Kostya's Boring Codec World

The terrorist country proves that it is recognized as one and keeps targeting civilians instead of fighting a war. So nothing new but it would still be nice to see its demise soon. Meanwhile I keep doing small things to distract myself from all this.

Since I have nothing better to do, I watch reviews of various games including the ones I know well. And one of those reviews mentioned that Macintosh version of King’s Quest VI: Heir Today Gone Tomorrow had peculiar intro. Actually every version of the game has something peculiar about its intro: DOS version uses Sierra’s own RLE-based SEQ format, Windows version uses standard MS Video 1 in AVI (it was my first sample with palette change messages), Amiga version is a reimplementation by Revolution Software on their Virtual Theatre engine altogether (maybe ScummVM will support it one day for all three and a half fans waiting for that). So, what’s with Macintosh version?

First of all, the files are QuickTime movies in the original Macintosh format where frame data is stored in the data fork and movie header is stored inside the resource fork. Since not all modern OSes support such files natively (or conveniently), I’ve hacked a support for such movies in MacBinary format that keeps all forks in one file. And what do we have inside?

Inside the files are video streams packed with Cinepak. One of the peculiarities is that they have palette specified in video header in the format different from the conventional MOV color atom format, let alone the fact it should not be present at all. I understand that for Cinepak and even more for Indeo 3 (I really should write an encoder for it one day) it was common to provide a palette so they rendered their output for 256-colour mode but in that mode Cinepak simply coded palette indices and here we have YUV420 output and a palette as a recommendation.

Then there’s a fun case with tracks in KQ6Movie. I understand that they split video and coded it in several tracks so they could use different palettes (and framerates as it turns out) for different segments. And those tracks are not in order. Tracks 0 and 1 seem to be the very beginning, track 2 corresponds to a scene somewhere in the middle and track 3 is the last intro scene. Other ten tracks are not in order either. Maybe there is some information hidden in the header telling the order but I’m too lazy to find it out (let alone implement).

All in all, this was unexpectedly weird.

This entry was posted on Friday, November 25th, 2022 at 1:35 pm and is filed under Game Video, Various Video Codecs. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.