You are my hero. Thank you for such a quick and easy explanation. Appreciate the the "why" at the start, so hopefully I can just adjust my settings and prevent it from getting out of sync. Learned a shocking amount in less than 5 min. 10/10
Thank you...I had experienced this problem before...but, in the old days needed to cut and edit so many segments to get it right. Your video helped me walk through the quicker method to fix it.
This is an absolutely OUTSTANDING video. Great job, Brad!!! I've been dealing with these sync issues all the time, and the retime solution is perfect. It's crazy because I have sync issues even in footage with the same framerate, sample rate, etc. I still haven't figured out why it sometimes happens, but this is a perfect workaround and very well presented!
I'm glad you enjoyed this one Chris! Weird how you get the drift issue even with the same frame rate and sample rate, but this technique should work for you 😄🙏🏼
Thanks man for the video. I was actually struggling with this a few days ago and couldn't figure out how to fix it. But this really simple solution just works so well!
Righteous Tutorial As Always But The Drifting Wasn't My Light Bulb Moment In Time - It Was The ARROW DOWN For Jumping To The End Of The Clip - What A Key Framing Game Changer !!!! Enjoy The Weekend With The Family , Cheers
I film concerts with multiple cameras and edit in multicam. My iphone is the one to fix because it records in 30fps instead of 29.97. Fortunately fixing is pretty simple, but it adds to a workflow with hours long hlg footage. Thank you for this, you are the first person I’ve seen to address this issue.
Haven’t seen many people talk about it online, so I thought it would be a good topic for a video. It would be great if FCP had some kind of “auto sync drift correction” feature!
When I switched to using an external audio recorder years and years ago this drove me crazy. It was difficult to find not only how to fix but why. Or I just wasn't searching the right way. Eventually I figured out the retiming audio trick and then realized the cause was different sample rates. Now everything stays in perfect sync in FCP no matter how long my videos are. That and since FCP will do auto sync I've never had a problem. I still see people say the only way to do this is to use FinalEyez (I think that's how it's spelled) claiming FCP's sync doesn't work. With all that said, I still do three claps at the beginning of each video so that I have initial spikes if something is out of whack.
Yeah, I noticed it something that not many people talk about, so I thought I would make a video about it since I’ve been using this trick for years. A few years ago I used to use PluralEyes to sync complicated multicam, multi clip projects but honestly, Final Cut Pro does such a good job that I don’t feel the need to do that anymore 😄🙌🏼
Once I worked with a project which contained more than a hundred clips and after that I decided that I will never record audio externally again. The only way to avoid drifting completely is using timecode devices, which will send similar timecode to the camera and audio recorder. This piece of tech is pretty expensive and most of the mirrorless cameras doesn’t support timecode directly. So, recording straight to the camera is the most efficient way for me at this moment.
For those curious as to why the audio captured in camera drifts out of sync with the audio captured on an external audio recorder, or why multi-cam footage drifts out of sync with itself: It is because each device that is being used to record video and sound is relying on its own internal clock-circuitry to tell that device how long one second of time lasts for. And the clocks in all of these different devices are not perfectly identical and synchronized to each other. Have you ever changed the clock on your microwave and the clock on your stove to match the clock on your phone? Have you noticed that, weeks later, the clock on the microwave no longer lines up with the clock on the stove, and neither of those clocks line up with your phone anymore? Why? Aren't they all measuring time the same way? The answer is no. They are not. They are all measuring time at slightly differing speeds. One second of time according to the microwave might be slightly longer than one second of time according to the stove. Imagine this: Three friends get in to three different cars. They line their cars up at a starting line and agree that all three of them will drive side-by-side in a straight line at 60 km/hr. Each person is controlling the speed of their own car, with their own foot, on their own gas pedal, determining their speed from their own speedometer. Will all three cars stay perfectly, precisely, and 100% accurately aligned side-by-side as the cars drive for miles and miles? No. And why not? Because those cars are relying on three separate people to manage the speed of each car, and each person will have slight variances in how fast they drive. Even if those differences are tiny, over miles and miles of driving, those differences become significant. How would you keep all three cars perfectly aligned? You'd have to have their gas pedals all remotely controlled by a single, external mechanism. If that external mechanism slowed down, all three cars would slow down identically to each other. If that external mechanism sped up, all three cars would speed up identically to each other. Likewise, how would you keep the clock on the microwave, the stove, and your phone perfectly aligned? You'd connect each of them to a common external timing reference (the internet, for example) that would control how each device measured the length of one second of time. In audio and video production, you need a common external SPEED reference that connects to each piece of equipment and tells each device how long one second of time should last for. If all devices are running off of the same external clock (i.e. Genlock, Wordclock, Blackburst), then they will never drift. But, if they are all using their own internal clocks to determine how long one second of time lasts for (just like the microwave, the stove, and your phone, or the three separate cars with three separate drivers), then they will all eventually drift from each other because they are literally running at different speeds. Ideally, you'd use an external speed reference (Genlock, Wordclock, Blackburst) plugged into all of your recording equipment to ensure that each device is measuring one second of time identically. But barring that, just know that even if all of your devices are set to the same frame rate (video capture) and sample rate (audio capture), unless those devices are receiving an external speed reference from a master source, they are all running independently from the timing created by their own internal clocks and they will always drift from each other, because they are all measuring time differently. Those differences are slight but over a long recording they become apparent. This is why time-stretching or pitch-shifting the audio will always be necessary in a system where each device is running off of its own internal clock, rather than having all of the cameras and audio recorders locked to a single, master speed reference.
Different audio sample rates do not cause drift. There is no inherent sync between audio and video from any two different devices unless the are physically locked to the same hardware reference clock. That is why SMPTE timecode and lockit devices exist. There is no inherent sync between any two video cameras if they are not genlocked.
Hi, thanks for the helpful video! I have a problem with my gopro footage - when I just play in the finder the audio is normal. The moment I drop it onto a timeline in final cut - it goes outta sync (the audio is delayed 1 second. Any idea what is causing that? Thanks for your videos, I have been learning a tone from you! :))
That's really weird! I haven't comes across that issue unfortunately. I'd be curious to see if you converted the footage (using something like the free Handbrake app - www.Handbrake.fr) to see if it still happen. Worth trying to convert it to see if that solves the problem.
@@Brad_West allright, thank you! Now we actually figured it out! Turned out that dropping video filmed in 25fps into timeline in 30fps results in all sorts of weird mishaps 🤷♂️😅
It’s so much better now! 😅 It’s a pretty tiny square room so the reflections and echo in there was awful. Now the acoustics are so much better. About 250 panels later 😂
Thanks for the info! One question though. When I re-time audio in Final Cut, it sounds quite bad. Any way to prevent this? The only way I can think to explain what I am talking about is if you play a video at a faster speed on TH-cam on Chrome, the audio sounds perfect no matter the speed, whereas if you do the same in Final Cut, it sounds very bad.
If that is happening then it sounds like you are having to stretch the audio too much. It's tough to troubleshoot without seeing what's going on, but it seems like there is another issue that would cause you to need to stretch it to the point where the audio sounds bad.
Yes!! I face this issue often! Also there is a frame glitch issue in the final exported video from Final Cut Pro...When there are multiple layers of 4k or effects, in that particular portion, a particular frame gets frozen in the final export..So I need to export the video again and it has no guarantee that the video has no freeze frames!Kindly help me out
That’s such a weird issue, I’ve never experienced that. Have you updated to the latest version of Final Cut Pro? If not, I would do that, or Google how to trash, Final Cut Pro preferences to see if that helps. Let me know if it does 😄👊🏼
I am recording video via an iPhone 13pro and it seems to be locked at 44.1khz my audio is in 48khz(separate mics). Is there any way to change or upscale my iPhone video??
Thx for this one! We are still getting drift, starting around 1hr of recordings, even though video frame rates (24 fps on iphone, riverside and fcp) are all the same and audio sample rate is 48 khz (rodecaster pro 2, riverside, fcp) overall, too. Any idea, why it is still happening? Another challenge, regarding the fix in a 2 person in one room podcast recording is: we need to keep the multitrack audio clips in total sync, to avoid echo from overspeak. So fiddeling with the retime editor is a bit risky, I think. Is there a way to rather fix the drift on the video clip, instead? After an hour or so, we see about 1-3 frames diff. And we just insert a gap of that size, which is not a nice solution, I have to admin. ;) Suggestions for that, anyone?
It's weird that you are still getting drift with the same frame rates and sample rates, but this technique should still work the same. You can definitely apply the retiming to the video clip to achieve the same results. Ideally you don't want to slow the clip down because then you will have some video frames that will essentially last for 2 frames in the timeline and might look a tad jittery. But if you are speeding the clip up it should go mostly unnoticed. Give it a try and please let me know how it works out for you! 😄
@@Brad_West It worked! Thx. Great advice, that it's also an option for the video clip. Yes, it's weird. @riverside is telling me, this might be due to low performance of our 2017 mac book pro (4 core), which is below their sys req. We are using the continuity cam option. Maybe this is too much. We do not see such a massive impact on Apple M1 pro (second device) Still a little though. (3 to 5 frames after 1.5 hrs or so) Cheers!
@@Brad_West since we are podcasting, I will simply introduce a clap fir syncing at the end of the recording as well. That should make it easier to set the correction
Here's why it happens: The audio recorder and the camera are two separate devices, running quite literally, at two separate speeds. It doesn't matter if they're both set to 48 kHz, they are still running at two SLIGHTLY different speeds. Each of these devices contains an internal clock that tells the device how long a second is, but the clock built in to the camera and the clock built in to the audio recorder are not identical, perfect, and synchronized to each other. Have you ever changed the clock on your microwave to match the clock on your phone, then weeks later noticed that they no longer match? It's because those devices are not measuring one second of time EXACTLY the same. They drift over the weeks because the microwave's internal clock is measuring one second of time slightly differently than your phone is. Not by much, mind you, but small differences in timing become apparent over long durations. If your microwave could connect to the internet and receive its clock data from the same server that your phone receives clock data, they would never drift. But because they are separate devices, measuring time with their own unique, separate, internal clocks, they will never perfectly measure one second of time the same as each other. They will always be running at slightly different speeds. A common SPEED reference (i.e. Genlock, Blackburst, Wordclock) needs to be sent to the camera and the audio recorder to ensure that each device measures one second of time at exactly the same rate. Without a common SPEED reference for each device, drift will always occur over longer duration recordings because each device is using it's own internal clock to determine how long one second is.
@@michaelayottemusic thanks for the detailed answer man!!!! i guess ill always have to redo the audio...... I thought there would be a better fix... thanks again!!
Thanks for the detailed response @michaelayottemusic. That is exactly right and this fix will still work on clips with the same sample rate or frame rate that drifts out of sync.
Have you ever struggle with audio drifting out of sync before?
Heck yes. But not anymore thanks to this video!
Happy to hear it @@geoffrey-long 😄💪🏼
1000/10 well done and thank you very much
Glad you liked it! 😄👊🏼
I just came on here to say thank you. Quick and easy and solved my problem. Thanks!
Glad it helped! Thanks for taking the time to comment 😄🙏🏼
You are my hero. Thank you for such a quick and easy explanation. Appreciate the the "why" at the start, so hopefully I can just adjust my settings and prevent it from getting out of sync. Learned a shocking amount in less than 5 min. 10/10
So happy to hear the Geoff! Hopefully this is the end of your out of sync multicams 😄👊🏼
oh god, thank you so much! this was really plaguing me. insanely simple fix.
I’m glad you found it helpful! 😄🙌🏼
Thank you...I had experienced this problem before...but, in the old days needed to cut and edit so many segments to get it right. Your video helped me walk through the quicker method to fix it.
So glad to hear it helped you! 😄🙌🏼
Great, great video Brad. This helped me out and I know it'll help many other users.
Awesome, thank you so much man!
This is an absolutely OUTSTANDING video. Great job, Brad!!! I've been dealing with these sync issues all the time, and the retime solution is perfect. It's crazy because I have sync issues even in footage with the same framerate, sample rate, etc. I still haven't figured out why it sometimes happens, but this is a perfect workaround and very well presented!
I'm glad you enjoyed this one Chris! Weird how you get the drift issue even with the same frame rate and sample rate, but this technique should work for you 😄🙏🏼
Thanks man for the video. I was actually struggling with this a few days ago and couldn't figure out how to fix it. But this really simple solution just works so well!
Glad it helped! Yeah it’s a really simple solution, but a life saver 😅
Thankfully never had this issue but this is a great fix , another fabulous video mate ! Thanks for sharing Brad, it’s a keeper ! Cheers
Glad you enjoyed it. Hopefully if you do ever experience it, you'll remember this tip 😄🤞🏼
Righteous Tutorial As Always But The Drifting Wasn't My Light Bulb Moment In Time - It Was The ARROW DOWN For Jumping To The End Of The Clip - What A Key Framing Game Changer !!!!
Enjoy The Weekend With The Family ,
Cheers
Haha I'm glad you learned another quick tip as well. Appreciate you watching 😄🤙🏼
It's crazy that I stumble upon this problem
then I search on TH-cam and you just uploaded the solution
Thank you
Haha, the timing couldn't be more perfect 😄👌🏼
Very useful. Thank you.
Glad it was helpful!
I film concerts with multiple cameras and edit in multicam. My iphone is the one to fix because it records in 30fps instead of 29.97. Fortunately fixing is pretty simple, but it adds to a workflow with hours long hlg footage. Thank you for this, you are the first person I’ve seen to address this issue.
Haven’t seen many people talk about it online, so I thought it would be a good topic for a video. It would be great if FCP had some kind of “auto sync drift correction” feature!
Many thanks Brad👍
Sure thing!
When I switched to using an external audio recorder years and years ago this drove me crazy. It was difficult to find not only how to fix but why. Or I just wasn't searching the right way. Eventually I figured out the retiming audio trick and then realized the cause was different sample rates. Now everything stays in perfect sync in FCP no matter how long my videos are. That and since FCP will do auto sync I've never had a problem. I still see people say the only way to do this is to use FinalEyez (I think that's how it's spelled) claiming FCP's sync doesn't work. With all that said, I still do three claps at the beginning of each video so that I have initial spikes if something is out of whack.
Yeah, I noticed it something that not many people talk about, so I thought I would make a video about it since I’ve been using this trick for years. A few years ago I used to use PluralEyes to sync complicated multicam, multi clip projects but honestly, Final Cut Pro does such a good job that I don’t feel the need to do that anymore 😄🙌🏼
THANK YOU SO MUCH!!!
You're welcome!
Once I worked with a project which contained more than a hundred clips and after that I decided that I will never record audio externally again. The only way to avoid drifting completely is using timecode devices, which will send similar timecode to the camera and audio recorder. This piece of tech is pretty expensive and most of the mirrorless cameras doesn’t support timecode directly. So, recording straight to the camera is the most efficient way for me at this moment.
Yeah in that situation, recording directly to camera is a way easier solution!
Super handy!!!
Glad you think so!
This rarely happens to me but this fix is great.
Hopefully if you ever experience this, you will remember this technique 😄👊🏼
For those curious as to why the audio captured in camera drifts out of sync with the audio captured on an external audio recorder, or why multi-cam footage drifts out of sync with itself:
It is because each device that is being used to record video and sound is relying on its own internal clock-circuitry to tell that device how long one second of time lasts for. And the clocks in all of these different devices are not perfectly identical and synchronized to each other.
Have you ever changed the clock on your microwave and the clock on your stove to match the clock on your phone? Have you noticed that, weeks later, the clock on the microwave no longer lines up with the clock on the stove, and neither of those clocks line up with your phone anymore? Why? Aren't they all measuring time the same way?
The answer is no. They are not. They are all measuring time at slightly differing speeds. One second of time according to the microwave might be slightly longer than one second of time according to the stove.
Imagine this:
Three friends get in to three different cars. They line their cars up at a starting line and agree that all three of them will drive side-by-side in a straight line at 60 km/hr. Each person is controlling the speed of their own car, with their own foot, on their own gas pedal, determining their speed from their own speedometer. Will all three cars stay perfectly, precisely, and 100% accurately aligned side-by-side as the cars drive for miles and miles?
No. And why not? Because those cars are relying on three separate people to manage the speed of each car, and each person will have slight variances in how fast they drive. Even if those differences are tiny, over miles and miles of driving, those differences become significant.
How would you keep all three cars perfectly aligned? You'd have to have their gas pedals all remotely controlled by a single, external mechanism. If that external mechanism slowed down, all three cars would slow down identically to each other. If that external mechanism sped up, all three cars would speed up identically to each other.
Likewise, how would you keep the clock on the microwave, the stove, and your phone perfectly aligned? You'd connect each of them to a common external timing reference (the internet, for example) that would control how each device measured the length of one second of time.
In audio and video production, you need a common external SPEED reference that connects to each piece of equipment and tells each device how long one second of time should last for. If all devices are running off of the same external clock (i.e. Genlock, Wordclock, Blackburst), then they will never drift.
But, if they are all using their own internal clocks to determine how long one second of time lasts for (just like the microwave, the stove, and your phone, or the three separate cars with three separate drivers), then they will all eventually drift from each other because they are literally running at different speeds.
Ideally, you'd use an external speed reference (Genlock, Wordclock, Blackburst) plugged into all of your recording equipment to ensure that each device is measuring one second of time identically. But barring that, just know that even if all of your devices are set to the same frame rate (video capture) and sample rate (audio capture), unless those devices are receiving an external speed reference from a master source, they are all running independently from the timing created by their own internal clocks and they will always drift from each other, because they are all measuring time differently. Those differences are slight but over a long recording they become apparent.
This is why time-stretching or pitch-shifting the audio will always be necessary in a system where each device is running off of its own internal clock, rather than having all of the cameras and audio recorders locked to a single, master speed reference.
This is 100% correct Michael. Thanks for sharing such a well thought out comment on here with everyone 🙏🏼
Awesome
😄🤙🏼
Different audio sample rates do not cause drift. There is no inherent sync between audio and video from any two different devices unless the are physically locked to the same hardware reference clock. That is why SMPTE timecode and lockit devices exist. There is no inherent sync between any two video cameras if they are not genlocked.
Thanks for the great explanation Mark! Appreciate you taking the time to watch 😄🙏🏼
Hi, thanks for the helpful video! I have a problem with my gopro footage - when I just play in the finder the audio is normal. The moment I drop it onto a timeline in final cut - it goes outta sync (the audio is delayed 1 second. Any idea what is causing that? Thanks for your videos, I have been learning a tone from you! :))
That's really weird! I haven't comes across that issue unfortunately. I'd be curious to see if you converted the footage (using something like the free Handbrake app - www.Handbrake.fr) to see if it still happen. Worth trying to convert it to see if that solves the problem.
@@Brad_West allright, thank you! Now we actually figured it out! Turned out that dropping video filmed in 25fps into timeline in 30fps results in all sorts of weird mishaps 🤷♂️😅
Ah I see@@twentytwentycoffee ! Glad you figured it out 😄
Dude what's the sound like in that room??? It's fully decked out in sound acoustic foam panel!
It’s so much better now! 😅 It’s a pretty tiny square room so the reflections and echo in there was awful. Now the acoustics are so much better. About 250 panels later 😂
Thanks for the info! One question though. When I re-time audio in Final Cut, it sounds quite bad. Any way to prevent this? The only way I can think to explain what I am talking about is if you play a video at a faster speed on TH-cam on Chrome, the audio sounds perfect no matter the speed, whereas if you do the same in Final Cut, it sounds very bad.
If that is happening then it sounds like you are having to stretch the audio too much. It's tough to troubleshoot without seeing what's going on, but it seems like there is another issue that would cause you to need to stretch it to the point where the audio sounds bad.
@@Brad_West I stretched it by the same amount in Adobe Audition and it sounded perfect. Thanks for the tutorial! I was worried there’d be no fix 😭
@Sillykids oh wow, that’s weird! How much did you have to stretch it by? Like what percentage?
@@Brad_West It was so small that Final Cut wouldn't even say it was anything different than 100% of its normal speed
I'm surprised that small amount made it sound weird.@@Sillykids
Yes!! I face this issue often! Also there is a frame glitch issue in the final exported video from Final Cut Pro...When there are multiple layers of 4k or effects, in that particular portion, a particular frame gets frozen in the final export..So I need to export the video again and it has no guarantee that the video has no freeze frames!Kindly help me out
I use M2 MacBook air
That’s such a weird issue, I’ve never experienced that. Have you updated to the latest version of Final Cut Pro? If not, I would do that, or Google how to trash, Final Cut Pro preferences to see if that helps.
Let me know if it does 😄👊🏼
How do you convert if shot at the wrong sample rate? I'm not finding an easy answer...
If you are wanting to just convert the audio, the a free app like Audacity will work.
I am recording video via an iPhone 13pro and it seems to be locked at 44.1khz my audio is in 48khz(separate mics). Is there any way to change or upscale my iPhone video??
I'm not 100% sure. I feel like there should be a setting for that. You might need to Google to see if it's possible.
iPhone uses variable frame rate. The 44.1khz is not even an exact 44.1lhz.
Thx for this one!
We are still getting drift, starting around 1hr of recordings, even though video frame rates (24 fps on iphone, riverside and fcp) are all the same and audio sample rate is 48 khz (rodecaster pro 2, riverside, fcp) overall, too.
Any idea, why it is still happening?
Another challenge, regarding the fix in a 2 person in one room podcast recording is: we need to keep the multitrack audio clips in total sync, to avoid echo from overspeak. So fiddeling with the retime editor is a bit risky, I think. Is there a way to rather fix the drift on the video clip, instead? After an hour or so, we see about 1-3 frames diff. And we just insert a gap of that size, which is not a nice solution, I have to admin. ;) Suggestions for that, anyone?
It's weird that you are still getting drift with the same frame rates and sample rates, but this technique should still work the same. You can definitely apply the retiming to the video clip to achieve the same results. Ideally you don't want to slow the clip down because then you will have some video frames that will essentially last for 2 frames in the timeline and might look a tad jittery. But if you are speeding the clip up it should go mostly unnoticed. Give it a try and please let me know how it works out for you! 😄
@@Brad_West all right. Will do. Thx.
@@Brad_West It worked! Thx. Great advice, that it's also an option for the video clip. Yes, it's weird. @riverside is telling me, this might be due to low performance of our 2017 mac book pro (4 core), which is below their sys req. We are using the continuity cam option. Maybe this is too much. We do not see such a massive impact on Apple M1 pro (second device) Still a little though. (3 to 5 frames after 1.5 hrs or so)
Cheers!
@@BorisCzizikowski Interesting! At least a 3-5 frame drift is relatively easy to fix. I wish Riverside could lock all the angle/sources together.
@@Brad_West since we are podcasting, I will simply introduce a clap fir syncing at the end of the recording as well. That should make it easier to set the correction
This does not work for me. I cmd-r but my audio does not stretch to fit in sync
When you hit Cmd R do you see the green bar above the clip? When you retime you need to grab the little handle on the green bar.
My audio ALWAYS drifts, and i have all of my equipment on 48khz .... why do you think that is?
Here's why it happens:
The audio recorder and the camera are two separate devices, running quite literally, at two separate speeds. It doesn't matter if they're both set to 48 kHz, they are still running at two SLIGHTLY different speeds. Each of these devices contains an internal clock that tells the device how long a second is, but the clock built in to the camera and the clock built in to the audio recorder are not identical, perfect, and synchronized to each other.
Have you ever changed the clock on your microwave to match the clock on your phone, then weeks later noticed that they no longer match? It's because those devices are not measuring one second of time EXACTLY the same. They drift over the weeks because the microwave's internal clock is measuring one second of time slightly differently than your phone is. Not by much, mind you, but small differences in timing become apparent over long durations. If your microwave could connect to the internet and receive its clock data from the same server that your phone receives clock data, they would never drift. But because they are separate devices, measuring time with their own unique, separate, internal clocks, they will never perfectly measure one second of time the same as each other. They will always be running at slightly different speeds.
A common SPEED reference (i.e. Genlock, Blackburst, Wordclock) needs to be sent to the camera and the audio recorder to ensure that each device measures one second of time at exactly the same rate. Without a common SPEED reference for each device, drift will always occur over longer duration recordings because each device is using it's own internal clock to determine how long one second is.
@@michaelayottemusic thanks for the detailed answer man!!!! i guess ill always have to redo the audio...... I thought there would be a better fix... thanks again!!
Thanks for the detailed response @michaelayottemusic. That is exactly right and this fix will still work on clips with the same sample rate or frame rate that drifts out of sync.
😂