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Ricardo Salveti: Ubuntu TV UI at Pandaboard, and next steps Published Jan 16 2012 via RSS

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Yesterday Canonical announced the first UI concept for the Ubuntu TV. Together with the announcement, the first code drop was released, so we could read and understand better the technologies used, and how this will behave on an ARM environment, mostly at a Pandaboard (that we already have OpenGL ES 2 and video decode working).

Getting Ubuntu TV to work

If are still using Oneiric, you can just follow the guide presented at https://wiki.ubuntu.com/UbuntuTV/Contributing, where you’ll find all needed steps to try Ubuntu TV at your machine.

As it’s quite close with Unity 2D (similar code base), and also based on Qt, I decided to follow the steps described at wiki page and see if it should work correctly.

First issue we found with Qt, was that it wasn’t rendering at full screen when using with latest PowerVR SGX drivers, so any application you wanted to use with Qt Opengl would just show itself on a small part of the screen. Luckily TI (Nicolas Dechesne and Xavier Boudet) quickly provided me a new release of the driver, fixing this issue (version that should be around later today at the Linaro Overlay), so I could continue my journey

Next problem was that Qt was enabling brokenTexSubImage and brokenFBOReadBack for the SGX drivers based on the old versions available for Beagle, and seems this is not needed anymore with the current version available at Pandaboard (still to be reviewed with TI, so a proper solution can be forwarded to Qt).

Code removed, patch applied and package built (after many hours), and I was finally able to successfully open the Ubuntu TV interface at my Panda

UI Navigation on a Pandaboard, with Qt and OpenGL ES2.0

Running Ubuntu TV is quite simple if you’re already running the Unity 2D interface. All you need to do is to make sure you kill all unity-2d components and that you’re running metacity without composite enabled. Other than that you just run ”unity-2d-shell -opengl” and voilà

Here’s a video of the current interface running on my Panda:

As you can see from the video, I didn’t actually play any video, and that’s because currently we’re lacking a generic texture handler for OpenGL ES with Gstreamer at Qtmobility (there’s only one available, but specifically for Meego). Once that’s fixed, the video playback should behave similarly as with XBMC (but with less hacks, as it’s a native GST backend).

Next steps, enabling proper video decode

Looking at what would be needed to finally be able to play the videos, and to make it something useful at your Pandaboard, the first thing is that we need to improve Qtmobility to have a more generic (but unfortunately still specific to Omap) way handle texture streaming with Gstreamer and OpenGL ES. Rob Clark added a similar functionality at XBMC, creating support for ”eglImage”, so we just need to port the work and make sure it works properly with Qtmobility.

Once that’s ported, the video should be streamed as a texture at the video surface, making it also work transparently with QML (the way it’s done with Ubuntu TV).

If you know Qt and Gstreamer, and also want to help getting it to work properly on your panda, here follows a few resources:

• Rob’s implementation of eglImage at XBMC: https://github.com/robclark/xbmc/commits/gstreamer-eglimg
• Qtmobility support for Meego and OpenGLES: http://qt.gitorious.org/qt-mobility/qt-mobility/blobs/master/plugins/multimedia/gstreamer/qgstreamergltexturerenderer.cpp
• IRC: #linaro and #ubuntu-tv at Freenode, look for robclark or rsalveti

As soon video decoding is working properly, a new blog post should be around explaining the details and how to reproduce it at your own Panda with Ubuntu LEB

Cheers!