directshow编程实现视频采集
时间: 2023-11-02 22:06:44 浏览: 47
DirectShow是Microsoft Windows平台上的一个多媒体框架,允许开发者通过它来处理音频和视频数据。使用DirectShow,可以实现视频采集和处理。
以下是使用DirectShow编程实现视频采集的基本步骤:
1. 创建一个DirectShow图形,并添加视频源过滤器。
2. 创建一个视频渲染器,并将其与DirectShow图形连接起来。
3. 设置视频源过滤器的输出格式。
4. 开始采集视频数据。
5. 处理采集到的视频数据。
6. 停止视频采集并释放资源。
下面是一份示例代码,用于演示如何使用DirectShow进行视频采集:
```cpp
#include <dshow.h>
#pragma comment(lib, "strmiids.lib")
int main()
{
HRESULT hr = CoInitialize(NULL);
if (FAILED(hr))
{
return hr;
}
IGraphBuilder* pGraph = NULL;
hr = CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC_SERVER, IID_IGraphBuilder, (void**)&pGraph);
if (FAILED(hr))
{
CoUninitialize();
return hr;
}
ICaptureGraphBuilder2* pCap = NULL;
hr = CoCreateInstance(CLSID_CaptureGraphBuilder2, NULL, CLSCTX_INPROC_SERVER, IID_ICaptureGraphBuilder2, (void**)&pCap);
if (FAILED(hr))
{
pGraph->Release();
CoUninitialize();
return hr;
}
IBaseFilter* pSrc = NULL;
hr = pCap->FindInterface(&PIN_CATEGORY_CAPTURE, &MEDIATYPE_Video, NULL, IID_IBaseFilter, (void**)&pSrc);
if (FAILED(hr))
{
pCap->Release();
pGraph->Release();
CoUninitialize();
return hr;
}
IBaseFilter* pRenderer = NULL;
hr = CoCreateInstance(CLSID_VideoRenderer, NULL, CLSCTX_INPROC_SERVER, IID_IBaseFilter, (void**)&pRenderer);
if (FAILED(hr))
{
pSrc->Release();
pCap->Release();
pGraph->Release();
CoUninitialize();
return hr;
}
hr = pGraph->AddFilter(pSrc, L"Video Source");
if (FAILED(hr))
{
pRenderer->Release();
pSrc->Release();
pCap->Release();
pGraph->Release();
CoUninitialize();
return hr;
}
hr = pGraph->AddFilter(pRenderer, L"Video Renderer");
if (FAILED(hr))
{
pRenderer->Release();
pSrc->Release();
pCap->Release();
pGraph->Release();
CoUninitialize();
return hr;
}
IAMStreamConfig* pConfig = NULL;
hr = pCap->FindInterface(&PIN_CATEGORY_CAPTURE, &MEDIATYPE_Video, pSrc, IID_IAMStreamConfig, (void**)&pConfig);
if (FAILED(hr))
{
pRenderer->Release();
pSrc->Release();
pCap->Release();
pGraph->Release();
CoUninitialize();
return hr;
}
AM_MEDIA_TYPE* pmt = NULL;
hr = pConfig->GetFormat(&pmt);
if (FAILED(hr))
{
pConfig->Release();
pRenderer->Release();
pSrc->Release();
pCap->Release();
pGraph->Release();
CoUninitialize();
return hr;
}
VIDEOINFOHEADER* pVih = (VIDEOINFOHEADER*)pmt->pbFormat;
pVih->AvgTimePerFrame = 333333;
hr = pConfig->SetFormat(pmt);
if (FAILED(hr))
{
pConfig->Release();
pRenderer->Release();
pSrc->Release();
pCap->Release();
pGraph->Release();
CoUninitialize();
return hr;
}
hr = pCap->RenderStream(&PIN_CATEGORY_CAPTURE, &MEDIATYPE_Video, pSrc, NULL, pRenderer);
if (FAILED(hr))
{
pConfig->Release();
pRenderer->Release();
pSrc->Release();
pCap->Release();
pGraph->Release();
CoUninitialize();
return hr;
}
IMediaControl* pControl = NULL;
hr = pGraph->QueryInterface(IID_IMediaControl, (void**)&pControl);
if (FAILED(hr))
{
pConfig->Release();
pRenderer->Release();
pSrc->Release();
pCap->Release();
pGraph->Release();
CoUninitialize();
return hr;
}
hr = pControl->Run();
if (FAILED(hr))
{
pControl->Release();
pConfig->Release();
pRenderer->Release();
pSrc->Release();
pCap->Release();
pGraph->Release();
CoUninitialize();
return hr;
}
LONG lEventCode;
hr = pControl->GetEvent(&lEventCode, NULL, 0, 100);
if (SUCCEEDED(hr))
{
pControl->Stop();
}
pControl->Release();
pConfig->Release();
pRenderer->Release();
pSrc->Release();
pCap->Release();
pGraph->Release();
CoUninitialize();
return 0;
}
```
这份代码创建了一个DirectShow图形,将视频源过滤器和视频渲染器连接起来,设置了视频输出格式并开始采集视频数据。在这个示例中,视频数据被简单地渲染到屏幕上。
需要注意的是,这份代码只是一个简单的示例,实际应用中可能需要进行更多的配置和定制。