Duplicated Subtitles on LG TV

[KemotiaDev]

Have you read the FAQ and checked for duplicate open issues?
SImilar issue (closed due to inactivity):
#6007

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

Related to Widevine and DASH

What version of Shaka Player are you using?

4.6.0 (shaka-player.compiled.min.js)

Can you reproduce the issue with our latest release version?
Didn't try. This was reported by customers in prod app

Can you reproduce the issue with the latest code from main?
Didn't try. It's hard to reproduce with our LG TV models

Are you using the demo app or your own custom app?
No

If custom app, can you reproduce the issue using our demo app?
Can't test it

What browser and OS are you using?
LG WebOS

For embedded devices (smart TVs, etc.), what model and firmware version are you using?
LG TV from 2022 and 2023
Example models:
LG 2022: 50QNED816QA
LG 2023: 43UR80006LJ

What are the manifest and license server URIs?

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

{
    "drm": {
        "retryParameters": {
            "maxAttempts": 2,
            "baseDelay": 1000,
            "backoffFactor": 2,
            "fuzzFactor": 0.5,
            "timeout": 30000,
            "stallTimeout": 5000,
            "connectionTimeout": 10000
        },
        "servers": {
            "com.widevine.alpha": **censored**
        },
        "clearKeys": {},
        "advanced": {
            "com.widevine.alpha": {
                "distinctiveIdentifierRequired": false,
                "persistentStateRequired": false,
                "videoRobustness": "SW_SECURE_CRYPTO",
                "audioRobustness": "SW_SECURE_CRYPTO",
                "sessionType": "",
                "serverCertificate": {},
                "serverCertificateUri": "",
                "individualizationServer": ""
            }
        },
        "delayLicenseRequestUntilPlayed": false,
        "persistentSessionOnlinePlayback": false,
        "persistentSessionsMetadata": [],
        "logLicenseExchange": false,
        "updateExpirationTime": 1,
        "preferredKeySystems": [],
        "keySystemsMapping": {},
        "parseInbandPsshEnabled": false,
        "minHdcpVersion": "",
        "ignoreDuplicateInitData": true
    },
    "manifest": {
        "retryParameters": {
            "maxAttempts": 3,
            "baseDelay": 1000,
            "backoffFactor": 2,
            "fuzzFactor": 0.5,
            "timeout": 20000,
            "stallTimeout": 5000,
            "connectionTimeout": 10000
        },
        "availabilityWindowOverride": null,
        "disableAudio": false,
        "disableVideo": false,
        "disableText": false,
        "disableThumbnails": false,
        "defaultPresentationDelay": 0,
        "segmentRelativeVttTiming": false,
        "raiseFatalErrorOnManifestUpdateRequestFailure": false,
        "dash": {
            "clockSyncUri": "",
            "ignoreDrmInfo": false,
            "disableXlinkProcessing": false,
            "xlinkFailGracefully": false,
            "ignoreMinBufferTime": true,
            "autoCorrectDrift": true,
            "initialSegmentLimit": 1000,
            "ignoreSuggestedPresentationDelay": false,
            "ignoreEmptyAdaptationSet": false,
            "ignoreMaxSegmentDuration": false,
            "keySystemsByURI": { **censored** },
            "sequenceMode": false,
            "enableAudioGroups": false
        },
        "hls": {
            "ignoreTextStreamFailures": false,
            "ignoreImageStreamFailures": false,
            "defaultAudioCodec": "mp4a.40.2",
            "defaultVideoCodec": "avc1.42E01E",
            "ignoreManifestProgramDateTime": false,
            "mediaPlaylistFullMimeType": "video/mp2t; codecs=\"avc1.42E01E, mp4a.40.2\"",
            "useSafariBehaviorForLive": true,
            "liveSegmentsDelay": 3,
            "sequenceMode": true,
            "ignoreManifestTimestampsInSegmentsMode": false,
            "disableCodecGuessing": false,
            "allowLowLatencyByteRangeOptimization": true
        },
        "mss": {
            "sequenceMode": false,
            "keySystemsBySystemId": { **censored** },
        }
    },
    "streaming": {
        "retryParameters": {
            "maxAttempts": 7,
            "baseDelay": 500,
            "backoffFactor": 2,
            "fuzzFactor": 0.5,
            "timeout": 12000,
            "stallTimeout": 5000,
            "connectionTimeout": 10000
        },
        "rebufferingGoal": 2,
        "bufferingGoal": 10,
        "bufferBehind": 30,
        "ignoreTextStreamFailures": false,
        "alwaysStreamText": false,
        "startAtSegmentBoundary": false,
        "gapDetectionThreshold": 0.5,
        "gapJumpTimerTime": 0.25,
        "durationBackoff": 1,
        "safeSeekOffset": 5,
        "stallEnabled": true,
        "stallThreshold": 1,
        "stallSkip": 0.1,
        "useNativeHlsOnSafari": true,
        "inaccurateManifestTolerance": 2,
        "lowLatencyMode": false,
        "autoLowLatencyMode": false,
        "forceHTTPS": false,
        "preferNativeHls": false,
        "updateIntervalSeconds": 1,
        "dispatchAllEmsgBoxes": false,
        "observeQualityChanges": false,
        "maxDisabledTime": 30,
        "parsePrftBox": false,
        "segmentPrefetchLimit": 0,
        "liveSync": false,
        "liveSyncMaxLatency": 1,
        "liveSyncPlaybackRate": 1.1,
        "liveSyncMinLatency": 0,
        "liveSyncMinPlaybackRate": 1
    },
    "mediaSource": {
        "codecSwitchingStrategy": "smooth",
        "sourceBufferExtraFeatures": "",
        "forceTransmux": false,
        "insertFakeEncryptionInInit": true
    },
    "offline": {
        "usePersistentLicense": true,
        "numberOfParallelDownloads": 5
    },
    "abr": {
        "enabled": true,
        "useNetworkInformation": true,
        "defaultBandwidthEstimate": 1000000,
        "switchInterval": 8,
        "bandwidthUpgradeTarget": 0.85,
        "bandwidthDowngradeTarget": 0.95,
        "restrictions": {
            "minWidth": 0,
            "maxWidth": null,
            "minHeight": 0,
            "maxHeight": null,
            "minPixels": 0,
            "maxPixels": null,
            "minFrameRate": 0,
            "maxFrameRate": null,
            "minBandwidth": 0,
            "maxBandwidth": null
        },
        "advanced": {
            "minTotalBytes": 128000,
            "minBytes": 16000,
            "fastHalfLife": 2,
            "slowHalfLife": 5
        },
        "restrictToElementSize": false,
        "restrictToScreenSize": false,
        "ignoreDevicePixelRatio": false,
        "clearBufferSwitch": false,
        "safeMarginSwitch": 0
    },
    "autoShowText": 3,
    "preferredAudioLanguage": "",
    "preferredAudioLabel": "",
    "preferredTextLanguage": "",
    "preferredVariantRole": "",
    "preferredTextRole": "",
    "preferredAudioChannelCount": 2,
    "preferredVideoHdrLevel": "AUTO",
    "preferredVideoLayout": "",
    "preferredVideoCodecs": [],
    "preferredAudioCodecs": [],
    "preferForcedSubs": false,
    "preferredDecodingAttributes": [],
    "restrictions": {
        "minWidth": 0,
        "maxWidth": null,
        "minHeight": 0,
        "maxHeight": null,
        "minPixels": 0,
        "maxPixels": null,
        "minFrameRate": 0,
        "maxFrameRate": null,
        "minBandwidth": 0,
        "maxBandwidth": null
    },
    "playRangeStart": 0,
    "playRangeEnd": null,
    "cmcd": {
        "enabled": false,
        "sessionId": "",
        "contentId": "",
        "useHeaders": false
    },
    "lcevc": {
        "enabled": false,
        "dynamicPerformanceScaling": true,
        "logLevel": 0,
        "drawLogo": false
    },
    "ads": {
        "customPlayheadTracker": false
    }
}

Please not that this is not a config from when the bug occured as we struggle to reproduce it as our customers do.
This is how we configure it in general.

What did you do?

Just Played the stream with subtitles

What did you expect to happen?
Subtitles to appear once

What actually happened?

Subtitles were duplicated. Same output as in this issue:
#6007

Subtitles are configured by

drmConfig.textDisplayFactory = () => corePlayer.provideTextDisplayFactory(videoElement, containerElement);
...
corePlayer.configurePlayer(drmConfig);

where

	provideTextDisplayFactory(videoElement: IVideoElement, containerElement: HTMLElement) {
		return new window.shaka.text.UITextDisplayer(videoElement, containerElement);
	}

Are you planning send a PR to fix it?
No

[avelad]

**What are the manifest and license server URIs?**
<!-- NOTE:
  You can send the URIs to <[email protected]> instead,
  but please use GitHub and the template for the rest.
  A copy of the manifest text or an attached manifest will **not** be
  enough to reproduce your issue, and we **will** ask you to send a
  URI instead.  You can copy the URI of the demo app to send us the
  exact asset, licence server, and settings you have selected there.
  If you send the URIs to email, the response time and resolution
  will be much higher.
-->

[KemotiaDev]

@avelad here it is
https://stream-od.akamaized.net/pfr/67171ac3-b78b-47e2-9dcb-8ebbe1e4725e/mp4/67171ac3_b78b_47e2_9dcb_8ebbe1e4725e(1940921_ISMUSP)_v2.ism/67171ac3_b78b_47e2_9dcb_8ebbe1e4725e(1940921_ISMUSP)_v2.mpd

It's a CastLabs DRMed stream

[avelad]

The stream is encrypted and has not provided a license server, without that we cannot test it.

[avelad]

In the main branch we have fixed a problem with duplicate subtitles, can you see if it solves your issue? Thanks!

[KemotiaDev]

Hi @avelad
Could you share a commit with this fix?
Unfortunately due to our project's nature and scale, we cant use the latest Shaka just like that, without spending days doing regression tests therefore we'd like to see how it was fixed and possibly apply this fix to shaka 4.6 which we use.

[avelad]

See: fa9feb3

Our branch policy is detailed at https://github.com/shaka-project/shaka-player/blob/main/maintained-branches.md, we do not have any plans to support 4.6 since it is a version that no longer has support, sorry.

[shaka-bot]

Closing due to inactivity. If this is still an issue for you or if you have further questions, the OP can ask shaka-bot to reopen it by including @shaka-bot reopen in a comment.

[KemotiaDev]

@shaka-bot reopen
Hi, we have checked this fix and the issue persists on LG TVs. FOr instance LG from 2023.
We checked against this version https://cdnjs.cloudflare.com/ajax/libs/shaka-player/4.10.9/shaka-player.compiled.js
Moreover, we were trying to apply the same change to some older build (4.6) but didn't help either