Graham, the general answer is that some receivers do convert format (composite to S-video, S-video to composite), and some don't. Some do in only one direction, others both. You have to check the specs or ask the manufacturer.

There are also outboard conversion devices available for this purpose, of varying quality.

However, as far as I know, no receiver converts anything to component video. Some do switch between component sources, but there is no conversion, just switching. Component has to be carried unchanged from the source to the display device.

Larry
www.fineelectricco.com