Video player displays `body` as title/hover-text even when `filename` is present

[twassman]

Steps to reproduce

1. Send an video message (m.video) containing both body and filename (differing from each other).
2. View the message.

Outcome

What did you expect?

The filename is the filename, and so should be displayed as the title of the video file (hover-text for the video area), while the body is the caption, and so should be displayed as a inline message (see spec as of v1.16).

What happened instead?

The body was displayed in both locations.

(This does seem to display correctly when the video message is quoted. It also displays correctly for m.file and m.image, but not for m.audio — see #31116.)

Operating system

No response

Browser information

No response

URL for webapp

staging.element.io

Application version

Element version: 1.12.3-rc.0

Homeserver

No response

Will you send logs?

No

[t3chguy]

I would argue from an accessibility standpoint, the title is akin to the alt text on an image which should be a description (caption) rather than the filename. Put yourself in the shoes of someone who is blind and relies on accessibility technologies such as a screenreader, they care little about the name of a file, more about what the media they received is attempting to convey.