CCE w/ 1, 2, 4, or 10 passes? Quality comparison

[Hlektron]

You be the judge. I've found that 4 and 10 passes are almost indistinguishable to one another, 2 passes produces a rather different output (a bit worse to my eyes, noisier too) and 1 pass is the worst of all (even blocky in some cases).
All in all, the differences are rather subtle, imho.
The differences are more pronounced in the heavily reduced Extras (stolen by 25%, the average bitrate for them was the mere 2083kbps.)

My CCE version is 2.70.0.10.

Because of the subtlety of differences, I've chosen a lossless format for the screenshots, although a compressed one (they're in tiff format with lzw compression). xs.to image-hosting service converted tiffs to png format. I don't know why, but nevertheless it's a lossless one as well.

The sequence of the screenshots are 1, 2, 4, 10 passes and last comes the original.
The movie used for the test was "Mulholland Drive"

[Hlektron]

The Extras:

[jdobbs]

The improvement become almost unnoticable after 3. In fact the CCE manual on older versions (when they were a little more forthcoming about this kind of thing) explained that it hits its limit at 4 passes.

My own testing (and I've done a lot of it) shows that for the vast majority of sources two passes is enough. For tough ones three. I've never been able to see any difference between 3 passes and 10.

The truth is that you should have all the information you need after one pass in order to do the best possible encode on pass two. That's why most encoders (like HC and ProCoder) only do two.

I think multiple passes (above 2) are mostly gimmick... just MHO.

[anonymez]

I think multiple passes (above 2) are mostly gimmick... just MHO.

agreed... or to compensate for an encoder's poor rate control