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Canon SLR Footage Framerate & Audio Sync Problem
Even though this may be a simple problem, thought it might be worth posting since these cameras are starting to become popular.
So, the cameraman was using the Canon T1i, which has 2 options, 1080 @ 20fps (that’s right, 20) or 720 @ 30fps. They thought resolution was the most important so they chose the 1080 option.
It also doesn’t have a mic input, so they recorded the audio separately on a digital field recorder.
Well, I’m having audio sync issues on the timeline. Oddly, it would seem I’m having trouble with the audio file, not the video, although it may be a linked problem. Basically the audio waveforms are not matching the audio playback, and it gets progressively worse as you get farther down the timeline. Also, the audio goes out of sync with the video at about the same rate. As a result, if you sync the video to the beginning of the audio track, the end is out of sync, or vice-a-versa, so either FCP is confused or I have bad material or a bit of both.
So, I tried converting both using Quicktime to mov’s. Then did the same with Compressor. Neither worked. I chose ProRes 422 24fps since it was the closest (but am open to other opinions) and 48KHz sampling. I am starting a brand new project to make sure it builds new waveforms. I have ensured the Sequence settings are set to 24fps (not 23.98) and 48KHz.
Still, the audio playback/waveforms/video do not want to match up. Audio/Video go out of sync about 1 sec from start to finish.
So, my super technical highly tricky (haha) workaround is this:
1. Find sync point at beginning
2. Find sync point at end
3. Subtract the two to get your difference in playback “speed.”
4. Don’t adjust video as it looks horrible, but instead adjust the “speed” of the audio by that amount, compensating in whichever direction you need to (it’s 50/50 folks)
5. Voila! done.This is not an ideal situation and if anyone has an inkling as to why this is happening and whether you believe it’s the video, audio, or sequence causing the problems, I’d love to fix the “problem.”
As always, thanks for the input.
Naiche
Mac Pro
Dual 2.8Ghz Quad-Core
16GB RAM
ATI Radeon 256MB
320GB 7200rpm
3TB 7200rpm Internal Software RAID0
Blackmagic Studio Card (working good so far) -
12 Replies
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Hi Naiche,
Make a test.
Do this with a duplicated of the Audio file, of course.
– Open any Audio file in QT, and see the Properties (Comm-J).
– Look if there is a TC track and DELETE.
Try if you can sync in FC.
rafael -
Hey Rafael,
I’m sorry but I’m not familiar with the term “TC Track.” I tried looking at the properties and only saw a Sound Track, that could be deleted, which I did, but FCP wouldn’t recognize it after that. I also tried extracting the Sound Track and saving as separate mov. This time FCP recognized it, but it was still out of sync.
Best,
Naiche
Mac Pro
Dual 2.8Ghz Quad-Core
16GB RAM
ATI Radeon 256MB
320GB 7200rpm
3TB 7200rpm Internal Software RAID0
Blackmagic Studio Card (working good so far) -
Someone on the other FCP forum was having a similar issue with not having sync between video shot on the DSLR and audio recorded. It’s not exactly the same and I don’t think there’s a resolution yet, but maybe reading it will spark something?
https://forums.creativecow.net/thread/8/1070880
If the video was recorded at 30 fps and the audio at 29.97 separately, wouldn’t that cause your issue then, too? Maybe you can try using Cinema Tools to conform the audio..
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Naiche,
Your picture is 20 fps but because the audio was recorded separately, in either 24fps or 30fps, it will progressively go more and more out of sync.
1) If you open the audio file in quicktime it should tell you the fps.
2) Check the framerate of your sequence in sequence settings. (Right click on the sequence icon in the browser, go to settings.)
3) Match the sequence framerate to your audio framerate. Your 20fps video footage might need to be rerendered but perhaps it will match up.
4) Last Resort Option: I don’t know how long your project is but if it isn’t too long and nothing else works, you might need to slice the audio up and manually resync it periodically.
Good luck.
Also:
According to Canon, they designed their video functions on their new DSLRs with journalists in mind, not filmmakers so that accounts for things like 20 fps. However, they have acknowledged the broad filmmaking interest in their cameras and seem to be responding. Supposedly a 24p firmware upgrade is coming to the 5D2.
If you’re interested in DSLR video stuff, the Magic Lantern website has useful info, a 5D filmschool, and free firmware.
Josh
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In Audio there are not FRAMES.
Unless you record with an associated TC, the audio shouldn’t have any problem when working with any time-base video.
When you record audio at 48Khz, you know that every 48.000 samples is a second. You don’t need nothing else to measure the time in Audio. if some time TC is used, is to make sync easier.
I really do not understand this issue. The audio that Naiche have it contents not Time Code.
There is something wrong with the WAVE files.
rafael -
I think eventually someone will figure this one out. There was no TC track with the audio. It was recorded on an M-Audio portable field recorder. It was recorded at 44.1Khz, but I’ve tried every combination of converting it to 48Khz, or changing the sequence settings to 44.1Khz. Either way I think Rafael is right that there is a problem with the file (or systemically the recorder).
The real oddity is that the waveforms didn’t line up with the audible sound of the file. In addition it went out of sync with video, 2 distinct things going on.
Anyway, I found my workaround. Just thought I’d see what everyone has to say on the issue.
Yeah, the other post seems like a different problem, but thanks for posting anyway.
Naiche
Mac Pro
Dual 2.8Ghz Quad-Core
16GB RAM
ATI Radeon 256MB
320GB 7200rpm
3TB 7200rpm Internal Software RAID0
Blackmagic Studio Card (working good so far) -
Has any one found a fix to this? having similar problems with the T1i?
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After all this time, I have not found a solution.
I have done similar projects since then, and even with the 720p/30fps footage I still get sync issues.
I am beginning to think that the problem is with FCP. You should be able to convert anything to make it work, but no conversion technique seems to work. Nor does any sequence setting adjustment work.
That said, Canon doesn’t seem to be taking this issue seriously either.
I have not heard of these issues with the Lumix or other HD DSLR cameras. Perhaps Canon is not the best choice moving forward.
We are left in the crappy position of having to manually sync audio after editing.
I have yet to try out the $149 third party solution DualEyes…
https://www.singularsoftware.com/dualeyes.html
…so can’t say if that works.Best of luck,
NaicheNaiche
Mac Pro
Dual 2.8Ghz Quad-Core
16GB RAM
ATI Radeon 256MB
320GB 7200rpm
3TB 7200rpm Internal Software RAID0
Blackmagic Studio Card (working good so far) -
What kind of SDHC card are you using? I was reading in the manual and in other sources on line that you need a class 8 or higher SDHC card to do longer takes. Haven’t went out and bought one yet to test, but the numbers logic kind of makes some sense.
In the meanwhile we’ve been doing a sync slate at the beginning and end of takes to have two sync places.
seems to be a quick fix, but nonetheless a hassle. -
I’ve been using Class 6 and haven’t had write issues, or at least that I’m aware of. Interestingly, using 720p, there was one time that the camera stopped recording at 2.85 GB around 14 mins. Perhaps this is why. Other times, I have been able to record a full 4GB file at about 20 mins or so.
Naiche
Mac Pro
Dual 2.8Ghz Quad-Core
16GB RAM
ATI Radeon 256MB
320GB 7200rpm
3TB 7200rpm Internal Software RAID0
Blackmagic Studio Card (working good so far)
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