感谢您的帮助，我能够更好地搜索正确的单词来使用 directshow。我在这里找到了如何使用 SampleGrabber 对象的教程：http: //msdn.microsoft.com/en-us/library/windows/desktop/dd407288%28v=vs.85%29.aspx
我可以实现它并对其进行一些修改，这样它不仅可以保存第一帧，还可以将每个帧保存为 PNG。为此，我使用电晕。但是，我只是猜测了一些东西，不太清楚哪些缓冲区包含我的数据以及以哪种形式。
所以，我基本上有 3 个问题：
我使用 SavePNG 对吗？生成的图像是颠倒的！
我可以用连接到相机的视频替换 BaseFilter 吗？
包含 pBuffer 我的 Imagedata，所以我可以通过简单地键入 pBuffer[123] 来获取 rgb 字节信息？
我正在使用 embarcadero 的 C++-Builder (XE2 16)。
这是我在网站上找到的代码，稍作修改（删除了错误处理以获得更好的视图。在每个 hr=... 之后有一个失败检查）：
void __fastcall TForm1::btn_kameraClick(TObject *Sender)
{
HRESULT hr = S_OK;
IGraphBuilder *pGraph = NULL;
IMediaControl *pControl = NULL;
IMediaEventEx *pEvent = NULL;
IBaseFilter *pGrabberF = NULL;
ISampleGrabber *pGrabber = NULL;
IBaseFilter *pSourceF = NULL;
IEnumPins *pEnum = NULL;
IPin *pPin = NULL;
IBaseFilter *pNullF = NULL;
BYTE *pBuffer = NULL;
hr = CoCreateInstance(CLSID_FilterGraph, NULL,CLSCTX_INPROC_SERVER,IID_PPV_ARGS(&pGraph));
hr = pGraph->QueryInterface(IID_PPV_ARGS(&pControl));
hr = pGraph->QueryInterface(IID_PPV_ARGS(&pEvent));
hr = CoCreateInstance(CLSID_SampleGrabber, NULL, CLSCTX_INPROC_SERVER,IID_PPV_ARGS(&pGrabberF));
hr = pGraph->AddFilter(pGrabberF, L"Sample Grabber");
hr = pGrabberF->QueryInterface(IID_PPV_ARGS(&pGrabber));
AM_MEDIA_TYPE mt;
ZeroMemory(&mt, sizeof(mt));
mt.majortype = MEDIATYPE_Video;
mt.subtype = MEDIASUBTYPE_RGB24;
hr = pGrabber->SetMediaType(&mt);
hr = pGraph->AddSourceFilter(L"C:/Users/Julian/Desktop/homogenität/1,1x_2,7y.mpg", L"Source", &pSourceF);
hr = pSourceF->EnumPins(&pEnum);
while (S_OK == pEnum->Next(1, &pPin, NULL))
{
hr = ConnectFilters(pGraph, pPin, pGrabberF);
SafeRelease(&pPin);
if (SUCCEEDED(hr))break;
}
hr = CoCreateInstance(CLSID_NullRenderer, NULL, CLSCTX_INPROC_SERVER,IID_PPV_ARGS(&pNullF));
hr = pGraph->AddFilter(pNullF, L"Null Filter");
hr = ConnectFilters(pGraph, pGrabberF, pNullF);
hr = pGrabber->SetOneShot(TRUE);
hr = pGrabber->SetBufferSamples(TRUE);
long evCode=0;
long cbBuffer=0;
hr = pControl->Run();
hr = pEvent->WaitForCompletion(INFINITE, &evCode);
hr = pGrabber->GetCurrentBuffer(&cbBuffer, NULL);
pBuffer = (BYTE*)CoTaskMemAlloc(cbBuffer);
hr = pGrabber->GetConnectedMediaType(&mt);
CComQIPtr< IMediaSeeking, &IID_IMediaSeeking > pSeeking( pGraph );
// for(int i=0;i<10;i++){
bool hui=true;int i=0;
while(hui){
REFERENCE_TIME Start = i * UNITS;
hr = pSeeking->SetPositions( &Start, AM_SEEKING_AbsolutePositioning,NULL, AM_SEEKING_NoPositioning );
// Sleep(10);
hr = pEvent->WaitForCompletion(INFINITE,&evCode);
if(hr!=0)hui=false;
hr = pGrabber->GetCurrentBuffer(&cbBuffer, (long*)pBuffer);
if ((mt.formattype == FORMAT_VideoInfo) &&(mt.cbFormat >= sizeof(VIDEOINFOHEADER)) &&(mt.pbFormat != NULL))
{
VIDEOINFOHEADER *pVih = (VIDEOINFOHEADER*)mt.pbFormat;
// hr = WriteBitmap(("hui"+(String)i+".bmp").c_str(), &pVih->bmiHeader, mt.cbFormat - SIZE_PREHEADER, pBuffer, cbBuffer);
hr = SavePNG(i,pBuffer, pVih->bmiHeader.biWidth, pVih->bmiHeader.biHeight);
}
else hr = VFW_E_INVALIDMEDIATYPE;
i++;
}
FreeMediaType(mt);
done:
CoTaskMemFree(pBuffer);
SafeRelease(&pPin);
SafeRelease(&pEnum);
SafeRelease(&pNullF);
SafeRelease(&pSourceF);
SafeRelease(&pGrabber);
SafeRelease(&pGrabberF);
SafeRelease(&pControl);
SafeRelease(&pEvent);
SafeRelease(&pGraph);
}
bool SavePNG(int i, Byte* m_pImageData,long m_Width,long m_Height)
{
// Make sure there is image data
if (!m_pImageData)
return false;
stringstream FilePath;
FilePath << "hui"<< i<<".png";
// Create a corona image
corona::Image* pImage = corona::CreateImage(m_Width, m_Height, corona::PF_R8G8B8, m_pImageData);
// Make sure the image was created
if (!pImage)
return false;
// Save the image to a PNG file
corona::SaveImage(FilePath.str().c_str(), corona::FF_PNG, pImage);
// Delete the corona image
delete pImage;
// Nothing went wrong
return true;
}
我希望我没有做任何可怕的错误......我真的试图研究一切^^有人知道我上面的3个问题吗？我在这里发现了一些非常错误的地方，我也很感激你告诉我，所以我可以修复和改进。
问候，朱利安