Echo in imported video

I'm in the process of archiving my old Videos to harddrive. Some of the videos are 6 years old, were recorded on different Camcorders, edited on a PC (ULead MediaStudio) and written back to tape.

Now when I import the videos to iMove, when I after importing the video play them back (in iMovie or after converting to H26 4 mov) I hear some kind of echo in the audio.

I'm using an Intel iMac 20" with 2GB of Memory and record to the internal harddrive and I have the latest versions of MacOS, iMovie and Quicktime. I have 70GB free diskspace - So I guess the machine config should not be the problem.

Did anybody experience similar problems, what could it be?

Is it because of the tapes were written with an older Camcorder (on Windows) or did the tapes go bad (but when playing the video in the Camcorder they sound ok) or is the Camcorder broken (it's a 1year old Canon ZR100) ?

thanks for any advice
-Uwe

20'' iMac (Intel), Mac OS X (10.4.9)

Posted on Mar 24, 2007 7:33 AM

36 replies

Uwe_Meier Author

Level 1

25 points

Mar 25, 2007 12:37 PM in response to Lennart Thelander

First of all, you need to repair your hard drive:
http://docs.info.apple.com/article.html?artnum=61352

You may need to run Disk Utility more than once.

Thanks for the links. Yes I agree. I will hold off any other tests until this problem is fixed.

Second, did you ever delete iMovie's prefs file?

Yes I tried that yesterday .. didn't help.

thanks
-Uwe

Mar 25, 2007 12:40 PM in response to Uwe_Meier

QuickTime Pro video recording is "device native" (same as the attached device), MPEG-4 or H.264 (good or better it's called). The latter will make 320X240 files unless you have a powerful computer which may allow larger dimensions.
Personally, I would quit while behind and pass the 50 tapes to some service that could handle the workflow.
If all your recordings are in 12 bit audio (not very uncommon) then they have the tools and hardware to fix them.
Or import in ten minute "chunks" via QuickTime Pro (about 2.16GB's each).

Mar 25, 2007 12:51 PM in response to Uwe_Meier

Final Cut Pro and iMovie: Cameras in SDL Mode Not Recognized
http://docs.info.apple.com/article.html?artnum=61033
Conclusion: Always use Standard Play, never Long Play

You can use two miniDV cameras, one 4-pin to 4-pin Firewire cable (no computer) and transfer the tapes to SP, 16-bit audio. And then import the transferred tape.

Try creating a new user, log in as that user and import. (That will exclude any third-party software you might have installed).

Mar 26, 2007 2:46 AM in response to Uwe_Meier

Ah! "..as if you speak through a metal pipe.." ..!

That's "out of phase"!

(..A similar problem occurs with some Canon camcorders on long takes of more than 10 minutes: the audio gradually creeps out of sync with the picture. 12-bit - LP - audio can be particularly prone to this..)

That means that either the left or right channel is just a fraction delayed behind the other channel, so that the peaks of the waveform on one channel coincide with the troughs on the other channel, and so the sound is "tinny", insubstantial, and "as if you speak through a metal pipe". That's exactly the right description!

The ways to fix it are, as I mentioned above, to Extract the audio from the clip(s), and then to copy the audio from one channel ..the left, say.. and paste it onto the right channel.

Unfortunately, you can't do that within iMovie itself, because you can't work on the left and right channels separately in iMovie. So you'd have to do it in GarageBand or in Audacity.

Audacity is rather like Sound Studio (..but Audacity is free..) ..and here's how to do that in Sound Studio ..click on 'Start Slideshow' on this linked page to see full-size pictures..

Otherwise, use GarageBand. Or use QuickTime Pro, as described in Dan's "Unofficial iMovie FAQ" here!

[..To get to your 'Extracted audio' you'll have to double-click on the audio clip(s) - when you've extracted the audio - to see what iMovie calls the audio; something like 'Extracted Audio 01.aiff' ..and then right-click (or Ctrl-click), in the Finder, on the name of your iMovie project and then choose 'Show Package Contents', and then look in the 'Media' folder, and that's where your extracted audio clip(s) will be. Make a copy of the clip(s) and put the copy on your Desktop - where it's not hidden away within the iMovie 'package'. You'll then have access to the audio and will be able to open it with Audacity, or some other audio editor. Otherwise, you can use GarageBand without needing to do all that copying and moving: just drag your iMovie project into GarageBand after you've extracted the audio..]

Uwe_Meier Author

Level 1

25 points

Mar 26, 2007 5:41 AM in response to David Babsky

thanks for the detailed analysis and instructions (and I'm also using Canon Camera ...).

If it would happen only for one or two tapes or if it would be a less manual procedure, I would do it that way. But since I can import those videos just fine on my old PC (and I have many to do), I will import them there and than batch convert them to a none PC format (I probably try it first from within parallels or boot camp) ... I just hate that I have to fire up my old windows machine again after I got used to the nice UI of MacOS.

gg07

Level 1

0 points

May 2, 2007 3:52 AM in response to Uwe_Meier

I have a similar problem with SONY HDR-HC5 HDV videocamera. I do not use a LP recording (so I'm supposed to record/export at 16 bit rate) but I do have echo in imported videos (and in addition also a random 'slooooow' audio/video playing, already identified as another bug of iMovie 6). Very frustrated: do I have to buy an expensive Final Cut to get rid of this problem or there is an 'in house' fix I can rely on? Thanks

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Echo in imported video