reprogramming source

[James Linder]

> On 22 Apr 2021, at 7:43 pm, James Linder via gstreamer-devel <gstreamer-devel at lists.freedesktop.org> wrote:
> 
> G’day
> 
> I have a capture card (sensoray 2263)
> 
> After setting the output to 1080 vlc and mplayer ‘reset’ the output to 720x576
> Running mplayer like this
> mplayer tv:///dev/video2 -geometry 1920x1080 keeps the card output at 1080 (but won’t set a 720x576 card to 1080)
> 
> Running my test pipeline
> 
> gst-launch-1.0 v4l2src name=source device=/dev/video2 ! queue ! videoscale ! video/x-raw,width=1920,height=1080 ! videoconvert ! xvimagesink force-aspect-ratio=false name=sink1
> 
> results in 720x576 weather or not I set the card to 1080.
> 
> Can anybody tell me how to tell gstreamer to ask/tell the card to output 1080?

Turns out CAPS are not passed back along the chain. Putting CAPS on the v4l2src means they are passed back to the card. In my example pipeline moving CAPS back to the src solved the issue.

James