[vorbis] 'Jukebox' quality?

[John Morton]

On Sun, 29 Oct 2000 14:58:30 -0800 Joe Soroka <vorbis at xiph.org> wrote:

> 
> In light of the recent study
> - http://www.airwindows.com/encoders/index.html - 
> posted at slashdot, I've come to realize how little I know about this whole field.
> 
> So, I'm making an appeal to the audio experts here.  I want 'jukebox' quality, 
> meaning ~0 artifacts while maintaining a good compression ratio, but not 
> quite 'archival' (read high bitrate) as I don't mind hanging on to the
> original cds.

Me too!

> Is r3mix's recommended "lame -V1 -b128 -mj -h" good enough?

In my experience, yes. These setting sound as good as 256kbit/s and way
better than 128kbit/s to my tin ears. A lot of nasty artifacts that I used
to get with early Fruanhofer and ISO derived codecs are nowhere to be
heard, and hasn't mucked up the stereo imaging or given noticable pre-echo
effects on anything I've tried.

>  Is this guy 
> and his study saying that it's *no where near* good enough as it seems?  Is 
> this study for real, or is it bunk?

Mostly bunk. The fact is that perceptual encoders are supposed to throw
out information that cannot be heard, so the image generated by the
encoded sample will almost necessarily be different - and it's difficult to
correlate a conspicous difference in the images to encoding errors without
listening to each sample. Trust your ears, basically. 

The graphs on r3mix are a little more useful as they will tell you whether
a particular encoder is using a low pass filter to drop anything over
16kHz, or whether it does a bad job of encoding the top 16-22kHz worth of
sound without one - but vorbix beta 1 flunked this test as it had a bug
that was specifically triggered by this kind of frequency sweep test, but
which otherwise didn't show up normally. 
  
> And I know that ogg is not quite there yet, but I'm a little confused as to ...
> Various stuff I've read on xiph.org seems to indicate that ogg/vorbis was 
> born out of a desire for a 'free-speech' lowbitrate streaming/compression
> format, not for '~0-artifact digital jukeboxes'.  Is this one of the goals for 1.0?  
> When can I completely throw out mp3 and put my cds in a timecapsule?

High bitrate encoding is in their at the moment, but I expect it will want
a lot more tweaking to do archival quality at bitrates that compete with
LAME. I think I heard that in theory vorbis could do 160 av VBR at
archival quality (without wavelets) compared to LAME's 180 av. That's way
after 1.0 is released, though.

John

--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To unsubscribe from this list, send a message to 'vorbis-request at xiph.org'
containing only the word 'unsubscribe' in the body.  No subject is needed.
Unsubscribe messages sent to the list will be ignored/filtered.