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Archive for January 6, 2012

HW video decode and XBMC support on a Pandaboard with Ubuntu LEB

January 6, 2012 95 comments

Part of the effort we spent during the Linaro 11.12 cycle was to try to enable at Pandaboard not only hardware graphics support (GLES with PVR SGX), but also hardware accelerated video decode, as TI had released all needed userspace to be used at Ubuntu Oneiric (11.10) release.

Unfortunately it didn’t just work with our images because at that time we were using a newer kernel already, based on the 3.1 series that is maintained by the Linaro TI Landing Team. Bug 880840 has all the details.

Luckily Sebastien Jan (from TI) was able to find the root cause of the problem, that was causing so much frame drops that was making the video playback basically unusable. The problem was related with PM support at omap’s hwspinlock implementation, as you can check at this link.

Kernel fix properly integrated and available at the Overlay PPA used by our Linaro Ubuntu Evaluation Build images, and finally able to have a similar user experience as was expected when TI delivered the user space components at their own PPA.

If you want to try it by yourself, just be sure you’re using at least linux-image-3.1.1-6-linaro-lt-omap at your board (all hwpacks >= 20110105 should have it included by default).

Playing videos with HW decode acceleration

Since today you’ll also easily find all the needed packages to enable HW video decode acceleration at our images (Pandaboard only at the moment, more boards coming soon). We just included and copied all needed packages from the TI PPA, so you don’t even need to enable it when installing the additional packages.

Installing the extra packages for video decode at your Pandaboard:

  • Grab the latest Pandaboard hwpack (lt-panda-x11-base-oneiric) and Ubuntu Desktop image from http://snapshots.linaro.org/oneiric (as example I used hwpack_linaro-lt-panda-x11-base_20120106-0_armel_supported.tar.gz and linaro-o-ubuntu-desktop-tar-20120105-0.tar.gz)
  • Create a Ubuntu LEB pandaboard image on a SD card, following the instructions described at https://wiki.linaro.org/Platform/DevPlatform/Ubuntu/ImageInstallation
  • Boot the card and install the ubuntu-omap4-extras-multimedia package: $ sudo apt-get install ubuntu-omap4-extras-multimedia
  • Reboot your pandaboard
  • Play a video with any video player that’s compatible with Gstreamer (e.g. Totem)

In the future we should also have this completely integrated at the hwpack itself, but unfortunately this is not possible at the moment without increasing the image size too much.

XBMC support

Another awesome thing we worked during previous cycle (11.12) was to make an XBMC version available that would use both GLES and Gstreamer, so it could also be used with a Pandaboard. Avik Sil did a great work making it all work with our images, and we were finally able to have XBMC 11 Beta (Eden) available at our Overlay PPA.

For proper support for Gstreamer Rob Clark did an awesome work improving the current patches, and also improving the support quite a bit. At our package you’ll find all latest patches available from Rob, from his current development tree.

To start using XBMC with the Ubuntu LEB image at your Pandaboard, you just need to install the xbmc package, with $ sudo apt-get install xbmc. For best user experience, please use the XBMC session available at LightDM (just log-out the default session and select XBMC instead). This will work a lot better because then there will be no other window manager or compositor taking extra resources from your board.

We also hope to deliver a set-top box image by the end of the current cycle (12.01), that will have XBMC installed by default. Please check the blueprint https://blueprints.launchpad.net/linaro-ubuntu/+spec/create-a-set-top-box-leb-image if you want to follow the progress of it.

Bugs and Issues

Unfortunately not everything is working perfectly at the moment, and issues with the Gstreamer and hw video decode support on Pandaboard are expected. The most annoying one that’s currently affecting XBMC is the issues with seek, as sometimes the video goes faster than the audio, and then it stops for a while until it’s in sync again. We hope to get this fixed soon, but that depends a bit of how much time Rob can spend on it.

In case of any other bug while trying to get video decode to work on your Pandaboard, don’t hesitate to open a bug at https://bugs.launchpad.net/linaro-ubuntu/+filebug or ping aviksil, robclark or rsalveti at #linaro on freenode.

Cheers!

Update: Check bug https://bugs.launchpad.net/linaro-ubuntu/+bug/915456 for the video hanging issue. Without polling XBMC should now play most videos just fine.

Update 2: XBMC-ready image already available at http://snapshots.linaro.org/oneiric/linaro-o-linarotv-xbmc/, just be sure to flash with http://snapshots.linaro.org/oneiric/lt-panda-x11-base-oneiric/.

Update 3: There’s a mem leak at the gst decode codec, check bug https://bugs.launchpad.net/ubuntu-omap4-extras-multimedia/+bug/915768 for progress on that.

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