Audio capture settings and encoding bitrates, apples and oranges?

[mkanel]

I plan on capturing some analog home video for conversion to DVD. For the audio I will capture at the highest quality PCM that I can with VirtualDub, those setting are 48,000 Hz, 16 bit, Stereo at 188KB/s. I will probably convert this file to AC3, if my AC3 bitrate is higher than the 188KB/s of my captured audio file am I wasting space? Or are they two separate things?

This is obviously not professionally produced studio sound but I would like to keep it close to the original sound quality, I just don't want to set a high bit rate like 256 KB/sec if I'm only wasting space.

Thanks. Mike.

[KpeX]

If you capture 16 bit PCM at 48000 Hz your bitrate will be higher than 188KB/s, guaranteed, something's wrong about those numbers.

[fccHandler]

You guys are mixing up your bits and your bytes. :p

48 kHz 16-bit stereo PCM is 192000 bytes per second, or about 188 kilobytes per second, where one kilobyte = 1024 bytes. But AC-3 is measured in kilobits per second, where one kilobit = 1000 bits = 125 bytes.

My 2 cents, I think 192 kilobits per second is a good choice for stereo AC-3 encoding.

[mkanel]

Ah! I get it. The old bits and bytes deception. I fall for that one every time, but now I know what to do.

Thanks guys.