Info abuot LAME switch: help!, I like "lame --longhelp" but... Options

[occipiter]

I'm looking for a good and complite help about some important switch for my personal "command line" VBR (and now don't tell me to use --alt-preset):
1) ATH 0, 2, 3 are clear, but what about ATH 4, 5? I can't find any kind of info
2) --nspsytune, is it so "perfect" as someone say? And the experimental switch like -X and -Z in "standard mode" are OK or need to be changed for this psy tune model?
3) --nssafejoint, I can use it whitout problem, what this switch do?
4) --ns-sfb21 n is a good idea to reduce bitrate, but what about quality?
5) --cwlimit n can change bitrate a lot, but change the sound?
6) --athaa-type n can help normal "command line" to do an --alt-preset like job?
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occipiter
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[Oge_user]

1) ATH 0, 2, 3 are clear, but what about ATH 4, 5? I can't find any kind of info

1) ath type 4 is used by default with vbr, i've never heard about 5 but i think it use less masking.

2) --nspsytune, is it so "perfect" as someone say? And the experimental switch like -X and -Z in "standard mode" are OK or need to be changed for this psy tune model

2) Alt Preset use --nspsytune by default so it should be very good.
IMO it's nspsytune it's better than gpsycho at lower bitrates.
-Z it's a switch that enable an alternate noise shaping method (called noise shaping 2): this setting increase bitrate demanding so it's not recommended to use -Z at lower bitrates.
nspsytune use -Z by default, so if you use --nspsytune with -Z then you'll disable -Z.
-X it's the quality measurement, Lame use -X 0 by default and it's better to not use another value for -X.

3) --nssafejoint, I can use it whitout problem, what this switch do?

--nssafejoint it's a 'safe' joint stereo method which use more stereo frames: it use joint stereo only when the channels are very similar.
--alt preset standard (and over) and --alt-preset cbr 224/256/320 use nssafejoint (don't know about abr presets).

4) --ns-sfb21 n is a good idea to reduce bitrate, but what about quality?

--ns-sfb21 increase masking for frequencies over 16khz so it decrease bitrate; the quality isn't affected too much but for vbr at high bitrates imo it's better to avoid --nssfb21 or -Y.
Besides only "--ns-sfb21 4" works.

5) --cwlimit n can change bitrate a lot, but change the sound?

cwlimit regards the tonality estimation and can't be used with nspsytune, i don't know more about this setting.

6) --athaa-type n can help normal "command line" to do an --alt-preset like job?

6) maybe ath type can help a little to reach a quality similar to alt preset, but you know that alt preset doesn't consist only of --ath-type n.

Hello
Oge

[LordofStars]

AltPreset quality isn't probable to reach with simple switches. The alt presets contain code level tweaks and you will not be able to make these changes in your encodings without a. code access b. using the alt presets.

[Gabriel]

You should try --verbose