Hi,

I understood that Hydrogenaudio recommends Lame 3.97 Beta as the MP3 encoder to use. On the other hand, this is not advertised on the official Lame www site, at lame.sourceforge.net, so I conclude that the Lame developers still recommend Lame 3.96.1 instead. Is my assumption correct?

Regarding 3.97, I am not sure which VBR settings are recommended: --vbr-old (enabled by default) or --vbr-new? I understood that --vbr-new allows a faster processing, but sometimes this leads to audible artifacts. I do not care about processing speed, I am only concerned with quality, and I use -q0 all the time. So, is --vbr-new recommended for both speed and quality, or is it for speed only?

I am also concerned with respect to the reason why the Lame developers are not making the 3.97 release yet. Here is a quote from a forum topic named "should I wait for lame 3.97 final?":


Does this mean there are problems with the 3.97 Beta output, in a way that it's not compliant to the MP3 spec? Or is it just that it's possible to further increase the quality, in a way that is not implemented yet, but standards compliance is already okay?

Best regards,
Cosmin

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EDIT: Inserted hyperlink

LAME developers have asked to include 3.97 beta in all recent listening tests. I guess that they would recommand it over 3.96, which has different issues corrected by 3.97 (ABR/CBR distortions, tested --vbr-new mode, -q0 bug fixed).



For both. Sometimes --vbr-new increase audible distortion over default VBR mode, but the opposite is also true. --vbr-new isn't always better, but overall quality seems nevertheless better.


Because it's not ready


LAME 3.97 fully respect MP3 standard.

yes, that's it

You mean this?



I believe the developers advocate vbr-new, as does HA, but I am not sure if they are only intending its recommendation for the new 3.98 alphas, in which it has been made default, as 3.97 still uses the old mode by default.

I think they're just trying to to finish 3.97; iron out any little bugs and try and squeeze the last bit of quality out before calling it a day and putting out the final version.

Of course its output is MP3 compliant - what that quote means is that any quality loss or inability that 3.97 has is mainly not due to its shortcomings, but the inherent and impossible to overcome (without breaking compliancy!) limitations of the MP3 format and specification themselves.

Thanks, guruboolez and TBO, for your answers.



Which is why I'm a little puzzled: if the devs advocate vbr-new, then why would they not turn it on by default?



I wonder if some Lame developer is reading this thread. I'd like to know more about the problems that they need to sort out. I'm a computer programmer myself, I have some background in compression, transform coding (including MP3's MDCT) and rate-distortion theory, I have some familiarity with the concepts of psychoacoustics in MP3 (but not with all of them, I admit)... who knows, maybe I can help. I do have a textbook that describes how MP3 works, but I don't have access to the actual specification. I know it's an ISO standard, and it must be purchased for a non-trivial amount$; but do I need to have that in order to implement something in Lame?

In short, I wonder what are the prerequisites to participate in Lame development.

Best regards,
Cosmin

I believe they only made the definitive decision after releasing 3.97b2. I doubt they will set vbr-new as default in 3.97 - but the 3.98 alpha branch, which represents the current development, does use it. Evidently, HA believes that 3.97's implementation of the mode is good enough to be recommended too, so it comes down to whether you take the word of the developers themselves as gospel or not.

Interesting. I downloaded 3.98a3, but neither the HISTORY document nor the --longhelp option shows this. I don't have a wav at hand to check that this is really the case, though. Will try tonight.

But okay, the fact that --vbr-new is enabled by default, or will be enabled by default in the near future, is enough assurance for me.



I'm in the middle, actually, hence the reason why I started this topic. Consensus between HA and the Lame devs is what I would prefer. I understand that HA forum members may have better equipment/ears/etc. to know better, but at the same time I'd think that the Lame devs know what they're doing, and I should listen to their recommendations as well.

So I understand that HA says 3.97 Beta is better, but at the same time, the fact that there isn't any mentioning about it on the Lame www site tells me they (or at least some of them) want their users to use 3.96.1 Release instead of 3.97 Beta. This is why I'm postponing my encodings until both Lame devs and HA agree on what's best, and this is also why I would prefer a 3.97 Release.

Best regards,
Cosmin

I don't believe that the official site or bundled documentation has been updated much recently, so it may not be very up to date. I think the LAME site only mentions the latest stable versions. Again, as I said, it doesn't seem to be very up to date so you may want to trust some other sources.

One more reason for confusion:

I understood that HA stated "3.97 Beta is now the recommended release, instead of 3.90.3". But what about the other releases between 3.90.3 and 3.97? Was HA not recommending, say, 3.93.1, or 3.96.1 over 3.90.3?

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Cosmin

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EDIT: Rewrote last paragraph

You are correct. None of the intervening versions, from 3.93.1 on, were ever officially recommended. The official recommendation went directly from 3.90.3 to 3.97 beta. It was certainly discussed often, and you can run a search if you want to see all the old threads on the topic, but the recommendation didn't change until 3.97.

Yes, that is true, and the reasoning is a little complicated (so I hope I've got it right ). 3.90.x was very well-tested. Subsequent versions presented a trade-off between testedness and quality. It wasn't until 3.97 that a version of LAME presented significant enough quality gains to allow it to supercede the well-testedness of the 3.90.x branch.

If I'm wrong and someone who can correct me spots my error, please correct me. The last time I stepped into a LAME discussion was, well, lame.

Just an inquiring mind.
Fell free to send a mail to the developpers list:
http://lame.sourceforge.net/contact.html

Regarding our recommendation, we never recommended an alpha or a beta version.

Thanks, I will.


Ok. Many thanks to everyone for replying. Let's summarize:

- Lame 3.97 Beta is indeed recommended by the HydrogenAudio.org forum, but users should enable --vbr-new when using VBR or ABR. (Otherwise, Lame 3.97 with the default, old VBR mode isn't that much different than the previous Lame releases.)

- Lame 3.96.1 is recommended by the Lame developers.

- It is everyone's call whether to follow the recommendation of the HA forum, or that of the Lame developers. I'd personally prefer consensus, and I suppose that will happen when Lame 3.97 is officially released.

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Cosmin

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EDIT: Confusion ended