BeagleBoard/gst-openmax

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This article explains how to use TI's OpenMAX-IL with GStreamer (e.g. on BeagleBoard).

OpenMAX IL is a standardized API to communicate with multimedia codecs (implemented either in hardware or software).

GstOpenMAX is a GStreamer plug-in that allows communication with OpenMAX IL components.

Setup

As the TI's OMXIL is hardware accelerated by DSP, you need to have the DSP properly set up following the DSP howto.

OpenMAX IL

The easiest way to use the DSP capabilities is through the OpenMAX IL API, but in order to compile TI's implementation a special DSP library is required.

libdspbridge

libdspbridge is a library which wraps up the ioctl calls to the dspbridge kernel driver. Originally it is in the userspace-dspbridge repository. But it is bloated and its build process is over-complicated. That is why we have started a slimmed version of it.

git clone git://gitorious.org/vjaquez-beagleboard/libbridge.git
cd libbridge
git co -b mybranch 23.3.3
make DESTDIR=/media/rootfs install

libomxil-ti

The original distribution of the TI's OpenMAX IL is in its gforge site. Nevertheless, its build process is overcomplicated. For that reason we started a repository which simplifies the build machinery, and also we are targeting a general code cleanup.

git clone git://gitorious.org/vjaquez-beagleboard/ti-omxil.git
cd ti-omxil
git co -b my-branch v3.28-2
make DBAPI_CFLAGS=-I/media/rootfs/usr/include/libbridge \
     DBAPI_LIBS="-L/media/rootfs/usr/lib -lbridge" DESTDIR=/media/rootfs install

gst-openmax

The official gst-openmax repository is git://anongit.freedesktop.org/gstreamer/gst-openmax

Nevertheless, for the TI's OpenMAX IL implementation some hacks are still required. And because of that, a unofficial repository is set up, which is the one we use in this document.

git clone git://gitorious.org/vjaquez-beagleboard/gst-openmax.git
cd gst-openmax
git checkout -b omap origin/omap
/autogen.sh --build=i686-linux --host=arm-linux --target=arm-linux
make DESTDIR=/media/rootfs install

Related stuff

In order to get the omapfb usable for video playback you need this kernel argument:

video=omapfb:vram:2M,vram:4M

And the GStreamer element:

git clone git://github.com/felipec/gst-omapfb.git
cd gst-omapfb
make DESTDIR=/media/rootfs install

Running

You should be able to use the gst-openmax elements now:

gst-launch-0.10 filesrc location="foobar.avi" ! avidemux ! omx_mpeg4dec ! omapfbsink

See also