Japanese subtitle is broken in IE 11

[zironycho]

Description

Japanese subtitle is broken in IE 11
used demo url

Steps to reproduce

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

1. open url on IE 11.
2. change cc to Japanese

Results

Expected

display Japanese subtitle

Actual

broken subtitle text

Error output

Additional Information

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

versions

videojs

It is just official demo page from videojs-contrib-hls

browsers

IE 11.

OSes

Windows 10 Home

plugins

videojs-contrib-hls

[gkatsev]

That's really interesting. The first thing I noticed is that the VTT file wasn't being served with the correct mimetype. I tried changing the mimetype using the Charles proxy but it was still not doing the right thing. We should probably still change the mimetype.
Also, adding the file as a <track> element seems to work just fine.
This is probably related to us defaulting a "string decoder" when a utf8 TextDecoder isn't available: https://github.com/videojs/videojs-contrib-hls/blob/a3ecfd0b346c7a55f198e772dc07ffd4b212a7e2/src/vtt-segment-loader.js#L314-L323
It should work fine if a TextDecoder polyfill is included on the page, we don't ship one by default because it often isn't needed and it's a pretty large piece of code otherwise.

[zironycho]

@gkatsev ❤️ Thank you for response and answer.
I will try that you suggested !!

[gkatsev]

After investigating it some more, we think this may be because we're downloading the text as arraybuffers in VHS/hls. @forbesjo is going to look into if we can just download it as just text, which may improve this behavior.

[gkatsev]

This is being worked on in VHS: videojs/http-streaming#105

[forbesjo]

The fix has been deployed in VHS, it should be picked up by video.js 7 some time soon

[gkatsev]

This is fixed in @vidoejs/http-streaming 1.2.1 and it's in Video.js as of commit 7b6aa5c, it'll be in the next release.