[Mesa-dev] Naked DXTn support via ARB_texture_compression?

Mathias Gottschlag mgottschlag at gmail.com
Sun Mar 20 12:23:09 PDT 2011

Argh, meant to reply to list.

If this nvidia library has a s3tc patent license, cannot this be used as 
a starting point, as done with the current dxt library? Unmodified, as 
an external binary? Wouldn't that circumvent the whole issue as you do 
not need a license for the hardware as it already has to be licensed if 
it was sold somewhere (well, at least on nvidia hardware, that is how I 
understand that FAQ entry, the part about narrow licenses does not seem 
to apply here), and you now suddenly have a licensed software encoder as 


On 20.03.2011 16:42, Jose Fonseca wrote:
> Petr,
> You don't believe that IHVs may have narrow licenses of the S3TC patent. How do you explain the statement:
>     WARNING:  Vendors able to support S3TC texture compression in Direct3D
>      drivers do not necessarily have the right to use the same functionality in
>      OpenGL.
> in http://oss.sgi.com/projects/ogl-sample/registry/EXT/texture_compression_s3tc.txt ?
> This is just a piece of evidence. I heard this from several different people now.
> I do not know what are the S3TC licensing terms from NVIDIA, ATI, Intel, or anybody in particular.
> S3TC patent seems to have been filed at least in US, Europe, and Japan, so this is not just an US issue as I've read several times elsewhere.
> Truth is that NVIDIA managed to release an opensource product that does S3TC compression and decompression. Therefore, if IHVs or another entity saw enough economic incentive they could make Linux opensource drivers with S3TC support a reality just as well. It all boils down to economics.
> If people are serious about supporting S3TC on open source drivers they should reach out the IHVs to ascertain the licensing status, perhaps convincing them to license for Linux open-source drivers, or license the patent themselves.
> A much more interesting preposing is to invest in Khronos ETC format. It's nearly equivalent from a technical POV, and I believe that the IP is available in much less onerous terms. I'm not sure about hardware support in desktop GPUs, but most mobiles stacks support it.
> Jose

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