Audio sample rate in A>D EE mode

Mike M. wrote on 8/28/2009, 8:46 PM

Hello:

I'm embarrassed to ask this question (I should know it).

I have a DV cam that I'm using to convert an analog feed into Vegas. The camera in the feedthrough (EE) mode can be set for either 12 or 16 bit. I've noticed that after DV capturing a file, I get either 32 khz for 12 bit or 48 khz for 16 bit.

Here's where I get confused. If I set the camera up for 16 bit/48 khz, then what do I set the audio sample rate for in Vegas's project properties (44.1......48...etc)?

The eventual output will be MPEG2 compliant files on a DVD.

Comments

Chienworks wrote on 8/28/2009, 8:53 PM

Can't think of any reason not to set it to 48K. That will match the source files and your most likely output format as well.

Mike M. wrote on 8/28/2009, 9:06 PM

Thanks Chienworks. That makes sense. Where I'm confused is the settings for:

1. Capture/source (based on what the DV camera outputs) settings
2. Project settings
3. Render settings

If I'm thinking this through correctly, then if there is a mismatch between say...2 and 3 then Vegas just has to do more work (re-sample?) during the rendering process.

Or

If I capture 12bit/32 khz, and the project is set for 44.1 or 48 khz.....what actually happens?

musicvid10 wrote on 8/28/2009, 9:25 PM

[i]"The eventual output will be MPEG2 compliant files on a DVD."

1. 16/48
2. 16/48
3. 192Kbs 48KHz Stereo AC-3

That simple. Really.

Chienworks wrote on 8/29/2009, 3:10 AM

Project settings are largely ignored when rendering. If your source is 48KHz, the project is 44.1KHz, and the render is 48KHz, then Vegas simple copies the 48KHz source sample rate to the output 48KHz sample rate. No resampling to 44.1 and back to 48 is done.

However, when previewing from the timeline, the audio will be resampled to the project properties. So this is why it's still a good idea to have the project properties match either the source or the output. Matching the source allows previewing to operate more smoothly. Matching the output assures that your preview is closer to the finished output. Personally i tend towards matching the output as i'd rather sacrifice smooth previewing to avoid surprises when rendering. But, in your case since the source and output match, it's an easy choice to set the project to match both.

gwailo wrote on 8/31/2009, 3:08 AM

Your captured DV file will be:

12 bit - 32kHz if this is what the camera setting was when you shot the material

Do not use this setting on your DV camera, it gives very low quality audio. The setting was created to allow users to record 2 tracks of audio to DV material and then record another 2 tracks in a 2nd pass which would give you 4 tracks total.

Always use 16 bit - 48kHz setting on any material you shoot.

This will always result in a 16bit - 48kHz captured file if you capture DV through firewire, no matter what settings you have for the project.

Always use 48kHz for any video project in Vegas. Vegas defaults to 44.1kHz for project settings, which it really shouldn't do. Reset the vegas defaults to 48kHz.

Leave it at 16 bit if you don't do any recording.

Change it to 24 bit if you want to have better recordings and your soundcard supports 24bit.

farss wrote on 8/31/2009, 3:45 AM

If you're adding any audio from a CD it will be 44.1KHz. In that case I'd suggest changing the project's resample quality to Best. That does use up a bit more CPU power. I work around this by using Vegas to convert the audio ripped from a CD to a new 48KHz file then use that in the project.

Bob.