Kostya's Boring Codec World

I’ve written a decoder for Ratvideo (and documented it as well). So why it’s not done? Because apparently it’s VIDPAK (from the creator of DIGPAK John W. Ratcliff—hmm, I wonder if his name has anything to do with the format name) so it’s a different thing that had been done. And since the format was created by an EA programmer for use in EA games it’s definitely Peter Ross’s fault for not REing it.

So the runtime-generated table turned out to be code for masked update and inter-coding mode proved out to be a fixed-size mask telling which pixels to update plus the values to update it with. Mentioned in the previous post mode with duplicating lines turned out to be an alternative coding mode where each next line uses a previous one as the reference, so that previous line is copied and updated depending on the mask. That’s another case where you need to look at the disassembly instead of what decompiler provides (if it manages to produce something in the first place) but the code is almost trivial.

I’m not going to look at any more game formats in the near future (unless some come to my attention), so it’s just boring stuff for me for now.

This entry was posted on Monday, October 21st, 2024 at 12:49 pm and is filed under Game Video. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.