What is the normal process of converting PrBoom+ demos to videos through viddump?

As the title implies, I partly know that viddump plays a fairly big role in converting this port's demos; and I remembered having read how to do this a few months back/

However, I'm having trouble finding the tutorial thread for this at the moment.

So, I'll be really grateful if anyone answer (title) or at least link me to the solution. Thanks.

Bump, I need an answer for this, still unable to figure out the process.

You mean this post?