mpegts: Share the cleanup code between the demuxer and lavf-internal parser functions

The lavf-internal parser functions are used when receiving
mpegts over RTP. This fixes memory leaks in this setup.

The normal mpegts demuxer close function was updated in ec7d0d2e in
2004 to fix leaks, but the parsing function used for RTP wasn't
updated and has been leaking ever since.

Signed-off-by: Martin Storsjö <martin@martin.st>
rtpdec: Reorder payload handler registration alphabetically

Signed-off-by: Martin Storsjö <martin@martin.st>
rtpdec: Split mpegts parsing to a normal depacketizer

This gets rid of a number of special cases from the common rtpdec
code.

Signed-off-by: Martin Storsjö <martin@martin.st>
rtpdec: Split handling of mpeg12 audio/video to a separate depacketizer

This also adds checking of mallocs.

Signed-off-by: Martin Storsjö <martin@martin.st>
rtpdec: Move setting the parsing flags to the actual depacketizers

This gets rid of almost all the codec specific details from the
generic rtpdec code.

Signed-off-by: Martin Storsjö <martin@martin.st>
avconv: Increase the SDP buffer size to fit xiph SDPs

Signed-off-by: Martin Storsjö <martin@martin.st>