selectProgram
Plays the channel numbered number of Tracks.programs, or chooses one again, the first with a picture, when number is null (#505). The media opens again on that channel, through the same rebuild as a video track change, and the picture, the sound and the subtitles are all chosen again from its tracks by the usual rules, unless a track change waiting beside it asks for one. The player keeps playing or stays paused. The choice is kept on the item as DemuxPolicy.program, so a later rebuild keeps it too.
Media that can seek opens again at the current position. A live sender, such as an IPTV multicast, opens again and joins the new channel where the sender is now, as a television does when it changes channel.
Throws
when nothing is open, or when a stop, a close, a new open or a later call ended the change first.
when the media has no programme number.
when the source can neither seek nor be joined live, as a pipe cannot, which can only be read once. Open the item again with DemuxPolicy.program instead.
when the reopen itself failed.