[meta-freescale] Gstreamer pipeline problem

[Chris Tapp]

On 12 Jul 2013, at 09:03, Philip Craig wrote:

> On Fri, Jul 12, 2013 at 5:50 PM, Chris Tapp <opensource at keylevel.com> wrote:
>> Hi John,
>> 
>> On 12 Jul 2013, at 01:22, John Weber wrote:
>> 
>>> Hi Chris,
>>> 
>>>> gst-launch videotestsrc ! v4l2sink
>>>> 
>>>> to work as there's no /dev/video1 ! Does anyone know where I can find instructions on how to get v4l2 working under Ubuntu 12.04 for a radeon HD 5450 card? Google has not been my friend ;-)
>>>> 
>>> 
>>> /dev/video1 is created when you have an actual video input like a video decoder or camera or UVC camera and it would be used with v4l2src (or in the case of i.MX6 CSI, mfw_v4lsrc).
>>> 
>>> videotestsrc should not need a video input device to work though as it is creates its own video data.  What is the error you are seeing?
>>> 
>>> What is your setup?  Board? Yocto version?  Yocto image?
>> 
>> Sorry, I don't make myself clear here. I wanted to try v4l on my Ubuntu development system first - it's this that isn't working:
> 
> If you don't already have a v4l2 output device on your dev system,
> then you're unlikely to be able to use v4l2sink. I had a quick look
> around for virtual v4l2 output devices, but didn't see any (I only
> found virtual input devices). I'm not sure that testing v4l2sink on
> your dev system is going to tell you much though. It would be roughly
> equivalent to testing with xvimagesink or autovideosink.

Thanks for the feedback.

That's unfortunate as I need a pipeline which can run on many different platforms, including 'standard pc'. This was one reason why I was using fakesink to capture the images - v4l looked like a way to go so that I could stream the video direct to the screen and get the full benefits of any acceleration supported by a platform (zero copy, etc.).

I've not found a lot of helpful information on the internet about v4l2 (less about output devices), so I've not even been able to identify one I can put in my system.

I'll have to have a look at using gst-plugins-gl to see if I can use the texture upload aspects (there was a thread on this recently I need to look at in more detail).

Mean time I'll also try v4l on the Wandboard to see if that gives any info on the problem I'm having with my fakesink pipeline.

Chris Tapp

opensource at keylevel.com
www.keylevel.com