'There is no frame delay added as you aren't coding / decoding, just copying a data stream. '
That is correct, however at the playback end there will be a DolbyE decoder that will require 1video frame equivalent time to restore the original discrete tracks and make them audible.
Accordingly, a DolbyE encoded track must be 1 frame in advance on tape.
And BTW, you could always do a simple sync check with the 2pop after you layback to tape.
cheers,
bogie
bogie:a DolbyE encoded track must be 1 frame in advance on tape
Not necessarily. Some stations require DolbyE track to by synchronous with video - and thus deal with the decoding delay themselves (by use of Video Frame Delay)
I've been capturing HDSDI from HDCAM SR stereo left and right A1/A2 with Dolby E on A3/A4 then laying back to tape without any sync issues. Terence said he'd done this for a while without any issues and I haven't had any either.
'Some stations require DolbyE track to by synchronous with video'
could you provide such an example?
thx,
The Dolby E encoded signal should be in sync with the stereo signal ON TAPE. This positioning allows further processing to be done to the final tape if required. The DolbyE signal will be advanced by 1 frame in the play-out chain to compensate for the Dolby decoder delay
from <http://www.bbc.co.uk/guidelines/dq/pdf/tv/hd_summary_delivery_formats_v1_7.pdf>
Our deliverables are: tapes we get are advanced a frame and then when we decode they are in sync in Avid. Then we encode and dolby is delayed. Our playback for air then ingests the show and adjusts the sync on their end. Confusing?.......yes!
I'm interested, why do you need to decode? Are you editing 5.1 within SN? More than simple cuts/dissolves (i.e. layering audio)?
If not then you *should* be able to just take the DolbyE in and out invisibly - it is just data and is only subject to delays on encode/decode cycles. Dolby make it 1 frame so it is easier to fix.
Do you have a link to the BBC spec with the 5.1 Brian as I don't have it in mine.
Thanks
Sure, here you go
regards
Brian
Yes, usuallly lots of editing.
Thanks Brian that's very useful indeed.
Our of interest Brian what sort kit have you been using for the BBC edits ?
I am interested to know how you are making those edits in SN.
Are you corralling the audio 6 mono tracks at a time?
How are you dealing with surround panning? And upmixing from stereo and mono sources?
Are you having to deliver mixed and m&e versions of the 5.1?
I have to hope that Avid have a solution to all of this with containerised audio sometime soon (other than DS ;-)
We haven't delivered Dolby E to them yet, only HD deliveries so far have been Stereo on HDCam.
Onlined on Symphony Nitris
Decoding the dolby (5.1+2 is what we get and make) brings in the the dolby mix on ch 1-6 and 7 and 8 are the stereo mix. The M/E or MixMin is brought in the same way. 16 channels of audio in your sequence and then any audio you have to add. In the edit room, we have 5 speakers set up to moniotr the dolby.
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