After a recent rant about search systems I decided to try to find any information about the format (I just happened to recollect that it’s supposed to exist). I don’t know if anybody was lucky but for me the search results were mentions in the list of FOURCCs, some passing references in two papers and that’s all. Now it will probably start returning more results from multimedia.cx domain though 😉
So what should we do when a generic search engines fail? Resort to the specialised ones of course. Thanks to the content search feature of discmaster.textfiles.com I was finally able to locate a CD which uses PhotoMotion technology with both video files and the official player (aptly named P7.EXE, I couldn’t have given it a better name myself). Even better, video files were encoded as both AVI and MM so I could check what output to expect.
Of course Peter’s decoder can’t handle them properly because of the larger header (26 bytes instead of usual 22 or 24 bytes) and uncompressed intra frames. But it was simple to write a simple stand-alone decoder for it to validate that both PhotoMotion and game samples are decoded fine.
This is no major achievement of course but at least it answers a question what that format is all about. So even if there’s still no information about an alleged VfW decoder, now we know what to expect from it.
This is a major archeological discovery! Thanks for sharing and updating the wiki.
That search engine is pretty interesting too.
P6.EXE, found on the IBM CD-ROM, also accepts the MM file format.
Using the debug flag (/d), P6.EXE will dump the MM header and give a summary of the different chunk types observed in the file. The mysterious 0x14 audio chunk is described as DIGISPEECH. Digispeech DS-201 is mentioned in AUDIO.REF in the same directory. This seems like an parallel port audio adapter device.
Interesting P6.EXE strings:
“Copyright 1983,84,85,86,87,88,89,90 John Bridges”
“MOVIEMAKER”
Baidu hit: https://en.wikipedia.org/wiki/John_Bridges_(software_developer)#IBM_Project
His Dr. Dobbs article on Differential Image Compression: https://jacobfilipp.com/DrDobbs/articles/DDJ/1991/9102/9102c/9102c.htm
https://jacobfilipp.com/DrDobbs/articles/DDJ/1991/9102/9102c/9102c.htm
A nice find indeed. And you can guess which other project of his GRASPed my attention (even if it’s not a stand-alone video).
It’s a pity all those old formats remain forgotten though. Maybe you can write a story about them?