What are the internal switches of Alt presets? Options

[Oge_user]

Hello to all.
Using the alt preset(s) in the Lame 3.92, i must say that
"alt preset 128 cbr" make a good job avoiding common problems
at this bitrate.
Can someone explain the internal switches or commands used by
alt preset 128 and alt preset insane?
And, if possible, the meaning?

[JohnV]

Originally posted by Kblood
Well, I surely thought there was some code tweaking also in:
--alt-preset <bitrate>
I thought some switches were affected depending on the bitrate...

Sure, there are different switches used for different bitrates, but those are not exactly code-level tweaks. Those are just normal preset alias settings implemented with different switches and bitrates, but which do not include actual code level tweaks like standard,extreme and insane.

Things that change depending on the bitrate are lowpass-values ,ns-bass values, nsmsfix values etc..

But the actual code level tweaks deal with:
- Tweaked block switching threshold
- Adaptive noise measurement (uses X3 when needed)
- Tweaked noise shaping functions
- Short block tweaks (bitrate, nsmsfix values)
etc.etc. which you cannot set with normal switches.