TMPGEnc Conctant or Variabile Encoding

[MI6]

Long time I have to use TMPGEnc 2.5 for encoding my DV files to MPEG 2. There is option to use Variable encoding in 1 Pass (Constant, Variable and Variable with 2 pass). Other version of TMPGEnc after 2.5, allows only encoding in Variabile mode with 2 Pass. That is too much time for encoding. Why only this option????
Regards.

[guns1inger]

The difference between the two is a) speed, and b) predictable file size. Variable 2-pass takes twice as long as single pass VBR. Two pass VBR has very predictable file size and should be about as accurate as CBR encoding. Single-pass VBR will not produce a predictable file size. Why is this missing from one version and not another - perhaps it wasn't working correctly in one release so they temporarily disabled it. I don't actually see the advantage to single pass VBR encoding. If you running time is short enough that file size isn't an issue then use CBR. If target size is an issue then you have to use 2-pass VBR.