When a program is changed, stream_added is called which sets the
need_newsegment to TRUE, then stream_removed is called, which calls
the flush_pending_data, which checks for the newsegment and causes
it to send a new-segment.
We must not send the newsegment when flushing the pending data on the
removed stream. We should only push it when flushing data on the newly
added streams (after they finish parsing their PTS header)
If a program/stream is changed, then a newsegment is sent which must
not be the same as the base segment since it happens later. We must
shift the start position by the time elapsed since the newsegment
and the current PTS of the stream
The program_stopped vmethod was called before stream_removed vmethod
was being called. Since we only did stream-related operations in there,
we just remove the program_stopped vmethod and do everything in the
stream_removed one.
Also, make sure we flush out all pending data before sending EOS.
We first activate new streams before shutting down old ones.
We emit no-more-pads after we add new streams and emit EOS before
removing old ones.
Also cleanup/refactor a bit more of the code accordingly
buffer timestamps are converted to GstClockTime to cover pcr/pts wraps.
multiple pcr/pts wraps are handled with an index which ensures at most
a single pcr wraparound between two entries.
the last seen pcr is recorded to have a nearby index point for short seeks
resuming playback might be delayed if the postion is not a keyframe
TODO: replace manual packet scanning and parsing in the initial duration estimation
