First off, it's really the driver's responsibility to save that info to the registry. Most drivers do that correctly, a few - most notably drivers for tuners and tuner-like devices - fail to do so. As more of a "courtesy" than a necessity, AbelCam compensates for poorly behaved drivers by saving and restoring a group of standard settings that are common to most devices.

If your device identifies itself to the system as being a tuner or tuner-like device (which is fairly typical for analog capture devices, including a few I'm currently using) then input source IS saved and restored. But if your device identifies itself as a camera, input source is not a "standard" parameter and it is NOT "seen", saved or restored. (Rationale: a camera has only one input source... the camera!)

TyCapture and VisioForge view devices in slightly different ways. Sometimes VisioForge does better than TyCapture when dealing with devices that fall outside standards. You might want to give it a try.