Hi all, We had a meeting on #v4l-meeting on the topic of subdev selections, and I can summarise the conclusions as follows. The full meeting log is available in [3]. Two main topics were discussed, the behaviour and functionality of the selection API and the naming of different rectangles. A conclusion was reached in both. - The sink COMPOSE rectangle in my latest proposal [1] is a hardware limit rather than something user configurable. This means the rectangle is correctly considered as COMPOSE BOUNDS target in V4L2 selection API as well. - This is actually correct in the previous proposal [2]. - There are no dependencies between sink / source pad coordinates as such: both refer to the coordinates of the sink COMPOSE BOUNDS rectangle. Source CROP BOUNDS also refer to the same, and this rectangle might be different from sink COMPOSE BOUNDS rectangle. - The COMPOSE rectangle will, as it was in the previous proposal, continue to be called the COMPOSE rectangle (and not SCALING rectangle). - The definition of the BOUNDS rectangle is "smallest rectangle which contains all valid ACTIVE rectangles". This does not specify what is the largest possible ACTIVE rectangle. - It was agreed to drop DEFAULT targets for now. The same had been done to PADDED targets already previously. - More documentation is needed: a few sample use cases to be included into documentation. - No need for COMPOSE on source pads, so COMPOSE rectangle is will not be a valid target on source pads. Sylwester's use case [4], composing into video buffers, can be equally implemented using the compose rectangle on the sink pad. It is to be discussed should this be rather implemented using the selection API on the video node instead. The source pad image size will be equal to the size of the source crop rectangle. - Information to the diagram on what rectangles refer to which coordinates to be added. I will also make the necessary changes to my selection patchset and re-post it. [1] http://www.spinics.net/lists/linux-media/msg43723.html [2] http://www.spinics.net/lists/linux-media/msg42991.html [3] http://www.retiisi.org.uk/v4l2/notes/v4l2-selection-api-2012-01-31.txt [4] http://www.spinics.net/lists/linux-media/msg43746.html Cheers, -- Sakari Ailus e-mail: sakari.ailus@xxxxxx jabber/XMPP/Gmail: sailus@xxxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
