filter
  IBaseFilter *pbf = NULL;
  for(int c = 0; c < 3; ++c){
    if(pbf){ pbf->Release(); pbf = NULL; }
    ULONG cFetched;
    IMoniker *pMoniker = NULL;
    if(pClassEnum->Next(1, &pMoniker, &cFetched) == S_OK){
      pMoniker->BindToObject(0, 0, IID_IBaseFilter, (void**)&pbf);
      pMoniker->Release();
    }
  }
  pClassEnum->Release();
  pDevEnum->Release();
  if(!pbf){
    fprintf(stderr, "Video Capture Filter not found\n");
    CoUninitialize();
    return 3;
  }

  IGraphBuilder *pGraph = NULL;
  CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC,
    IID_IGraphBuilder, (void **)&pGraph);
  pGraph->AddFilter(pbf, L"Video Capture");

  IBaseFilter *pF = NULL;
  CoCreateInstance(CLSID_SampleGrabber, NULL, CLSCTX_INPROC_SERVER,
    IID_IBaseFilter, (LPVOID *)&pF);
  ISampleGrabber *pGrab = NULL;
  pF->QueryInterface(IID_ISampleGrabber, (void **)&pGrab);
  AM_MEDIA_TYPE amt;
  ZeroMemory(&amt, sizeof(AM_MEDIA_TYPE));
  amt.majortype = MEDIATYPE_Video;
  amt.subtype = MEDIASUBTYPE_RGB24; // check
  amt.formattype = FORMAT_VideoInfo;
  pGrab->SetMediaType(&amt);
  pGraph->AddFilter(pF, L"Grabber");

  ICaptureGraphBuilder2 *pCapture = NULL;
  CoCreateInstance(CLSID_CaptureGraphBuilder2, NULL, CLSCTX_INPROC,
    IID_ICaptureGraphBuilder2, (void **)&pCapture);
  pCapture->SetFiltergraph(pGraph);
  pCapture->RenderStream(&PIN_CATEGORY_PREVIEW, &MEDIATYPE_Video,
    pbf, NULL, pF);

  IMediaControl *pMC = NULL;
  pGraph->QueryInterface(IID_IMediaControl, (LPVOID *)&pMC);
  pMC->Run(); // start render
  pGrab->SetBufferSamples(TRUE); // Grab

  pGrab->GetConnectedMediaType(&amt);
  fprintf(stdout, "amt.lSampleSize = %dbytes\n", amt.lSampleSize);
  VIDEOINFOHEADER *pVIH = (VIDEOINFOHEADER *)amt.pbFormat;
  BITMAPINFO bmi;
  ZeroMemory(&bmi, sizeof(bmi));
  BITMAPINFOHEADER *pH = &bmi.bmiHeader;
  CopyMemory(pH, &pVIH->bmiHeader, sizeof(BITMAPINFOHEADER));
  fprintf(stdout, "%dx%d %dbits\n", pH->biWidth, pH->biHeight, pH->biBitCount);

  // OpenCV from here
  // only 24bit support
  cv::namedWindow("Src", CV_WINDOW_AUTOSIZE | CV_WINDOW_FREERATIO);
  cv::namedWindow("Diff", CV_WINDOW_AUTOSIZE | CV_WINDOW_FREERATIO);
  cv::Mat frm(pH->biHeight, pH->biWidth, CV_8UC3);
  cv::Mat imgBkg(pH->biHeight, pH->biWidth, CV_8UC3);
  cv::Mat imgDiff(pH->biHeight, pH->biWidth, CV_8UC3);

  int cnt = 0, bkg = 0;
  while(1){
    hr = pGrab->GetCurrentBuffer((long *)&pH->biSizeImage, (long *)frm.data);
    if(FAILED(hr)){ if(cv::waitKey(50) == 'q') break; else continue; }
#if 0
    // im->origin 0: left-top, 1: left-bottom
    IplImage *im = cvCreateImage(cvSize(frm.cols, frm.rows), IPL_DEPTH_8U, 3);
    if(!im->origin) cv::flip(frm, frm, 0); // reverse top <-> bottom
    cvReleaseImage(&im);
#else
    cv::flip(frm, frm, 0); // reverse top <-> bottom
#endif
    cv::imshow("Src", frm);
    if(++bkg == 1) frm.copyTo(imgBkg);
    // cv::subtract(frm, imgBkg, imgDiff); // mask=noArray(), dtype=-1
    cv::absdiff(frm, imgBkg, imgDiff); // differential
    cv::imshow("Diff", imgDiff);
    int k = cv::waitKey(10);
    if(k == 'q') break;
    switch(k){
    case 'c': {
      char fname[2048];
      sprintf(fname, "c:\\temp\\src_%06d.png", cnt);
      fprintf(stdout, "save [%s]\n", fname);
      cv::imwrite(fname, frm);
      sprintf(fname, "c:\\temp\\bkg_%06d.png", cnt);
      fprintf(stdout, "save [%s]\n", fname);
      cv::imwrite(fname, imgBkg);
      sprintf(fname, "c:\\temp\\diff_%06d.png", cnt);
      fprintf(stdout, "save [%s]\n", fname);
      cv::imwrite(fname, imgDiff);
      ++cnt;
    } break;
    case 'b': frm.copyTo(imgBkg); break;
    default: break; // skip
    }
  }

  cv::destroyAllWindows();
  // OpenCV end

  pMC->Release(); // Filter Graph
  pCapture->Release(); // Capture Graph
  pGrab->Release();
  pF->Release(); // Sample Grabber
  pGraph->Release();
  pbf->Release(); // Capture Filter
  CoUninitialize();
  return 0;
}