1st & Nth pass setting

[cpuuk]

If you go on premise that the DivX parameters for 1st pass and Nth pass can be different, anyone got any rules of thumb of what can be set in 1st pass and what should be set in Nth pass? In other words are there settings that can be counter-productive during a multi-pass.

My primary interest is in the DivX "Psychovisual Enhancements", should I set this to the same setting in both 1st and Nth Pass, or should it be set to a lighter setting in the 1st pass and a stronger setting in the Nth pass (or visa-versa)?

[Acaila]

As a general rule of thumb, don't change anything between the first and second (or later) pass!

However Psychovisual Modelling only shifts bits around, it doesn't save anything, so I don't think it can hurt very much if you change it between passes. But why would you want to? It's not like a heavy setting gives a huge speed decrease.

[cpuuk]

I found that Strong Psycho reduces the final file size enough to make it worth using.

[Acaila]

In that case you should definately not change settings between 1st pass and later passes.

[cpuuk]

Thx. I'll also run some tests and report back.

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Update; OK I ran GK28 DivX505, 2x pass against an animated film vob. All settings stayed the same, just twiddled with the Psyco settings.

Test1- 1st pass Pyscho=strong, 2nd pass Pyscho=light = smallest file

Test2- 1st pass Pyscho=strong, 2nd pass Pyscho=strong = next smallest

Test3- 1st pass Pyscho=light, 2nd pass Pyscho=light = largest file

The size difference between smallest & biggest file was only 1M, so no biggy whichever option is used. Would the file size have different if I used a non animated movie to test again? Will try again later to find out.