How low can the CQ value in CCE go?
 

I know that CQ value in CCE above 40 gets bad quality but how low can the CQ value go before it becomes unneccessary(doesn't increase quality).

Really don't understand the question : when you lower the CQ, you lower the quality (not increase as you tell).

Can you be more explicit ?

I mean in CCE, lowering the CQ value increases quality.

Oh, I didn't knew what you all called CQ in CCE, know I see, that is the Quality setting. Okay :-).

On CCE 2.50, there is a visible result till 0. Don't know wich is the version you are using.

I'm using CCE 2.67.00.09, so I guess I can go as low as I want.

He is refering to the Q factor when using CCE OPV mode (One Pass VBR). As the Q factor rises, quality lowers, and also filesize. I never use above 40, and RoBa method people say 60 in the boundary for bad quality, above this value great distortions starts to happen.
The lowest value I have ever used was 16, and it looked dawn good. Hard to spot any artifacts. But I never tried anything lower.

[]'s
Vmesquita

<edited>I didn't understand at first, now the answer is right</edit>

I didn't say the quality raised till 0, I just tell that there are visible effects till the value of 0 !

But the problem of this setting is that it is a balance between quality of complex (moving) area and quality of flat (not moving) ones.

If you set the Q factor to 0, you will have perfect result in high motion zone but you will lose every slow motion part of your picture (pixels that are supposed to move very sligthly during a scene will stay static).

For my part I never went under 17.

DialHot,

You are confusing Q factor with Flat Part Priority. Q Factor is a concept that only exists in One Pass VBR mode, and it's like CQ in Tmpgenc. Flat Part Priority is that things that gives priority to DCTs or mosquitos... He is talking about Q factor.

[]'s
Vmesquita