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faruk · Posted - Mon Aug 04, 2003 4:56 am

I'd like to dub on a Betacam film with Cool Edit Pro using a Layla 24 sound card. Do I need any other hardware for the process? Could you briefly explain what needs to be done? Thank you in advance for your concern

SteveG · Location: United Kingdom

I'll not be too surprised if you get no replies to your question as it stands (okay it is a bit early!) - you've just asked the equivalent of 'tell me everything' without explaining in enough detail what you've got to work with. I presume that by 'dub' you mean add a soundtrack to video material already recorded (this is the normal meaning of the word in this context, just in case anybody else was wondering), and the one question I have to ask you first is this: Do you already have synchronous live sound that you want to incorporate into your final soundtrack? It makes a huge difference to the following answer...

faruk · Posted - Tue Aug 05, 2003 1:29 am

First of all, I mean exactly "adding a soundtrack to video material already recorded"by "dub". The hardware that I own is a Betacam equipment and a layla 24 sound card. I want to add a new sound channel synchronous with the video on a Betacam cassette. I hope it is more clear now. Thank you for your prompt reply!

SteveG · Location: United Kingdom

You still haven't said whether there is sync sound...

Assuming that there is, since this is the worst case - you have two methods. The first is guaranteed to work, and the second I haven't fully researched.

The first method is to take the sync sound from the existing soundtrack, and feed it into a mixer along with the wild sound (FX, etc) that you've recorded in approximately the right place in CEP, and feed the results back to the track you are dubbing onto. Since this is beta, there should be enough tracks to do this unless you made the mistake of using the only track you can dub onto for the original sound... Anyway, this is guaranteed to keep the sync sound in sync, because you are just adding to it, and moving it across the running tape. And you can do fades, and EQ it, etc.

The second method, which is probably the one you are wondering about, would involve syncing CEP to the video timecode. Now, if you can convert VTC to MTC (you need a box to do this), then you might be able to sync-slave CEP to the video feed. But CEP will only do this if it's playing a track, so you'd need a blank track to sync to. What I'm not sure of is whether, whilst playing one track with CEP as a SMPTE MTC slave, you can record another at the same time in multitrack mode. I'm not sure, because it doesn't say in the manual, and I haven't got a VTC-MTC converter here to try it with.

CEP can also act as a SMPTE master clock source - although once again this is in the form of MTC, and you would need to be able to lock your VTR up to it. VTR ability to do this varies. Decent edit-capable machines can, as a rule, but machines that you can dub onto are usually portables, and they don't always have the option, I think. But however you look at it, you have to be able to find a way of locking CEP and your video source, or this isn't going to work, because of the drift inherent in the VTR.

This whole sync thing is a bit of a Holy Grail, and a right can of worms for anybody doing this. Normally, you'd do it in post by just digitising eveything you've got, and exporting an AVI file for the audio work, laying it back afterwards when this is complete. You can do at least a part of this in CEP (it imports AVI files), but the layback isn't quite so straightforward, I believe, although once again I must stress that I haven't tried it - I've only ever imported stuff and discovered that whilst CEP is quite happy to strip the audio from the AVI, and play it along with the video, it won't lay it back again. Maybe this will change with Audition - it would be very useful if it did, because it would make this whole problem a lot simpler to deal with.

Ralph · Location: Hungary

The first thing you need when doing any kind of serious audio-for-video work is a soundcard that will synchronize playback to the incoming LTC that you get out of the BETA, otherwise the material you record or play back will no longer be in sync with the video after a few minutes. You either need a soundcard that can do this by itself, like the MOTU 2408 mk3 (not the older ones, only the mk3!), but I wouldn't recommend it at all with CEP, you'll regret having been born if you try to get these two to work together. Allegedly, Frontier Design's Tango24-Dakota package and CEP are a match made in heaven. Another choice is to buy a soundcard that has a word clock input, and a synchronizer like MOTU's digital timepiece that will read incoming LTC, convert it into MTC for CEP and word clock signal for the soundcard. Then you can start synchronizing your audio to the BETA (or any LTC source). Any other solution will sooner or later fail. I don't know about the Layla 24, but first thing is to check if it has word clock input. If it does, buy a synchronizer. If not, you're out of luck. If you have an LTC reader or LTC to MTC converter (e.g. the SYNCMAN or the BIPORT 2x4 from MIDIMAN) you can still get CEP to start playback or recording in sync with the video, but in a few minutes they will be out of sync, and CEP will automatically reposition playback which will cause an audible glitch, be prepared for that.
Naturally, CEP MUST be in slave mode, because the BETA won't sync to CEP's MTC out. You won't easily find an MTC to LTC converter, anyway. The AVI file Steve suggested is no solution, because in the end you have to sync the finished audio to the BETA LTC again, so you're back to the original problem.
Unfortunately, audio-for-video is very poorly supported on the PC. You may be better off with a Mac or buy a used Amiga with an AD516 souncard, and all your problems are solved.
Hope this helps!
Ralph:D

SteveG · Location: United Kingdom

Thanks for the info anyway, Ralph, even though I suspect that it's going to be a bit frustrating for faruk. You have rather confirmed that my suspicions about this are likely to be correct.

jamesp · Posted - Wed Aug 06, 2003 9:50 am

As Ralph said, the MOTU Digital Timepiece is a great box to have for these situations and it will almost certainly do MTC to LTC if you want it to. It can also output word clock as an spdif signal so it might be worth seeing what options you have for clocking the Layla.

Cheers.

James.