How to enable Unknown CC in Livestream video

Hi @Everyone,

I want to enable Unknown CC in Livestream video (http://wnow_live_test-f.akamaihd.net/i/ ... aster.m3u8) in my app. 
Following red rectangle in this image: http://imgur.com/a/Y05hx
I had tried set globalCaptionMode = "On" in Video Scene, but it do not show.
Ans I tried with normal, Closed caption can show, not Livestream. 
So, How can I handle enable video Closed caption.

Thanks so much!