[vorbis] APPLAUD.WAV problems

Bostjan 00 at email.si
Wed Feb 13 15:36:37 PST 2002



Hi!

<<<<<<
 > 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
Yes, high frequency noise. It is definitely there, up to "-q 4.99", even if
you have to strain a bit to hear it at that level.
>>>>>>

I'm glad to see that you noticed it too. This artifacts led me to use at
least -q 6 to make sure that the compressed file is transparent.

<<<<<<
 > 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.
Yes, it disappears completely at "-q 5": that's where the lossless stereo
encoding kicks in. It looks like the lossy stereo encoding cannot encode the
big differences between the two channels in this sample.
>>>>>>>

I see.

<<<<<<
 > 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.
Maybe the lossy stereo encoding will be tuned a little bit more before 1.0.
>>>>>>>

I really hope so.

The ironic fact is that Gian-Carlo seems to have noticed this
lossy-stereo-coding problem already and has tuned his OGG encoders to
eliminate it.

Gian Carlo, would you mind explaining how did you tune your encoders - at
least to the guys that hold on this project? I believe that your suggestions
would help OGG making one step ahead towards being the best lossy encoder
available.

<<<<<<
 > I'm sure that many others have noticed this problem. Is it possible,
 > Nicola, that your speakers fade out high frequencies?
No, it definitely looks like a problem concerning the grey matter between
the ears. :^(
>>>>>>

I really don't think so :)
Your input helped me to understand better.
Thank you very much Nicola.

Regards,
Bostjan

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