Important (imho)! I found this site in the internet: http://www.plusv.org/ PlusV is an audio enhancement algorithm similar to SRB of Mp3Pro, but 1) better than SBR 2) Fully open-source It seems to me wise to include PlusV into new versions of Ogg Vorbis. P.S. what about some long-awaited features in Ogg Vorbis? 1) ability to turn off the frequency filter in the encoder (especially for high bitrates) 2) CBR encoding Thanks and best regards. --- >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-dev-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 Wed 29 January 2003 11:55, Rany . wrote:> Important (imho)! > I found this site in the internet: > > http://www.plusv.org/ > > PlusV is an audio enhancement algorithm similar to SRB of Mp3Pro, > but 1) better than SBR > 2) Fully open-source > > It seems to me wise to include PlusV into new versions of Ogg > Vorbis.Already discussed. See the "SBR" thread in the archives (16th of october 2002).> P.S. what about some long-awaited features in Ogg Vorbis?<snip>> 2) CBR encodingAlready available? (oggenc --managed with -m and -M) Lourens -- GPG public key: http://home.student.utwente.nl/l.e.veen/lourens.key --- >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-dev-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.
"Rany ." wrote:> Important (imho)! > I found this site in the internet: > http://www.plusv.org/We already had this, search the archives.> P.S. what about some long-awaited features in Ogg Vorbis? > 1) ability to turn off the frequency filter in the encoder (especially for high bitrates)According to vorbis/lib/modes/psych_44.h, there's no lowpass for q6 and higher for 44.1kHz input, a lowpass at 48kHz for q5 and 20.5kHz for q4, etc. The complete line is tatic double _psy_lowpass_44[11]={ 15.1,15.8,16.5,17.9,20.5,48.,999.,999.,999.,999.,999. }; So, why do you want to set the lowpass, as it's very high, i.e. nonexistant already in high bitrates? If you'd raise it for those modes that actually use a lowpass, you'd just decrease overall quality in many other aspects. I also see no point in lowering it, as Vorbis does a pretty good job encoding the frequencies the current filters let through. Anyways, libvorbis has a function "vorbis_encode_ctl" where you can set those parameters, and oggenc already has this (undocumented) feature. I haven't used it, yet, and never will - so if you want to figure out how it works, look at oggenc.c and encode.c in vorbis-tools/oggenc for parameter names and arguments.> 2) CBR encodingYou can do something close to that already with the bitrate management engine, e.g. limit the bandwidth to a certain bitrate within a 2-seconds window. An oggenc command line would look like `oggenc --managed -m <bitrate> -b <bitrate> -M <bitrate> input.wav`. I'm not quite sure why you'd want this, though - quality suffers and CBR is only required in pretty exotic environments. <p>Moritz --- >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-dev-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 Wed, 2003-01-29 at 05:55, Rany . wrote:> Important (imho)! > I found this site in the internet: > > http://www.plusv.org/ > > PlusV is an audio enhancement algorithm similar to SRB of Mp3Pro, but > 1) better than SBR > 2) Fully open-source > > It seems to me wise to include PlusV into new versions of Ogg Vorbis.As Lourens has pointed out already, this has been discussed in October 2002, and Monty decided that it's not worth including. I would also like to add that PlusV is patented technology, and their royalty-free patent license is incompatible with Xiph's licenses. See http://www.plusv.org/patent-license.php> P.S. what about some long-awaited features in Ogg Vorbis? > 1) ability to turn off the frequency filter in the encoder (especially for high bitrates)Other front ends may not have this option, but at least with oggenc you can set the lowpass filter cutoff however high you want. If you set it high enough, the filter is effectively disabled. Hope this helps, Carsten Haese <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-dev-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.
Rany --
do you have a pointer to this plusV algorithm? Is it similar to SBR? My
understanding is that Coding Technologies has core patents on the SBR algorithm
and similar types. is plusV known to be patent free?
-----Original Message-----
From: Rany . [mailto:rany74@mail.ru]
Sent: Wed 1/29/2003 8:07 AM
To: vorbis-dev@xiph.org
Cc:
Subject: Re: [vorbis-dev] PlusV algorithm
Well, I've seen the old discussion about the SBR, and I don't
agree that Ogg is comparable to Mp3Pro. Ogg easily beats Mp3Pro at medium and
high bitrates. But Mp3Pro is FAR better at low bitrates <=64 kbps. All
benchmarks say that Mp3Pro is the very best codec for such bitrates.
What is Mp3Pro? It is Mp3 for low frequencies + SBR for high ones. Ogg
(better than Mp3) for low frequencies + PlusV (better than SBR) for high
frequencies - might be the best codec for lower bitrates too. Sounds cool,
doesn't it?
> oggenc --managed with -m and -M
Thank you.
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