For context and rationale, see:
* {T233675}
* {T202154}
This extension has long been one of the largest extensions in terms of its share in the startup.js payload for all page views in production. From [Grafana: Startup manifest size](https://grafana.wikimedia.org/d/BvWJlaDWk/startup-manifest-size) it currently registers **54 module bundles** which transfer about 2KB on every page view during the critical path just to communicate the client about their existence.
I've thus far restisted the temptation to reduce this proactively knowing that a lot of this will be cut away once the transition from Kaltura to video.js completes (ref T100106).
However, I think there's a number of modules here even ignoring the legacy Kaltura parts that can potentially be reduced, and we may be able to do some very quick/easy consolidation or removal of unused modules besides that as well.
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2021 progress:
[x] https://gerrit.wikimedia.org/r/722899 : **-10** modules by merging dependencies into `mw.EmbedPlayer` (removed `mediawiki.absoluteUrl`, `mediawiki.client`, `fullScreenApi`, `jquery.debouncedresize`, `jquery.embedMenu`, `mw.EmbedTypes`, `mw.MediaElement`, `mw.MediaSource`, `mw.MediaPlayers`, `mw.MediaPlayer`)
[x] https://gerrit.wikimedia.org/r/722898 : **-1** module by merging `mw.PopUpMediaTransform.styles` into `mw.PopUpMediaTransform`
[x] https://gerrit.wikimedia.org/r/723195 : **-2** modules by removing unused `mw.EmbedPlayerVlc` and `mw.EmbedPlayerGeneric`
[x] https://gerrit.wikimedia.org/r/723199 : **-2** modules by merging `jquery.triggerQueueCallback` and `jquery.mwEmbedUtil` into `mw.MwEmbedSupport`
[x] https://gerrit.wikimedia.org/r/723201 : **-1** module by merging `mw.MwEmbedSupport.style` into `mw.MwEmbedSupport`
[x] https://gerrit.wikimedia.org/r/723635: **-1** module by merging `mw.ajaxProxy` into `mw.TextSource`
[ ] https://gerrit.wikimedia.org/r/723638 : **-2** modules by merging `mw.EmbedPlayer.loader` and `mw.TimedText.loader` into `mw.MediaWikiPlayer.loader`
[] https://gerrit.wikimedia.org/r/723639: **-1** module by merging `mw.TextSource` into `mw.TimedText`
[ ] MABYE: `mediawiki.UtilitiesTime` is used by `mw.EmbedPlayer` and `mw.TextSource`, after the step above will be used by `mw.EmbedPlayer` and `mw.TimedText`, but `mw.TimedText` also depends on `mw.EmbedPlayer`, so `mediawiki.UtilitiesTime` can be merged into `mw.EmbedPlayer` ?
[ ] Consider merging some of the smaller mw.EmbedPlayer* modules. Sizes (library-lines): Kplayer-496, IEWebMPrompt-46 (plus 18 lines of styles), ImageOverlay-316, OgvJs-266 (has fairly small dependencies), VLCApp-101 (mediawiki.Uri dependency). Or maybe merge them all into a single module? It means some extra code would be loaded when not needed, but we could use package files to not run it when not needed, or just let it all run because it shouldn't conflict with others