Use media kit as the default video playback for windows

[bdlukaa]

I could experience gains of 30% to 40% in performance by using media_kit on Windows

Features

• Play from url
• Play from file
• Update volume
• Update speed
• Seeking

Screenshots

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There seems to be a minor flickering when reordering the views in the multiple view

[bdlukaa]

I will keep this as a draft because it's causing crashes to the app. media_kit is not stable enough to give it a try for now

¹ For some reason, it seems it's blocking the UI thread, so app behaves extremely slow. Sometimes, it's unusable
² When navigating to another screens, the VideoController object is kept alive (so that is a gapless playback when coming back to the grid). This seems to be causing crashes since the Video object is not into view

cc @alexmercerind

[alexmercerind]

For some reason, it seems it's blocking the UI thread, so app behaves extremely slow.

The video rendering does occur on render thread. A "hit" due to multiple videos will definitely be there (should improve in release mode). If there are no videos in the view, there should be no frame drops/delays etc.

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Crash:

There shouldn't be any crashes on Windows. I & other users have confirmed the recent fix which addressed last few race(s). There are a number of cases/situations in the test application where we haven't been able to see any crash since latest fixes.

As for any crash, let's see what further feedback I get. Personally, I'm unable to.

Performance:

There isn't any scope of improvement in terms of performance AFAIK. In comparison to package:dart_vlc, the performance offered by package:media_kit is already very-high. Everything is being rendered off the GPU.

[curtishall]

@alexmercerind I know you are busy, when you have time can you review this PR? It's blocking #31

[alexmercerind]

LGTM (+ recommendations) !

You can try use the current package:media_kit branch that I'm working on.

https://github.com/alexmercerind/media_kit/tree/perf/win32-copy-separate-id3d11texture2d

The level of performance should be further improved as compared to main branch. There are few more performance improvements which I'd like to make, however I won't be able to get this branch/PR over the line before this month (though it's usable in current state).

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As far as media-kit/media-kit#28 is concerned, I don't think it will ever be. You have to create your own solution here. Primarily because libmpv does not offer such functionality out-of-the-box & implementing one from scratch will be:

• Redundant.
• Requiring more maintenance cost.
• Of different level of abstraction than that of package:media_kit (if custom implementation is made).

100% of implementation of package:media_kit is in pure Dart, only video rendering is platforms specific C/C++.
You're free to play around.

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There seems to be a minor flickering when reordering the views in the multiple view.

I see the last commit with ValueKey, that should improve IG. I'm not sure however.

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One final recommendation I'd like to give is that you can try to specify width & height parameters in the VideoController.create method. It will create a less sized D3D Texture / EGLSurface (and thus squeeze the performance).

Especially in grid layouts, where video won't be visible in large sizes, a fixed width & height texture will work & take less resources. However, when viewing same camera on larger screen, a different VideoController without fixed width & height can be used (& disposed upon exit).

[bdlukaa]

One final recommendation I'd like to give is that you can try to specify width & height parameters in the VideoController.create method. It will create a less sized D3D Texture / EGLSurface (and thus squeeze the performance).

Indeed. By doing that, I got a ~15% performance improvement