audio/video: Copy over more metas by default
Submitted by Sebastian Dröge @slomo
Link to original bug (#751647)
Description
For audio/video decoder/encoder/filter/etc we're currently copying all metas without tags and with audio/video tags only.
We could also copy over things with e.g. the video-dimensions tag if the input and output caps are the same, or even in other cases by calling the meta's transform function.