rtpsrc, ristsrc: drop stream-start message posted by the internal udp sink(s)

Fixes #1368 (closed)

This looks like the right thing to do. Other's opinion would be nice, we'd be doing the same in rtspsrc (if not already done). I believe this affects elements used within playbin*/decodebin*

Makes sense to me too and I thought we already did that in rtspsrc...

Looking now, rtspsrc drops EOS message, which equally seems like a good idea. Here we drop stream-start. Let's sync them then !

Dropping EOS might fix some problems I have notice but never understood.

added 2 commits

• e6f22e21 - rtpsrc: drop stream-start & eos messages posted from the internal udp sink(s)
• a7150fcf - ristsrc: drop stream-start & eos messages posted from the internal udp sink(s)

Compare with previous version

See gst-plugins-good!685 (merged) for rtspsrc.

resolved all threads

assigned to @gstreamer-merge-bot

mentioned in commit gkiagia/gst-plugins-bad@914161f9

mentioned in commit gkiagia/gst-plugins-bad@fc9a612e

added 6 commits

• a7150fcf...d8b37973 - 4 commits from branch gstreamer:master
• 914161f9 - rtpsrc: drop stream-start & eos messages posted from the internal udp sink(s)
• fc9a612e - ristsrc: drop stream-start & eos messages posted from the internal udp sink(s)

Compare with previous version

merged

changed milestone to %1.17.90

mentioned in commit den_erpel/gst-plugins-rtp@699d7a05

mentioned in commit den_erpel/gst-plugins-rtp@934ebdd8