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double system inputs

Posted: Thu Nov 20, 2008 9:18 am
by videojim
I may have to use separate recording devices to record a message by a speaker that I am videotaping. If I video record his voice and clap-sync it with a separate audio recorder how easy will it be to sync the two sources in Casablanca? Is it possible to be that precise with it? Obviously, single system audio/video is more desirable, but may not be the best quality because I don't have a lav mic,or podium, and I have a good digital audio recorder that I can use. Thanks.

Re: double system inputs

Posted: Thu Nov 20, 2008 9:53 am
by TimKennelly
It's not hard to sync as long as your recorder is maintaining the same pace as the video recording is.

Split the separate audio after input into three pieces, the start, a small (say ten seconds) section with a very distinct (voices or several claps, etc) audio and then the remainder.

Add the short, distinct middle section to an audio channel, Create and listen.

If the two (main track, added track) are way off, use Range to tweak, then Create to listen again.

Do this until you eliminate reverb (in sync), then Add the first section before and the last section after the existing added segment, Range to butt up to middle section.

Headphones are best for this process.

Re: double system inputs

Posted: Thu Nov 20, 2008 1:10 pm
by videojim
If audio is all one piece, say a story, then how do I break it up and stay in sync?

Re: double system inputs

Posted: Thu Nov 20, 2008 5:44 pm
by TimKennelly
I don't get what you are saying.

If video is all one piece, audio is all one piece, put them together.

If you do that right, if your audio recorder is pacing the video as I first mentioned, then make a Scene of the results and Split that any way you want to.

Re: double system inputs

Posted: Fri Nov 21, 2008 3:17 am
by IanPearson
Just to add a little to what Tim has explained.

Using your RCA jacks, input your recorded sound source into your Cassie “audio edit / record” bin.

Using the “split function, split this as Tim suggests. Go into the “audio mix” screen and add the short 10 second section to and audio track. Then using the “Range” function, position the audio clip at the same point on your video footage (which presumably will still have the cam audio recording as well). Again as Tim explained adjust the position of the audio so that there is no reverb and this will now be in sink with your video.

Now add the first audio spit in front of the newly positioned second split and butt the end up to the second split. Finally add the last split immediately after the second split and use the correction function to mute all the original sound and render the lot.

The separate audio should now be in sync with the video.

Ian

Re: double system inputs

Posted: Sat Nov 22, 2008 8:18 am
by videojim
Sounds tricky, but I will t ry it. Thanks for the input. Am just now getting used to the way this system works, but it turns out to be incredibly easy to work with.

Re: double system inputs

Posted: Sat Nov 22, 2008 10:28 am
by IanPearson
It does sound tricky, but it’s not really and it’s one of those operations that is far harder to explain in words, than it is to demonstrate.

However, like all processes there are usually alternative ways to do things.

Having given it a little more thought, in your particular case, you could as you suggest just use a clapper board or similar and with both the cam and the audio recording, clap the board just prior to the interview.

When the recording is complete, again feed the separate audio into your Renomee using the RCA sockets and trim the audio to the point where you hear the clapper board start.

Then in the audio mix screen, add your audio to one of the audio tracks such that the start is placed before the cam clapper board point. Then using the range function scroll the audio track to the point where the clapper board operates, which you can use both the audio scrub and visual video to fine tune the required point.

Now again using the audio correction function, mute the cam original audio.

At this point I would now make a scene of the whole interview, so you can then trim this scene to the start and end of the interview as required. If your not sure what making a scene entails, then please let me know and I will explain.

There is one other thing you need to be aware, as Tim hinted in his first reply, if the cam speed and separate audio recording are not quite the same speed, the sync will be OK at the beginning of your interview, but may slowly come out of sync as it progresses. If this is the case you may need to split the interview up first into two or three sections and do a new sync point at the start of each split.

Ian

Re: double system inputs

Posted: Sat Nov 22, 2008 7:49 pm
by ShadowVision
I know that you're mixing two sources simultaneously to add layers to your sound design here, but on my documentary, I had two audio tracks and had to pick one to use from the two cameras and mics. I often went with the one from the DVX, but now I have an H4 that I use as a pass through and for sync.

The H4 is a cheap ($250), but surprisingly decent field recorder. My new HDV Sony cameras do not have XLR connections, so, I'm using the H4 a lot. It has an line out and today on a shoot, I used the H4 as a Beachtec type device and it worked very well.

What I've done is convert the audio track (the H4 captures in wav or mp3) from the H4 to a video (using sample-video) and then use the insert option to put in the video I want. And with only one dialogue audio track, this works wonderfully. If the audio is mono I copy that channel and make it stereo. Aside from tone control and other filters, I've not enhanced the audio any more than that, which is something I'd like to talk about.

As far as music and other audio components (like sound effects), I add those later in mix.

Re: double system inputs

Posted: Sun Nov 23, 2008 7:42 am
by CKNewman
I have some questions about using and importing audio from WAV/MP3 recorders. I recently purchased a Zoom H4 to record lectures with microphones mixed through a Mackie mixer. It works very well recording MP3s at 128kbs and using 1/4" cables from the Main Out on the Mackie to the inputs on the H4. I wonder if using XLR cables would yield a listenable difference?

What steps did you take to get the audio recorded by the H4 into your Cassie? The SE7 manual states that "It is possible to import from CD and DVD." Can the Casablanca also import audio files with the USB interface, or should we bring the audio from the H4 into a PC, burn a CD, and then import?

Re: double system inputs

Posted: Sun Nov 23, 2008 10:20 am
by HansJoachimKoenig
Hi Craig,
if you want to import your audio digitally to your Cassie you would have to do the procedure
you have described. Burning an audio CD on PC and import CD contents in audio record menu of Cassie.
If you import to your Cassie analogue I would use the headphone output of H4 using an adaptor
1/4"/RCA to your analogue inputs of the Cassie. Try different headphone levels for best results.
To compare the results of digital and analogue importing just burn a short CD piece of voice recording
and compare with same piece analogue imported.
If you are satisfied with the sound quality this would be the fastest way of transfering your voice audio.
It's worth a try.