Hello,
congratulations to the Ogg Vorbis team - RC2 sounds good.
But... RC2 in 128 kbps mode seems to clip off all frequencys
beyond 16 KHz. On the tracks I tested Beta 4 gave response
even beyond 18 KHz.
Some testings on a randomly chosen track:
(other tracks gave similar results)
Artist: Judas Priest
Album: Jugulator
Title: Bullet Train
Beta4: 127 kbps, ~ 18 KHz (!)
RC2: 132 kbps (!), ~ 16 KHz
This seems even more strange to me as RC2 benefits from channel
coupling...
BTW: As 128 kbps mode produces average bitrates higher than 130 kbps
(please keep in mind that I am testing with Heavy Metal music, so
results for Britney Spears and Back Street Boys may vary ;-) )I would
be happy if 112 kbps mode is back in RC 3...
bye,
Maik Merten
--
MetalUnleashed: http://www.metalunleashed.de
DHTML-Bibliothek: http://www.fortunecity.de/wolkenkratzer/flick/403
ICQ: 45648209
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On Tue, 14 Aug 2001, Maik Merten wrote:> Hello, > > congratulations to the Ogg Vorbis team - RC2 sounds good. > But... RC2 in 128 kbps mode seems to clip off all frequencys > beyond 16 KHz. On the tracks I tested Beta 4 gave response > even beyond 18 KHz.It is better to cut off at 16kHz than to try to go higher and only introduce artifacts anyway in these modes. Even if you can hear above 16kHz, that does _NOT_ mean you will be able to detect a cutoff at 16kHz. In fact, this is extremely hard. It is much better to encode what we can hear good rather than to encode what we can't hear and artifact what we can. MP3 was never designed to handle more than 16kHz either. Trying to go beind that usually only worsens the sound unless real high (>=256kbps) bitrates are used. Vorbis will encode fine above 16kHz in 160kbps and higher modes, but 128kbps is simply not enough (for now). Judging a codec by its bandwidth (like with frequency sweeps and spectral plots) is like judging wine by its colour.> Some testings on a randomly chosen track: > (other tracks gave similar results) > > Artist: Judas Priest > Album: Jugulator > Title: Bullet Train > > Beta4: 127 kbps, ~ 18 KHz (!) > RC2: 132 kbps (!), ~ 16 KHz > > This seems even more strange to me as RC2 benefits from channel > coupling...Have you done a listening test on both files to see which _sounds_ better? (Granted, RC2 isn't tuned that well yet so it may be worse.)> > BTW: As 128 kbps mode produces average bitrates higher than 130 kbps > (please keep in mind that I am testing with Heavy Metal music, so > results for Britney Spears and Back Street Boys may vary ;-) )I would > be happy if 112 kbps mode is back in RC 3...I think this is normal. Metal tends to bloat the bitrates of VBR perceptual codecs. -- GCP --- >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@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
I don't usually go as low as 128...but I did tests at every bit-rate and also experienced that frequency fall off in files encoded at ~128... ORK At 13:49 14/08/01 +0200, you wrote:>Hello, > >congratulations to the Ogg Vorbis team - RC2 sounds good. >But... RC2 in 128 kbps mode seems to clip off all frequencys >beyond 16 KHz. On the tracks I tested Beta 4 gave response >even beyond 18 KHz. > >Some testings on a randomly chosen track: >(other tracks gave similar results) > >Artist: Judas Priest >Album: Jugulator >Title: Bullet Train > >Beta4: 127 kbps, ~ 18 KHz (!) > RC2: 132 kbps (!), ~ 16 KHz > >This seems even more strange to me as RC2 benefits from channel >coupling... > >BTW: As 128 kbps mode produces average bitrates higher than 130 kbps >(please keep in mind that I am testing with Heavy Metal music, so >results for Britney Spears and Back Street Boys may vary ;-) )I would >be happy if 112 kbps mode is back in RC 3... > >bye, > >Maik Merten > >-- > MetalUnleashed: http://www.metalunleashed.de >DHTML-Bibliothek: http://www.fortunecity.de/wolkenkratzer/flick/403 > ICQ: 45648209 > >--- >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@xiph.org' >containing only the word 'unsubscribe' in the body. No subject is needed. >Unsubscribe messages sent to the list will be ignored/filtered.--- >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@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.