A while back someone asked if it was possible to get an LE system to sync (resolve) to incoming timecode?
Mike Aiton replied….
Get yourself one of those Rosendahl mif boxes which converts ltc to midi and if you are reviewing against a dvtr deck, don’t forget to reference your LE interface to the decks digital output.
Do bear in mind though that your audio will NOT be precisely aligned to frame edges – so DON’T lay back.
Pete added…
MTC doesn’t support positional reference, so after playback starts (albeit at the right frame) there’s no communication between master and slave. This means the two systems will drift apart as they’re not referencing each other any more???
MTC is ONLY a positional reference. They will be referencing each other if you follow Mike’s advice as they’ll be clocked together and thus play synchronously.
Mike Aiton came back with a detailed post…
LTC would be your positional information. The spdif from the deck would be the speed/reference info. No it will not drift (or at least no more than a dvtr on internal can anyway) as once the position of the tc is reached, the LE then resolves play to it’s reference (spdif from the dvtr). This is identical behaviour to any syncronisation system. The only difference between this an HD system with a sync IO or Sync HD is two fold:
1) the HD system has machine control so the PT system can tell the deck to go somewhere, which it then subsequently chases via ltc or serial tc (a choice on the system and then resolves to it’s reference (which in an HD system is usually means both vtr and PT being locked to black and burst). which leads me to point two:
2) the LE timecode in your system could get to the frame required and then resolve to the spdif clock. There could be up to almost a frame error in your Le system. The HD system would lock the timecode to the edges of the video frame. There would be no error.
Do not confuse 9 pin transport commands to a vt with timecode lock and then release to resolve play. Your Le will not drift as long as you do the spdif referencing. Just be aware of the potential to be at worst almost a frame out.
Rafi then chipped in with…
You can use Motu’s MTP AV USB version. you must connect video black burst to it and connect the word clock out from it to one of the external clock enabled interfaces DIGI makes (i.e. Mbox 2 pro or 003). This configuration gives almost sample accurate lock.
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