Back in the day, when I was still using LAME, I was aware of the fact that the program would cut off frequencies above a certain level (lowpass). With 192 kbps this was usually around 20Khz (which is the highest frequency a human can hear, as far as I know), and at 128 something like 16Khz. Does Vorbis do something similar? If so, does someone have a chart of the cutoffs at the different quality settings? -- GMX - Die Kommunikationsplattform im Internet. http://www.gmx.net <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.
> Does Vorbis do something similar? If so, does someone have a chart of the > cutoffs at the different quality settings?Cannot find the message in the archives, but if memory serves me well, Monty said that Vorbis cuts at 16KHz at "-q 0" and at 18KHz at "-q 3", the default. Then it goes to 22Khz somewhere around the 4 or 5 quality level. I made a few tests and verified these numbers. <p> -- "I was wondering if there's any kind of definitive nickname for Perl programmers, the way we call ourselves Pythonistas?" - Aahz Maruch "Masochists." - Daniel Klein Nicola Larosa - nico@tekNico.net <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.
When I tested -q4 after the RC3 release I was getting very little energy above 17.5Khz. It may well be a maximum of 20.5 but it must have a very long lowpass gradient/width (I'm not sure of the scientific term). Ross Levis.> Hi! > Below is Monty's mail. As he writes "lowpass is set in > lib/modes/psych_44.h", where you can read the following: > > q - kHz > ------------- > 0 - 15.1 > 1 - 15.8 > 2 - 16.5 > 3 - 17.9 > 4 - 20.5 > 5 - 48. > 6 - 999. > No lowpass filter above -q6.--- >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.