On Tue, Jul 29, 2014 at 05:10:09PM -0400, enpeng xu wrote: > Hi Topi, > > On mesa mailing list,I saw you posted some patches for supporting > OES_external_image externsion, you also added yuv buffer format support, > it's really useful, but looks like just part of codes merged into mesa, > can you let me know why? what's the status of your patch?
There the yuv support dealt specifically with formats NV12 and YV12 where where luminance and chroma components are located in separate planes. In terms of i965 this meant sampling of multiple texture images per one sampler, and imposing a few difficulties. First, the i965 backend would need to be augmented to support multiple surfaces per sampler. Second, the program would need to be augmented with additional instructions converting YUV samples into RGB equivalent. Neither is trivial to implement or to maintain, and impose addtional constraints to the maximum number of textures to be supported and to the number of available hardware registers for the rest of the program. Hence people were more inclined to an implementation that would be based on latest native hardware support. For example, there is now possibility to sample YUV formats with one hardware surface as long as Y is in its own plane and UV is packed in another. Unfortunately in the end priorities got shifted and I dropped the ball. Thanks, Topi _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
