As I mentioned previously, I don’t want to work on game codecs for a while, so I picked other stuff instead. For instance, I’ve fixed a bug in my Indeo 3 encoder (which nobody uses, myself included), refactored some NihAV code and added a couple of decoders.
First, there is PDQ2 decoder. It actually turned out to be slightly more interesting than I expected as there’s a version of the codec for Saturn version of the game (it’s not that different yet somewhat different nevertheless).
Then I’ve finally managed to figure out MoviePak. After locating a decompressor binary and trying to disassemble it as raw M68k code I could locate enough code and data to figure out that since it uses JPEG codebooks it’s likely to be based on JPEG. And after learning a bit more about how it works and NOPing out A-line _StripAddress calls (that was the most interesting part actually—you can’t find it without knowing terminology and even then just barely; I was lucky to try searching for information about 68881, learning terminology and finally finding a reference of Macintosh Toolbox calls) I managed to make Ghidra happy enough to produce a usable decompilation. After that it was just a question of re-using JPEG decoder with a slightly different header format, which finally made me do a refactoring of JPEG decoding.
And since I’ve factored out common JPEG decoding support for MoviePak, Radius Studio and actual motion JPEG decoder, I decided to add a video codec for effects used in proDAD Adorage video editor (its FOURCC is pDAD, quite surprisingly). This one could be reverse engineered just by looking at the frame data. Each frame consists of 20-byte header, JPEG image plus alpha channel coded as PNG or JPEG. Since I have not bothered to write a motion PNG decoder (it’s very uncommon after all and I’m not NIHing image library—at least not yet), I decode just the first part. Maybe I’ll add a PNG decoder support and re-visit this decoder for proper alpha support, but for now this seems unlikely.
I’ll keep working on some boring stuff nobody cares about but maybe I’ll have a codec or two to write about as well.
I sent you email days ago.
I find free ninja decompiler/interface much better than ghidra.
It ended up in spam for some reason (this happened not just to your mails either), thanks for the notification.
As for Binary Ninja, I tried it once and was not impressed. Ghidra has a lot of deficiencies but it seems to do most of the things I want it to do (even if not in the most efficient manner sometimes).