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Update FAQ regarding S3TC patent

Posted: 24 Dec 2017, 04:47
by Thunderforge
The OpenMW has an FAQ regarding the S3TC patent
When does the S3TC patent expire, when it does can we play Morrowind then?

The patent expires on “Oct 2, 2017” but it can be renewed before then. If it does expire, then OpenMW will feel comfortable enough to allow code into OpenMW for decoding/decompressing textures on the fly for systems that do not support it, such as the Raspberry Pi.
October 2, 2017 has come and gone, and it was indeed expired. In fact, discussion has already occurred about how this impacts OpenMW. I think this FAQ should be updated or deleted entirely.

Re: Update FAQ regarding S3TC patent

Posted: 27 Dec 2017, 20:33
by lgromanowski
Thunderforge wrote:
24 Dec 2017, 04:47
The OpenMW has an FAQ regarding the S3TC patent
When does the S3TC patent expire, when it does can we play Morrowind then?

The patent expires on “Oct 2, 2017” but it can be renewed before then. If it does expire, then OpenMW will feel comfortable enough to allow code into OpenMW for decoding/decompressing textures on the fly for systems that do not support it, such as the Raspberry Pi.
October 2, 2017 has come and gone, and it was indeed expired. In fact, discussion has already occurred about how this impacts OpenMW. I think this FAQ should be updated or deleted entirely.
I'm also in favour of deleting this point, but lets wait what psi26a, raevol, and others think about it.

Re: Update FAQ regarding S3TC patent

Posted: 28 Dec 2017, 04:50
by Thunderforge
Looks like the S3TC patent is also talked about in the "Can I play Morrowind with OpenMW on other platforms like the Raspberry Pi?" section, so that will have to be revised as well (probably not deleted though).

Re: Update FAQ regarding S3TC patent

Posted: 28 Dec 2017, 10:00
by raevol
I'm in favor of deleting it, this is definitely @psi29a 's baby though.

Re: Update FAQ regarding S3TC patent

Posted: 28 Dec 2017, 15:57
by lysol
Wasn't the S3TC decoding/whatever implemented into OSG after the patent expired?

Re: Update FAQ regarding S3TC patent

Posted: 28 Dec 2017, 19:28
by psi29a
We can always have a blurb that it no longer effects us, that the patent hasn't been renewed. Give tips on how to get s3tc support in various distros?

Re: Update FAQ regarding S3TC patent

Posted: 28 Dec 2017, 23:06
by raevol
psi29a wrote:
28 Dec 2017, 19:28
We can always have a blurb that it no longer effects us, that the patent hasn't been renewed. Give tips on how to get s3tc support in various distros?
That's not a bad idea. Could you draft a new bit of text for it? Sorry I'm volunteering you haha.

Re: Update FAQ regarding S3TC patent

Posted: 29 Dec 2017, 17:13
by psi29a
The S3TC patent is expired, but we're still dealing with the after effect. To enable support for S3TC using the FOSS Xorg video drivers/modules on Ubuntu or Debian, please install the libtxc-dxtn-s2tc package. If you use the binary drivers from Nvidia or AMD, this has no effect.

Please note that there is hardware that does not support S3TC, such as the Raspberry Pi (1, 2 and 3) as of this writing. Even with the package installed, the hardware, VC4, does not support decoding S3TC encoded textures and will give you a pink textures as a result. There is work being done in OSG to allow software decoding of S3TC encoded textures at run-time before uploading to the GPU, but it is not yet ready for release.
Is this OK? Please correct me if I'm wrong about the run-time decoding of S3TC textures... but I thought that was where OSG was heading.

Re: Update FAQ regarding S3TC patent

Posted: 30 Dec 2017, 05:12
by AnyOldName3
OSG does it, but it's not yet made it into a release simply because they've not done one since the feature was introduced (so it'll only be available if OpenMW is built using a git revision of OSG). Scrawl's OSG On Steroids fork has it, too, though, so up-to-date OpenMW packages made since the patent expiry should support software decoding. This relies on the package maintainer keeping their OSG On Steroids builds up to date, and they don't exactly have releases (although the version number increases sometimes to stay in sync with the mainline OSG 3.4 branch).

When a recent enough OSG build is used, creating a certain environment variable whose specific name and value I can't remember will enable software S3TC decoding in OpenMW.

Re: Update FAQ regarding S3TC patent

Posted: 25 Mar 2018, 18:37
by psi29a
Has this made it into an OSG version yet (3.4.1?) or in our OSG fork yet? Does anyone happen to have the specific commit or set of commits that implements this?