Need a callback per frame

ISampleGrabber::SetCallback( pMyCallback, 0 );

The zero tells the sample grabber to call you back with a pointer to the original media sample. No data copy is made.

See ISampleGrabber::SetCallback docs for more info.

Also see Using the Sample Grabber.

-Nick

nickhaddady at 2007-9-26 >

Read this post and I think that it would help me also. All I need to for a function to be called when the frame is updated (I don't need the buffer) but I'm having a problem with setting up the callback, I want to call VideoFrame() on each frame, but I'm at a loss to set this up (old time C programmer who struggles w/ C++):

void VideoFrame();

BOOL Play(HWND hChildWnd, LPCWSTR szFileName, int top, int left);

IMediaSeeking *pMediaSeeking = NULL; // For playback speed

IBaseFilter *pGrabberF = NULL;

ISampleGrabber *pGrabber;

BOOL Play(HWND hChildWnd, LPCWSTR szFileName, int top, int left)

// initialize Graph

hr = CoCreateInstance( CLSID_FilterGraph, NULL, CLSCTX_INPROC,IID_IGraphBuilder, (void **)&pGraph );

// Load the File to render

//Add Sample grabber filter and interface

hr = CoCreateInstance(CLSID_SampleGrabber, NULL, CLSCTX_INPROC_SERVER, IID_IBaseFilter, (void**)&pGrabberF);

hr = pGraph->AddFilter(pGrabberF, L"Sample Grabber");

ZeroMemory(&mt, sizeof(AM_MEDIA_TYPE)); mt.majortype = MEDIATYPE_Video; mt.subtype = MEDIASUBTYPE_RGB24;

hr = pGrabberF->QueryInterface(IID_ISampleGrabber, (void**)&pGrabber);

hr = pGrabber->SetCallback((ISampleGrabberCB *)VideoFrame,(long)0); <FAILS

//....Sets Events Notification, other stuff

Chandler at 2007-9-26 >