syncing .bwf in vegas

M

mikewest13

Well-known member
Hey guys,

I am in the pre-production stages of my first short horror movie. It's one of those typical no budget short deals. I am finding it hard to get a sound techician for free, i know big surprise! I have found a couple companies willing to give me a day package for $300 which includes the equipment, operator and recording the audio to an external source other than the camera.

The audio file is going to be a .bwf (broadcast wave file), and i wanted to know how hard it is going to be to sync up with the video in vegas. There is going to be a clapper for the audio with a timecode btw.

thanks in advance for your help

Mike
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Well, most importantly- are you going to be recording that timecode into the video? (TC-In from the digi slate, or whatever)
 
I hope i am.... This is my first shoot, so alot of things are new to me... the sound technician said that his slate will do the time coding for the audio.

Stupid question, but does that mean i should have a slate for the video as well? I have no idea how the slate works with TC and the video and audio.
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What camera are you using?

Basically speaking, when it comes to TC things work off "Clocks" .. Some audio recorders will generate a clock, or the slate might generate a clock, or a stand-alone generator might generate the clock ... ALL other devices (including CAM) will "slave" to the master clock ... this means that they will bake the clock they are receiving into their recorded video/audio.

When it comes to edit, the TC in the video/audio match and will easily sync.

There's no point timecoding audio if the video isn't timecoded also .... you can't match them together in post if only one has the time-code. No low-end cameras will take TC-in. The cheapest I think is the XL-H1. None of the Z1/DVX/HVX/A1/PD170/etc cams will take TC-in.

For cams without TC-in, you don't need to bother with TC on the audio at all .. because there's no point if there's nothing to sync to.

For these cams, search the forums for options ... typical is to use the camera's internal mic (or basic mounted mic) to record clapper board and sync manually.

You could also record free-run timecode for audio and video, arrange them by time on the timeline, and manually slip the audio video (globally) to find sync. There will be creep this way, but better than doing everything from clapper.

Regarding vegas' ability to sync, it will position BWF on the timeline correctly, but for video I use scripts to position them on the timeline by media TC.

Kris
 
edit- if you have no idea what I'm talking about, either research it more or just use a clapper... it's the most simple and effective way, used for decades.

unless you're using a nice camera with tc-in of course
 
We are using an XL2, that should have a tc in, correct?

Setting both clocks to the same time could work i guess... i'd like to save as many headaches in post as i can though :)

should i slate each scene, record the #'s to the script so that later on its easier to find the right takes i want?
 
No TC-in on XL2 .. there was NO tc-in on ANY cam in this range until very recently .. (xl-h1 and xh-g1).

XL2 is great cam, though :)

I'd set the xlr to record free-run and get the audio guy to also free-run their TC ... This is better than nothing.

Probably best go by the assumption that you'll be using clapper yeah- do you have a scene/shot list? If you do, note this info on the slate .. then you won't need to write on the script- the video will tell you which shot it is! Or you could do it your way too-- up the "shot" number on the slate each time and scribble down what you were recording ... None of this is ideal but some system is better than none. To be honest we've slated recent films but not really referred to it, so don't worry too much ,,, getting the performance/shot is more important than numbering it correctly :) For a short, you won't have so much takes that you'll lose track.

Most simple way is to note shot and take # on the slate, get the sound guy to note the info for his takes.

If you do record free-run then give me a shout once you've got it in vegas, I'll clean up the scripts I use for this kinda stuff and send you some code to help slip stuff into sync.
 
no TC in on the XL2, so should i even bother with a clapper for the audio recordings?

record free run just means having both units "real time" set the same so that in post, it lines up pretty closely.

yes, for this short i won't have too many takes, likely 3-4 different set ups, wide master, OTS, CU, etc... then a take or two of each depending on if the actor gets it right, or we try it a bit different in an extra take., so 4 x 3 = 12 per scene.

we will have a shot list, that's kinda what i meant, sorry....

how does the video tell you what take it is?

can a slate be as simple as a small chalk board, lol?

and thanks for the offer, i will definatley take you up on that if we shoot without a tc.
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No no No! If you are recording to anything other than the camera, you really need to use a slate (either TC or "dumb").

I just wrote up a whole thing on TC in the audio forum - you should take a look there.

But, from the Vegas perspective, if you want to synch the audio correctly, you line up the 'clap' with the spike in the audio track. It's actually pretty cool to watch. The sticks are out of focus until the single frame where the clap occurs, where they go into focus and then immediately out of focus again.

With cameras that do not have TC in/out (like the XL2) using TC in your recordings is a bit of overkill, but can still be helpful. You have a visual representation of the TC on the slate, and it is embedded in the BWF, so if you lose your sound logs/reports, you are not completely SOL.

As far as using free-run TC and trying to approximate the timecode on the camera, again, I just wrote something on this that I had not thought of before. Depending on your TC source, you can get somewhat close. I use a Denecke TS2-SB TC slate as my TC master. When I first turn it on, it starts at 00:58:30. So, if you set the camera clock to 00:58:30 and then immediately turn the slate on, you will be pretty darn close (still off by frames and maybe a second or two, but not bad). The problem is you cannot re-jam later to fix the drift. It's a one shot per day deal.

As far as keeping track of the TC for each shot, any sound person worth his/her salt will be turning in daily reports to you with the sound files.

Here is an example of the sound report I turned in on my last shoot:

http://www.bwgproductions.com/examples/sound_report.pdf

Hope this helps.

Phil
 
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