Capture settings for audio quality?

Peyton wrote on 7/22/2003, 9:57 AM
Howdy, y'all!

We're capturing from a monophonic source, a Sony analog camcorder. Where can we set audio settings for capturing? We really *don't* need the high-quality stereo sound from the low-quality, mono source.

Re-rendering the clips to a lower-quality sound just adds a step on the way to the DVD.

Thanks!
Peyton

Comments

Chienworks wrote on 7/22/2003, 10:52 AM
Two questions ... you don't say anything about your capture process, and since the answer to your question varies widely depending on the process, how are you capturing? Secondly, why are you re-rendering to a lower quality before making the DVD? Leave that step out completely.
Peyton wrote on 7/22/2003, 3:52 PM
OK, I'll describe what we do, and used to do, as best as I can from memory. I'm at work, the software is at home.

We connect the analog camera to the digital camera (a Sony VX2000), which serves as an analog/digital converter, so we don't need a capture card. The digital camera gets Firewired to the computer, and is detected by Vegas. We uncheck "Enable control of digital device" in the Capture preferences, after having clicked File/Capture. We start and pause the analog camera, confirm that the picture appears on the display for the digital camera and in the capture window, hit Play on the analog camera and Capture Video on the capture window. The tapes are about 2 hours long, so we come back after almost 2 hours, and click the Stop button in the capture window, once blue screen has appeared. An "out point" can be set in the resulting AVI at the beginning of the blue for rendering and preparation in DVD Architect.

The resulting AVIs are about 22 GB in size. Placing that file into DVD Architect yields an estimate that it will use about 7.2 GB of a DVD disk - kinda big. Previously, we have used Vegas to render the AVI to an MPEG, with sound quality turned way down to mono and 96Hz, if I remember right. That yields MPEGs of about 3.9 GB, and they fit nicely on a DVD.

I suspect that the difference between the two methods may be that the video is being captured with super-awesome AC-3 sound off of a monophonic analog camcorder. I haven't found any setting in the capture options of Vegas or the preparation options of DVD Architect that would yield lower quality sound.

The only reason I would re-render to a lower quality is to get the 2 hour deposition to fit on the DVD. If I can accomplish that without an extra render step, I'd be very pleased.

Cheers,
Peyton
Chienworks wrote on 7/22/2003, 8:17 PM
OK, a few points ... The audio is being captured as an uncompressed 16 bit stereo 48KHz format because that's just the way that DV captures work. You can't alter that unless you change to a radically different capture method, such as capturing with an analog card instead of through firewire. However, this has no bearing on the size or quality of the audio in the DVD file. This is determined by the rendering process. Normally you can set the bit rate used by the audio while rendering and this is completely independant of the audio quality of the .avi file. You should be doing only one audio render.
fishtank wrote on 7/23/2003, 9:39 AM
I'm not familiar with rendering for DVD, but I would think that he would be better off rendering to 48KHz mono instead of 96KHz if that is possible. He stated that the audio is low quality to begin with and using a high sample rate would be a waste of file space.

Just my two cents!