Hey guys. I think Vorbis is pretty cool, but since the current OggEnc only offers 44.1kHz, it limits what I wanted to use it for. So I've been using Lame to get 16kHz mono Vorbis files. I'm curious about whether Lame does Vorbis encoding the "right" way for non-44.1k stuff, or whether it just encodes as it would for 44.1k & changes the sample rate on the output, but I'm not sure if you guys would know how Lame calls the Vorbis encoder... Anyway, I've been resampling to 16k & applying a 6.4k lowpass filter using ResampAudio (Thanks heaps, Jelle, for the link!), then using Lame to compress the output file to about 28kbps average bitrate with Vorbis' Mode A, & I think it should be possible to compress music to 20kbps, but that can't be done currently without doing some vicious filtering beforehand, & also using 12/11/8 kHz sampling. I think that if one of Ogg's aims is to completely replace the Real & MPEG formats, then Ogg might be able to tighten the screws on them by offering lower sample rates & higher compression options. (Think about the number of 22kHz/56kbps MP3s floating around.) What sort of changes would need to be made to enable encoding of all sample rates? And I must also mention that "lame --ogg -v4" outshines "lame -b32" in this realm, & is comparable to "lame -V8". Shawn roleypup@yahoo.com __________________________________________________ Do You Yahoo!? Yahoo! Shopping - Thousands of Stores. Millions of Products. http://shopping.yahoo.com/ --- >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.
At 09:06 PM 11/20/00 -0800, you wrote:>Hey guys. I think Vorbis is pretty cool, but since the current OggEnc onlyoffers 44.1kHz, it Wrong. Oggenc supports different sample rates correctly. Libvorbis itself also supports different sample rates, but is tuned for 44.1kHz, so other things aren't handled optimally yet (the information on sample rates is fed through to the encode engine, it just doesn't do all that much with it yet). Last I checked, lame still didn't have updated vorbis support - has this changed recently? If not, it's possibly worse than oggenc at different sample rates. It most likely isn't any different.>number of 22kHz/56kbps MP3s floating around.) What sort of changes wouldneed to be made to enable>encoding of all sample rates? And I must also mention that "lame --ogg-v4" outshines "lame -b32">in this realm, & is comparable to "lame -V8".It already allows encoding of different sample rates - but a lot more changes will be needed for optimal performance at these bitrates and sample rates (changes in the codebooks, the psychoacoustics, etc.) It'll be done eventually, but finishing off the 1.0 feature list is higher in priority than tuning for other sampling frequencies, I think. What does -v4 do? I thought lame just ignored all the options when encoding vorbis. Maybe this did get updated. Michael --- >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 wrote:> >Hey guys. I think Vorbis is pretty cool, but since the current OggEnc only offers 44.1kHz,Michael Smith wrote:> Wrong. Oggenc supports different sample rates correctly.Oops. My stupidity for not actually trying it. *embarrased blush* Even so, it's a little misleading to have "OggEnc input files must currently be 44.1kHz, 16 bit stereo WAV files." on the help screen. Perhaps it should read something like "Best quality will be achieved with 44.1kHz, 16 bit stereo WAV files". I just tried encoding something with the latest OggEnc, & it's a fair bit faster than with Lame. The only advantage it seems that Lame has now, is that it supports mono encoding & OggEnc does not.> Libvorbis itself also supports different sample rates, but is tuned for 44.1kHz, so otherthings aren't handled optimally yet (the information on sample rates is fed through to the encode engine, it just doesn't do all that much with it yet). I guess that's what I meant.> Last I checked, lame still didn't have updated vorbis support - has this changed recently? Ifnot, it's possibly worse than oggenc at different sample rates. I don't think it has. It most probably is worse. The compile that I was using was a prehistoric one from - http://doslame.nm.ru/ - run by someone calling themself "tofikman". But in optimising OggEnc specifically for 44.1k, is it likely to reduce quality for other sample rates compared to before optimisation?> finishing off the 1.0 feature list is higher in priority than tuning for other samplingfrequencies, I think. Okay, you guys know what you're doing. Optimising for different sample rates sounds like a major overhaul. I noticed that at lower bitrates, MP3 gets a lot of obvious artifacts that make it sound messy, whereas Vorbis tends to sound more dry, & a lot more clean, which I think is a good thing. Is that what's supposed to happen, or are obvious artifacts there that I can't hear? BTW, where's the 1.0 feature list?> What does -v4 do? I thought lame just ignored all the options when encoding vorbis.I actually meant "-V4". Here's what Lame does with the "-V?" switch (which may have been changed recently) - * "lame --ogg -V0" => Vorbis mode E * "lame --ogg -V1" => Vorbis mode C * "lame --ogg -V4" => Vorbis mode B * "lame --ogg -V5" => Vorbis mode A * V2, V3 - ?... V6-V9 - mode A I think "--ogg" assumes "-v", which in turn assumes "-V4", so Lame probably runs Vorbis mode B by default. And unfortunately, there's no way to call mode D with the "-V?" switch. From memory (this isn't my home computer) Lame takes note of the "--resample", "-mm", "-a", & "-b" switches, as well as some id3 switches, although, a compile of OggLame that I used previous to that (which had no MP3 output) ignored id3 switches. Oh, what does Vorbis call what MP3 calls "id3"? Shawn roleypup@yahoo.com __________________________________________________ Do You Yahoo!? Yahoo! Shopping - Thousands of Stores. Millions of Products. http://shopping.yahoo.com/ --- >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.