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Recording Video and Audio Separately (help me please) DAW Software
Old 17th November 2009
  #1
Gear Head
 
mattpoole's Avatar
 

Recording Video and Audio Separately (help me please)

I am recording an Orchestra in a few weeks for a Christmas Cantata.

What do I need to do to get the audio to be able to sync with the video properly? I have done this in the past and had issues with the video and audio being slightly different speeds. With the two being different speeds I had to do a lot editing to make the audio and video stay synced up of a long period of time.

I am using Logic Pro or Pro Tools 7 and a Firepod or Digi 002.

I don't have the specs on the camera right now. I know it has a digital tape and is professional quality.

- thanks
Old 18th November 2009
  #3
With ProTools LE, there's not the option to acquire the audio sync'd to
a video source (via the Sync I/O box).

However, by recording audio on the camera as well as your acquisition
device (Protools, Field Recorder, etc) it's possible to manually align
the acquired audio from the camera to the high-fidelity recording. Snaps, pops
are helpful as alignment points (the purpose of the old slate "cracks" in
film).

The mis-alignment that you're experiencing is most likely due the frame-rate
settings that you chose on the camera.

What NLE are you planning to use?

jeff
Old 18th November 2009
  #4
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One way that you can do this, if your audio recorder can play back at the same time that it is recording, is to play SMPTE time code (LTC) from the audio recorder into the camera's audio input and record it in the camera while filiming. Then, in the studio, play the video from the camera back along with its audio track, using the camera's audio track as a timecode sync signal for the audio recorder. It requires (1) preparing an SMPTE timecode audio track on the audio recorder ahead of time, and (2) some kind of audio playback device or interface that can sync to incoming LTC.

-synthoid
Old 18th November 2009
  #5
What I usually do is use one of my cameras as the sync master
and set its timeclock to free run. If you have an audio acquisition
system that can read the video sync (like the HD Sync I/O box or
the Motu Timepiece), then you can print the BWF audio files with
the exact time.

Later on, in FCP or whatever, you can use the multi=clip interface
to align all the media from various sources ( multiple cameras, multiple
audio sources).

I haven't ever used SMPTE from the audio source to sync the camera.
That's sort of backwards from the way I think most people do it.

In this case, since we don't know the camera and we know he's using either
Logic or Protools LE, his sync'ing options are not fully known until he finds
out what camera he has access to.

jeff
Old 18th November 2009
  #6
if you're using Final Cut Pro...

...the low budget way to do it is to simply record it on your rig at 48khz, make sure the cameras all have top-mics and record it to tape as well (watch the levels, make sure it doesn't clip when they get close), then use this software here once all the material is ingested. you may have to put your recorded audio on a video slug track, and it still may take a little fiddling to line things up perfectly, but I've used it a LOT recently and it's saved me hours and saved the producers of the projects I've been doing tonnes of cash too.

(NB. there's a beta version for Vegas as well if you're on that...)
Old 18th November 2009
  #7
Quote:
Originally Posted by terminal3 View Post
...the low budget way to do it is to simply record it on your rig at 48khz, make sure the cameras all have top-mics and record it to tape as well (watch the levels, make sure it doesn't clip when they get close), then use this software here once all the material is ingested. you may have to put your recorded audio on a video slug track, and it still may take a little fiddling to line things up perfectly, but I've used it a LOT recently and it's saved me hours and saved the producers of the projects I've been doing tonnes of cash too.

(NB. there's a beta version for Vegas as well if you're on that...)

That looks like a very handy piece of software indeed!

thanks,
jeff
Old 18th November 2009
  #8
Gear Head
 
mattpoole's Avatar
 

Thanks for your replies. I'm waiting to hear back from the camera man on what kind of Camera he is using. All I know right now is that it uses a tape and has firewire.

Quote:
Originally Posted by terminal3 View Post
...the low budget way to do it is to simply record it on your rig at 48khz, make sure the cameras all have top-mics and record it to tape as well (watch the levels, make sure it doesn't clip when they get close), then use this software here once all the material is ingested. you may have to put your recorded audio on a video slug track, and it still may take a little fiddling to line things up perfectly...
Will this software help if my problem is not the initial lining up of the audio and video, but keeping them lined up over a long period of time? In the past I've been able to manually line up my audio and video, but after a while I have to make adjustments because the video and audio are apparently slightly different speeds.
Old 18th November 2009
  #9
Quote:
Originally Posted by mattpoole View Post
Thanks for your replies. I'm waiting to hear back from the camera man on what kind of Camera he is using. All I know right now is that it uses a tape and has firewire.



Will this software help if my problem is not the initial lining up of the audio and video, but keeping them lined up over a long period of time? In the past I've been able to manually line up my audio and video, but after a while I have to make adjustments because the video and audio are apparently slightly different speeds.
I suspect it won't as it appears to align to transients.

What you're experiencing is likely the framerate of the camera.
Depending on your framerate settings, you may need to "pull" the
audio to match it (if acquired on another device).

if you let us know the make of the camera, we can likely help you avoid
the issue altogether.

jeff
Old 18th November 2009
  #10
Gear Head
 
mattpoole's Avatar
 

the camera is a Panasonic AG-DVC7
Old 18th November 2009
  #11
that is a toy camera dressed up like a professional tool. When you were having problems in the past, what sample rate were you recording at? If you had drift, is it possible for you to determine the extent of the drift? For example, in a 1 hour clip, was the drift about 30 seconds? If it was, then it may be as simple as applying a 1% pullup / pulldown to your audio, if you have that ability in Logic. It still won't be perfect, but it will be much closer and require much finer adjustment. The problem is that the camera has no timecode or genlock ability, so there is simply no way of synching external audio to it easily unless you generate timecode from your DAW and then record to the camera as audible timecode. The new AVID editor natively has the ability to read audible timecode and there are a few tools available from 3rd parties to support audible timecode on FCP.
Old 18th November 2009
  #12
Gear Head
 
mattpoole's Avatar
 

Quote:
Originally Posted by tsvisser View Post
that is a toy camera dressed up like a professional tool. When you were having problems in the past, what sample rate were you recording at? If you had drift, is it possible for you to determine the extent of the drift? For example, in a 1 hour clip, was the drift about 30 seconds? If it was, then it may be as simple as applying a 1% pullup / pulldown to your audio, if you have that ability in Logic. It still won't be perfect, but it will be much closer and require much finer adjustment. The problem is that the camera has no timecode or genlock ability, so there is simply no way of synching external audio to it easily unless you generate timecode from your DAW and then record to the camera as audible timecode. The new AVID editor natively has the ability to read audible timecode and there are a few tools available from 3rd parties to support audible timecode on FCP.
i agree about the camera, in the past it seems like over a half hour or so i would get about 5 seconds off.

i think the audio was the slower of the two.
Old 18th November 2009
  #13
what about your sampling rate?
Old 18th November 2009
  #14
Gear Head
 
mattpoole's Avatar
 

44.1
Old 19th November 2009
  #15
That's your main problem, if you want to record audio that is going to be used for video, you should record at 48KHz. At this point, most likely the drift will be pretty minimal. In rare instances, you may have to pull up or pull down audio depending on exact frame rate and drop frame.
Old 19th November 2009
  #16
Gear Head
 
mattpoole's Avatar
 

Quote:
Originally Posted by tsvisser View Post
That's your main problem, if you want to record audio that is going to be used for video, you should record at 48KHz. At this point, most likely the drift will be pretty minimal. In rare instances, you may have to pull up or pull down audio depending on exact frame rate and drop frame.
thanks!
Old 19th November 2009
  #17
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Quote:
Originally Posted by jmarkham View Post
I haven't ever used SMPTE from the audio source to sync the camera.
That's sort of backwards from the way I think most people do it.
it's definitely backwards; it's a hack that lets you work around a camera that knows nothing about timecode. it doesn't sync the camera -- it simply records the timecode into the camera, so that when you play the video and audio out of the camera, you get correct timecode out of it. it's the same idea as recording audio on both camera and in a separate recorder, except that by recording timecode instead of audio into the camera, you can line things up automatically instead of manually.

-synthoid
Old 19th November 2009
  #18
in the context of professional film and video production, the sound department is almost always responsible for timecode (SMPTE / LTC) master, not camera department, so its not such a backwards way to do it at all in my opinion.

It is unusual, in that professional camera crews would rarely be utilizing cameras without timecode ability, although I have been seeing a lot of Canon 5D MK II shots recently, in which case I usually just slate the scenes with a digital slate slaved to my audio recorder.
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