I finally got RC3 built on my home machine (had to sneakernet in a tarball of libcurl to get it to build :-( ) and started testing it out on the range of quality levels, side by side with lame using it's range of vbr quailty modes. Overall, it sounds pretty good, but I haven't really tested a good range yet, as I ended up starting on udial.wav... vorbis handles it ok up to quality 3, but from 4 onwards (presumably a high frequency cutoff is removed) there are very obvious artifacts, and they continue to be present all the way out to 10.0. Lame handles this a lot more gracefully - the sine sweep is cut of until about V2 or 3 (but the hiss is still present), and it sounded pretty close to the original at V0 (though I could still got 12/16 in an ABX test, the difference was barely perceptable). Now I _know_ that high frequency sine wave sweeps are a completely contrived sample to test an audio codec with, but I'd hate to think that some idiot kid on slashdot will end up badmouthing vorbis because it goes to pieces on a sample like this. It would be a lot nicer if it failed to include the sweep and didn't contain artifacts. That said, fatboy.wav and hihat.wav where sounding pretty sweet most quality levels. Nice work :-) 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@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
On Tue, 15 Jan 2002, John Morton wrote:> Now I _know_ that high frequency sine wave sweeps are a completely contrived > sample to test an audio codec with, but I'd hate to think that some idiot kid > on slashdot will end up badmouthing vorbis because it goes to pieces on a > sample like this. It would be a lot nicer if it failed to include the sweep > and didn't contain artifacts.Vorbis is doing you a favor. If you play udial on a stereo system with tweeters and have the volume a bit too loud, it will blow them out. Really. Anyone using that clip to test a codec will auto-LART themselves sooner or later. Now, it's been a while since I saw it, but I seem to remember it did clip. If it does, there's no guarantee it'll play back fine, even if the encoder handles it ok. But that's why Vorbis now has...(see next post :) -- GCP <p>--- >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.
> Overall, it sounds pretty good, but I haven't really tested a good range yet, > as I ended up starting on udial.wav...url ? <p><p>Bye. --- >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.