--merange settings for HD content

[Biggiesized]

The x264 wiki (http://mewiki.project357.com/wiki/X264_Settings#merange) mentions that 16 is a good default for the --merange setting in the commandline. However, when you use more complicated motion estimation methods, the wiki states you can increase this value beyond 16 as it is helpful for HD content.

What's the next logical setting above 16 given this circumstance? Is 32 the highest you'd (reasonably) want to go? If you have high motion HD footage, is it insane to go beyond that? Will one setting (e.g. 32) work equally well for 720p and 1080p content, or should 1080p be slightly higher?

[Digital Corpus]

Granted, my tests have only been with broadcast quality HD TV (sometimes not that great) but I only kept my 1080p encodings at --merange 32 and dropped motion estimation down to diamond with a practically negligible drop in quality. In my 720p encodings, psnr and ssim had no change between using uhm at 32 pixels and diamond at 16 pixels. Your milage may vary if you are using Blu-ray content which is of a considerably greater quality.

[nurbs]

--me-range 32 and dropped motion estimation down to diamond
The maximum me-range used for diamond and hex is 16.

The presets never use a me-range greater than 24 so it's probably not that useful. Keep in mind that me-range is the range searched around the best predictor for the motion.

[Digital Corpus]

I actually didn't see that in any documentation until today when looking at the wiki.

[Biggiesized]

What's your take, DS?

[jpsdr]

Placebo preset set the value at 24.