井泉

#include <stdio.h>
#include <dshow.h>
// change here
#define	FILENAME L"C:\\DXSDK\\Samples\\Media\\butterfly.mpg"
// note that this sample fails on some environment
int
main()
{
IGraphBuilder *pGraphBuilder;
IMediaControl *pMediaControl;
IBasicVideo *pBasicVideo;
CoInitialize(NULL);
CoCreateInstance(CLSID_FilterGraph,
NULL,
CLSCTX_INPROC,
IID_IGraphBuilder,
(LPVOID *)&pGraphBuilder);
pGraphBuilder->QueryInterface(IID_IMediaControl,
(LPVOID *)&pMediaControl);
pMediaControl->RenderFile(FILENAME);

pGraphBuilder->QueryInterface(IID_IBasicVideo,
(LPVOID *)&pBasicVideo);

pMediaControl->Run();
// The image will be saved when OK is clicked
MessageBox(NULL,
"Grab Image",
"Grab",
MB_OK);

// Must Pause before using GetCurrentImage
pMediaControl->Pause();
// get width and height
long height, width;
pBasicVideo->get_VideoHeight(&height);
pBasicVideo->get_VideoWidth(&width);
long bufSize;
long *imgData;
HRESULT hr;
/*
The second value is NULL to resolve required buffer size.
The required buffer size will be returned in variable "bufSize".
*/
hr = pBasicVideo->GetCurrentImage(&bufSize, NULL);
if (FAILED(hr)) {
printf("GetCurrentImage failed\n");
return 1;
}
if (bufSize < 1) {
printf("failed to get data size\n");
return 1;
}
imgData = (long *)malloc(bufSize);
// The data will be in DIB format
pBasicVideo->GetCurrentImage(&bufSize, imgData);

// save DIB file as Bitmap.
// This sample saves image as bitmap to help
// understanding the sample.
HANDLE fh;
BITMAPFILEHEADER bmphdr;
BITMAPINFOHEADER bmpinfo;
DWORD nWritten;
memset(&bmphdr, 0, sizeof(bmphdr));
memset(&bmpinfo, 0, sizeof(bmpinfo));
bmphdr.bfType = ('M' << 8) | 'B';
bmphdr.bfSize = sizeof(bmphdr) + sizeof(bmpinfo) + bufSize;
bmphdr.bfOffBits = sizeof(bmphdr) + sizeof(bmpinfo);
bmpinfo.biSize = sizeof(bmpinfo);
bmpinfo.biWidth = width;
bmpinfo.biHeight = height;
bmpinfo.biPlanes = 1;
bmpinfo.biBitCount = 32;
fh = CreateFile("result.bmp",
GENERIC_WRITE, 0, NULL,
CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
WriteFile(fh, &bmphdr, sizeof(bmphdr), &nWritten, NULL);
WriteFile(fh, &bmpinfo, sizeof(bmpinfo), &nWritten, NULL);
WriteFile(fh, imgData, bufSize, &nWritten, NULL);
CloseHandle(fh);

free(imgData);
// Release resource
pBasicVideo->Release();

pMediaControl->Release();
pGraphBuilder->Release();
CoUninitialize();
return 0;
}