TTML Caption Styling broken

[damanV5]

Description

Caption styling seems to be broken for mp4 embedded captions.

Steps to reproduce

Explain in detail the exact steps necessary to reproduce the issue.

1. Using videojs : 7.20.3 and videojs contrib dash : 5.1.1
2. Using videojs player options -> html5 : { dash : { useTTML : true } }.
3. Video Stream is LIVE with DRM Protection.
4. Captions are embedded mp4 i.e. with a mimeType: application/mp4.

Results

Caption displays but styling is broken. Also, I am not able to hide the empty grey strip.

Expected

Captions should be visible inside the black strip and not outside it.

Actual

Black strip and captions are displaying separately i.e. appears broken.

Error output

Additional Information

Please include any additional information necessary here. Including the following:

versions

videojs

7.20.3

browsers

Chrome

OSes

what platforms (operating systems and devices) are affected?

plugins

videojs-contrib-dash : 5.1.1

[damanV5]

@heff / @dmlap / @boushley / @squarebracket I would be grateful for any help on the above issue.