Compression test

[soniv]

In gordian, when you are about to star the compression there is a field called compression test/check and it´s assigned with 5%.What does it mean? When we choose to compress credits with different compression rate we see number 20. How compressed is that? I´ve read the ideal for credits is 12.
THANX

[hakko504]

Compression test 5% means that you do a first pass of 5% of the movie. It uses a AVIsynth command called SelectRangEvery to get sequences of 14 frames (in earlier versions 13) separated by 280 frames (14/280=5%) to reduce the number of frames to encode.

The setting for credits is a quantizer level, which ranges from 2 to 32 where 2 is only a little compressed an 32 is very compressed. 20 is usually the lowest setting where you still can make out what is going on on the screen. 12 would make a better looking credit but will inevitably use more bits, so 20 is probably the best compromise between quality and size for credits. Do feel free to change this number if there is something else going on on the screen except just texts in the credits. If I remember correctly 12 is the recommended value for DivX3.11, but that codec will usually give a lot worse results when the quantiser (or DRF) is higher than 10.