Closed captions

I have added a .srt file using "ContentNode.subtitleConfig = Trackname: "pkg:/source/CraigVenter.srt" "  attribute, now i can able to render close caption data in video player.

In a video player ContentNode i am getting "subtitleTrack: "/tmp/plugin/KEBAAAngDiiH/pkg:/source/CraigVenter.srt" URL.  I want to read the actual caption when video is being played,  is there any scene graph attributes for this. 

Please let me know any solution for this, I will really appreciate for any help.