Videomaker – Learn video production and editing, camera reviews › Forums › Technique › Sound › sync external soundtrack
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July 5, 2008 at 11:30 PM #41532AnonymousInactive
I bought a Canon MiniDV camcorder thinking that that it had an audio input, which it does not. The picture quality is fantastic when the lighting is good, so I don’t want to buy another one for the sake of getting audio in.
I have had mixed results trying to use my laptop for direct audio recording. The built in sound card is noisy, the hard drive is too slow, and there are lots of other things that seem to interfere. Most laptops just are not intended to be used for recording.
So, what I need to be able to do is to record audio using portable digital audio recorder and some high quality condenser mics (phantom powered). I want to process the audio prior to synchronizing it with the video from the camcorder.
What I need to know is, how easy or difficult is it to sync the audio? What software (Windows) do you recommend? Are there any portable audio recorders you would recommend? I would prefer to use something with a USB or Ethernet interface. I don’t have a firewire port on my laptop. Price and portability are a big deal. The less expensive and more portable it is, the better.
Any tips or tricks that I can do while recording to make the synchronization process smoother?
I’m fairly new at this. Any ideas/advice is welcome.
July 5, 2008 at 11:41 PM #175981RobParticipant
are you sure your camcorder has no mic input? they usually do, but it’s a 1/8″ jack instead of XLR. If you do have the 1/8″ look into purchasing the BeachTek XLR adapter.
To answer your question though, i believe what they do in hollywood makes it easy to sync the audio. Of course film doesn’t record audio. So what they do is hit record on the camera to start rolling, then they use the clap board. When they get into post they can match up the audio of the director saying “take 5, blah blah blah” which is also seen by the camera because its on the clapboard, and then they can match up the sound of the clapboard snapping shut with the image recorded of the clapboard snapping shut. make sense?
July 6, 2008 at 4:43 AM #175982GilbyGoodParticipant
The recorders that are used on pro film has a crystal sync and the clapboard is used to find the point of sync. In super-8 film I used pulses (one per frame) to sync up the film and the tape. As to how to sync up a tape to your video I don’t know but maybe someone else can give all of us more information.
July 6, 2008 at 9:57 PM #175983AnonymousInactive
Yes, I am absolutely positive my Canon ZR700 camcorder does not have a usable audio input. The model BELOW it and above it did! Screwy, but a blessing in disguise. I want top-notch audio, so this is a better way to go.
You guys are right on about how to sync the recordings. I spoke with a recording engineer at one of the local studios, and he said pretty much the same thing. He suggested when I begin the recording, do something that produces a loud, instantaneous transient on both the camcorder soundtrack and the audio recorder soundtrack. Import both into the software and “nudge” the transient peaks into place with a waveform editor. Sounds like a plan.
I am looking at getting the Zoom H4 portable recorder, and using uncompressed audio for the highest possible quality. Is there any advantage to spending more to get the Marantz PMD660? It costs more, and it costs $250 to get the software to manipulate its proprietary format. The H4 comes with software.
July 6, 2008 at 11:14 PM #175984AnonymousInactive
All the advice about starting with a clap would be useful if your camera didn’t have a built-in mic. But when put your video on a timeline that splits it into an audio and a video track. Set the audio track to display audio as a waveform. Import whatever flavor of digitally recorded audio you like and when placed on the time line, it displays itself as a waveform. You don’t even have to look very closely to see that the waveforms will practically match. Then it is a fairly simple matter to fine tune the synch. You don’t need to start your recording with some loud sound just to synch the sound, cause then you also have to never stop either device and make that “synch point” part of the timeline.
This is no difficult thing. I used to teach senior citizens to synch audio on linear editors and that takes a bit of skill. Since the mics and the camcorder are not in exactly the same spot, there will be noticeable differences where the camcorder records extraneous noise. But you can do your synching anywhere both tracks were running at the same time. Even if you stop one machine or the other, re-synching takes just a few seconds.
So far as recording devices go, you get what you pay for. And that is even more so with mics. I don’t know why you are having problems with using your computer to capture audio. The processing required for this task doesn’t begin to tax a computer’s resources. But as you suggested, you may have a defective sound card. So what you really want to look into first is the mics you plan on recording with. Not knowing what you are recording, I have no advice. But select your first recorder by getting the cheapest name brand digital recorder capable of utilizing your mics. If you’re recording uncompressed or even WAV or WMA files, the device isn’t really doing anything much.
In closing, I strongly recommend against anything you’ve heard is something good to have. If you don’t know exactly why you need the item and exactly what you plan on using it for, you’re wasting money. Why would you want to buy into some specialized audio format you’re not already using? Don’t repeat advertising jargon, how does it make the sound you record better or easier to work with? I know a lot of folks that will tell me a bulldozer is better than a sedan, but that’s cause I asked which moved dirt easier. If you don’t already know you need something, forget about it! Hopefully you already know how to record good audio. But pretty much no matter what you do, I’m sure you’ll be getting less bad audio by not using the built-in mic.
Good luck & have fun.
July 7, 2008 at 1:23 AM #175985AnonymousInactive
WOW! Thanks for the information.
I’m considering a pair of AKG condensers along with with the Zoom H4 (it provides phantom power). X-Y setup on the mics, at close range to my guitar. Don’t know if I can swing the 451 ($$$), but AKG makes some less expensive condensers that might do just as well.
I’ve worked with audio quite a bit, but my experience with video is quite dated, and limited.
Until recently, I used a desktop workstation, and had no problems. The laptop(s) have been an entirely different experience. The issues with my current laptop are this – First, I have to drop the ground lug on the AC line to get rid of the power supply switching noise – regardless of whether I use the internal sound card, or an external M-Audio interface. I went through hell tracking this down, and wasted a lot of money in the process. The manufacturer’s tech support was less than useless. When I finally figured out the solution was as simple as getting a $1 ground-lift adapter, I was not thrilled. The really bad issue is, if I try to record at the highest bit rates, I get dropouts from other processes that interrupt the internal bus (probably omething to do with the Intel Speed Step, which is not manageable in the BIOS on this laptop). I’ve since discovered that many people have had similar issues with various laptops. Of course, there’s no problem whatsoever using your average destop clone, but portability is what I am after. It’s all water under the bridge anyway. Getting a truely portable stand-alone recorder is what I really needed all along.
Thanks again for all the helpful info…
July 7, 2008 at 1:33 PM #175986pcassidyParticipant
I second the post that syncing audio and video is easy by matching waveforms. I do it all the time using Adobe Premier Pro. A problem you are going to run into is that the sync will drift as the video progresses because the recording clocks of the camera and audio recorder are not the same. A drift of 100 ms is significant and has to be corrected. This can be done by stretching the audio using an application like Adobe Audition.
If there are any dropouts in you audio recording, maintaining sync will be impossible. In my setup I use a firewire connection to the recording PC and I have a lot of problems with dropouts.
July 7, 2008 at 8:54 PM #175987AnonymousInactive
In my setup I use a firewire connection to the recording PC and I have a lot of problems with dropouts.
Yeah, bingo. That’s common with laptops using a Firewire interface device, per my earlier comments. That’s why I bought the Zoom H4, which is a stand-alone portable device capable of superb audio recordings. I have all but abandoned the idea of using a Firewire based interface in real time with my laptop. It’s a joke. With the H4, I will either use the card reader or USB to transfer the recording to my laptop HDD for synchronization with the video and post production editing.
As far as time drift, for the most part I am recording clips that are about 4-5 minutes long, start to finish. I would be surprised if there were any preceivable drift over such a relatively short duration, but I suppose it could happen.
Waveform matching is what my studio-engineer friend told me to do, so that’s the way I will go. Will Windows movie maker allow me to line-up the audio from the camera and the wav file from the H4 side-by-side using a waveform view? I don’t really want to spend money on additional software if I can avoid it.
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