Tizen Developers

I am using av-play api to play my media and VOD content. But i have a feature to implement subtitle as it is a general feature. 

i am using webapis.avplay.getTotalTrackInfo(); to return the embedded subtitle in the url.

The subtitles works just fine when i use vlc media player on my PC to play the url but why it is not working in my AV-PLAY player?

my subtitle object returned by the method is as follows:

1. 3:Object
   1. extra_info:"{"track_num":"0","track_lang":"","subtitle_type":"0","fourCC":""}"
   2. index:3
   3. type:"TEXT"

i am using  webapis.avplay.setSelectTrack('TEXT',trackIndex); to set the subtitle track