Hello,
I\'ve done some listening tests (again) of some things.
I concentrated only at stereo 128kbps (overkill) and mainly at 2 clips (main_theme
and joe satriani)
I concentrated at reducing all artifacts as much as possible and not at overall
high-end sound quality.
1) Leonid\'s fix
Twinkling artifacts don\'t gone, but sound a little bit different.
Some time ago I tried -Y option and it produced sometimes really bad twinkling.
With Leonid\'s fix -Y option significantly reduces artifacts, but only when used with
-X1.
Resume: I think Leonid\'s fix is right and with -Y -X1 it produces nice results
(sometimes I got better results than Fraunhoffer).
2) ATH
Without Leonid\'s fix and without -Y -X1 it produces audible artifacts. I tried to
divide ATH and useful values was from 10 to 100 (it was depending on type of music) -
I know it seems too much (20 to 40 dB).
for (i=start ; i < end; i++) {
freq = samp_freq*i/(2*576); /* freq in kHz */
ATH_l[sfb]=Min(ATH_l[sfb],ATHformula(freq));
}
++ ATH_l[sfb]=ATH_l[sfb]/20;
}
same for short blocks
If I let ATH unchanged, joe satriani sounds worse (more flanger) than with lame v3.1x
3) Decoders - I tried winamp2.5, MS Media Player and mpg123 0.59q. Each decoder
sounded another way (and produces another kind of artifacts). Winamp is buggy/broken
(I\'m sure about it, with joe sat. it produces artifacts in left channel regardless I
tried to swap chanels in original wav and reencoded it - again artifacts in left
channel). Best results I get with mpg123 but I can\'t listen under Linux (damned Li(v
|| f)e!).
When I played with ATH coefficients a bit, near all artifacts gone on first clip. But
when I tried another song and tuned ATH, I broke first settings. Should ATM be
variable/adaptive?
I\'m sure with ATH we can outperform Fraunhoffer, but it needs _MUCH_ tuning.
My new top quality lame at 128kbps is:
v3.27 with Leonid\'s patch, with ATH divided by 20, and with swiches -X1 -Y.
Please try it with hard-to-encode samples at lower bitrates, because my test was
limited to a few clips.
Bye, macik
PS: I was surprised, but try to encode \"fatboy.wav\" using Lame and any mpeg1layer2
encoder - layer2 produces much better results at any bitrate. Is there serious bug in
layer3?
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