--r3mix はあいかわらず --vbr-old 向けなんだなぁ。 --remix から /** * please, do *not* DOCUMENT this one * it is a developers only switch (rh) */ っていうのが外れておおっぴらに使えるようになるのはいつになるんだろう?
>Excellent news ! >The fast vbr-mtrh mode by Mark Taylor and Robert Hegemann (also main designer of vbr-old) >is, after a very long development cycle, tuned for high frequent quality. > This means it'll give a VBR performance boost up to 248% ( 2.5x faster ) and yield virtually the same quality. ・・・・・・
--scale <arg> scale input (multiply PCM data) by <arg> --ath-adjust n ATH auto adjust types 1-3, else no adjustment --adapt-thres-type n n=1 total energy or n=2 approximated loudness --adapt-thres-level x ?? --cwlimit <freq> compute tonality up to freq (in kHz) default 8.8717 --ns-sfb21 x change ns-treble by x dB for sfb21 -X n selects between different noise measurements -Y lets LAME ignore noise in sfb21, like in CBR -Z toggles the scalefac feature on/off
Now the -X parameter selects between different approaches to make this decision:
-X0 the actual is better if it has less distorted scalefactor bands, or if it's equal to the best so far and the sum of noise over the thresholds is less than the best so far
-X1 the actual is better if the maximum noise over all scalefactor bands is less than the best so far
-X2 the actual is better if the total sum of noise is lower than the best so far
-X3 the actual is better if the total sum of noise is lower than the best so far and the maximum noise over all scalefactor bands is less than the best so far plus 2db.
-X4 this is a bit complicated, I think Greg Maxwell should explain this ;)
-X5 the actual is better if the sum of noise over the thresholds is less than the best so far or if they are equal and the total sum of noise is lower than the best so far
-X6 the actual is better if the sum of noise over the thresholds is less than the best so far or if they are equal and if the maximum noise over all scalefactor bands is less than the best so far or if they are equal and the total sum of noise is less or equal the best so far
All these are EXPERIMENTAL and may disappear sooner or later. Maybe we find the one and only criterion someday.
>>274 *NOTE* No psy-model is perfect, so there can often be distortion which is audible even though the psy-model claims it is not! Thus using a small minimum bitrate can result in some aggressive compression and audible distortion even with -V 0. Thus using -V 0 does not sound better than a fixed 256 kbps encoding. For example: suppose in the 1 kHz frequency band the psy-model claims 20 dB of distortion will not be detectable by the human ear, so LAME VBR-0 will compress that frequency band as much as possible and introduce at most 20 dB of distortion. Using a fixed 256 kbps framesize, LAME could end up introducing only 2 dB of distortion. If the psy-model was correct, they will both sound the same. If the psy-model was wrong, the VBR-0 result can sound worse.
>>334 --nspsytune uses Naoki Shibata's advanced psycho accoustic model enhancements. Improves many things:
1. Method to calculate tonality 2. Method to calculate ATH 3. Use -X0 and 'careful noise shaping' when encoding in CBR mode 4. Method to switch between long and short block 5. Allocates more bits to short block in which attack exists 6. Method to calculate masking in mid-side stereo 7. Method to switch between midside stereo and regular stereo frames 8. Better bitreservoir handling
Allows lower bitrates and is overall more efficient and quality yielding than the default LAME gpsycho. Fixes problems on most of the hardest tracks and solved all JS problems I know.
--athtype
slightly adapted ATHtype compared to 3.89 and 3.88. principles