How to adjust the display ratio to original size

[forestzhu]

Hi all,
I am a beginner of a gstreamer.
I met an issue in coding a gstreamer program,can anyone give me a hint ?
 
If the videosink must to be used has no "force-aspect-ratio" or "pixel-aspect-ratio" property.
How to adjust the output video to the original ratio?
Maybe videoscale can do this job.
But where can I get some example code for usage of videoscale?

With thanks!
alex
July 25

[forestzhu]

OK ,I overcome it myself.
The key issue is getting the size of the screen first.
And then add a capfilter between videoscale and videosink.

With pleasure!

alex
July 25