1906787 - WebVTT regions - adding a region fails and can only be fixed by reboot

Status: NEW

(Core :: Audio/Video: Playback, defect, P3)

Description

[Hamish Willee]

For MDN I have been updating the WebVTT docs. I can't get anything to work with captions at all.

1. As soon as I assign a VTTRegion to a cue, all cues stop displaying

   • you can test by uncommenting the line in attached file
   • There are no console errors.
   • Commenting the line back does not restore the text track. To do that I have to reboot Firefox

2. For the WebVTT file format, the spec indicates something like this will work, but these are not displayed. I think I'm being caught by the same bug as above.

WEBVTT

REGION
id:fred
width:20
lines:2
regionanchor:50,50
viewportanchor:50,50
scroll:up

00:00:00.000 --> 00:00:03.000 region:fred
<v Fred>Hi, my name is Fred</v>

00:00:00.100 --> 00:00:03.000 region:fred
<v Fred>Hi, my name is Fred2</v>

Comment 1

[Hamish Willee]

Attachment: Test code - with line to comment out to verify failure