I was recently talking to a friend of mine who produces what's widely referred to as "techno", music that's heavy on electronically generated loops and effects, samples, and has plenty of bass. He doesn't like ogg for a few reasons - he sent me a rather long email, and I've stripped out the nonsense from it (he has some technically irrelevant reasons for not liking ogg) but he also made some claims that I wanted to follow-up on. I've modified his email and included the points below. Each paragraph is a claim. I would very much appreciate some public discussion. Is there truth to his claims? Thoughts? -- start of email -- Ogg has to this day, fundemental problems with low frequency encoding. Sometimes refered to as "pre-echo aliasing" ... it is something that is a problem for music (primarly electronic which is why I don't use it) with low end bass and subsonics. If you have the ability to test this on a proper sound system, you will hear it dead out. Most people don't realise that you need a certain amount of distance from the generation source to your ear for the bass wave to resonate correctly. This is why sometimes when you are at a rave and you could be 10 feet from the bass bins and there is very little bass, but you step back 20 feet and its knocking you on your ass. This same principle holds with headphones. You are not typically going to get the "subsonics" out of it listening to the files on headphones. It may sound slightly out of tune, or out of phase. Good head phone definitely help, but even high end sony's like the MDR-7506's and the MDJ-700s are only just able to produce the subsonics effectively to hear it. [Ogg is not free from patents.] The entire concept of a phsychoacustical model or a perceptual model for endcoding the material (not just the encoding step itself) is covered under at least 50 different patents by companies world wide, and rightfully so ... Not only can you patent the process of encoding the file, but the principles of how you get there. Why? Because they are novel ideas, and obvious which is what patents are for. They are just "creative enough" to warrant protection by government, and frankly I have no problems with it having patents myself relating to next generation video streaming technology and systems which relate to digital cinema. However, the second that someone starts making "serious" amounts of money off of Ogg, you can bet the patent lawyers will be on Xiph faster then a fat kid on a smartie. [Ogg is too little, too late.] There are audio and video encoding systems coming out in the next year that will futher push the envelope without comprimise and many of those are based completely on wavelets which is really where Ogg should have gone in the first place ... <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.
Jem wrote:> to his claims? Thoughts?I´ll give it a shot. :)> Ogg has to this day, fundemental problems with low frequency encoding. > Sometimes refered to as "pre-echo aliasing" ... it is something that is aI know what he aims for, but personally I haven´t found this problem. I mostly listen to EBM, synth and so on and I haven´t been able to tell the diffrence from the CD. What quallity is he encoding in? I´ve tested OGG in "disco/club" enviroments as well with studioequipment. Sure you can tell that there are artifacts, anything else would be a lie. But not nearly as much as in MP3.> [Ogg is not free from patents.] The entire concept of a phsychoacusticalCan´t comment on this due to lack of knowledge.> [Ogg is too little, too late.] There are audio and video encoding systemsNo, it is certanly not. There is really no collected effort in the open source/free software movement for a free multimedia platform other than OGG that I am aware of. None that have come this far anyway. It is important to have a free option for all heavely patented formats out there. Remember that many gamedevelopers and online radiostations has begun to use OGG. The main thing OGG lacks right now is a hardware decoder (read portable audio system). <p>Hopefully this will give you a hand, even though things like quallity is quite biased and personal. Best regards, Andreas Karlsson --- >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.
Jem wrote:> Ogg has to this day, fundemental problems with low frequency encoding. > Sometimes refered to as "pre-echo aliasing" ... it is something that is a > problem for music (primarly electronic which is why I don't use it) with > low end bass and subsonics. If you have the ability to test this on a > proper sound system, you will hear it dead out. Most people don't realise > that you need a certain amount of distance from the generation source to > your ear for the bass wave to resonate correctly. This is why sometimes > when you are at a rave and you could be 10 feet from the bass bins and > there is very little bass, but you step back 20 feet and its knocking you > on your ass. This same principle holds with headphones. You are not > typically going to get the "subsonics" out of it listening to the files on > headphones. It may sound slightly out of tune, or out of phase. Good head > phone definitely help, but even high end sony's like the MDR-7506's and the > MDJ-700s are only just able to produce the subsonics effectively to hear > it.First of all, I have no clue what this guy is talking about. "Pre-echo aliasing", whee ... examples please. Because lateron he rants about subsonics getting lost, which, are not audible/easily masked by any other sounds anyways (and this has nothing to do with artifacts). A lossy/perceptual encoder can safely discard anything below 20Hz, so what's the problem? It should do that by design - throw away useless information. By the way, by doing so, Vorbis (and any other reasonable lossy encoder) does bad producers a favor. Filtering out subsonic rumblings that do nothing but randomly shift the DC offset of a wave (please excuse my probably wrong choice of words) and thus distort the whole thing *should* be filtered out by the producer in the first place. If he talks about audible bass that actually makes sense in music, I really can't relate - this sounds like some subjective bias against Vorbis for one reason or the other. Blind tests with hidden references would be useful, and if he can prove that he hears some obvious and important bug at a reasonably high bitrate, his feedback could be valuable.> [Ogg is too little, too late.] There are audio and video encoding systems > coming out in the next year that will futher push the envelope without > comprimise and many of those are based completely on wavelets which is > really where Ogg should have gone in the first place ...Afair, wavelets in audio compression are 99% buzzword and 1% improvement. They ARE useful, but the result of previous discussions were that they're simply not worth the effort. Vorbis I is already revolutionary enough - it's good enough to compete with other Codecs for quite a long time (until we get Vorbis II and major buttkicking, even with wavelets :) ). <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-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.
> [Ogg is not free from patents.] The entire concept of a phsychoacustical > model or a perceptual model for endcoding the material (not just the > encoding step itself) is covered under at least 50 different patents by > companies world wide, and rightfully so ...This is one point where your friend is correct. AT&T started the research that lead to perceptual encoding over 50 years ago. There's a ton of patents in the field that cover a ton of really really technical audio compression topics. Ogg Vorbis tries to avoid those patents by implementing a format that's different from the commonly known patented ones. However, it's quite possible that there's a patent covering some methods used in Vorbis compression. In fact, someone from Thompson Multimedia was at some point sure enough of that fact to discuss it in an interview. I am not a patent lawyer - if you're concerned about this, you should contact an attorny.> Not only can you patent the > process of encoding the file, but the principles of how you get there. Why? > Because they are novel ideas, and obvious which is what patents are for. > They are just "creative enough" to warrant protection by government, and > frankly I have no problems with it having patents myself relating to next > generation video streaming technology and systems which relate to digital > cinema.Well, now he's assulting the assumption that patented audio codecs shouldn't be patentable. He's missing the fact that these audio compression codecs aren't novel in the way that patentable inventions are - they're just mathematics. They're remarkable mathematics, but so is set theory. So is addition for that matter. If he claims mathematics can be patented, point him to the Onion article "Bill Gates patents One, Zero".> However, the second that someone starts making "serious" amounts of money > off of Ogg, you can bet the patent lawyers will be on Xiph faster then a > fat kid on a smartie.I wouldn't be surprised if this is the case.> [Ogg is too little, too late.] There are audio and video encoding systems > coming out in the next year that will futher push the envelope without > comprimiseAsk your friend if he can compress random data too. He seems to miss the fact that any compression requires compromise, somewhere. -- Ross Vandegrift ross@willow.seitz.com A Pope has a Water Cannon. It is a Water Cannon. He fires Holy-Water from it. It is a Holy-Water Cannon. He Blesses it. It is a Holy Holy-Water Cannon. He Blesses the Hell out of it. It is a Wholly Holy Holy-Water Cannon. He has it pierced. It is a Holey Wholly Holy Holy-Water Cannon. He makes it official. It is a Canon Holey Wholly Holy Holy-Water Cannon. Batman and Robin arrive. He shoots them. --- >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.
Jem wrote:> [Ogg is not free from patents.] The entire concept of a phsychoacustical > model or a perceptual model for endcoding the material (not just the > encoding step itself) is covered under at least 50 different patents by > companies world wide,IANAL, but as I understand it, a patent cannot cover "the entire concept" of something as general as "audio compression using perceptual encoding". Instead, you patent a specific method of doing something, describing in detail exactly how your process works. Something that accomplishes the same result by a different means isn't covered by the patent.> and rightfully so ...This, of course, is a political judgment, not a legal statement, and is irrelevant.> [Ogg is too little, too late.] There are audio and video encoding systems > coming out in the next year that will futher push the envelope without > comprimise and many of those are based completely on wavelets which is > really where Ogg should have gone in the first place ...IANAAEE (... not an Audio Encoding Expert), but IIRC, Monty was well aware of wavelets when he created Vorbis, and intentionally chose not to use them. Craig <p> -------------- next part -------------- A non-text attachment was scrubbed... Name: part Type: application/pgp-signature Size: 190 bytes Desc: not available Url : http://lists.xiph.org/pipermail/vorbis/attachments/20021226/678b7a6e/part-0001.pgp
Ugh, this one is so far off that it's almost a troll, but eh, I'll answer.> Ogg has to this day, fundemental problems with low frequency encoding.It did about two years ago. Since then, these claims have persisted, yet folks who claim it don't manage to pick it out in ABX testing (or pick out something unrelated).> Sometimes refered to as "pre-echo aliasing" ... it is something that is a > problem for music (primarly electronic which is why I don't use it) with > low end bass and subsonics. If you have the ability to test this on a > proper sound system, you will hear it dead out.I have such a system and cannot, in fact, hear it dead out. There are artifacts in Vorbis left to hear, but they don't live in the low bass. Now, preecho *does* exist, but it's in fact least audible in the range the guy is complaining about. Most psychoacoustic studies would suggest preecho perception doesn't kick in in until a few hundred Hz.> It may sound slightly out of tune, or out of phase.This has nothing to do with it; an MDCT codec can be neither out of tune nor out of phase (unless you mean something else by phase).> phone definitely help, but even high end sony's like the MDR-7506's and the > MDJ-700s are only just able to produce the subsonics effectively to hear > it.Uhh.. those are nothing close to 'high end'. They may be expensive, but not high end. They're a notch or so above 'free with walkman'.> [Ogg is not free from patents.] The entire concept of a phsychoacustical > model or a perceptual model for endcoding the material (not just the > encoding step itself) is covered under at least 50 different patents by > companies world wide, and rightfully so ... Not only can you patent the > process of encoding the file, but the principles of how you get there.a) "Bullshit" b) Does he have a legal degree and/or opinion rendered by a qualified patent attourney? c) In that case, I suggest he quits claiming to be an authority.> Because they are novel ideas, and obvious which is what patents are for. > They are just "creative enough" to warrant protection by government, and > frankly I have no problems with it having patents myself relating to next > generation video streaming technology and systems which relate to digital > cinema. > > However, the second that someone starts making "serious" amounts of money > off of Ogg, you can bet the patent lawyers will be on Xiph faster then a > fat kid on a smartie.The writer of this makes it sound all very logical, unfortunately it's all incorrect. He doesn't have the *slightest* concept of how patents work. Even most reporters get it closer than this.> [Ogg is too little, too late.] There are audio and video encoding systems > coming out in the next year that will futher push the envelope without > comprimise and many of those are based completely on wavelets which is > really where Ogg should have gone in the first place ...Also bull dressed up in buzzwords he sorta understands. The technical details are wishful thinking (for fun, ask him to define what a wavelet is, I'll bet he can't). Making it sound good doesn't make it true, and being an expert in one field (eg, DJing) doesn't make you an expert in IP law, signal processing, filter design, etc. The envelope will always get pushed. This year, we got to push it. We'll get to push it again even if we trade the lead now and then. ...but I'd not even bother telling him. He sounds pretty convinced of himself, and I don't have time to argue with anyone that convinced and that confused. It's like the old vinyl/CD fidelity argument, or old tube/transistor argument or old Ford/Chevy argument. No amount of evidence ever changes anyone's mind. Monty --- >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.
Jem wrote:> Ogg has to this day, fundemental problems with low frequency encoding. > Sometimes refered to as "pre-echo aliasing"Huh? Ask him to explain what that is, I bet he can't.> This is why sometimes when you are at a rave and you could> be 10 feet from the bass bins and there is very little bass, > but you step back 20 feet and its knocking you on your ass. Did you study physics? They normally demonstrate this effect in Physics 101, it's called "interference". Set up a constant tone coming out of a pair of speakers and walk around the room. You'll notice that the volume level changes depending on where you are. This effect is more obvious with low frequencies than high frequencies. This nothing to do with any encoder/compressor, it's just physics in action. Connect an laboratory signal generator to your amp and it will still happen. <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.
On Thu, 2002-12-26 at 18:51, Jem wrote:> Ogg has to this day, fundemental problems with low frequency encoding. > Sometimes refered to as "pre-echo aliasing" ... it is something that is a > problem for music (primarly electronic which is why I don't use it) with > low end bass and subsonics.You should ask your friend to provide us some samples to test. Vorbis applies a low-pass filter, so low frqs shouldn't be affected by compression. Lossy stereo can damage bass effects because we are very sensitive to phase differences between channels, but vorbis try to save stereo information at low frqs, so... I don't know :)> Most people don't realise > that you need a certain amount of distance from the generation source to > your ear for the bass wave to resonate correctly.No, it depends on many factors: placement of the speakers, how the walls reflect the sound, etc... <p>> This is why sometimes> when you are at a rave and you could be 10 feet from the bass bins and > there is very little bass, but you step back 20 feet and its knocking you > on your ass.Sometimes standing waves play funny tricks :) Bye. <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.
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