Dynamic pipeline (videosink swapping)

Rob Kramer rob at teegee.cloud
Mon Apr 4 06:33:11 UTC 2022

On 4/4/22 13:40, Nirbheek Chauhan via gstreamer-devel wrote:
> playbin uses decodebin, which will autoplug elements that are rank
> MARGINAL or higher. The new va decoders are ranked as NONE, since they
> are new. To autoplug them, you need to change their rank. This is one
> way to do it:
> export GST_PLUGIN_FEATURE_RANK=vampeg2dec:257,vah264dec:257,vah265dec:257,vapostproc:257
> This will set the rank to PRIMARY+1, which is higher than the vaapi
> elements, which will make the app prefer va over vaapi.

Thanks again, that seems to select the vampeg2dec element, and seems to 
work with my dynamic sink plugger example..

In the dot file, there is no mention of VASurface anymore though. Is 
that expected, or are things being copied between video and main memory? 
When using gst-play-1.0, it does look like the vampeg2dec version uses 
~5% less CPU (~10% vs ~15%).

I've uploaded a dot-file from gst-play, in case you'd like to have a 
look: https://pastebin.com/VYPXJP2d



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