[vorbis] APPLAUD.WAV problems

[Bostjan]

Hi Nicola!

<<<<<<<<<<
> BUT the APPLAUD.WAV test case
> ( http://lame.sourceforge.net/download/samples/applaud.wav )
> still produces **VERY** easily audible high-frequency artifacts when
encoded
> with OGG RC3 up to q4.9 (!!!). Things are **MUCH** better from q5.0 on.
Really? On that file I could not hear *any* artifact, even at "-q 0"! Could
you pinpoint one or more time offsets where the atifacts are located,
>>>>>>>

They are always approx. equally present trough all the track.

<<<<<<<
and maybe try a longer description of them?
>>>>>>>>>>

I'm not an expert of audio artifacts, but I'll try to explain as I can,
using some info from a previous Mark Kanof's post.

1. At -q 0 there are very noticeable CHIRPS ("high-frequency distortions
added to the audio, will sound like short chirps, whistles, sometimes can
shwoosh up like a high-pitched glissando (slide).")-----BUT I consider this
to be normal at such low bitrates.

2. From approx. -q 1 on the CHIRPS seem to fade out, but there is a *VERY*
noticeable BOOSTING OF THE HIGH FREQUENCIES (or high frequency noise) - like
if you boosted TREBLE with an equalizer. High frequency boosting has already
been discussed on this forum

The effect becomes less pronounciated as you move towards - q 4.9, but still
EASILY audible (16/16 ABX). At -q 5 it suddenly fades out (I've heard that
something changes in the encoding method at that point), but also the
bitrate jumps substantially.

LAME does a **MUCH** better job, even at 128 kbps (!!). This really confuses
me, because I use OGG and consider it to be a better performer otherwise.

I'm sure that many others have noticed this problem. Is it possible, Nicola,
that your speakers fade out high frequencies?

Cheers,
Bo¹tjan

<p>--- >8 ----
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