[GStreamer][WebRTC] Excessive tag events with bitrate update at startup

[cadubentzen]

18068fa

[GStreamer][WebRTC] Excessive tag events with bitrate update at startup
https://bugs.webkit.org/show_bug.cgi?id=290045

Reviewed by Philippe Normand.

Codec parsers like h264parse emit too many tag events at startup, while carrying
only small bitrate updates. As time passes, bitrate updates are sent
less frequently.

Reduce the overhead in the pipelines at startup by forwarding tag events only every
1 second in RealtimeIncomingSourceGStreamer.

Canonical link: https://commits.webkit.org/292399@main

37acfc6

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	✅ 🧪 win-tests
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🛠 wpe-cairo
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🛠 gtk
	✅ 🛠 vision	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	✅ 🧪 api-gtk
✅ 🛠 🧪 merge	✅ 🧪 vision-wk2	✅ 🧪 mac-intel-wk2	✅ 🛠 playstation
	✅ 🛠 tv	✅ 🛠 mac-safer-cpp
	✅ 🛠 tv-sim
	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 8372988)

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	🛠 mac	✅ 🛠 wpe	🛠 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	🧪 wpe-wk2	🧪 win-tests
✅ 🧪 webkitperl	🧪 ios-wk2	🧪 api-mac	✅ 🧪 api-wpe
	🧪 ios-wk2-wpt	🧪 mac-wk1	✅ 🛠 wpe-cairo
	⏳ 🧪 api-ios	🧪 mac-wk2	✅ 🛠 gtk
	🛠 vision	⏳ 🧪 mac-AS-debug-wk2	🧪 gtk-wk2
	✅ 🛠 vision-sim	🧪 mac-wk2-stress	🧪 api-gtk
	🧪 vision-wk2	🧪 mac-intel-wk2	🛠 playstation
	🛠 tv	🛠 mac-safer-cpp
	🛠 tv-sim
	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 800a262)

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	✅ 🧪 win-tests
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🛠 wpe-cairo
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🛠 gtk
	✅ 🛠 vision	⏳ 🧪 mac-AS-debug-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	✅ 🧪 api-gtk
	✅ 🧪 vision-wk2	✅ 🧪 mac-intel-wk2	✅ 🛠 playstation
	✅ 🛠 tv	🛠 mac-safer-cpp	🛠 jsc-armv7
	✅ 🛠 tv-sim		🧪 jsc-armv7-tests
	✅ 🛠 watch
	✅ 🛠 watch-sim

[cadubentzen]

EWS failure seems unrelated.

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 0cb70f2)

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	🛠 ios	✅ 🛠 mac	🛠 wpe	🛠 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	🧪 wpe-wk2	🧪 win-tests
✅ 🧪 webkitperl	⏳ 🧪 ios-wk2	⏳ 🧪 api-mac	🧪 api-wpe
	⏳ 🧪 ios-wk2-wpt	🧪 mac-wk1	🛠 wpe-cairo
	⏳ 🧪 api-ios	⏳ 🧪 mac-wk2	🛠 gtk
	🛠 vision	⏳ 🧪 mac-AS-debug-wk2	🧪 gtk-wk2
🧪 services	🛠 vision-sim	🧪 mac-wk2-stress	🧪 api-gtk
	⏳ 🧪 vision-wk2	⏳ 🧪 mac-intel-wk2	🛠 playstation
	🛠 tv	🛠 mac-safer-cpp
	🛠 tv-sim
	🛠 watch
	🛠 watch-sim

[cadubentzen]

@philn I found an easier solution after seeing that the high frequency of tag events with small bitrate updates only happens at startup! Therefore, applying some simple backpressure should already be enough to reduce the overhead.

[philn]

LGTM but please fix the typo ;)

[webkit-early-warning-system]

EWS run on current version of this PR (hash 37acfc6)

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	✅ 🧪 win-tests
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🛠 wpe-cairo
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🛠 gtk
	✅ 🛠 vision	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	✅ 🧪 api-gtk
✅ 🛠 🧪 merge	✅ 🧪 vision-wk2	✅ 🧪 mac-intel-wk2	✅ 🛠 playstation
	✅ 🛠 tv	✅ 🛠 mac-safer-cpp
	✅ 🛠 tv-sim
	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-ews-buildbot]

Safe-Merge-Queue: Build #51983.

[webkit-commit-queue]

Committed 292399@main (18068fa): https://commits.webkit.org/292399@main

Reviewed commits have been landed. Closing PR #42690 and removing active labels.