DFXP-TTML for live issues

Sep 3, 2012 at 11:40 AM


I am seeing a weird behavior when using TTML for a live scenario. Whenever i switch to a specific language caption stream, the first caption from that stream seems to become stuck, and regularly disappear and reapper, as if the lines change, but the text remains the same.

When switching to a different language, this behavior then resets, with a new message in that language, that also gets stuck.

I am unsure where to look for the cause of this behavior. I have upgraded to latest SMF and SmoothStreaming Client and the problem persists.

Anybody have any ideas for solving this, or where to dig further?

- Loke

Sep 27, 2012 at 1:16 PM


I do not know if it is the same problem, but I have observed that the TTML display in the sample SMF player seems to be dependent of the DVRWindowLength in the smooth streaming manifest.

When it is different from 0, I encounter the same problem as you : After DVRWindowLength seconds since the encoder starts pushing data to IIS, the subtitles do not follow the video anymore but constantly loop.

Reloading the player does not change the result : The subtitle corresponding to the frames present  at player reload are played in a loop.

Hope this help, or someone has a clue to make the SMF smoothstreaming sample player working ...


Oct 1, 2012 at 4:07 PM

May be you could try to set SMFPlayer.IsStartPositionOffset to false.

It has worked for me ...


Aug 1, 2013 at 2:52 AM
It did not work for me...

what a problem!