mpegtsmux - allow setting PMT pids
Add optional PMT_%d fields to the prog-map that allow overriding the automatic PMT PID selections in the MPEG-TS muxers.
Also add an example program of how to construct prog-map structures.
Add optional PMT_%d fields to the prog-map that allow overriding the automatic PMT PID selections in the MPEG-TS muxers.
Also add an example program of how to construct prog-map structures.