Extending DRI2 For Video Handling Still Desired
Rob Clark of TI was the one to make the original proposal last year about extending DRI2 to better handle video playback. "Current solutions use the GPU to do a scaled/colorconvert into a DRI2 buffer from the client context. The goal of this protocol change is to push the decision to use overlay or GPU blit to the xorg driver. Eventually this should replace Xv. With a few additions, like attributes, it could perhaps be possible to implement the client side Xv API on top of dri2."
At the GStreamer Conference this morning in San Diego when Rob Clark was presenting on OMAP4 / DMA-BUF / GStreamer and his nice Wayland video playback demo, he also talked briefly about "DRI2Video" support.
The TI developer has working experimental code for DRI2 video support for their hardware, but he hasn't pushed anything mainline and isn't yet comfortable with pushing it as part of the DRI2 specification with the X.Org Server. He also isn't sure if it's worth bothering improving the X.Org implementation any further seeing as the future is likely with Wayland.
DRI2Video comes down to combining concepts of X-Video and DRI2 and allowing the X.Org Server (DDX driver) to allocate GEM buffers and pass them to client processes and then the buffer can be YUV and can support zero-copy overlays. DRI2Video would lead to significant bandwidth savings during video playback compared to just using X-Video at present, but still the demoed Wayland video playback implementation is superior to the X.Org/DRI2 video playback improvements.
So there's no guarantee that DRI2Video will ultimately be merged and see the light of day, but at least it's not completely dead and that the Texas Instruments developer is already playing with video enhancements for Wayland.