x264 options that don't affect 2nd pass when running 1st pass

[Inventive Software]

Hope that title makes sense. Basically, can people please list options that don't affect the second pass quality when you run the first pass, thus speeding up the first pass?

Only one I know of is --trellis. :)

[Dark Shikari]

Everything does, technically--but mostly by an immeasurable amount.

The only options that affect second pass quality, by definition, are those that apply themselves unevenly to different parts of the video, changing the bitrate and/or frame distribution.

The only option I have found that measurably affects second pass quality is --subme, which generally gives bad results at below 3 or so, probably due to reduced quality frame decision in the first pass. AFAIK the frame decision algorithm doesn't allow subme higher than 4, so higher isn't as useful in that regard.

--subme 3 --me hex --partitions none will give a fast but still pretty accurate first pass.

[Inventive Software]

Thank you Dark Shikari. Is there anything else you've found?

[morph166955]

--subme 3 --me hex --partitions none will give a fast but still pretty accurate first pass.

What do you think the difference would be if you used dia instead of hex with those settings?

[Dark Shikari]

What do you think the difference would be if you used dia instead of hex with those settings?Probably basically none--a tiny speed difference, and an even smaller quality difference. Dia is not really that much faster than hex, so I generally don't use it that often.