 <p>LeadTools and VisioForge SDKs are just wrappers for DirectShow + some custom filters from them! There is no real alternativ to DirectShow for capturing on a Windows PC. Maybe on Win8 with MediaFoundation? Some Hardware Vendors have there own capture programms, but most of them just use DirectShow.</p> <p>I think your problem is not DirectShow. How long is your callback working? Because if your doing some analysis on the image, then you need to do this fast. Not the time in your callback is importent, but the presentation time in the mediasample you get! This should be +33ms from the previews sample.</p>