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--alt-preset medium
Gabriel
post Apr 10 2002, 15:22
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I'd like to introduce a medium preset, for medium bitrates (and medium quality). Here are the switches I'm currently playing with:

--alt-preset standard --lowpass 17.5 -b 80 -Y --athaa-sensitivity -11 --nsmsfix 3 -V3

disclaimer: i KNOW that this won't be transparent, it's not the purpose

I'd like your opinions about this.


edit: following options were tested but gave bad results:

--interch 0.17
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NeoRenegade
post Apr 10 2002, 16:08
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I'm all for it. I want to be able to put more songs on a CD than I can right now with --alt-preset standard, without being forced to use ABR or devise my own (undoubtedly crappy) commandline.

Because, let's just face it, ABR can be almost as much as a waste or bottleneck for some samples as CBR.

Thanks for posting that line, Gabe. I'm going to give it a try. smile.gif
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sam
post Apr 10 2002, 16:20
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Yeah, I with NeoRenegade. I tend to put all my albums from a particular group on one CD. I find that most of the time there are around 8-10 albums to do, sometimes they all fit on with aps, sometimes I've got 50 megs to much. So an 'apm' for the just too much case would be great, and saves me from cooking up my own (undoubtedly crappy) commandline aswell.
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indybrett
post Apr 10 2002, 16:30
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Why not just use --alt-preset standard -Y

That knocked about 40MB off of one Metallica CD compared to APS.
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mr1337pants
post Apr 10 2002, 16:51
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QUOTE
Originally posted by indybrett
Why not just use --alt-preset standard -Y

That knocked about about 40MB off of one Metallica CD compared to APS.

Agreed, I remember reading a reply by Dibrom to a post (question) about using alternative switches in conjunction with --aps in order to save bits. He explained that -Y effectively lowpasses at 16KHz and only encodes higher freqs when it wouldn't require too many bits (I don't remember much more than that). But I do recall Dibrom saying that decreasing the lowpass is the most graceful way to retain quality and reduce bitrates.

Gabriel- What kind of bitrates are you thinking of? If a new --ap switch is implemented for the 150~190Kbps, it might as well just replace --r3mix biggrin.gif

edit- grammar
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Dibrom
post Apr 10 2002, 19:01
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Well, I am interested in working on a lower bitrate preset at some point (still probably going to be awhile before I'm done with anything), but I want to make sure that it is the best way to do it and that it is thoroughly tested.

Out of curiosity Gabriel, how much of a lower bitrate does that line give than just --aps -Y as someone already asked? Can you give some figures?

Also, I think part of the problem with that line is that you tune many of the settings just beyond where a lot of the internal --alt-preset tunings will no longer kick in at all. For example, the --athaa-sensitivity and --nsmsfix (and even the -V to some extent) settings you suggest are effectively well out of range of the "trigger" area so I'm doubting they will have much effect at all anymore..
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Gabriel
post Apr 11 2002, 08:21
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Those switches seems to provide encoding in the range of 130-180kbps

Yes, you're right some switches are pushed to their sensitivity limit (msfix and athadjust)

Honestly the change in msfix doesn't affect the bitrate that much.
But for the ath adjust, it's another thing. In some tracks ap standard uses about 30 kbps for this adjustment.

This is quite high, and for something in the range of 130-180 it seems to me that this is way too high. A -11 change is high, and so the sensitivity is quite low, but it's still there. I think that a minimum sensitivity is better than no ath adjustment.

For the internal settings: yes, if you mean thanging the quantization on high ath adjustment levels or high ms values, probably it won't appear. Probably the only internal thing left which really does something is the different quantization on short and long.
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Dibrom
post Apr 11 2002, 10:43
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QUOTE
Originally posted by Gabriel
Honestly the change in msfix doesn't affect the bitrate that much.


If that is so, then I would seriously suggest leaving the default settings that --aps uses. They were tuned that way for a reason, because they specifically eliminated artifacts in some samples, and if the bitrate savings is not significant (more than 10kbps on average), it would seem better to leave it as it is I think.

QUOTE
[b]But for the ath adjust, it's another thing. In some tracks ap standard uses about 30 kbps for this adjustment.


This is another matter... and you're probably right that there isn't going to be a way to get the bitrate down significantly without doing something related to the ath or athadjust...

From my experiments with --alt-preset normal (which produced some incredibly low bitrates and still sounded good on quite a bit of music), it's actually possible to get away with a significantly raised ATH (if I remember, it was around --athlower -18 or so.. I'll have to look it up again) on most music such as pop or rock. The problem comes on quieter music where this high ATH causes noise pumping and ringing problems. I think this could actually be solved if the athadjust code was modified in a manner to try and be much more aggressive in these cases and only for this particular preset...

The only other issue, which is sort of related, was that the preset was more likely to have problems with -Z in some cases, but again mostly only on the lower volume music, so in those cases it had to be switched off... this worked but not as well as I would have liked.

The --alt-preset normal was actually on the right track I think... with a properly tuned athadjust, it could probably work great even nearly as good as --aps, at around the bitrate you are speaking of..

QUOTE
For the internal settings: yes, if you mean thanging the quantization on high ath adjustment levels or high ms values, probably it won't appear. Probably the only internal thing left which really does something is the different quantization on short and long.


Yeah, this is what I'm talking about. It really wouldn't be so difficult to find new thresholds for the new preset, it would just take some time to test it all.
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Gabriel
post Apr 11 2002, 11:05
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I don't really like the idea of highering the ath (btw 18dB seems huge). I think that if you higher the ath, then you're relying on athadjust to lower the ath to its original value. It will lower the ath quicker than normally because the sound level is relatively closer to the ath than in normal situation.
So you have a slight delay before ath is restored to its original value. After it's restored (ie lowered by athadjust), athadjust as a more limited range to lower again.

So it seems to me that highering the ath is similar the lowering the athadjust, except that there will be a little delay.

So it seems to me that directly lowering the athadjust is a better way.

Btw the bit graph of encspot gives you a good visual idea of the athadjust effect.
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Dibrom
post Apr 11 2002, 11:19
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QUOTE
Originally posted by Gabriel
[b]
(btw 18dB seems huge)


Looking back through some of the information, it was actually 16db. And yes, it was a pretty huge jump, it still worked pretty well in a lot of cases (coupled with much more usage of -X3).

QUOTE
So it seems to me that directly lowering the athadjust is a better way.


This could be... I'll have to run some experiments again, it's been so long that I don't remember all of the results I found messing with the athadjust stuff. Probably won't be till next weekend though. At any rate, if you are seeing a 30kbps savings from this and it doesn't harm quality very significantly on quieter music, then coupled with -Y, it could be a good solution.

QUOTE
Btw the bit graph of encspot gives you a good visual idea of the athadjust effect.


Yeah.. Those graphs would have been really handy back when I was working on revamping the --alt-presets wink.gif
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Gabriel
post Apr 11 2002, 12:33
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each time preset std is the first parameter


test.wav

std: 176.2
lowpass 17.5: 176.2
Y: 176.1 (ok, there is nearly no high freq content in this track)
athaa-sensitivity -11: 158.2
nsmsfix 3: 165.5
-V3: 163.2

cumulated switches: 136.7
cumulated -b 80: 136.2

r3mix: 140.4

-------------------------------------------------

big.wav:

std: 205.2
lowpass 17.5: 203.4
Y: 203.3
athaa-sensitivity -11: 201.0
nsmsfix 3: 203.9
-V3: 192.2

cumulated switches: 184.8
cumulated -b 80: 184.6

r3mix: 174.4

--------------------------------------------------

fatboy.wav

std: 265.3
lowpass 17.5: 264.0
Y: 264.8
athaa-sensitivity -11: 263.1
nsmsfix 3: 260.8
V3: 256.0

cumulated: 247.5
cumulated -b 80: 247.0

r3mix: 209.2

-----------------------------------------------------

t1.wav

std: 167.4
lowpass 17.5: 166.6
Y: 165.9
athaa-sensitivity -11: 153.6
nsmsfix 3: 166.3
V3: 158.0

cumulated: 144.3
cumulated -b 80: 140.5

r3mix: 138.0

------------------------------------------------------

spahm.wav

std: 289.4
lowpass 17.5: 288.2
Y: 285.7
athaa-sensitivity -11: 284.2
nsmsfix 3: 286.8
V3: 285.7

cumulated: 276.3
cumulated -b 80: 275.1

r3mix: 190.3

--------------------------------------------------------

stair.wav (a small part of Stairway to heaven - a guitar riffle)

std: 219.4
lowpass 17.5: 210.0
Y: 189.0
athaa-sensitivity -11: 218.1
nsmsfix 3: 218.6
V3: 199.0

cumulated: 173.8
cumulated -b 80: 173.8

r3mix: 215

-------------------------------------------------------

peaceful:

std: 215.1
lowpass 17.5: 212.0
Y: 209.7
athaa-sensitivity -11: 209.3
nsmsfix 3: 215.0
V3: 200.4

cumulated: 192.5
cumulated -b 80: 192.5

r3mix: 187.2

--------------------------------------------------------

velvet:

std: 227.2
lowpass 17.5: 218.6
Y: 218.3
athaa-sensitivity -11: 226.8
nsmsfix 3: 226.9
V3: 213.9

cumulated: 200.7
cumulated -b80: 201.7 ???

r3mix: 197.0
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Wombat
post Apr 11 2002, 19:44
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Hello,

i just tested my standard samples in and it averaged ~151 kbit

But the quality suffers to much in my opinion

Most degrading sounds this --interch 0.17 Try it with peaceful
for example.

What does this switch try to do? I never heard about it before.

regards

Wombat
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JohnV
post Apr 11 2002, 20:06
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QUOTE
Originally posted by Wombat
Most degrading sounds this --interch 0.17 Try it with peaceful
for example. 

What does this switch try to do? I never heard about it before.
It's Takehiro's new switch, inter-channel masking (only in 3.92alphas iirc).
http://www.geocrawler.com/archives/3/7323/2002/2/0/7860123/
http://www.geocrawler.com/archives/3/7323/2002/2/0/7860199/

"This enables LAME to calculate the inter-channel masking which means - The masking in left channel sound made by sound in right channel and vise-verse".

I think Takehiro meant this switch to be used with low bitrate (under 128kbps), because the channel separation gets worse, but quality at low bitrate may become better.


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Wombat
post Apr 11 2002, 20:18
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Thanks John,

just like you said, used with aps here it simply doesnīt seem to work at all
and even isnīt meant to work here.

I will play around with it.

Wombat
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Gabriel
post Apr 12 2002, 07:50
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You're right about the interch options. Probably the target bitrate for normal is too high to choose this compromise.

Let's edit the upper results without interch...

....and assemble all the results in 1 post
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Gabriel
post Apr 19 2002, 08:33
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I have the feeling that -Y mainly reduces on electric guitar samples. Anyone found a non-guitar sample where it provides a significant bitrate reduction?


I also posted the r3mix bitrates as a comparison. After all, replacing r3mix is perhaps possible, as it seems to be in the same bitrate range.
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Shadow RD
post Apr 21 2002, 04:24
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Gabriel,

I saw your bitrate reductions using all of those switches. Did you happen to check the reduction in sound quality associated with your custom commandlines? Which ones gave the best trade-off of bits saved vs quality loss? Also some of us over at r3mix discussed the name of "medium" here:

http://66.96.216.160/cgi-bin/YaBB.pl?board...&num=1019269361

RD.


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Dibrom
post Apr 21 2002, 04:38
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QUOTE
Originally posted by Gabriel
I have the feeling that -Y mainly reduces on electric guitar samples. Anyone found a non-guitar sample where it provides a significant bitrate reduction?


I also posted the r3mix bitrates as a comparison. After all, replacing r3mix is perhaps possible, as it seems to be in the same bitrate range.


I have in the past. The samples I've seen which benefit from -Y in regards to bitrate savings seem to vary pretty wildly. I wouldn't limit it to electric guitar samples, but instead to samples where high frequencies may be prominent and where the signal is noisy which, not surprisingly, is usually what leads to bloated bitrates in the first place. I've found samples from various electronic and experimental genres, ambient music, even classical music with high amounts of background noise, in addition to rock/metal.

I can't provide any samples off the top of my head this very moment, but maybe I can soon. I just got done moving again and so now I can finally get back to working on LAME some (including working on this lower bitrate preset and performing some listening tests), so I'll see if I can give some more clear examples of this.
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jkeating
post Apr 22 2002, 11:24
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If you'r searching for a song where -Y gives a HUGE bitrate reduction, I have a song (Ark/Burn the sun/Torn [Metal prog]) where it takes down from 234 to about 175 (!!!) kbps with aps.
If you can't find it I can find a way to upload it to someone.
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Gabriel
post May 13 2002, 09:00
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?
How to remove a post?
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Dibrom
post May 13 2002, 09:06
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QUOTE
Originally posted by Gabriel
a little up...


At this point, I'm waiting to see what happens with nspsytune2. I've been talking to Naoki some and I'm supposed to be doing some help with the tunings but I'm still waiting for him to email me a build with his latest enhancements. I don't think it makes sense to work seperately from this because the possible improvements could have a fairly significant impact and are really the more appropriate ways to try and improve quality (which would lead to similar quality at lower bitrates).
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Gabriel
post Aug 26 2002, 15:45
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up
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Gabriel
post Sep 3 2002, 12:11
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What about 3.93 and --preset medium?

I know that Dibrom would like to use some of Takehiro's changes for preset medium. Those changes should be in 3.94, not 3.93.

Do you think that it would be a good or bad thing to introduce a preliminary --preset medium in 3.93? (personnaly, I'd go for it)

I am asking because I hope that with the 3.93 release, it will be the end of our --alt-preset vs --preset strangeness, and it should be the beginning of a clear path for most people: use --preset
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David Nordin
post Sep 3 2002, 13:28
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sounds like a plan to me. B)

Considering "--preset"
Will we see: (?)
--preset ABR xxx
--preset CBR xxx
--preset standard
--preset medium
--preset extreme
--preset insane

will standard, medium & extreme be possible to combine with --vbr-mtrh?
^ Personally I'd like mtrh to be default for all modes, it seems many use other codecs due to 'LAME's slowness' wink.gif

-Y (default for "medium" and optional for rest?)


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Gabriel
post Sep 3 2002, 14:00
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In 3.93 --alt-preset is the same as --preset
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