Kostya's Boring Codec World

You may remember Tsunami Media as a company founded by ex-Sierra people that released a couple of games and ceased its existence.

MobyGames lists the following titles (characteristic is mine):

• Ringworld: Revenge of the Patriarch—an adventure game based on Ringworld novel by Larry Niven. ScummVM supports its but I played it long before that.
• Wacky Funsters! The Geekwad’s Guide to Gaming—a collection of arcade games with wacky design (I’ve only played its sequel though).
• Protostar: War on the Frontier—a reportedly good strategy game inspired by the same source as Star Control II so they share a lot of game design (and yes, they have a common ancestor so it’s not a rip-off. I’ve never played it myself but what I saw looks interesting.
• Blue Force—Police Quest in anything but name. ScummVM supports it but again, I played it long before that.
• The Geekwad: Games of the Galaxy—another collection of standard arcade games but with wacky design. I especially liked quizzes there.
• Flash Traffic: City of Angels—one of the first interactive movies. The Mike has blogged about it.
• Return to Ringworld—a sequel to the Ringworld obviously. ScummVM supports it (so I can re-play it and check whether that empty platform where you seek for the details is really that horrible).
• Man Enough—FMV dating game.
• Silent Steel—yet another interactive movie.
• Free Enterprise—some business simulator.

As you can see, some of the adventure games are supported by ScummVM already but FMV-based ones are not which makes me wonder why.

Man Enough uses the same engine as the previous games (I checked personally. FMV sections there turned out to be animations in the same format as in Ringworld II (I hacked a quick RLB extractor and animation decoder to check that). Side note: whoever added a support for the engine was tired (for a very good reason given below) and hadn’t recognized that it uses LZW compression (so the decompressor is still slightly beautified REd code). Also in this game you have RLBs with elements following each other and those aligned to 16-byte boundaries. So maybe it’d be better just to check if you have first entry right after the library header or not (they all have TMI- header so you can’t mistake it for anything else).

Flash Traffic is special since while it uses the same engine it has all resources stored separately instead of a single library archiving them all. Additionally while TMI format they use is the same, the compression is different. Here you have LZ77-like method which can copy verbatim, copy 32-bit words from already decoded area, fill region with repeating pattern of two bytes, or simply zero region. I have a working implementation for it so I can unpack various resources from the game just fine (but beside BFI or MPEG files that have been supported since long time why should I bother?).

Silent Steel is their newer FMV game that’s mostly just one large MPEG video file and some logic around it (that’s why there was an interactive DVD re-release of the game later).

And now here’s the most important reason why Flash Traffic and Man Enough are not supported up to this day: Tsunami Media hardcoded game logic into the binaries, so while for SCI or SCUMM games you can write a virtual machine and interpret original bytecodes, here you need to decompile game logic from the DOS executable (it’s not an easy task even today) and re-implement it yourself. That’s why tsage engine in ScummVM is full of ${game_name}/${game_name}_scenesN.cpp files for each of the three games it supports. I’m pretty sure the developers won’t refuse somebody else’s contribution for the other tsage games support so you’re welcome to try.

This entry was posted on Sunday, August 1st, 2021 at 1:14 pm and is filed under Game Video. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.