Consider the following pipeline:

src ! ... some elements ... ! capsfilter ! ... ! sink

In camerabin2, some of these elements are bins and camerabin2 itself is a self-contained pipeline. There are situations where it is desirable to change the caps on the capsfilter and send a renegotiate event to the source. However, there may be buffers between the source and the capsfilter with the old caps.

It may be desirable in some use cases to allow these buffers with the old caps to pass only until a buffer is encountered with the new caps. This would be to avoid loss of any captured buffers.

A simple solution is to set the caps on the capsfilter to "new caps; old caps" but some may consider this too permissive.

This ticket is a placeholder for if a generic solution ever becomes desirable.