[Scummvm-devel] DXA file format for videos

Max Horn max at quendi.de
Tue Apr 25 04:34:00 CEST 2006

On Di, April 25, 2006 13:24, Gregory Montoir wrote:
> Travis Howell wrote:
>> So I think it would be a good idea to use the DXA file format for video
>> playback in all games supported by ScummVM.  The DXA file format would
> As a prerequisite, it might good to know what epic-interactive/rune-soft
> think of this idea (that's more or less part of their technology,
> afterall).
> I don't think the .DXA file format has been re-used since Feeble Files
> and Software Tycoon ; but still, it would be best to have some kind of
> authorization.

Considering the extreme simplicity of the scheme (XORing a frame with the
previous frame, the compressing the result using zlib), I am pretty sure
there is little they could do against it. For the frame xoring, there is
definitely prior art. So is there for compressing the result. And using
zlib likely isn't turning this into an "original" protecable technology.
But of course IANAL.

We certainly can ask them out of courtesy, but if done, it should be
executed in such a way that makes it *very* clear that it's likely
unprotected technology anyway. Else, the standard reaction of many
companies is to deny such requests, or only agree with them under certain

Anyway, we might want to change the name from DXA to something of our own,
to make it look less like we are copying some advanced video compression
scheme. zXOR, ZOR, XORz, ZXC (zlib xor compression) etc., many
possibilities up there ;-).


More information about the Scummvm-devel mailing list