AMD Polaris Doesn't Support ETC2 Texture Compression

[bridgman]

Why is it only supported in hw in stoney and not polaris? Is there no win to do it in hw opposed to software or does it make you compromise on other functions?

I feel bad derailing this fine JPEG vs PNG deathmatch thread and talking about ETC2, but AFAIK the primary place where hardware support for ETC2 is desireable is the combination of embedded systems and very low power CPUs. Android is probably another good example, since AFAIK ETC2 is actively used there.

In all other cases ETC2 is less common and the cost of converting ETC2 textures to another format supported by HW is acceptably low.

[Adarion]

Oh, well.
As long as the compatibility is given by driver-internal conversion without too much impact - it will work for me. I mean, does the sheer hardware of intel, nv or others actually support things or do they also use driver "emulation" or conversion for a lot of things?
It's supported, by some means, that is what counts most.

And bridgman's post explains why Stoney seems to has it probably in HW and the big fat dedicated Polaris card's don't.

I do use RAW, JPEG and PNG for pixel/bitmapish graphics. And they all have their benefits and drawbacks. And JPEG does not have to look full of compression artifacts. It still is the best format for transmitting photos via the web since it still offers the smallest file size (of the three) for this kind of image. PNG is awesome for drawings, comic graphics and so on and you won't ever see a compression artifact (maybe unless you use optipng or pngquant to the extreme and have hi-fi-eyes). RAW is great when you are outsides, photographing and working on the pictures later in Darktable. Finally I export it as JPEG once I am satisfied.
None of them supports layers, though. In that case GIMP's xcf is nice or you do vector graphics (inkscape / SVG). But SVG is computing intensive once you get to really detailed things or use a lot of filters (been there, done that). But - you can scale it up to the size of the solar system and it will always be nice and crisp.
Benefits. Drawbacks. Everywhere.

[Tomin]

None of them supports layers, though. In that case GIMP's xcf is nice or you do vector graphics (inkscape / SVG).

I've understood that xcf is not stable so it can vary between versions of GIMP and it's not supported by any other programs than GIMP, but I'm not really an expert here. Maybe someone who knows better could tell me if my understanding is correct or not. So, is there a format that is free and has features comparable to xcf (features like layouts) that can be used for long time storage without worrying about possible incompatibility in future?

[DrYak]

PNG is awesome for drawings, comic graphics and so on and you won't ever see a compression artifact (maybe unless you use optipng or pngquant to the extreme and have hi-fi-eyes).

Even with optipng, the value of the pixels stay the same. The software only work by tweaking the "deflaite/gzip" compression (and prefilters) used to compress pixel values. (Just like 7z can produce better ZIP files then pkzip or winzip, thanks to tweaked algorithme). It's similar to advpng, or pngout.

pngquant is the one about trading quality for size: it works by reducing the size of the palette (using, eg.: only 256 dicrete colours, instead of any random combination of R,G&B. Or reducing to even less then 256 colors).

I'ts one of the possible techniques to reduce size by sacrificing fidelity.

[DrYak]

I feel bad derailing this fine JPEG vs PNG deathmatch thread and talking about ETC2

phoronix, what else...
(surprising that no troll has managed to complain about the cancerness of systemd in this thread yet )

More seriously:

In all other cases ETC2 is less common and the cost of converting ETC2 textures to another format supported by HW is acceptably low.

As other have mentioned ASTC to be superior to ECT2, could we safely assume that the recompression from ECT2 to ASTC is also not suffering too much from generation loss ?

(Not that ECT2 seem to be of any importance on the desktop as of yet. But I'm sure that one day, somebody is going stumble upon a casual game that shares the same ECT2-compressed assets between the PC and mobile version).