Grain Retention Switches for X264

[Soopafresh]

I wish to keep the grain of the source when I convert to h264. I can do this, but the bitrate required is ridiculous. There were older experimental versions of x264 around which had "keep grain" switches but I can't figure out how this is accomplished in the newer builds.


Yucky Poo

[poisondeathray]

Grain acts like noise , and requires a higher bitrate

psy-trellis and psy-rd are the switches that enchance grain. For example
--psy-rd 1.1:0.5 would mean 1.1 for psy-rd and 0.5 for psy-trellis

The new preset system has a grain retention setting --tune grain for heavy grain sources. These are the settings when activated:

Optimize for grainy content: deblock -2:-2, psy-rd 1:0.25, no-dct-decimate, ipratio 1.1, pbratio 1.1, aq-strength 0.5, deadzone-intra 6, deadzone-inter 6, qcomp 0.8

Recent builds use mb-tree which redistributes bits to more challenging scenes like action scenes. Many people tend to find it causes problems with fades. If the grain occurs in fade and dark sequences like your screenshot above, you might consider turning mb-tree rate control off

[Soopafresh]

Thanks PDR, I'll give it a shot

[creamyhorror]

Bumping up qcomp will probably keep more grain and fine detail, but it comes at a high bitrate cost. 0.7 is about as high as is comfortable for me. Increasing it weakens mbtree strength, since it moves closer to constant-quantizer encoding (which is qcomp=1.0).

Also, pbratio shouldn't have any effect when mbtree is enabled, so I wonder why it's set in that grain tuning.