Dash - CC CEA-608 stops displaying

[mikeszutu]

Have you read the FAQ and checked for duplicate open issues?
Had a previous question ticket open but closed it.

If the problem is related to FairPlay, have you read the tutorial?

No

What version of Shaka Player are you using?

4.14.11

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?
Both

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

What browser and OS are you using?
Chrome on Mac OS

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

What are the manifest and license server URIs?

Highly sensitive and currently geo fenced.

What configuration are you using? What is the output of player.getNonDefaultConfiguration()?

{"drm":{"servers":{"com.widevine.alpha":"https://**************/widevine"},"advanced":{"com.widevine.alpha":{"distinctiveIdentifierRequired":false,"persistentStateRequired":false,"videoRobustness":"","audioRobustness":"","sessionType":"","serverCertificateUri":"","individualizationServer":""}}},"manifest":{"retryParameters":{"maxAttempts":3},"defaultPresentationDelay":30,"raiseFatalErrorOnManifestUpdateRequestFailure":true},"streaming":{"retryParameters":{"maxAttempts":3},"rebufferingGoal":6,"bufferingGoal":20,"bufferBehind":0,"ignoreTextStreamFailures":true,"gapDetectionThreshold":0.4,"observeQualityChanges":true,"maxDisabledTime":0},"abr":{"switchInterval":2}}

What did you do?

CC works initially but stalls out and append fails to be called on our textDisplayer class. Playing a different asset doesn't fix the issue or toggle the cc on or off.

What did you expect to happen?
CC to work flawlessly end to end.

What actually happened?

Bug is that CC is broken since version 4.12.3 and is fine on 4.12.2

I believe this change that was introduced:
if (metadataTimestamp) { could be the issue? Previously it was checking if (metadataTimestamp && metadataTimestamp.data) {, if metadataTimestamp.data doesn't exit as a property won't this soft exist? on Math.round(metadataTimestamp.data) / 1000; (Referring to function getTimestampAndDispatchMetadata in file media_source_engine.js)

Are you planning to send a PR to fix it?
No

[lepinese]

@mikeszutu I was curious if your issue was resolved with this fix?

We've had a significant increase in 2010 INVALID_MP4_CEA errors in production the past few weeks ever since we upgraded to the 4.11.17 version and I'm wondering if my issue is related to yours or if it's different.

We've been following your tickets and we tried installing the 4.14.15 version but sadly we still get the error.

I am currently trying to reproduce the error with the 4.11.14 version to see if there might be something in the 4.11.15 version other than this that could be breaking.

FWIW the debug mode didn't really seem to show any interesting information :

[lepinese]

Having tested intensively with the 4.11.14 and the 4.11.15 versions, I can confirm our issue happens in the latter but not in the former.

This makes me think one of these commits might have introduced the bug but as stated in my previous comment it isn't this one since the 4.14.15 version doesn't fix the issue.

On our end, the only way I've managed to reproduce it is simply to let any media play and the error randomly appears after 30 mins to 2 hours of play. It doesn't happen at the same seek time of the media.

[mikeszutu]

@lepinese yeah i don't believe it address the 2010. We been trying to case this down ourselves but it's not obvious. 2010 is thrown right away on loading of the content and I've noticed that some segments from the CDN might be corrupted and 2010 gets thrown? I'm curious to see how this decision is made

[mikeszutu]

@lepinese Hmm i think the issue was introduced 12 months ago?
Concern is related to this change here:
if (parsedTRAF.baseMediaDecodeTime === null) {
// This field should have been populated by the Base Media Decode
// Time in the tfdt box.
shaka.log.alwaysWarn(
'Unable to find base media decode time for CEA captions!');
throw new shaka.util.Error( <- This
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.TEXT,
shaka.util.Error.Code.INVALID_MP4_CEA);
}