Advice on Syncing Audio CD Tracks

[beardedboss]

Does anyone have any tips for syncing Audio CD tracks to a Timeline.

Currently I have a show which was shot with 4 cameras
I have used PluralEyes to sync up all of the cameras and audio fine.
But I am having trouble getting a sync of the Audio CD Tracks

I have an exact copy of the Audio CD that was used in the show.
I have ripped it with AudioGrabber to WAV Files 44.1k

Even with PluralEyes it only manages to sync half of the tracks and leaves out the rest, of the ones that it has synced, they are still not completely in sync, they start slighty late off beat and end out of sync towards the end.
I have reported this issue to Bruce at PluralEyes and we have come to the conclusion that PluralEyes wont sync due to their being an indifference with the audio files.

I was told that the fact that they are 44.1 and the camera audio is HDV 48k that would not make a difference, I tried converting the files to 48k and still the same problem, finally I attempted to sync manually the CD Audio Tracks in both 48.1 and 44 and whilst I can get them to start in sync with the camera audio, as they play they go out of sync.

I am wondering what needs to be done to add these audio tracks to sync in with the camera audio. I've read some people on here use Sony Vegas to do audio for shows. Is it possible in Edius 6.05 as I don't have any other editor installed, but could at a push maybe download and install a trial copy to do the job.
Thanks for any advice.

[Ron Evans]

This depends on the cameras used. Video is synced to the video frames sync for all traacks but the audio on some cameras is not locked to same reference to video frame sync on record and can drift within the frame. DV for instance spec says it only has to be within 1/3 a frame. So although the video tracks will be in sync there is a possibility that the audio from two DV cameras in an extreme could be almost 2 frames off. The issues gets worse when there is audio from a separate audio recorder.

All your audio should be 48k. It does make a difference. The computer is simplistic --it is counting clocks. 44.1 is a smaller number than 48 so if it is expecting a 48k file, the 44.1 file will finish early. However if the original audio clock was not in sync with the video clock it will be off over any long period of time. Some NLE's will recognise the file format and resample but it is better to always use a 48k file.

My approach is to get the tracks in rough sync using the audio waveforms in Edius . Fine tune the video sync by looking at the cameras in multicam mode to make sure they are in video sync. I then export the audio for each track as a wav file. I use Vegas to get the audio sync using the closeup camera as the reference file ( sync all the others to it) so that the closeup lip sync is correct. In Vegas one can move the audio at audio clock level, not frame sync, so the movement is very fine. The tracks can also be stretched or squeezed to get exact sync over the length of the show. This is also how I would integrate a track from audio recorder ( we use a Zoom ) or other sound effects. Same is true for CD tracks resampled to 48k, place them one at a time. I render a 48k wav file of the mix from Vegas and take back into Edius for final project export.

Edius can shift the audio on a track in either direction but cannot stretch or squeeze as easily/visually like Vegas to take account of clock drift over time.


Ron Evans

[beardedboss]

Thanks for that Ron.

I was thinking that I needed to do something like that.

The show is a Dance Show mostly dance and just 2 singers singing to karaoke backing.
For most part there is no lip sync needed, only sync to the existing cameras.
The show was filmed with 4 HDV cameras, 1 AH1 and 3 FX7E's.
I used PluralEyes to sync up all of the cameras, they synced perfectly, all audio from the four are completely in sync.
Like I say, It was only when I tried to all the Audio CD Tracks onto another track did I have probs, the Audio wouldn't sync, as explained.

I'm not sure if I have the knowledge to do the sync thought, could do with a tutorial. I know I could install a trial of Vegas, do I have have to use the full version or can it be done in the cheaper one, Vegas Home Studio is it called?

I know that it wouldn't be worth me purchasing the Full Vegas for doing this all the time. I tried Vegas and didn't care for it, the main gripe, the audio scrubbing is no good, it's not a proper scrub, rocking the reels like a tape audio is no comparison to EDIUS's Audio Scrub, which is same as Premiere, which I came across from, some time ago.

[beardedboss]

Just to clarify, I want to keep the audio tracks (all 4) from all the cameras and then add the Audio CD Tracks on top of the mix to enhance it, then mix the lot down.

The original cameras where all captured from HDV to Canopus HQ Fine AVI

[Ron Evans]

I think Vegas Studio Platinum HD is the lowest version that has the full capabilities you would need. You could try a trial of them all to see !!

The easiest for you is to mix from Edius the 4 tracks and export as a WAV file. Take into Vegas and use as the guide track. Line up the individual CD tracks on a track below the WAV file from Edius and expand the timeline so that you can see that the waveforms line up exactly. Under the options menu one can turn on or off quantize to frames. You want this OFF. The audio clips can now be moved in audio clock increments. If the audio from the CD is re sampled to 48K they should line up enough to be in sync for a single song without the need to stretch or squeeze. Do the same for all the CD tracks you want to overlay. You now have a few options. Do an audio mix in Vegas of these two tracks and take back to Edius or just render the track you put the CD tracks on and take that back to Edius then mix in Edius. I would do both and then choose what you want once your back in Ediuis.

By the way scrubbing in Vegas can be just like the others. You need to set the cursor in the right place. I have my Shuttle Pro V2 set up so that they all work the same way.

I use 4 cameras most of the time for my theatre shoots they run from the beginning to the end with no breaks, no tape changing to worry about as they are all AVCHD and an EX3 so sync is no issue.Just one clip from each of the cameras for each ACT. However as I said I make sure that the picture is in sync looking at them in multicam. I then export the audio as wav file and do the full audio mix in Vegas. What looks in sync in Edius can be just out a little even though most of the time I use the wireless mic at stage level, shotgun mic from one of the cameras and stereo from the fixed camera to give some depth to the mainly mono sound track.

If you need any more info just send me a PM.

Ron Evans