32k vs. 48k log and capture issues

[Dan Riley]

I don’t work with firewire in at the moment (I use a capture card with SDI)
but you should be able to set your capture preset to 32k.
Under Audio/video setting- capture presents- to
whatever present you are using, double click. A capture preset editor should come up.
Under quicktime audio settings, format… can you not select something other than 48k ?

Dan

[Bret Williams]

Having just dealt with this some posts below about a week or so ago…

You can’t actually set you capture settings correctly for 32k. It will only do 16 bit, not 12. I found this actually was screwing with my footage.

I just used the 48k standard DV setting. After each batch capture you’ll get a warning about capture setting mismatch, but other than that, everything was perfectly normal.

If you’re capturing whole tapes all bets are off. But on normal 1-2minute captures I had no issues.

[E-money]

yeah, it’s weird. under Audio/Video Settings , Capture Presets, the only preset i can select is DV NTSC 48kHz. in fact, all of the presets end in 48khz.
not sure if this is just a FCP 5.1.4 thing or what. i mean, you would think that FCP would just read the tape and import accordingly.

i’m tempted to just import using 48khz settings… i mean, do you think it would throw my project off that much?

[Andrew Kimery]

I’ve never had a problem using “48” to capture “32” and I get 32k tapes across my desk more often than I’d like. To play it safe you could capture in 20min chunks to help avoid the possibility of audio drift.

-A

[Bret Williams]

It doesn’t have a 32khz preset, but if you can make your own. Except it doesn’t have 12bit support, which is what 32khz is recorded as. I don’t know why. I can’t remember if it’s been always been that way or not.

[Boyd Mccollum]

I’m still running 5.1.2. In the capture preset you can select DV audio to capture at 32kHz 16 bit 2-chan.

I thought 32kHz was 12 bit, but there you go. I’d duplicate the preset you want to use and set the audio to 32kHz. Should work okay. Afterall, FCP can capture HDV which is 32kHz 12bit.

[Michael Gissing]

[boydmcc] “Afterall, FCP can capture HDV which is 32kHz 12bit.”

HDV like DV can be set to 32khz four track. Like DV please don’t ever do this. The nornal setting for HDV is two channel 16 bit 48Khz. Fortunately this is the default on all cameras. Internally the audio is recorded to tape as mpeg, but comes out as PCM 16bit 48Khz.

[Don Greening]

To successfully capture 12 bit 32k audio with FCP:

Go the FCP Menu and choose Audio/Video Settings……
Go to Capture Presets and choose the Codec you want to capture with then hit Duplicate. For example, if you’re using DV NTSC 48k then rename the duplicate DV NTSC 12 bit 32k. Down on the lower right of the dialogue box change the the format to 32,000 KHz 16 bit 2 channels. Click OK.

Still within Audio/Video Settings go to A/V Devices. Click the Options button beside Firewire DV. Change the bit depth to 12 bit. You’ll notice that the sample rate automatically changes to 32,000 KHz and in the channels box above make sure you’ve got it set to 4 instead of the usual 2. The important thing to remember here is that changing the items in the A/V settings is not part of your new capture preset. After you’re done capturing your 32 KHz audio you need to come back to the A/V Devices settings and manually change everything back to 16 bit 48 KHz.

Now you can go back to the settings in your new capture preset and set the first 2 channels or the second 2 channels for capturing. Following the above routine I’ve successfully captured over 80 minutes of 12 bit 32 KHz audio in one shot with no audio drift. Once your capturing is done you can drop your 12 bit 32 Khz audio into a DV NTSC 48 Khz timeline and it will play fine without having to render. Just remember to render everything under safe RT and the high quality audio setting (in User Preferences) prior to final output.

FYI I’ve used the above workflow since FCP v.1 with a Dual 800 G4 and a 2.7 G5. Haven’t needed to do this on my MacPro and FCP 5.1.4 yet. My 32KHz tapes have been from an XL2 but captured to HD using firewire and a Sony Handycam model # DCR-HC30.

– Don

“Please take a moment to fill out your profile, including your computer system and relevant software. Help us help you.”

[Boyd Mccollum]

[Michael G] “The nornal setting for HDV is two channel 16 bit 48Khz. “

I didn’t know this!

[Michael G] “Internally the audio is recorded to tape as mpeg, but comes out as PCM 16bit 48Khz.”

When it’s recorded using MPEG-1 Layer 2, the audio bitrate is 384Kbps – which is a 4:1 compression over DV audio, which is using uncompressed 16-bit PCM at 1536Kbps. So while it may be sent out PCM 16bit 48khHz, it’s sending out data that’s already been compressed. (i knew there was some reduced quality issue with HDV audio, but I was thinking it was the 12bit 32kHz thing 🙂

[Kate Gallow]

thank.you.so.much.