Skip to content

ext_image_copy_capture_session_v1 should clarify how to select the format

The compositor can advertise multiple formats and the client can choose any one of them for its buffers.

While the text of the protocol is sufficient for clients to make an intelligent choice, none of the once I have looked at do.

  • grim chooses the first advertised format.
  • wayvnc chooses the last advertised format.
  • wl-screenrec chooses the last advertised format.

This makes it impossible, in practice, for compositors to send more than one format. Even if there was an implied priority, some clients choose the first format and some the last.

While these could all be reported as bugs to the individual clients, it is curious that all of them have fallen into the same kind of behavior. We should rectify this as soon as possible, by adding a warning in the protocol, to not ossify on compositors being only able to send a single format.

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information