Can't select subtitle on IOS

Wowza Streaming Engine
1

Hello,

I have followed the guide at https://www.wowza.com/docs/how-to-configure-closed-captioning-language-selection-for-video-on-demand-streaming

I can via the captionLanguages decide what subtitle is the default one, and that works;

[HTML]

captionLanguages

String

eng,spa,dut

[/HTML]

But, on the IOS unit, on the subtitles menu, I can select “Off,” “Auto” or “Hidden text on unknown” . The last one is the only one that gives text on the device. Same thing happens in Safari in OSX when I load my url http://stream10.sli.se:1935/test/definst/mp4:bunny/bigbuckbunny.mp4/playlist.m3u8.

My expectation was to select “Auto” on the device to get the Wowza default subtitle, and that the other subtitles available in the ttml file should be presented to the user of the IOS device. Is that simple not the case, or am I doing something wrong?

In this test case; Wowza Streaming Engine 4.01., IOS 7.0.6

2

Try enabling WebVTT in your configuration then restart and try again.

3

Ok, so then I also need to convert my subtitles to WebVTT then? (they are in ttml-format at the moment)

If so, could you please give me an hint on how I handle more then one subtitle language of the same movie? In ttml-files I can have many languages in the same ttml-file, but I have not yet seen any WebVTT that has more then one language in it. Do I have to have specific names on the WebVTT files in order to be recognized as a specific language, or how do it works?

You would not have to convert your files. Wowza accepts many ways of input for the captions, webvtt files and TTML files being 2 of those ways. Then Wowza converts those captions to the format that the various streaming protocol accept. iOS accepts either CEA-608 or WebVTT.

So WSE can take TTML files as input and send WebVTT as output to HLS/iOS.

You need to make a decision of whether to use CEA-608 (the default) or WebVTT to HLS/iOS.

CEA-608: is supported on older iOS versions, but only supports one language and only English, Dutch, French, Italian and German.

WebVTT - is much newer to HLS but seems to have better support in iOS 7.x all the time. It can support more than one language and should support any language expressible in UTF-8

4

If you add that property, restart, and test again you should see the language selection. Please also zip up your [install-dir]/conf and [install-dir]/logs directories and send it to support@wowza.com referencing this post so we can review this issue further.

5

We have received your ticket and will be responding to ticket

#83394
6

Ok, so then I also need to convert my subtitles to WebVTT then? (they are in ttml-format at the moment)

If so, could you please give me an hint on how I handle more then one subtitle language of the same movie? In ttml-files I can have many languages in the same ttml-file, but I have not yet seen any WebVTT that has more then one language in it. Do I have to have specific names on the WebVTT files in order to be recognized as a specific language, or how do it works?