LAFCPUG: Audio FAQs

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Revision as of 20:58, 11 June 2008

How do I capture four (or more) tracks of audio at once?

How do I capture four (or more) tracks of audio at once?

Assuming you are capturing via Firewire...

Go to Audio Video Settings> Capture Presets

Click Edit

From the QuickTime Audio Settings > Input

You can choose to :

• Capture the First 2 channels
  
• Capture the Second 2 channels
  
• Capture mix of 4 channels
  

Mixed you can do in one pass and you still wind up with 2 audio tracks mixed down
Two pass you will have all 4 channel on separate tracks, but you would capture the First 2 normally, then change it to Second 2 channels.

Another way

From Martin Baker:
Up to 24 channel audio capture is supported in FCP5. Most capture cards support up to 8 channels of embedded audio through SDI (though Kona 3 offers up to 16 channels of embedded). I'm not aware of any capture cards which offer more than 8 AES or analogue inputs.

So depending on how many channels you want to capture, the other possibility is to use a separate audio interface such as MOTU or RME. If the interface has Core Audio drivers available then it should appear as a device in FCP's Capture Preset Editor. There may be A/V sync issues with this method although if you can genlock the audio interface then I would imagine it would work fine.

I doubt there is anyone who has ever tried this but in theory it would work.

I hear popping & clicking sounds

Q. Why do I hear popping and clicking sounds when I play my timeline?

From Jude Cotter
A. You will hear these sounds if there is a mismatch between the clip audio format and the sequence audio format. Most commonly this happens when attempting to use MP3s. The best thing to do is to convert the files to 48khz AIFFs, and import these to work with in FCP. You can do this either in iTunes or QuickTime.

• In iTunes go to iTunes > Preferences > Advanced > select the ‘Importing’ tab. Then set ‘Import Using’ to ‘AIFF Encoder’, ‘Setting’ to ‘Custom’, ‘Sample Rate’ to 48.000kHz, ‘Sample Size’ to ‘16 bit’ and ‘Channels’ to ‘Stereo’. Find your tracks in the iTunes Library and select ‘Convert’ from the ‘Advanced’ menu.
  

This option is best if you need to batch convert a lot of songs.

• In QuickTime, open the file and choose File > Export. Change the ‘Export’ setting at the bottom of the window to ‘Sound to AIFF’. Click on ‘Options’ and check that the settings are correct. Then save to the location of your choice.

Other things that could help:

• Before you output your sequence to a movie file or to tape, you must perform an Audio Mixdown. This does not mix all your audio tracks to two tracks; it merely serves as an audio render for the entire timeline - it creates a single preview file that is less stressful for the computer to play. You can find this in FCP under Render > Only > Mixdown.

Imported songs from a CD

Q. I imported some songs from a CD and it worked at first, but now the files are missing and won't play.

From Jude Cotter
A. If you import audio files directly from a CD, FCP (on OSX) does not automatically create a file on your hard drive - instead, it makes a "dependent" or "reference" clip to the CD.

This means that once you eject the CD, FCP no longer has access to the audio file. To ensure that you always have access to the file for use in FCP, you must convert any CD tracks to AIFFs and store them in your computer before importing them into FCP.

To do this:

• In iTunes go to iTunes > Preferences > Advanced > select the ‘Importing’ tab. Then set ‘Import Using’ to ‘AIFF Encoder’, ‘Setting’ to ‘Custom’, ‘Sample Rate’ to 48.000kHz, ‘Sample Size’ to ‘16 bit’ and ‘Channels’ to ‘Stereo’.
  
• Find your tracks on the CD and select ‘Convert’ from the ‘Advanced’ menu.
  

This option is best if you need to batch convert a lot of songs.

• In QuickTime, open the file and choose File > Export. Change the ‘Export’ setting at the bottom of the window to ‘Sound to AIFF’. Click on ‘Options’ and check that the settings are correct. Then save to the location of your choice.

Then import the files you have created into FCP.

Other things that it could be:

• If you did all this before importing the files and they‘ve still gone missing, it could be that the name of the files has been changed on the hard drive, so that FCP no longer recognises them as the correct files. Either change the names of the files back to what they were, or reconnect them in FCP by deselecting ‘Matched name only’ in the reconnect dialogue box.

Why do I hear beeping?

Q. Why do I hear a beeping sound when I play my timeline?

From Jude Cotter
A. The beeping noise is the audio render alert. It means that you need to render your audio. A normal render should do this, as long as you have ‘Audio’ checked under Sequence > ‘Render Selection’ and/or ‘Render All’.

From Nick Meyer
B. Increase your Real Time Audio Mixing track allocation in User Preferences to perhaps 16 tracks rather than the default 8.