Sorry for the crosspost but it's relevant to Vorbis and Icecast I believe. I'm seeing more and more streaming stations using AACplus, with many listeners being amazed at the sound quality. Most say that a 48kb/s sounds better than a 128kb/s MP3, which would put Ogg Vorbis at around 96kb/s IMO. That means only half the bitrate is required in AACplus compared to Ogg Vorbis for the same sound quality. Up until this codec was available, Ogg Vorbis compared favourably with all the others. Is there anything that can be done to bring Ogg Vorbis up to this type of quality in the future, or is it about as good as it's ever going to be? I would rather use patent free and open codecs, but this type of bitrate saving, particularly for streaming, cannot be ignored, and I'm concerned that this will slow the uptake of Ogg Vorbis and may reverse it's popularity in time. Ross.
Hi Ross, I Agree with your statement. I think the problem is with bringing the quality to the same level, that the principal might be registered. Although sometime back on this list sombody (Hans-Jurgen?) mentioned that it would be possible to implement AACplus in oddcast because oddcast is free. Now if that is true, technically it would be possible to use the same technics (SBR and PS) added on Vorbis OGG. Kind regards, Dennis Heerema -----Original Message----- From: "Ross Levis" <ross@stationplaylist.com> To: <vorbis@xiph.org>, <icecast@xiph.org> Date: Sat, 26 Feb 2005 00:31:11 +1300 Subject: [Icecast] AACplus> Sorry for the crosspost but it's relevant to Vorbis and Icecast I > believe. > > I'm seeing more and more streaming stations using AACplus, with many > listeners being amazed at the sound quality. Most say that a 48kb/s > sounds > better than a 128kb/s MP3, which would put Ogg Vorbis at around 96kb/s > IMO. > That means only half the bitrate is required in AACplus compared to Ogg > Vorbis for the same sound quality. Up until this codec was available, > Ogg > Vorbis compared favourably with all the others. > > Is there anything that can be done to bring Ogg Vorbis up to this type > of > quality in the future, or is it about as good as it's ever going to be? > > I would rather use patent free and open codecs, but this type of > bitrate > saving, particularly for streaming, cannot be ignored, and I'm > concerned > that this will slow the uptake of Ogg Vorbis and may reverse it's > popularity > in time. > > Ross. > > _______________________________________________ > Icecast mailing list > Icecast@xiph.org > http://lists.xiph.org/mailman/listinfo/icecast
Ross;> I'm seeing more and more streaming stations using AACplus, with many > listeners being amazed at the sound quality. Most say that a 48kb/s sounds > better than a 128kb/s MP3, which would put Ogg Vorbis at around 96kb/s IMO.I haven't done any listening tests comparing those rates, but I would *seriously* doubt that claim. It would depend a lot on what mp3 encoder you are using... There are a lot of bad encoders, and many more recommendations for using poor encoder settings. Not every mp3 encoder is created equal. And not every encoder setting is a good one. (Side rant: The p2p networks are flooded with poor quality 128k mp3's. The reality is those files are brainwashing a generation of music listeners to accept poor quality encodings. They have accepted that a 128k mp3 has to sound bad. I have some p2p mp3's of songs from some cd's I have. And I can assure you, the quality between those mp3's and the ones I made are substantial.) Roberto's public listening test showed that at 128k, mp3 was only slightly worse than the best full AAC at 128k. (And other tests have shown there really are some very poor quality mp3 encoders.) (Technically, it's possible mp3 might even be better, although the odds are against that.) http://www.rjamorim.com/test/ Methods such as AACPlus, mp3pro, and so on do pretty well at producing tolerable quality at lower bit rates, but they do it by giving up any chance to sound 'correct' by trying to be 'good enough'. And by the higher bit rates (above 96k), they can't match the quality of their own full, non 'pro' / 'plus' encoders (AAC, mp3, etc.) In other words, it may sound okay (very listenable), but you wont mistake it for the original in a listening test. Considering that at 128k, mp3 is only slightly worse than AAC, and you are saying people are saying that 48k aacplus is better than 128k mp3, then that would be like saying that 48k aacplus is as good as 128k aac. That just isn't even close to being true. So even though I haven't done any listening tests comparing 48k aacplus against 128k mp3 against ~96k vorbis, I find it very very hard to believe that 48k aacplus would actually sound closest to the original cd. For streaming, 48k aacplus may indeed be more than good enough. But I sure wouldn't call it "near cd quality".... You might want to go over to HydrogenAudio.org and look through their messages, their FAQ, and maybe post a question or two. (Be prepared to get flamed, though. Some of the older members aren incredibly intolerant of any newbie.)> That means only half the bitrate is required in AACplus compared to Ogg > Vorbis for the same sound quality. Up until this codec was available, Ogg > Vorbis compared favourably with all the others.At normal listening rates, OggVorbis is still one of the best. Especially with the tunings that were done outside of Xiph. But at lower 'streaming radio' rates, no, Vorbis isn't the best. It wasn't tuned / designed for those rates. Roberto's 32k rate listening test didn't show Vorbis in a good light... I doubt a 48k test would be much different.
Ross Levis wrote:> I'm seeing more and more streaming stations using AACplus, with many > listeners being amazed at the sound quality. Most say that a 48kb/s > sounds better than a 128kb/s MP3, which would put Ogg Vorbis at around > 96kb/s IMO. That means only half the bitrate is required in AACplus > compared to Ogg Vorbis for the same sound quality. Up until this codec > was available, Ogg Vorbis compared favourably with all the others.I am very sceptic about these claims. There are people claiming Vorbis can reach 128 kbps MP3 quality (whatever this may be) at bitrates below 64 kbps. The aoTuV encoder ( http://www.geocities.jp/aoyoume/aotuv/ ) has some very nice low bitrate tunings enabling very listenable 48 kbps encodings. You can get a more feature-complete binary at rarewares.org. AAC may be ahead of Vorbis at low bitrates, but Vorbis is not hopelessly behind. Maik Merten
ah, there?s a new aoTuV test-version released yesterday. Actually I like the -1.001 quality setting very much. This gives a ~< 48 kbps stream using parts of the -2 (~ 32 kbps) tunings. Definately worth a listen. Maik
I will definately check it out once a Win32 binary is available. Ross. ----- Original Message ----- From: "Maik Merten" <maikmerten@gmx.net> To: <vorbis@xiph.org> Sent: Sunday, February 27, 2005 3:18 AM Subject: Re: [Vorbis] AACplus ah, there?s a new aoTuV test-version released yesterday. Actually I like the -1.001 quality setting very much. This gives a ~< 48 kbps stream using parts of the -2 (~ 32 kbps) tunings. Definately worth a listen. Maik
Mathieu Gollain
2005-Feb-26 16:26 UTC
[Vorbis] aotuv experimental [20050225] (was : AACplus)
A Win32 binary is already available at : http://www.geocities.jp/aoyoume/aotuv/test.html Ross Levis a ?crit :> I will definately check it out once a Win32 binary is available. > > Ross.
On Fri, Feb 25, 2005 at 02:46:22PM +0100, Dennis Heerema wrote:> Now if that is true, technically it would be possible to use the same > technics (SBR and PS) added on Vorbis OGG.No, because the specific SBR extensions are part of the MPEG patent pool. As it is, the current/future direction of Vorbis is to move away from a pure transform-domain encoding anyway. SBR would still be applicable, but some of the same mechanics would be built into the rep model. SBR's fundamental basis is 'each octave is closely related to the octave below it'. It then implements something akin to an 'exciter' that represents most of the upper part of the spectrum as a parametric set of harmonic duplications of the lower octaves. The basic idea is both sound and one that's been underexploited (upper octaves are often harmonic duplications of lower octaves). One can take advantage of that without using SBR, and that's the direction I'm going. But there's more than the harmonic structure here; if strong tones (the harmonic structure) of the audio is subtracted out, and you're only looking at the leftover 'noise' in time, the subband correlation is very strong in time as well. I don't know if AAC(classic)'s Temporal Noise Shaping is also exploited by the SBR extensions in any way, but I certainly plan to exploit that fact in future Vorbis. Monty
Others have already chimed in, and I thought I could resist, but I guess I can't...> I'm seeing more and more streaming stations using AACplus, with many > listeners being amazed at the sound quality. Most say that a 48kb/s sounds > better than a 128kb/s MP3,That's claiming a bit much. Even against the original Blade this would require not paying much attention. What's true is that the artifacts sound very different, so if you're listening for mp3-like high-end problems, you probably won't hear them.> which would put Ogg Vorbis at around 96kb/s IMO.Not really. 64kbps Ogg is still a little better than the 48kbps AAC+SBR we're talking about. That's not to say the low bitrate AAC+SBR isn't very good; as a new codec, it's quite an improvement to classic AAC at low bitrates. But many of the press-release claims are (understandibly) pushing the envelope of what is really believable. Also, it's absolutely true that at the lowest bitrates (32/48kbps) AAC+SBR currently has a decent edge over Vorbis low bitrate. Everyone is still moving forward and the lead changes back and forth. The low bitrate race is pretty much down to new AAC and Ogg these days. At low bitrate, AAC is ahead, at mid-bitrate Vorbis is still leading.> Is there anything that can be done to bring Ogg Vorbis up to this type of > quality in the future, or is it about as good as it's ever going to be?Of course. Development of these things tends to move forward in bursts. I've done little Vorbis research work since 1.0 as there have been other things to do. I'll get back to it if only because it's what I'm best at and audio codec research feels good ;-)> I would rather use patent free and open codecs, but this type of bitrate > saving, particularly for streaming, cannot be ignored, and I'm concerned > that this will slow the uptake of Ogg Vorbis and may reverse it's > popularity in time.The bitrate savings isn't as big as you fear and we'll take the lead back again. Everyone is improving. Who would have ever thought back in '98 that LAME would get as good as it is today? I'm curiously surprised that AAC hasn't moved forward farther than it has... Monty
Monty wrote:>> I'm seeing more and more streaming stations using AACplus, with many >> listeners being amazed at the sound quality. Most say that a 48kb/s sounds >> better than a 128kb/s MP3, > > That's claiming a bit much. Even against the original Blade this > would require not paying much attention. What's true is that the > artifacts sound very different, so if you're listening for mp3-like > high-end problems, you probably won't hear them.You have to admit though that even Vorbis -q -1 in Vorbis 1.1 and aoTuV B3 does sound pretty impressive at circa 48kbps.>> which would put Ogg Vorbis at around 96kb/s IMO. > > Not really. 64kbps Ogg is still a little better than the 48kbps > AAC+SBR we're talking about.I've not heard any of the AAC codecs, mainly due to the difficulties in playing them under lInux, but q -0 Vorbis compares very well (IMHO) to 128kbps MP3. Certainly q 1 does, and that's still only circa 80kbps.> That's not to say the low bitrate AAC+SBR isn't very good; as a new > codec, it's quite an improvement to classic AAC at low bitrates. But > many of the press-release claims are (understandibly) pushing the > envelope of what is really believable.I'll never forget what you wrote on the "Dare to Compare" Ogg Vorbis page. You were so convinced, simply by the hype, that WMA 8 was so good at low rates. That was until you heard it. This sounds like good advice to me - people should listen for themselves.> Also, it's absolutely true that at the lowest bitrates (32/48kbps) > AAC+SBR currently has a decent edge over Vorbis low bitrate. Everyone > is still moving forward and the lead changes back and forth. The low > bitrate race is pretty much down to new AAC and Ogg these days. At > low bitrate, AAC is ahead, at mid-bitrate Vorbis is still leading.Have you had a chance to try out aoTuv B3 yet? As far as I can remember, aoTuV's quality -2 sounds like quality -1 in Vorbis 1.0, but at considerably lower bitrates. Geoff.