Multi channel sync issue

[ronnievanoverveld]

Hi,

For a Dutch TV series, the video department has recorded audio on camera and with the new Tentacle Track E. Strange thing is that audio on camera is 1,5 frame out of sync (Later). So; track 1 (Tentacle), right timing, track 2 and 3 camera audio (1,5 late).
We now want to do media management in Avid MC, but want to first get rid of the delay. Is there a program (Soundminer?) which can take care of this problem in batch (lots of data!)? It's important to keep the timecode meta data in the files, but cut the 1,5 frame delay.

I hope I described it understandable ;-).

Thanks in advance for your suggestions.

Ronnie

[JFreak]

VLC can do this and is free. Batch modification of your vid+multitrack takes time though, so consider doing it in PT when you actually work with it.

[ronnievanoverveld]

Thanks!
OK; I'll try VLC.

Maybe I'll do it in PT, but does PT remind the Meta data once the audio is on the timeline?

[JFreak]

What do you mean by reminding meta data? Everything you have in the session is meta data, if you separate audio from video and move it X samples it is spot on.

[ronnievanoverveld]

TC is in Time of day for the original footage. Never worked in Pro Tools with that kind of timecode, so maybe it's no problem. I have the audio as separate multichannel files.
The thing is that they already found out the delay before recording, but recorded it this way anyway.. #fixitinpost..

[JFreak]

TC is the real time of your video and if you know audio is out of sync you just fix it and there is no problem

[ronnievanoverveld]

The problem is that we want to fix it before it's imported into Avid MC for video editing. It's a series with a lot (30) of long recording days, so it'll take a long time in Avid to fix this (and Avid doesn't go 'between' frames easy).
They normally put together all the footage based on TC of the day, so we need the audio to have TC time of day. I hope this makes sense.

Of course audio delay fixing can be done when audio post production starts, but then the video editor will have to listen to a lot of phasing issues.

[JFreak]

First of all you need to decide whether it is audio or video that is out of sync, in other words which one you will move to a new timecode. Second, you separate the two, and last you move one or the other by fixed amount of samples.

Say you know your audio is off by one frame of 30 frames per second and your session sampling rate is 48k, then your offset is 48000/30=1600 samples

[ronnievanoverveld]

Sorry, maybe I didn't explain it good (difficult in another language).

The separate audio channels are not in sync with each other. They did a clap test on camera, 1 channel with Tentacle Track E, 2 channels audio on camera. The 2 audio channels on camera are not in sync with video (and the Tentacle audio). (No difference in distance in micing with the test recording).
So we need to get those 3 audio channels in sync with each other. Ideally in a batch process as there are many files...Of course it's easy in PT to match them visually, but I think I will lose the Time of Day TC.

[JFreak]

You do not lose time of the day TC but you can only have it correct on audio or video. So if you think video is correct, fix your audio. If you think audio is correct, fix your video. And the way you do it is separate audio and video, then move the audio with some number of SAMPLES not milliseconds or frames.