Shaka-player not rendering CEA-608 Closed Captions

[pravarkulkarnixperi]

Have you read the FAQ and checked for duplicate open issues?
Yes

What version of Shaka Player are you using?
v4.2.2

Can you reproduce the issue with our latest release version?
Yes

Can you reproduce the issue with the latest code from main?
Yes

Are you using the demo app or your own custom app?
Demo App

If custom app, can you reproduce the issue using our demo app?
Yes

What browser and OS are you using?
Google Chrome 106.0.5249.119

For embedded devices (smart TVs, etc.), what model and firmware version are you using?
NA

What are the manifest and license server URIs?
Manifest URL - https://connect-integration-msp-edge.connectcdn.net/mm/dash/live/7197_DASH_DAI/LIVESERVICE_1234/group=TG_WIFI_HD.mpd

License server URL - https://connect-integration-msp-edge.connectcdn.net/core/v5/drm/widevine/get_license

What configuration are you using? What is the output of player.getConfiguration()?
We are using default player configuration at https://shaka-player-demo.appspot.com/

What did you do?

1. Load manifest url and license url in demo player(https://shaka-player-demo.appspot.com/)( used goole chrome with web security off to avoid CORS error issues)
2. Start playback and turn on close caption (language is shown as "Unrecognized()"
3. No closed captions are seen

What did you expect to happen?
We are expecting to see closed captions when we turn on closed captions. Similar thing is working on reference dash if player(https://reference.dashif.org/dash.js/nightly/samples/dash-if-reference-player/index.html), we are seeing correct closed captions.

What actually happened?

Not able to render closed captions(CEA-608) on Shaka player.

No closed captions of Shaka-player

Dash-if player is showing closed captions with same stream.

[pravarkulkarnixperi]

any update on this??

[joeyparrish]

No updates at this time. Nobody has looked into this issue yet. If you want to start debugging it yourself, you should look into lib/media/, in media_source_engine.js, closed_caption_parser.js, and everything in lib/cea/.

You can also try various older versions of Shaka Player. If this is a regression, and you can tell us a version that did work for your content, it should be much, much easier for us to find the root cause by bisecting and finding a particular revision that broke it. See https://index-dot-shaka-player-demo.appspot.com/ for an index of older releases.

Sorry we haven't been able to look into your issue yet.

[joeyparrish]

Just had a quick chat with @avelad, who started investigating this issue. It appears that we're missing an offset into the MDAT data, so we begin parsing at the wrong location.

[pravarkulkarnixperi]

@joeyparrish thanks for update

[pravarkulkarnixperi]

@joeyparrish Is this fix available on https://shaka-player-demo.appspot.com/demo/ ? Because I am still seeing no captions in Shakaplayer demo app above

[joeyparrish]

Yes, it should be. The fix was in the v4.3.0 release.

I just tried to check the content URLs from this issue, but I'm denied access to the license server. I can't disable CORS because I'm on a Chromebook at the moment, and can't control Chrome's command line options in this context.

[pravarkulkarnixperi]

I am still able to reproduce the issue. Can you guys please look into it.

[avelad]

It’s broken when the stream is encrypted