How Do I use the V4L2 interface for video output?

[Philip_FSL]

One of the best sources of information and example source code for using the V4L2 interface in the Linux BSP are the unit tests provided by Freescale.  This code provides a concise example of how to accomplish basic functionalities which can be used a building blocks for your more complex use cases. The unit test source code can be accessed using the following ltib command:

./ltib -m prep -p imx-test

Afterward, the source code will be located in your ltib project directory in the following location:

<ltib install dir>/rpm/BUILD/imx-test-<version>/

This source code contains a wealth of information that hopefully will help you shorten the time it takes to get up and running with these sometimes complicated APIs.

[Philip_FSL]

For the fb test, you just need to have the framebuffer driver in the system.  For ipudev, libipu is necessary.

GStreamer does not require X Windows.  You can directly use the ipulib sink or the v4l2 sink plug-in for rendering video in a non-X environment.

[fcs]

Does Freescale provide the source code for imx-test anymore? I finally found it here. Is there an official version?

https://community.freescale.com/thread/288297

[Philip_FSL · Accepted solution]

Yes.  Getting the source is the same process as before.  Using LTIB perform the following: ./ltib -m prep imx-test .  This will unpack the sources in the rpm/BUILD/ directory of your LTIB project.

[fcs]

I couldn't find the source code for the unit tests anywhere in any package, is it in imx-test-11.09.01-1.arm.rpm?

$ ./ltib -m prep imx-test

The options prep, scbuild, scinstall and scdeploy are only allowed when working

on a single package, not a list.  You need to supply the option -p|--pkg <pkg>

$ ./ltib -p imx-test

Processing platform: Freescale iMX5x Based Boards
===================================================
using config/platform/imx/.config

Processing: imx-test
======================

Started: Tue Oct 16 23:23:24 2012
Ended:   Tue Oct 16 23:23:27 2012
Elapsed: 3 seconds

Build Succeeded

lucid@ubuntu:~/Desktop/B/ltib$ find . |grep imx-test
./rpm/BUILD/linux-2.6.35.3/patches/0247-ENGR00131944-Fix-imx-test-build-failure-issue-on-mx2.patch
./rpm/RPMS/arm/imx-test-11.09.01-1.arm.rpm
./dist/lfs-5.1/mxc-misc/imx-test.spec

[Philip_FSL]

Sorry about that.  There is a command line option missing: ./ltib -m prep -p imx-test

[fcs]

Thanks, that works. I hadn't seen any documentation for that

[sidebranch]

Thank you, indeed these might be useful building blocks.

What are the prerequisites for the graphics related test tools?

imx-test-11.09.01/test/mxc_fb_test/

imx-test-11.09.01/test/mxc_ipudev_test/

I am building the software from scratch, not running the supplied image, and would like to learn what I need to bring up in order to run these tests.

Same question for the Freescale supplied GStreamer components; do these require the X Windows to be up and running on the target?