Careful with those stones.

Added junk? Ah I have to protest as all I did was completing the information already in there

Well okay I did add "Advanced Encoder Settings" but I think that's not junk...

--advanced-encode-option lowpass_frequency=X (where X is the lowpass frequency in khz)

isnt mentioned in the wiki its my favorite option i couldn't live without it

Looks superb. Many thanks to everyone who helped create and maintain the wiki. It is very much appreciated. Now I don't have to worry about being the only person to update it whenever John33 decides to change versions or a few URLs without me knowing


EDIT: There is one thing that may be confusing to the average user and may require further explanation in a footnote. I think the terms "channel coupling" and "noise normalisation" need to be explained a bit, so the average user can make an informed decision on what q to use. They won't know whether it is good or bad, if you know what I mean.

The problem is that changing it may not be "recommended" for average users.

But what problem does it solve, actually? I mean I put in INT and ITP because they try to fix problems (Pre-Echo and Microattack, respectively).

And I don't really know what they mean I mean, I know the concept, but I'm afraid I will write it mistakenly.

However, I have replaced the plain column title with a Wiki internal link, which you can see here. So. Will someone please click on those links and write something correct?

*it fixes the muffeled sound issue at low quality settings (like q0)
*of course it has the side effect of adding a bit more artifacts in the upper frequencies when moved up higher than the default
*can be used to set a custom bandwidth at any given bitrate (higher or lower) i remember reading (quite a long time ago, and i dont know where) some opinions that the lowpass fillter was set to high at q -1

it might not be 'recomended' for average users... but then again, average users probably wouldn't mess with it anyways

Well the section title does say "Advanced Encoder Settings"...

If you can distill the benefit of lowpass_frequency into one line, I think you can add it to the wiki page. Don't worry about formatting, I'll beautify it for you Or PM me and I'll put it in.

i think it might also be nice to have a table with the default lowpass values for the quality values, but i think they are different for libvorbis and aotuv, do you think that would be a good and informative addition? i can make a list of them pretty easily if it would be a good idea.. they are all floating point values, so maybe just rounding them to the nearest tenth or hundredth?

Headline: "Adjusting the Lowpass frequency"

(being a new member, i would rather stay away from adding to the wiki for now )

Good headline unfortunately it doesn't really show the usefulness of adjusting the Lowpass frequency.

I suggest the title should be "Fixing Muffled Sound at Low q"

If you don't want to edit the wiki that's okay... um do you see how many posts I have made before editing the wiki? Heh I'm just as new as you

Anyhoo, do post the table here (in this forum). I think you can round it to the nearest integer. I think a 0.1 Hz difference should not be significantly different. And I don't know if Xiph's and aoTuV's are different.

And if possible, also do a 1-paragraph writeup of when you use the switch, what's its effect, what encoder version is used, etc.

No that's why we are going to stay clear of it and not mention it at all (adjusting the sliding lowpass filter can cause inherient problems too). If you want to know though I think it's around 18 kHz for -q 4 and above that it's really of no importance. -q 0 is around 15 kHz. I did write a page in reguard to Noise Normalization a long time ago it's there. It's under Noise normalization. Aoyumi fixed the switching levels too for it. It's much lower than I thought it was last time I checked.



-q 0 actually sounds quite well for streaming IMO. If there wasn't Noise Normalization it would sound much worse. The noise is pleasing to my ears.

the lowpass at q4 was 20khz, aotuv has it at 18.3khz
q3 was at 18khz, aotuv is at 17.2
q0 is the same in both I think

(I'm making a table of the lowpass frequencies at the whole number quality values, and sample rates... this is gonna take me a little while )

q0 is good for streaming cause of the bitrate, but IMO a 15khz cutoff is way to low

have any of you even tried q0 with out the cutoff at all? (don't compare it to the original, compare it to other codecs at the same bitrate) (do it with pop, rock doesn't do as good )

That's absurd. If you really have to go ahead, but add it in as 5th column. People shouldn't touch it period. Forget about sampling rates. If you are going to do that you might as well just tell people what type of block switching mode it uses for various sampling rates. That's going over board and is more information then people need to know about.

ogg vorbis lowpass frequency:
the first column is the quality setting (-q)
the top row is the samplerates( 8999- means everything below 9000hz, 9000+ means that the lowpass frequencies in its column are valit untill it reaches the next 'step' in samplerate which would be 15000, etc.)
lowpass frequencies are in KHz
This table is valid for Sample Rates of 6000-96000.
(I didn't test beyond that.)
OggEnc v2.6 (Lancer 20051121 based on aoTuV b4b)

Note: The lowpass frequencies were slightly higher in older versions, like oggenc v1.0.1. At 44100hz: q3 17.9, q4 20.5.

Note2: More info is a good thing I personally got some good knowledge from creating this table.

edit: added a better explanation of how to read the table.. i hope

Look, when you go above q5, it seems Ogg Vorbis has been designed for dogs. But, I'm confident that these Japanese tweakers knew what they were doing in setting lowpass values. Is it the judgment of the best codec engineers that high figures for the lowpass will improve quality even for people who cannot hear 20 khz?

one thing to keep in mind, 44100hz sample rate audio can only produce a max audio frequency of 22050hz, so once the lowpass filter goes above that mark, it no longer has any effect.

if you can't hear to 20khz then setting the lowpass filter above that won't improve how you hear it, increasing the bitrate would though. on the other hand, maybe your dogs would enjoy the really high frequencies

Uhhh... I don't really understand what the numbers mean... care to explain?

the lowpass filter is a "sliding lowpass" filter. What that means basically is that adjusted via a template for a specific quality level. There is no reason to touch. Any reason would just assert "magical thinking". 999 means that there is no lowpass filter applied. It's the kind of that that whips people into frenzy. If people are concerned about it then they should only use a -q 5 and up.



I don't think people have a "sub-sonic" hearing. There are discussions about this for legimate technical purposes all of the time for various other reasons. Streaming purposes you don't need to reconstruct the upper half of the spectrum. The encoder has precomputed channel coupling point just like it has a precomputed lowpass filter setting. It's no coincidence that it was designed that way for a specific purpose. Therefore this isn't going to be mentioned on recommended settings page.

"oggenc2 -q 0 --advanced-encode-option lowpass_frequency=999"

By doing this you are just forcing the encoder allocate less bits to each band and making the Noise Normalization code redistribute by band noise energy more. If you want to do this, that's fine but don't spread bad information... again "Magical Thinking".

Thanks very much, HotshotGG; I do now understand (sorta).
I remember Dibrom wringing his hands over how people would misuse options in LAME.
I especially enjoyed the contest to use LAME options to create the worst sounding files possible. Subsequently many of those options were removed!
BTW, I hope people have noticed that Aoyumi has posted on page 7 of the news discussion about the latest 128 kbps codec shootout.

That's one reason why Vorbis doesn't have many advanced-encode options with the exception of a few. The encoder control interfaces allows developers to add more for various "tweaking" purposes, but the end users end up playing around with them too much or start creating this ridiculous tweaks that they believe really do make a difference for their own purposes. The whole goal is to simplify the encoder for the average user that's why -q switches are used in Vorbis and to give the technically astute user a little more freedom, but nothing that's going to alter the zeitgeist of encoding. Yes, you are right LAME was a perfect example of this. One people start altering the ATH levels then you know you are in trouble.

the problem with that view....

oggenc input.wav output.ogg
^ is the only thing anyone should use, since it is the default that the developers chose

and
lame infile.wav outfile.mp3
also because its the default that the devs chose

the same goes for our own computers.
who doesnt have a custom wallpaper... its not the default that the developers chose.
etc. etc.

everyone has their own favorite encoding settings, so everyone has their own 'recomended' settings, I am just sharing mine. what is the best settings for one person, is probably not the best settings for another. I have never bought into the whole 'if you move up the lowpass filter you end up with crap above and crap below' and I never will.

i like my encoding setting: oggenc2 -q 0 --advanced-encode-option lowpass_frequency=999
and often i have to listen quite closely to be able to hear a difference from the original (i can hear up to around 21khz, so I am far from deaf)

Ahh... generally reformatted the Wiki page for this thread. Check it out here.

Annnddd... one thing still irks me: If only the OggDropXPd manual is done ... well anyways I created a stub for OggDropXPd you can check here, there's a section I call "Manual".

If someone would be kind enough to write the details down there... I'm at my office PC and it has no OggDropXPd... yet!

I still don't get the lowpass filter switch... if it accepts only one parameter, then how do I specify the lowpass freq?

lowpass_frequency=XX is the paramer to --advanced-encode-option
XX is the lowpass frequency in KHz, so you can use stuff like 17.98245 for a lowpass frequency

oggenc -q 0 --advanced-encode-option lowpass_frequency=18 input.wav

^^ just copy and paste encodes at quality 0 with a lowpass of 18khz

it doesn't belong in the wiki if you add any information related to I will remove it. Zealous magical thinking doesn't outweigh the needs of many. I will make a note of it though, but I more than willing to bet QuantumKnot would agree with me 120% anyway.



The page looks good. . Keep working on it.

After much soul-searching well not that much actually I agree with you. AFAIK these values (whatever they're supposed to mean) are tuned between versions. Unless we want to change the Wiki page into a changelog I don't see a reason to write it in.

After all, the page is called "Recommended ..." and these lowpass selftunes, I believe, are not recommended

More meat has gone into the OggDropXPd manual. I decided not to use the downloadable manual from rarewares. I know this decision may or may not cause disagreement...

... or not so please check out the OggDropXPd page at Wiki and tell me what y'all.

Hi,
i got a problem: Always when i convert files with one of the commandline encoders listed above i can't play it with my mp3-player (or only some files). i played them in foobar and there i get the message "files is corrupted" but it plays. Can anyone tell me why the encoder creates corrupted files?
Thanks in advance.
Greetz

The short answer is they don't create corrupted files, but tell us what command line you're using and we'll take it from there.


Sorry, I know it's well after the fact, but there's no disagreement here. You seem to be doing a good job, so do please carry right on with it.

Ahh... you have put me to shame, John. I had been abandoning this page for quite some time...

Well, I've just updated it. Some slight rewords, now it's not *the* manual but a *quickstart* manual. The description for all the advanced settings may be waaaaaaay over the head for Vorbis newbies.

Inputs welcome.

Hurrah! Pop open those champagne bottle cause version 1.0 of the Encoding QuickStart for OggDropXPd is *finally* complete!

Check this out and please give feedback.

Peace!

The Rarewares links in the main post don't seem to be working. Had to go download the files manually.

The links are probably out-of-date.

Use the wiki page referenced in the first post.

Oookay, more than 6 months since aoTuV beta 4.51 (aka aoTuV b4b) has been released (in 2005-11-17).

Anyone got a bone to pick with aoTuV beta 4.51?

Can we modify the wiki section here (and elsewhere on the same page/wiki) so that the recommended aoTuV is now beta 4.51?

If no one disagree, let's -- within this week or so -- change the page.

Wiki page modified.

What about adding these to the table in the wiki?

This has been discussed before. Please read the posts.

The answer is: no, never.

aoTuV beta4.51 has been updated to aoTuV Release 1 (2006/08/23).

link

Interesting. We will have to make a note of that for the wiki. Thanks.

The first page of this thread should be updated as well.

Well, the first post already links to the wiki and explicitly said that one should check the Wiki for more up-to-date info.

I'd like to have ogg aoTuV r1 in "Win32 DLL (not reference)", but on the aotuv page, there is only this for b4.51 ... ?

@om: try this. http://homepage3.nifty.com/blacksword/

hi all
I have a problem about the vorbis encoder...
If my CPU is Pentium D
which vorbis encoder should I use?

the SSE3 one on the website which i previously provided. you could also download the MT version as well if you want.

And, aoTuV's beta 5 is released. Which is better quality-wise anyway? Lancer's build or OggdropXpd's?

Also, unfortunately, John's Rarewares.org has been suspended.

- Spike

Nobody has ever been able to ABX the differences between Blacksword's Lancer builds and john33's ones which are based on Aoyumi's reference implementation. Hence you can safely use the faster Lancer builds.

Edit: Grammar, grammar!

which vorbis decoders are safe for ABX-ing?

<deleteme>links to rarewares files seems to be borken</deleteme>

Aaaaahhh... they're borken!

I blame roberto