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Broken character encoding in closed captions on iOS8


we have a problem with broken characters encoding on iOS8 (iPhone), it works well on iOS7.

Try e.g. this file: Czech characters are broken.

We are using Wowza 4.1.0 and WebVTT format for closed captions. Subtitles are in UTF-8.

What’s a problem?

Thanks for help!


Hello Dominik,

Will you kindly zip up your /conf and /logs folders and send them to to open a ticket.

Thank you,



This will now be handled in the created ticket (105672).



Please also include any caption files and smil files you might be using with your email to support.

Thanks again.


Hello there and welcome to the Wowza support forum.

Here is a note from Wowza support regarding iOS 8:

We are aware that since iOS8 has been available we have seen several issues relating to video delivery, not just Wowza related, and we have already seen several updates from Apple to resolve many video issues.

At present we are both testing and monitoring the situation however until Apple provide further updates we do also believe there may be on going problems when using iOS8.

All I can suggest at this time is to take further updates when made available by Apple. We are continuing to look at how we can provide workarounds where possible but as this time do not have further updates for iOS8 issues.

Kind regards,


Yes, encoding is fixed in iOS 8.3, now we have problem only with position of closed captions. They are partly hidden under bottom of screen edge.

Hi there,

Is there any update on this issue? We have the exact same problem.

It looks like a client (Safari on iOS8?) problem.



More about…What is Character Encoding


I believe we have the same issue too. Any updates on the issue?

We are using Wowza 3.6.2 and we have set cupertinoLiveCaptionsUseWebVTT to true. At the very least iOS 8.2 and 8.1.1 doesn’t show the text in UTF-8, eg. äöå which are used in Finnish and Swedish. Here is a link for iOS Can you confirm this? If we look at the WebVTT files separately that wowza creates they are correctly UTF-8.

Please if anyone has insight on this, that will eg. iOS 8.3 fix this or is this something we can fix or workaround with Wowza?

I have now tested with iPhone 4S updated to iOS 8.3 and character encoding problem related to this matter seems to be solved. Finally we can start to serve HLS emdedded with captions!