Clips are slightly out of sync

[Vinicius5DCC]

Hi, I've been trying to figure out a way to get two or more clips perfectly in sync but since I can't move a clip less than a frame and one frame is way too much for getting them in a perfect sync, what can I do to solve this? 

I'm sure there is way I can to fix this, right? Any tips? 

Thank you in advance.

Take care.

[Richard M Knight]

As you said video clips can only be moved in one frame jumps. There is no real way around this. Audio on the other hand cane be moved down to sample level, often 48000th of a second. If you unlink the audio from the video and select 'audio time units' instead of timecode you can then move the audio at this higher resolution. I often do this to align audience reaction audio to stage audio to remove time delay echos. With regards to video with modern rolling shutter cameras the top of the frame is not in sync with the bottom anyway.

[Vinicius5DCC]

Thanks for the help, Richard.

Richard, I have three cameras and I also have a professional mixed audio track. I'm using the audio from the cameras just to get them in perfect sync. 

I can get the professional audio track in perfect sync with camera 1. No problem so far since I can move the audio track in higher resolution. But how can I get camera 2 and 3 in perfect sync with camera 1? Unlinking their audio seems pointless to me since I won't be able to move camera 2 and 3 in higher resolution anyway...

So, multiple cameras are suppose to be slightly out oof sync? 

Sorry if I'm missing something.

[RobShultz]

Maybe try using Multicam. Highlight your best audio first in the project panel and then the other sources. Right click, create multi camera source sequence sync to audio. From there you can add the multicam sequence to your timeline and add the multi cam button to the program monitor. Play the sequence and cut to the camera shots that you want.

[R Neil Haugen]

If you have separate audio, something that has no video ... simply selecting all the media both camera and the audio, Premeire will auto-select the audio-only file to sync to. It's normally a pretty easy process to setup.

Then it creates a multicam sequence and depending on how you select that to open it, it appears as either a stack of all the cams on different video tracks for selecting the 'cut' order (blue on the timeline), or a single track (in green) as-cut.

Neil

[Michael Grenadier]

unless you're shooting in a professional environment where all the cameras are "genlocked" there's gonna be some drift between the cameras.  If you had a very precise clock, you'd see that video which is shot in 1 frame increments and those frames would not be perfectly aligned between the cameras.  The fact is that you may hear the difference between the different audio tracks, but it's highly unlikely you'll be able to perceive any problem with the synch within a frame.  and regardless, you're just gonna have to live with it.

[Vinicius5DCC]

Thanks. Point made.

It's hard for me watching this slightly off sync videos on my timeline though. I'm a musician so maybe that's why this bothers me so much. 

Thanks again, guys.

[Richard M Knight]

In the natural world sound is allways behind the picture, due to the fact that the speed of light is a lot faster than the speed of sound. The human brain expects this and it looks natural. If you have close sync in a video and it still looks 'wrong' there's a good chance the sound is before the pictures, the brain cannot cpoe with this. Try moving your 'wrong' pictures a frame earlier it might all heal up.

As an asside, what is real sync?

I have made a dozen or so dvds of organ recitals, shot around the organ consoles. When the organist presses a key you expect to hear the note but with some stops there is a delay before the pipe speaks so the sound is late. The pipes themselves are often tens of feet away and some are closer than others. So just listening live at the console the sound is 2 or 3 frames late. The  recordist I work with mics the organ about 80 feet down the nave so that is 2 frames late. When we made the first dvd we tried various sync variations and the only one that looked right was to have the note heard as the key was pressed, this, in real life, never occurs. 

In St Paul's cathedral in London there is a rank of trumpet pipes over the west door,  a couple of hundred feet from the rest of the organ. If using these pipes with the main organ the organist has to play the pipes a beat early so that their sound is in sync with the other stops. Of course if you are sitting at the west end everything is even furthur out of sync.

[R Neil Haugen]

Richard has a great comment!

Besides this video/video-post thing, I'm also a musician and have performed in, directed, and recorded various music things. Including directing a hand-bell choir performing in a loft at the back of the sanctury while the organist and the main pipe installation were at the front, 200 feet away.

Timing when 'we' played against the organ was tricky enough, as if we played what sounded "with" the organ, our sound got to the audience in-between as as notably late. So it took some practice on my part to keep my group directed ... and ahead of the organ.

Then the organist decided to change "stops", the selection of pipes, for one section. To the "antiphonal organ" stop of pipes that were also in the balcony with us. Oh, that was a joy ...

Of course, we needed to play exactly with those pipes, but before and after, when he was using the main organ, play ahead of him. Right ...

We hadn't been doing too bad before he added the antiphonal organ. After that, we never 'stuck the landing' for getting accurately "with" the organ. And got some comments that it was awesome, others that well it was nice but can't the bells keep up with the organ?

I did a video recording, and from that, told people I could prove the organ wasn't keeping up with the bells! Because naturally, with the bells right next to the camera, our sound arrived first most of the time.

So ... as both someone with years in camera work and now video post, and as a life-long musician ... recording music live is a hassle. And there are always compromises.

Neil

[Vinicius5DCC]

Thanks again, guys.

Maybe I didn't make myself clear on my issue with the sync between the cameras. I'll do my best this time:

I'm shooting myself while I'm recording guitar on a song, so there are multiple guitar takes until I get it right. Once I get a good take, I stop shooting. Then I will record a second guitar part and I start shooting again, and like the first guitar part, there are multiple takes until I get the right one. So, this process repeats with the third guitar part... Pretty much the same.

Now, since the shooting was made with just one camera, but there are three different guitar takes, it's just like having three cameras, since there are three clips on my timeline. The clips will be synced using the click track that the cameras's mic picked up as a reference, so there shouldn't be an issue getting allin  clips sync.

The problem is: it's impossible to align the click tracks from the three cameras because camera 1 will be less than a frame "earlier" than camera 2 on my timeline. And the camera 3 may be a little "late" from camera 2. I can get the professional audio in pefect sync with one of the cameras but the other two will look slightly off.

I won't use the audio from the cameras in the final project, they will be used just to get all cameras in sync, so there is no point on moving their audio.

Thanks so much for the help!

[R Neil Haugen]

Thanks for the description ... I would not have thought of that from your earlier comments.

So it sounds like you take say the three different guitar video tracks, three synced audio tracks (one for each different guitar part) ... and try and sync the audio with video while you're cutting between camera views while the audio program plays.

Shooting a higher frame rate, and using that for the sequence frame rate ... say 59.94/60fps might make the sync close enough to be less noticeable to you. Although if you dropped that back to 24/23.976/29.97 for output, not sure how that would all look ... hmm.

Neil

[Vinicius5DCC]

I tried doing exactly what you just suggested. I was surprised that I didn't notice any difference regarding the sync issue at al. I was shocked, actually.