Sync issues with Multicam

tedsled

Newbie Joined: Jan 30, 2023 16:35 Messages: 5 Offline

Solved by

Jan 30, 2023 16:52

Newbie here.

Quick word on my setup. Four video cameras all shooting at 1080P/60. Audio is recorded on each using the internal mics. The REAL audio is also being recorded via a mic/interface/computer and the software Reaper. I am rendering the audio from Reaper to be used as the master audio track. Video is being cut in my living room with lots of light and sound deadening materials. Subject is a singer/guitar player. I'm trying to make a music video. We are doing one song at a time to keep file sizes reasonable.

Finally figured out that the audio based sync in multicam doesn't seem to work if there is a substantial amount of delay between each camera. Like the time it takes to walk from one to the next and start them recording is apparently way too long.

So, I tried editing the original video from all four cameras so they all begin and end within a second or two of each other and I did the same with the imported audio file (produced via my DAW, Reaper and rendered as a WAV file) and then performing the audio sync again and I thought at first it worked because, well it was working.... for a while.

However I discovered while attempting to create the video that about two minutes into the operation, the video suddenly glitched and was now off by maybe a second, maybe a bit more. It was sudden, not like it slowly drifted out of sync and it affected all four cameras.

I've viewed each of the video files from each camera and they look fine...no glitches anywhere. Same for the audio file. No clue why this is happening.

Tearing hair out (and there's far too little left!).

Could sure use some help. I'll be happy to provide any and all specifics on cameras, video stats, computer hardware and so forth if it is needed.

Thanks
ted

optodata

Senior Contributor Location: California, USA Joined: Sep 16, 2011 16:04 Messages: 8630 Offline

Jan 30, 2023 17:11

Quote Finally figured out that the audio based sync in multicam doesn't seem to work if there is a substantial amount of delay between each camera. Like the time it takes to walk from one to the next and start them recording is apparently way too long.

Something else is going on because you should be able to sync all the clips regardless of how much dead air/other sounds preceed or follow the sections of interest. I've never had a problem doing that with up to 4 cameras, all started manually at varying times.

Maybe try adding/syncing one clip at a time rather than all of them at once. Also try syncing to a video clip rather than from your WAV file and only add that at the end to see if that makes a difference.

If you still have trouble, place two of the clips on the main timeline, select both then click on the Sync by Audio button that will appear above the timeline. When that's done, cut the starting position of each clip at the same point so they both start at the exact same time.

Do the same thing with each other clip until you have them all physically starting at the same place, then spearate them horizontally and use the Range Produce tool to produce each one individually. If SVRT is available on the Produce page, it'll only take a couple seconds and you won't lose any video quality.

PD should automatically import each clip as it's produced, and then you can simply import all of them into the MultiCam Designer from the Media Room and not worry about syncing them so you can get straight to work

tedsled

Newbie Joined: Jan 30, 2023 16:35 Messages: 5 Offline

Jan 30, 2023 17:51

Quote

Something else is going on because you should be able to sync all the clips regardless of how much dead air/other sounds preceed or follow the sections of interest. I've never had a problem doing that with up to 4 cameras, all started manually at varying times.

>>>>I wish that worked for me, but until I closely edited the original video files so each started and ended very close to each other I was getting wild things like one video clip and the imported audio being moved to the very end of the other video clips.

Maybe try adding/syncing one clip at a time rather than all of them at once. Also try syncing to a video clip rather than from your WAV file and only add that at the end to see if that makes a difference.

>>>>Tried that. Even with only one video clip and the imported audio file, it still started acting up about two minutes in.

If you still have trouble, place two of the clips on the main timeline, select both then click on the Sync by Audio button that will appear above the timeline. When that's done, cut the starting position of each clip at the same point so they both start at the exact same time.

>>>>>I'm not sure I know how to do that just yet. Still a newbie.

Do the same thing with each other clip until you have them all physically starting at the same place, then spearate them horizontally and use the Range Produce tool to produce each one individually. If SVRT is available on the Produce page, it'll only take a couple seconds and you won't lose any video quality.

>>>>>I KNOW I don't know how to do any of that!!! The whole reason I bought this software is for the multicam function. I sure would like it better if it just worked cuz I'm not a video person, at least not yet.

PD should automatically import each clip as it's produced, and then you can simply import all of them into the MultiCam Designer from the Media Room and not worry about syncing them so you can get straight to work

>>>>>But I HAVE to sync them together, right? I mean I need the audio to sync up with his lips while he's singing. Whole point, right?

Edit again: I see what you are talking about. Sync each individual clip with the audio I want to use, one at a time. Then they should be "synced" without using the sync feature in MultiCam, right? Sorry, I misread that the first time around.

One last thing I might mention. I have had better results when I had the talent clap his hands in a random fashion at the beginning of each song we recorded. Seems like the analysis does better keying off transients rather than just straight music.

Thanks so much for the reply. I'm gonna keep trying things and if anything else comes to mind I'd sure appreciate any additional help.

Edit...I see how inline comments are handled on this forum. Sorry about that.

This message was edited 3 times. Last update was at Jan 30. 2023 17:59

optodata

Senior Contributor Location: California, USA Joined: Sep 16, 2011 16:04 Messages: 8630 Offline

Jan 30, 2023 18:10

Clapping hands, or creating any kind of clean, short, obvious sound is a good idea if you won't otherwise have those kinds of sounds in your recordings. It's a lot easier for PD to sync on those that it is on chord changes and other similarly subtle changes

tedsled

Newbie Joined: Jan 30, 2023 16:35 Messages: 5 Offline

Jan 30, 2023 18:26

Quote Clapping hands, or creating any kind of clean, short, obvious sound is a good idea if you won't otherwise have those kinds of sounds in your recordings. It's a lot easier for PD to sync on those that it is on chord changes and other similarly subtle changes

Indeed and that's why I thought I had cracked the code on this. It's the sudden glitch at about two minutes and the loss of sync that's got me in a tizzy.

I had one idea: tell all the musicians I work with that they can't write a song longer than two minutes if they want me to try and make a video for them!!! Muy main gig is running a recording studio and I've been an audio engineer for decades. It's just that so many of the folks I work with want some kind of performance video for online streaming and I thought I'd dip my foot into the video world. I'm finding the workflow paradigm is completely different, at least for this specific type of video and I'm having a hard time getting my arms around it. That's why I was so attracted to the Multicam ability. I mean I can switch from one camera to another.

I get the whole NLE method of storyboarding every single thing and shooting things as clips. But in this case, it's much more like producing a live video stream using a video switcher and doing things on the fly. It would take extraordinary effort to script every aspect of a live music event. And even then, there's no guarantee that the talent would stick to it!!

optodata

Senior Contributor Location: California, USA Joined: Sep 16, 2011 16:04 Messages: 8630 Offline

Jan 30, 2023 20:00

I'm not sure what's happening 2 minutes in. There's no reason any clips should go out of sync in either the MC Designer or on the main timeline, but is the glitch only present when you're previewing the clips? In other words, if you produce the project, is everything normal?

If so you'll probably need to lower the timeline's preview resolution as I believe that setting carries over to the MCD tool as well. See this FAQ.

optodata

Senior Contributor Location: California, USA Joined: Sep 16, 2011 16:04 Messages: 8630 Offline

Jan 30, 2023 20:12

Also I agree that the MCD tool is a lot like using a video switcher, but you can also pause and go back and swap any camera and also slide the switch point forward or backward as needed.

Be aware that you can't save the project while the MCD is open, so remember to hit OK and exit the tool then save the project every so often so you won't lose too much work if anything bad happens. You can then go back to the MCD to continue - just remember that any changes you made to the synced clips on the main timeline will be deleted if you make more edits in the MCD, so make sure you're happy with the results before doing any main timeline edits on those clips.

See this related post and this one for more info

This message was edited 1 time. Last update was at Jan 30. 2023 20:14

tedsled

Newbie Joined: Jan 30, 2023 16:35 Messages: 5 Offline

Jan 31, 2023 11:31

Quote Also I agree that the MCD tool is a lot like using a video switcher, but you can also pause and go back and swap any camera and also slide the switch point forward or backward as needed.

Be aware that you can't save the project while the MCD is open, so remember to hit OK and exit the tool then save the project every so often so you won't lose too much work if anything bad happens. You can then go back to the MCD to continue - just remember that any changes you made to the synced clips on the main timeline will be deleted if you make more edits in the MCD, so make sure you're happy with the results before doing any main timeline edits on those clips.

See this related post and this one for more info

Once again, thanks for the help. In my research I found another post from about 7 years ago that mentioned the preview resolution as well. I'm gonna try that and see if it works. I'll post the results.

I'm a little bit surprised this machine can't handle Full HD as it's a pretty strong box, but if I can accomplish my goals at a lower rez, I'm good with that!!

This message was edited 1 time. Last update was at Jan 31. 2023 11:32

tedsled

Newbie Joined: Jan 30, 2023 16:35 Messages: 5 Offline

Mar 08, 2023 17:36

So it turned out to be something wrong with just one of the three songs we did. Of course, it was that one I tried first! The other two synced perfectly and I was able to produce a video of each (albeit a rather boring one! This was a learning experience and proof of concept more that an attempt at a commercially ready product). At some point I wanna take another look and see if I can figure out what went wrong. Make sure I don't repeat whatever happened for a paying customer.