Webm autoplaying/sizing issues in preview sidebar

[zach-adams]

For me the webm sidebar preview is autoplaying at full volume when a webm is selected, and they don't seem to be sizing properly, demo:
https://share.cleanshot.com/n6SmGsFc

It seems like this was a feature added in 2.21 (#135), the proposer @exgphe suggested adding an option for users to opt out of dynamic previews, but I don't think that was included. I think there's 2 main issues here:

1. It's set to autoplay the preview at full volume by default
2. It does not seem to be sizing correctly in the preview sidebar (width of the preview video container seems to be set too wide for some reason)

The first issue is much more impactful for me personally since it makes simple browsing through files/folders very disruptive. Thankfully I think it should be a relatively easy fix since all you'd need to add is the "muted" attribute to the HTML5 video tag here (then again I know very little about Swift or this API so I could be wrong):

QLVideo/previewer/PreviewViewController.swift

Lines 262 to 263 in 25201c2

	<video controls autoplay width="width=\(snapshotSize.width)" height="\(snapshotSize.height)">
	<source src="\(url.lastPathComponent)" type="video/webm" />

and/or here:

QLVideo/previewer/PreviewViewController.swift

Lines 189 to 190 in 25201c2

	<video controls width="width=\(size.width)" height="\(size.height)">
	<source src="\(url.lastPathComponent)" type="video/webm" />

I do think the dynamic preview feature is cool, but I can't imagine the majority of people want their webms to autoplay at full volume by default.
Having an option to mute autoplaying previews and maybe a separate option to disable the dynamic previews for webms (to fallback to the simple thumbnail image like in v2.20) would go most of the way to fixing this issue.

I'm not sure what the fix is for the sizing issue. I've attached the webm from my demo in case it's just an issue with that specific webm (there is no audio so the volume issue won't apply):

1636854785842.webm