영상 캡쳐 - DirectShow

ISampleGrabber

.SetMediaType()

.SetBufferSamples()

.GetCurrentBuffer()

.GetConnectedMediaType()

#if !defined(AFX_UUIDS_H__3F5BAE08_581B_4008_ABB4_0A4D2D3456C6__INCLUDED_)
#define AFX_UUIDS_H__3F5BAE08_581B_4008_ABB4_0A4D2D3456C6__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

// SampleGrabber {C1F400A0-3F08-11D3-9F0B-006008039E37}
DEFINE_GUID(CLSID_L544_SampleGrabber,
0xc1f400a0, 0x3f08, 0x11d3, 0x9f, 0xb, 0x0, 0x60, 0x8, 0x3, 0x9e, 0x37);

#endif // !defined(AFX_UUIDS_H__3F5BAE08_581B_4008_ABB4_0A4D2D3456C6__INCLUDED_)

class CSampleGrabStillApp 
{
...
private:
    // DirectShow interfaces
// {
    void CaptureScreen();
// }
    IGraphBuilder    *    m_pGB ;
// {
    IBaseFilter        *    m_pSG ;
// {
} ;


...
#include "myuuids.h"
// {
#include <qedit.h>
// }
...
CSampleGrabStillApp::CSampleGrabStillApp() : m_hInstance(NULL),
               ...
               m_pGB(NULL), m_pSG(NULL)
{
...
}

HRESULT CSampleGrabStillApp::OnFileOpen()
{
...
    // 필터그래프매니저 생성
    // Get the interface for DirectShow's GraphBuilder
    JIF(CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC_SERVER, IID_IGraphBuilder, (void **)&m_pGB)) ;

    // Add a Filter ... Put a filter in the graph
    LIF(CoCreateInstance(CLSID_L544_SampleGrabber, NULL, CLSCTX_INPROC_SERVER, IID_IBaseFilter, (void **)&m_pSG)) ;

    LIF(m_pGB->AddFilter(m_pSG, L"SampleGrabber"));
// {
    AM_MEDIA_TYPE mt;
    ZeroMemory(&mt, sizeof(mt));
    mt.majortype = MEDIATYPE_Video;
//    mt.majortype = MEDIATYPE_Audio;
    mt.subtype = MEDIASUBTYPE_RGB24;
//    mt.subtype = MEDIASUBTYPE_PCM;

    CComQIPtr<ISampleGrabber> pSampleGrabber(m_pSG);
    if (pSampleGrabber != NULL)
    {
        LIF(pSampleGrabber->SetMediaType(&mt));
        LIF(pSampleGrabber->SetBufferSamples(TRUE));
    }
// }
    // Render File ...
    // Have the graph construct its the appropriate graph automatically
    JIF(m_pGB->RenderFile(wFileName, NULL)) ;
...
}

HRESULT CSampleGrabStillApp::OnFileClose()
{
...
    // Release Filter Graph Manager
    SAFE_RELEASE(m_pGB) ;
// {
    SAFE_RELEASE(m_pSG) ;
// }
    // 기본 윈도우 타이틀로 변경
    SetWindowText(m_hWnd, m_szAppTitle) ;

    return S_OK ;
}
...
void CSampleGrabStillApp::CaptureScreen()
{
    if (m_pSG == NULL)
        return;

    HRESULT hr;

    CComQIPtr<ISampleGrabber> pSampleGrabber(m_pSG);
    if (pSampleGrabber == NULL)
        return;

    long lBufferSize;

    hr = pSampleGrabber->GetCurrentBuffer(&lBufferSize, NULL);
    if (FAILED(hr))
        return;

    BYTE* pBuffer = new BYTE[lBufferSize];
    if (!pBuffer)
        return;

    hr = pSampleGrabber->GetCurrentBuffer(&lBufferSize, (long *)pBuffer);
    if (SUCCEEDED(hr))
    {
        AM_MEDIA_TYPE mt;
        pSampleGrabber->GetConnectedMediaType(&mt);
        VIDEOINFOHEADER *pviHeader = (VIDEOINFOHEADER *)mt.pbFormat;

        ::SaveImage(pviHeader->bmiHeader, pBuffer);
    }

    delete pBuffer;
}


...
// Initialize CLSIDs
#include <initguid.h>
#include "myuuids.h"
...
LRESULT CSampleGrabStillApp::KeyProc(WPARAM wParam, LPARAM lParam)
{
    switch (wParam)
    {
    ...
    // TODO: Place code here.
    case 'F':
        ToggleFullScreen();
        break ;
// {
    case VK_SNAPSHOT:
        CaptureScreen();
        break ;
// }
    }

    return (DefWindowProc(m_hWnd, WM_KEYUP, wParam, lParam)) ;
}