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    <p>With DirectShow you typically create a pipeline, that is a graph and you add filters to it, like this:</p> <p>Camera -> [possibly some extra stuff] -> Sample Grabber -> Null Renderer</p> <p>Camera, <a href="http://msdn.microsoft.com/en-us/library/windows/desktop/dd377544%28v=vs.85%29.aspx" rel="nofollow noreferrer">Sample Grabber</a>, <a href="http://msdn.microsoft.com/en-us/library/windows/desktop/dd377544%28v=vs.85%29.aspx" rel="nofollow noreferrer">Null Renderer</a> are all standard components shipped with clean Windows. Sample Grabber can be set to call you back via <a href="http://msdn.microsoft.com/en-us/library/windows/desktop/dd376987%28v=vs.85%29.aspx" rel="nofollow noreferrer"><code>ISampleGrabberCB::SampleCB</code></a> and give you data for every video frame captured. Null Renderer is the termination of pipeline without displaying video on monitor (just video capture).</p> <p><code>SampleCB</code> is the keyword to bring you sample code you need. Having data received with this call, you can convert/wrap it into IPL/OpenCV class as suggested by @praks411.</p> <p>Having it done as simple as this, you don't need DirectShow BaseClasses, and the code will be merely regular ATL/MFC code and project. Make sure to use <code>CComPtr</code> wrapper class to deal with COM interfaces to not lose references and leak objects. Some declarations might be missing in very latest Windows SDK, so you need to either use Windows SDK 6.x or just copy missing parts from there.</p> <p>See also:</p> <ul> <li><a href="https://stackoverflow.com/questions/12680600/how-to-capture-frames-using-delphi-dspack-without-displaying-it-on-tvideowindow/12680676#12680676">How to capture frames using Delphi/DSPack without displaying it on TVideoWindow?</a> (Delphi code, but good description and figures)</li> <li><a href="http://www.codeproject.com/Articles/34663/DirectShow-Examples-for-Using-SampleGrabber-for-Gr" rel="nofollow noreferrer">DirectShow: Examples for Using SampleGrabber for Grabbing a Frame and Building a VU Meter</a></li> <li><a href="http://alax.info/trac/public/browser/trunk/Utilities/SetLifeCamStudioResolutionSample" rel="nofollow noreferrer">SetLifeCamStudioResolutionSample</a> - A small DirectShow project showing how to set capture up, including resolution on camera, and Sample Grabber, and also missing SDK declarations; related Q is <a href="https://stackoverflow.com/questions/7383372/cant-make-iamstreamconfig-setformat-to-work-with-lifecam-studio">Can&#39;t make IAMStreamConfig.SetFormat() to work with LifeCam Studio</a></li> <li><a href="http://msdn.microsoft.com/en-us/library/windows/desktop/dd407288(v=vs.85).aspx#build_the_filter_graph" rel="nofollow noreferrer">Building the Filter Graph</a> on Sample Grabber and Null Renderer</li> </ul>
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    1. POGet iplImage or Mat from directshow to opencv
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    1. COThank you very much! I looked into the "setlifecam...", and maybe it is you who wrote that piece of code? Some error occured when running the code, when setting the resolution, but I fixed that with first identieng available settings and then choose one of it. But it is one thing I dont understand. I understand what a null renderer is, (i think), but I cant find anything in the code that feels like its a null renderer. Can you tell me where it is? Or is it:pCaptureGraphBuilder->RenderStream(&PIN_CATEGORY_CAPTURE, NULL, pCurrentOutputPin, NULL, pBaseFilter) ?
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    2. COThis piece of code (SetLife...) indeed does not use Null Renderer (I just gave you what was small enough to get familiar with, and readily available, and also close to your original Q of changing resolution). You will need to look up a Null Renderer snippet somewhere else, e.g. here [Building the Filter Graph](http://msdn.microsoft.com/en-us/library/windows/desktop/dd407288(v=vs.85).aspx#build_the_filter_graph) - also has a good description.
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    3. COOkay, thank you very much!
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