Hi I just tested Mpeg Dash with DVR and it only seems to be working with the live application is that correct ?
You are correct, DVR is only functional with live applications, but you can set a player to start at a specific point in an on demand file and allow "scrubbing", but this is player dependent.
There is an internal feature request for Closed Captioning with MPEG-DASH, to be created as a future enhancement, and this has been forwarded to our Product Manager for consideration to be added to the core product. I added your request as an "up vote" for this feature request. Though do note that there is no definitive timeframe as to when we will support these new features. Please do check back in periodically to our Software Updates page to see if your feature request has been deployed.