Embedded Timed Text for closed-captioning? Is that possible? I am going to be working on a video project that needs closed captioning. The requirement we got from the client says....

Closed Captioning


Embedded Timed Text subtitle track (ISO/IEC 14496-17)


After doing some research I haven't been able to find anything that would let you embed a Timed Text file into a video. Is that even possible? What would be the process for accomplishing this? I am using Adobe Premiere.
http://en.wikipedia.org/wiki/MPEG-4_Part_17
"Timed Text" Format comes in many flavors

example tools would be ffmpeg, subler, mp4box