What exactly does avid 2:1 mean?

[dglasgal]

About the Avid compression ratios: Is 2:1 compressing the
footage by a factor of 2, or is it compressing it to a quality equal
to half of the uncompressed D1 SD signal, say compressing it to the
quality equal to Digibeta? Basically what does the "1" represent in
that ratio; does it represent the quality of the native footage or
another standard such as a completely uncompressed D1 SD signal?

So If I'm taking in a DVC Pro 50 (a signal that is natively
compressed at 3.3:1) into the Avid at 2:1, what is the new quality
compression of my new signal? Is it 6.6:1 ?


Thank you !!

 

[MichaelP]

2:1 is taking an uncompressed video signal (the :1) and compressing it by a factor of 2 thus, 2:1. When capturing DV50, it is not compounded as you say with a 6.6:1 since the DV50 is first decompressed to an uncompressed signal, then captured as 2:1. So the original capture compression will still be there with any artifacts that may exist then captured at 2:1. Although there may be some concatenation, it is not a 6.6:1 ratio.

Michael