Issue

It looks like something may have regressed in configuration as we're currently in a rather strange situation.

• Allowed upload formats include: video/mp4.
• Allow playback formats include: video/webm.

This leads to the situation where uploading a mp4 file is allowed, but can't be displayed:

{F35176667}
{F35176667 media=video}

Rendered as:

And webm is allowed to be displayed in theory, but can't be uploaded:

Result in upload failure:

Other

I note that this works fine in the upstream Phacility install, e.g. at https://secure.phabricator.com/T6916#179235

I note that in our instance configuration (admin-only: https://phabricator.wikimedia.org/config/edit/files.viewable-mime-types/) we have the following, which controls whether something is displayed:

{
  ..
  "video/mp4": "video/mp4",
  "video/ogg": "video/ogg",
  "video/webm": "video/webm",
  "video/quicktime": "video/quicktime",
}

-  "video/mp4": "video/mp4",
   "video/ogg": "video/ogg",
   "video/webm": "video/webm",
-  "video/quicktime": "video/quicktime",

And for upload handling, https://phabricator.wikimedia.org/config/edit/files.video-mime-types/:

`files.video-mime-types Default unchanged
video/mp4
video/ogg
video/webm
video/quicktime

Which suggests that webm could be uploaded, but I'm guessing it's detected as something else for some reason, aside from ofc webm being much harder to generate for most people, but that's a separate question :)