Update now that Parsoid's change is live:
- For paged media (PDFs/DjVu/etc.), correct previews are now done (because there's nothing VE needs to do beyond its current architecture).
- For video media, it now shows the 'correct' preview (e.g. thumbtime is respected) but it doesn't show the "play" button, so it's not a perfect preview, and you can't play it, which is T103096: Preview video while editing with VE.
- For audio media, the preview is wrong, and you can't play it.
@Jdforrester-WMF the new html5 structure (for TMH) assumes that JS controls will be provided. If those are not provided, then a controls attribute needs to be added to enable the standard browser controls.
There was some discussion on this when we implemented it, but basically it comes down to: HTML5 video assumes that you can guarantee the same environment for all your content, or that you have different end points for different environments. You can't have JS in one environment and then no JS in the other, with the same HTML content.
So either add the video.js modules, or add custom JS to add the controls attribute for this specific situation.