Called when a source file is ready to be processed.
HRESULT retVal = object.Process(pStream);
If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.
The IImageDecodeFilter::Process method is called when Windows Internet Explorer needs to process an image of the registered MIME type.
The pStream parameter contains a simplified IStream implementation optimized for sequential read-only access. It does not support random access, or other stream-related functionality. Access beyond end-of-file is permitted; however, the call to ISequentialStream::Read will return S_FALSE.
Draw the decoded image onto the surface that is obtained from the IImageDecodeEventSink::GetSurface method. Images that require a large amount of memory will result in a severe degradation of performance.