[vorbis] Compression Artifacts at -q 5. Help!

Myles Buckley mylesb at conexsys.net
Sun Jun 15 20:10:58 PDT 2003

Warning - OT reply but worth the read....

Lawrence Wade [mailto:vorbis at glowingplate.com] wrote on Sunday,

>At 11:29 AM 6/16/2003 +1000, you wrote:
>>The problem is more complex than that - figuring out exactly which
>>compilers/versions are broken, and on what platforms, and with what
>>is quite difficult. Actually, doing anything at all with autoconf is
>>difficult, but this is more difficult than most :-)
>    Oh. Okay, then I can understand.
>    My programming style is so much brute force and ignorance that 
>Microsoft tried to hire me to write security patches for Outlook Express. I

>haven't cut my own source since I finished a horrible C++ course in 
>university. Forgive me for not knowing what is and isn't realistically 
>>If you want to contribute checks for "known-bad" sets of
>>compiler/platform/options/etc., we'd happily add them - but it's a lot of
>>work for pretty minimal (these days - _most_ people who compile their own
>>software have more recent development tools) gain.
>    I generally compile my own stuff because, even on a newer system where 
>all binaries are readily available, I find it to be faster and easier than 
>fighting through dependencies - for some reason, compiling from source just

>*works* 90+% of the time.
>    Into the READMEs:
>This codec does some pretty big math involving Fourier transforms and other

>scary things. Some combinations of compilers, assemblers, linkers, 
>libraries and processors don't play nicely together, causing subtle 
>calculation errors which might or might not always be apparent during 
>playback. Typical symptoms include reverb-ish artifacts most apparent 
>during playback of quiet musical passages.

I know that this i COMPLETELY off topic but I just -gotta- know.

houldn't you suggest reverb-ish artifacts that sounds like "wet chewing"??


<p>>Combinations which are known to cause problems include:
>  - gcc/egcs-2.91.66 on Intel/AMD (RedHat 6.x users take note!)
>  - [add more]
Leko stage lighting, fogmachines and too much free time...

>Potential solutions in order of preference: upgrade the operating system, 
>upgrade the compiler and libraries, or install precompiled binaries 
>(including .rpm files).
>Since these compiler combinations have caused bizarre mathematical, 
>performance and reliability problems with many other software packages, it 
>is *highly* recommended that you find a means to use another compiler.
>    That way, people have at least been warned...
>    Lawrence Wade, BOFH
>    www.glowingplate.com

<p>You really should have that url from my favourites linked somewhere on your
homepage :)

-Myles Buckley

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