# Web OS Hosted App Subtitle Problem
**URL:** https://forum.webostv.developer.lge.com/t/web-os-hosted-app-subtitle-problem/28179
**Category:** Web App Development
**Created:** [April 23, 2026, 11:46pm UTC](https://forum.webostv.developer.lge.com/t/web-os-hosted-app-subtitle-problem/28179 "2026-04-23T23:46:08Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@VisionDev](https://forum.webostv.developer.lge.com/u/VisionDev)
#### Post date: [April 23, 2026, 11:46pm UTC](https://forum.webostv.developer.lge.com/t/web-os-hosted-app-subtitle-problem/28179/1 "2026-04-23T23:46:08Z")
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Hello, we’re developing a player for WebOS, but we’re building it as a web-hosted app. The issue we’re facing is that we can’t extract subtitles or audio from MKV files using the player. If anyone knows of a solution, could you please
After doing a little research, I realized that a permit like this is required. How can I go about getting one?
“requiredPermissions”: [“media.operation”] |
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Unfortunately, we can’t extract subtitle and audio files from content in the MKV format. Does the web-hosted app option require special permission for this, or is there an option we can use?
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### Author:  [@narae0.kim](https://forum.webostv.developer.lge.com/u/narae0.kim)
#### Post date: [April 23, 2026, 11:50pm UTC](https://forum.webostv.developer.lge.com/t/web-os-hosted-app-subtitle-problem/28179/2 "2026-04-23T23:50:50Z")
In webOS TV apps, only an external subtitle in the form of .vtt (WebVTT) is officially supported. For more information, please refer to [Video and Audio Format specifications](https://webostv.developer.lge.com/develop/specifications/video-audio-260#Subtitle-format). Thank you.