¶VDXA is not a typo
Okay, since everyone keeps asking about this....
The "VDXA" in the "Enable 3D video filter acceleration (VDXA)" option in VirtualDub's Preferences dialog is not a typo. It stands for VirtualDub eXternal Acceleration and is an additional API I added in 1.9.3 to allow video filters to use Direct3D 9. However, for some reason everyone keeps confusing it with DirectX Video Acceleration (DXVA), which is an entirely different API for video decoding acceleration in Windows, which is completely separate and which VirtualDub doesn't use.