Hi! I would like to share with you an interesting test result. I re-encoded a song 10 times (the 2. made from the 1., the 3. made from the 2.,... the 10. made from the 9.), with a beta4 (CVS 20010620) and with an RC2 (CVS 20010817) library version, 256 kbit/s mode, channel coupling disabled at RC2. The beta4 is very good at the 10. encoding too, but the RC2 has some interesting quality bugs. So, the songs: They are OGG files (not compressed zip), just rename them to OGG! 1. encoding with beta4: http://www.geocities.com/mpxplay/010620_01.zip 10. encoding with beta4: http://www.geocities.com/mpxplay/010620_10.zip 10. encoding with RC2: http://www.geocities.com/mpxplay/010817_10.zip I tested on lower bitrates and with channel coupling too. With similar results... Attila --- >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.
----- Original Message ----- From: "Attila Padar" <galileog@externet.hu> To: <vorbis@xiph.org> Sent: Thursday, August 23, 2001 9:36 PM Subject: [vorbis] RC2 vs. beta4 (test)> Hi! > I would like to share with you an interesting test result. > I re-encoded a song 10 times (the 2. made from the 1., > the 3. made from the 2.,... the 10. made from the 9.), > with a beta4 (CVS 20010620) > and with an RC2 (CVS 20010817) library version, > 256 kbit/s mode, channel coupling disabled at RC2.How did you disable channel coupling? Additionally, it has been stated many times that you _should_ _never_ _transcode_ _any_ _lossy_ _codec_. -- 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.
Gian-Carlo Pascutto asked:> How did you disable channel coupling?With a small modification in vorbisenc.c . The RC2 has non-coupled modes too, but they are used for mono and multicannel files only. It's selectable with an -ocp option in AudioCV. other: if you can't download my test files from here, visit http://www.geocities.com/mpxplay and the files are linked on the bottom of the page. Attila --- >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.
Hi again! It seems the bug is in the noise masking of RC2, because if I turn off the noise masking in the MODE_44_C.H , I don't get the same bug after the 10. encoding either (but I get a double-size file)... The beta4 also uses noise masking on 256 kbit/s, but - it seems in the test file - it encodes the sound correctly. I wonder, how do the developers think it: is this really a bug or it isn't? Or maybe the noise filtering is too much, and you should use less noise with more tone and peek filtering. Attila --- >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.