[vorbis] masking problems in Vorbis beta?

[Jack Moffitt]

there was a reponse to this on the mp3encoder list, and i'll sum it up for
everyone who hasn't read it yet.

There are bugs in vorbis still, and we know about them.  This test is
exactly what trips the bug (short block triggering) and so of course it's
going to look upsetting.  Monty and Greg have already shown that in a
short amount of time you can make these bugs go completely away in a
specific case with some tuning/messing around, and Monty is working on the
grand master fix for it all.

Vorbis isn't perfect yet.  But every day its getting better, and when this
short block bug gets fixed, we can rerun the tests and prove it.

jack.

On 27 Jun 2000, Bill Pringlemeir wrote:

> 
> This page contains details of his analysis.
> 
>  "http://users.belgacom.net/gc247244/analysis.htm"
> 
> Look at the `original signal' line to explain the low frequency cut
> off in the ogg analysis.
> 
>  "http://users.belgacom.net/gc247244/ns-ogg.png"
> 
> Frequencies above 16 kHz and hard for most people to hear.  I don't
> really think that it matters for human ears.  These test are the type
> that anal retentive audiophile weenies like to do.
> 
> Examine his critic of the MP3 encoders.  His best test is with an
> actual song.  Although I would think that Ogg Vorbis would do better at
> pure tones, since it uses MDCT.  This is somewhat distressing to me.
> 
> The last thing to note is the human ear hears in a logarithm mode.
> All of his graphs are linear, which can make things look worse than
> they are, 3 or 6 db is not much of a difference.
> 
> Maybe someone else can provide better details; I am certainly not
> an insider. `Ich Bin Ein Auslander'
>        
> Bill
> 
> >>>>> "Martin" == Martin Reinecke <martin at MPA-Garching.MPG.DE> writes:
> 
>  Martin> Hi all, I just came across the following page:
>  Martin> http://r3mix.net In the "News" section there is a fairly
>  Martin> negative critique of Vorbis; especially it is mentioned that
>  Martin> Vorbis "has terrible masking problems". There is also a
>  Martin> Vorbis-encoded frequency sweep which shows strong
>  Martin> deficiencies at high frequencies, but I suppose this is due
>  Martin> to the quite low bitrate of the distributed encoder.
> 
>  Martin> I would be glad if one of the Vorbis insiders could comment
>  Martin> on that critique. Does the guy have a point or are the
>  Martin> problems caused by the low bitrate?
> 
> -- 
> Ask me the DIFFERENCE between PHIL SILVERS and ALEXANDER HAIG!!
> Another dimension is not a sham, I watch! 
> 
> 
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