If you would like to write an encoder that actually encodes audio, and specifically trades everything off to perform terrific on 'EncoderHell' (the test tone noise), please do so
Quite easy... strip out the psycho-acoustic model from a good MP3 encoder (like LAME) and you get a crappy MP3 encoder that performs very well in you sonogram test.
I don't think it's possible for an encoder to mangle the audio quality and have a pristine 'sonogram' as differenced with the source material. A pristine sonogram would be uniformly BLACK when this was done- none of the encoders remotely approached this
I'm sorry, from what you're saying, I just don't think you really understand what perceptual encoders are. First, if you have a 10:1 compression ratio, your sonogram cannot be all black (that would be lossless). Now, writing an encoder for which everything is grey (instead of black and white as the sonograms you found) is very easy to do, but it will sound like sh*t.
Very simple experiment: take a signal and add white noise so you get a 20 dB SNR. It'll sound _very_ noisy. Now, while preserving the noise energy, shape that noise to look like the signal (of course, still 20 dB lower). The audio you'll hear will sound quite OK (though not perfect) and much better that with the white noise. You have just used a (quite simple) psycho acoustic model.
Using the same reasoning, any MS employee who has seen the SAMBA code shouldn't be allowed to work for MS anymore?
I'm serious. The fact that the source was stolen should not matter. Maybe accessing the MS source code would prevent you from claiming a "clean room implementation", but not from working on OSS at all.
Just another idea... what if GPL'd code is found in Windows. I'd like MS being sued (by FSF?) over copyright infringement....plus it would look bad for them trying to fight OSS developers working on wine/samba/...
If you are a big fan of classical you will have an opinion on _which_ parts of the sonic information are expendable
No, when a certain frequency component is discarded, it's not because the listener won't mind, it's because even if it's there, the listener cannot hear it. If you can't hear a sound, why encode it? Now, there are sometimes problems with classical music, but that's because it's often hard to predict exactly what you can and can't hear.
with an oscilloscope I can get a more precise answer
Yes, the guy's sonogram is more *precise* but it is still irrelevant. I could write an encoder that gives a much better result when evaluated with this "precise" sonogram, but yet will sound like crap.
This is the point of perceptual encoding. The goal is not to produce the best result in terms of signal-to-noise ratio or spectral distortion, but to cause the encoder "errors" where the "non-precise" ear won't hear it. And if you don't hear it, you don't care, even if your oscilloscope of spectral analyser tells you there's an error.
The most critical part of a perceptual encoder is the "psycho-acoustic model", which tries to model as best as it can the sensitivity of the ear at a given frequency, given the rest of the spectrum. This is not an easy task, and you have to make lots of approximations. Given two encoders that produce the same quantitive result (SNR,...), the beat one will be the one with the best psycho-acoustic model and your $10 k oscilloscope of spectral analyser won't see that at all.
He's measuring the MP3 encoders, and Ogg Vorbis is not an MP3 encoder, but an Ogg Vorbis (duh!) encoder, it doesn't use exactly the same encoding scheme, though it is still a perceptual encoder (based on time-frequency masking).
OK, now we see what parts of the spectrum are thrown away at very low bit rate, but why is it supposed to be "probably the most rigorous analysis of any encoders anywhere on the web"? First off, the *only* way to evaluate the quality of a perceptual encoder is to listen to it, period. Who cares what is rejected (non encoded) if you don't hear it.
Also, while using the 32 kbps bitrate amplifies the effects of perceptual quantization, so it's easy to see them, the problem is that not all the encoders where meant to work at this bitrate.
Think about it, when standard institutes want to evaluate audio/speech codecs, they don't calculate sonograms like this, they make subjective tests. They make a bunch of listeners hear the result of many encoders on *many* audio files. That's right you need many files to evaluate a codec. Some will perform better for certain musical instruments, some will perform better with or without background noise, echo,...
For all these reasons, I do NOT consider this analysis rigorous at all!
When we made it hard, they just didn't buy or used special programs to get around our schemes.
...and here's the reason: aside from the (obvious) financial reasons, if a piece of software has an annoying copy-protection scheme, a cracked copy is more interesting than a legal one, since it's more flexible to the user.
I think that's what's going to hurt the RIAA. As long as you can play your CD's anywhere, you'll keep buying them. However when they're going to place so many restrictions as to where your CD's will play, a pirated (unwatermarked) copy will be so much more interesting that you'd even be willing to pay as much for a pirated copy than for the original. Right now, for most people, there's at least a (moral) incentive to buy an original CD. This will soon be gone and I wouldn't be suprised if the RIAA looses money with SDMI.
-Hi, I want to *buy* a book from Amazon, but I can't, since I forgot my password. Could you please e-mail it to me (so I don't have to turn to B&N instead)?
I'm pretty sure you'll get your password this way.
I Just thought that what I would find much more useful is a filesystem that simply knows how to work with other version control systems, like CVS. You could tell the filesystem that for a certain number of file in your CVS, it should ask cvs to commit every time the file is changed. That has two advantages:
1) You select which files are version-controlled. Most of the files on a fs shouldn't be.
2) You history is compatible with other version control systems. (and can be remote,...)
...Only if you have some activity on the drive, you'll need to wipe the history often. You can have a "deamon" that deletes the history when the disk is too full, but then there wouldn't be much difference with the DOS delete/undelete (well, it would be a bit more powerful, but not that much).
IMHO, it's a very bad idea. I don't know about speed, the problem is about capacity loss. Imagine, it basically means that you cannot delete files from the drive. Simple operation: download source code, untar, compile and install, delete source code. That (now useless) source code wil live on your drive forever. Also, when your disk is full, it's full, and it'll stay full until you guy a larger one. Anyway, you get the idea.
You could have a RC filesystem that has a "real delete" option, but then why not just use CVS, as for most of the files, you don't want revision control.
OK, I think everybody how wanted a copy of it now has one. Now, where do we go from here? For now, DeCSS is totally useless as an application. Is there any work being done in integrating it within (well, maybe as a plugin) in a Linux DVD player? Otherwise, we really look like our purpous wasn't to make a Linux player after all. Of course, I may be wrong and there's already a DeCSS Linux DVD player, in which case, I'd like to know.
What about GPL'ed code sent on newsgroups?
on
Deja For Sale
·
· Score: 2
Seriously, I'm pretty sure there are many posts that cannot be sold so easily... Let's say I write a piece of GPL code and send it on comp.os.linux.whatever (or alt.sex.goat if you prefer!) with the license. If any company wants to redistribute it, they have to make it available for free download. Not knowing it's GPL is not an excuse (posting any copyrighted material would be).
To me, the simple fact that they ask that you pay to access copyrighted information (GPL or not) that they don't own, seems illegal.
I don't think they've got any hope of DA->AD->DA resistant watermarking
I'm sorry, but building watermarking that resists DA->AD->DA conversion is very, very easy to do. You can just apply the same principle behind CDMA that is, add broadband signal with a lot of redundency, and you're all set. Now, resisting to mp3 encoding/decoding is a bit harder to do, but still feasable. Resisting to all the other kinds of attacks, like phase distortion and time scaling, is much harder.
Personnaly, I don't think you can come up with some kind of watermarking that will resist any attack, but we'll see soon enough.
Their $10,000 would have been better spent on a few hours by a professional cryptographer in reviewing the algorythm
What's been broken is not about cryptography, it's the watermarking system. Watermarking means adding to the audio a message that the ear cannot hear, but that contains copyright information. Breaking the watermarking system means either removing that message (which is probably impossible) or, at least, changing it so it is not recognizable anymore.
After all, it might have been a good idea to break it that soon. I work in speech coding (not that far from audio coding) and, though this is still subject to debate, I believe that watermark cannot work. An indication of this would be that (if I understood correctly) all the watermarking systems have been completly broken. If it had been only one, then they could have picked the strongest one (which would have been bad). If it had been only a detail, they could have fixed it...
But maybe the answer is that it's not posible to have watermarking that really works. If this is true, the ones pushing SDMI have two choices:
1) Come up with a new watermarking system every 6 months, have it all broken with 1-2 weeks, and be effectivly stalled for years. Even if they finally find something that works after 4 years, it would be way too late anyway.
2) They could release something they know to be broken and play the same game the MPAA is playing with CSS. Only in that case, they'll get even less sympathy, because everybody will know that they knew from the start that their watermark was broken.
What other frontiers or environments are left for computers to work in?
What about very hot environments? It would be pretty easy to make a computer work at very cold temperature, but what about one that would work at very hot temperature like would be needed for a mission to Venus (200-400 C). This is really a fundamental semi-conductor problem. Does anyone know what's the hottest environment they've managed to make a processor run so far?
> Still, if M$ actually had a monopole then they wouldn't need to mess
(I'll bite) Well, I know for sure that Bill Gates alone has a couple tens of kilograms worth of (electric) monopoles, that is protons and electrons.
(Side note, is it a marginal phonomenon or is the general "Slashdot community" trying to piss off all the non American/non native english speaker in there with spelling and related stuff?)
Their page doesn't talk (directly, that is) about Windows, so it's still OK. However, I think going one step further (like using this to pressure computer shops into selling Windows with every PC) would be claiming that MS has a monopole on operating systems. They should be very careful about that (I don't know why I'm saying that, I know they won't!)
I compress with "delete" and decompress with "undelete". I still have a couple minor glitches to figure out, but they are mostly implementation details that cause problems when the disk is almost full. Anyway, I'll apply for a patent right now!
A device that can be used to store information in such a way that it will not be readable afterwards. The device works by connecting pins to it and sending information that will be written to it. The clever part is that it is totally secure in that it is impossible for an intruder to have access to the data.
Examples of WOM are wooden sticks, raw pieces of plastics, glass, or other material,... In general any object that doesn't allow to read the information you write to it is considered WOM and should be licensed by me.
Slashdot Mirror
If you would like to write an encoder that actually encodes audio, and specifically trades everything off to perform terrific on 'EncoderHell' (the test tone noise), please do so
Quite easy... strip out the psycho-acoustic model from a good MP3 encoder (like LAME) and you get a crappy MP3 encoder that performs very well in you sonogram test.
I don't think it's possible for an encoder to mangle the audio quality and have a pristine 'sonogram' as differenced with the source material. A pristine sonogram would be uniformly BLACK when this was done- none of the encoders remotely approached this
I'm sorry, from what you're saying, I just don't think you really understand what perceptual encoders are. First, if you have a 10:1 compression ratio, your sonogram cannot be all black (that would be lossless). Now, writing an encoder for which everything is grey (instead of black and white as the sonograms you found) is very easy to do, but it will sound like sh*t.
Very simple experiment: take a signal and add white noise so you get a 20 dB SNR. It'll sound _very_ noisy. Now, while preserving the noise energy, shape that noise to look like the signal (of course, still 20 dB lower). The audio you'll hear will sound quite OK (though not perfect) and much better that with the white noise. You have just used a (quite simple) psycho acoustic model.
Using the same reasoning, any MS employee who has seen the SAMBA code shouldn't be allowed to work for MS anymore?
...plus it would look bad for them trying to fight OSS developers working on wine/samba/...
I'm serious. The fact that the source was stolen should not matter. Maybe accessing the MS source code would prevent you from claiming a "clean room implementation", but not from working on OSS at all.
Just another idea... what if GPL'd code is found in Windows. I'd like MS being sued (by FSF?) over copyright infringement.
If you are a big fan of classical you will have an opinion on _which_ parts of the sonic information are expendable
No, when a certain frequency component is discarded, it's not because the listener won't mind, it's because even if it's there, the listener cannot hear it. If you can't hear a sound, why encode it? Now, there are sometimes problems with classical music, but that's because it's often hard to predict exactly what you can and can't hear.
with an oscilloscope I can get a more precise answer
...), the beat one will be the one with the best psycho-acoustic model and your $10 k oscilloscope of spectral analyser won't see that at all.
Yes, the guy's sonogram is more *precise* but it is still irrelevant. I could write an encoder that gives a much better result when evaluated with this "precise" sonogram, but yet will sound like crap.
This is the point of perceptual encoding. The goal is not to produce the best result in terms of signal-to-noise ratio or spectral distortion, but to cause the encoder "errors" where the "non-precise" ear won't hear it. And if you don't hear it, you don't care, even if your oscilloscope of spectral analyser tells you there's an error.
The most critical part of a perceptual encoder is the "psycho-acoustic model", which tries to model as best as it can the sensitivity of the ear at a given frequency, given the rest of the spectrum. This is not an easy task, and you have to make lots of approximations. Given two encoders that produce the same quantitive result (SNR,
Ogg Vorbis?
He's measuring the MP3 encoders, and Ogg Vorbis is not an MP3 encoder, but an Ogg Vorbis (duh!) encoder, it doesn't use exactly the same encoding scheme, though it is still a perceptual encoder (based on time-frequency masking).
OK, now we see what parts of the spectrum are thrown away at very low bit rate, but why is it supposed to be "probably the most rigorous analysis of any encoders anywhere on the web"? First off, the *only* way to evaluate the quality of a perceptual encoder is to listen to it, period. Who cares what is rejected (non encoded) if you don't hear it.
...
Also, while using the 32 kbps bitrate amplifies the effects of perceptual quantization, so it's easy to see them, the problem is that not all the encoders where meant to work at this bitrate.
Think about it, when standard institutes want to evaluate audio/speech codecs, they don't calculate sonograms like this, they make subjective tests. They make a bunch of listeners hear the result of many encoders on *many* audio files. That's right you need many files to evaluate a codec. Some will perform better for certain musical instruments, some will perform better with or without background noise, echo,
For all these reasons, I do NOT consider this analysis rigorous at all!
"If I were allowed by company xyz to tell you that their product sucks I would, but since I am not allowed, I won't tell you that is sucks"
When we made it hard, they just didn't buy or used special programs to get around our schemes.
...and here's the reason: aside from the (obvious) financial reasons, if a piece of software has an annoying copy-protection scheme, a cracked copy is more interesting than a legal one, since it's more flexible to the user.
I think that's what's going to hurt the RIAA. As long as you can play your CD's anywhere, you'll keep buying them. However when they're going to place so many restrictions as to where your CD's will play, a pirated (unwatermarked) copy will be so much more interesting that you'd even be willing to pay as much for a pirated copy than for the original. Right now, for most people, there's at least a (moral) incentive to buy an original CD. This will soon be gone and I wouldn't be suprised if the RIAA looses money with SDMI.
Can I hold Linus responsible if my kernel crashes, etc
Don't worry, uncle Bill will never let this happen. Otherwise, he'll end up as the poorest man on earth within days!
-Hi, I want to *buy* a book from Amazon, but I can't, since I forgot my password. Could you please e-mail it to me (so I don't have to turn to B&N instead)?
I'm pretty sure you'll get your password this way.
I Just thought that what I would find much more useful is a filesystem that simply knows how to work with other version control systems, like CVS. You could tell the filesystem that for a certain number of file in your CVS, it should ask cvs to commit every time the file is changed. That has two advantages:
...)
1) You select which files are version-controlled. Most of the files on a fs shouldn't be.
2) You history is compatible with other version control systems. (and can be remote,
...Only if you have some activity on the drive, you'll need to wipe the history often. You can have a "deamon" that deletes the history when the disk is too full, but then there wouldn't be much difference with the DOS delete/undelete (well, it would be a bit more powerful, but not that much).
Is this a good idea?
IMHO, it's a very bad idea. I don't know about speed, the problem is about capacity loss. Imagine, it basically means that you cannot delete files from the drive. Simple operation: download source code, untar, compile and install, delete source code. That (now useless) source code wil live on your drive forever. Also, when your disk is full, it's full, and it'll stay full until you guy a larger one. Anyway, you get the idea.
You could have a RC filesystem that has a "real delete" option, but then why not just use CVS, as for most of the files, you don't want revision control.
OK, I think everybody how wanted a copy of it now has one. Now, where do we go from here? For now, DeCSS is totally useless as an application. Is there any work being done in integrating it within (well, maybe as a plugin) in a Linux DVD player? Otherwise, we really look like our purpous wasn't to make a Linux player after all. Of course, I may be wrong and there's already a DeCSS Linux DVD player, in which case, I'd like to know.
Seriously, I'm pretty sure there are many posts that cannot be sold so easily... Let's say I write a piece of GPL code and send it on comp.os.linux.whatever (or alt.sex.goat if you prefer!) with the license. If any company wants to redistribute it, they have to make it available for free download. Not knowing it's GPL is not an excuse (posting any copyrighted material would be).
To me, the simple fact that they ask that you pay to access copyrighted information (GPL or not) that they don't own, seems illegal.
I don't think they've got any hope of DA->AD->DA resistant watermarking
I'm sorry, but building watermarking that resists DA->AD->DA conversion is very, very easy to do. You can just apply the same principle behind CDMA that is, add broadband signal with a lot of redundency, and you're all set. Now, resisting to mp3 encoding/decoding is a bit harder to do, but still feasable. Resisting to all the other kinds of attacks, like phase distortion and time scaling, is much harder.
Personnaly, I don't think you can come up with some kind of watermarking that will resist any attack, but we'll see soon enough.
Their $10,000 would have been better spent on a few hours by a professional cryptographer in reviewing the algorythm
What's been broken is not about cryptography, it's the watermarking system. Watermarking means adding to the audio a message that the ear cannot hear, but that contains copyright information. Breaking the watermarking system means either removing that message (which is probably impossible) or, at least, changing it so it is not recognizable anymore.
After all, it might have been a good idea to break it that soon. I work in speech coding (not that far from audio coding) and, though this is still subject to debate, I believe that watermark cannot work. An indication of this would be that (if I understood correctly) all the watermarking systems have been completly broken. If it had been only one, then they could have picked the strongest one (which would have been bad). If it had been only a detail, they could have fixed it...
But maybe the answer is that it's not posible to have watermarking that really works. If this is true, the ones pushing SDMI have two choices:
1) Come up with a new watermarking system every 6 months, have it all broken with 1-2 weeks, and be effectivly stalled for years. Even if they finally find something that works after 4 years, it would be way too late anyway.
2) They could release something they know to be broken and play the same game the MPAA is playing with CSS. Only in that case, they'll get even less sympathy, because everybody will know that they knew from the start that their watermark was broken.
What other frontiers or environments are left for computers to work in?
What about very hot environments? It would be pretty easy to make a computer work at very cold temperature, but what about one that would work at very hot temperature like would be needed for a mission to Venus (200-400 C). This is really a fundamental semi-conductor problem. Does anyone know what's the hottest environment they've managed to make a processor run so far?
> Still, if M$ actually had a monopole then they wouldn't need to mess
(I'll bite) Well, I know for sure that Bill Gates alone has a couple tens of kilograms worth of (electric) monopoles, that is protons and electrons.
(Side note, is it a marginal phonomenon or is the general "Slashdot community" trying to piss off all the non American/non native english speaker in there with spelling and related stuff?)
Their page doesn't talk (directly, that is) about Windows, so it's still OK. However, I think going one step further (like using this to pressure computer shops into selling Windows with every PC) would be claiming that MS has a monopole on operating systems. They should be very careful about that (I don't know why I'm saying that, I know they won't!)
For 0-bit lossless compression...
I compress with "delete" and decompress with "undelete". I still have a couple minor glitches to figure out, but they are mostly implementation details that cause problems when the disk is almost full. Anyway, I'll apply for a patent right now!
Unfortunatly (well, fortunatly), I've got prior art for you!
A device that can be used to store information in such a way that it will not be readable afterwards. The device works by connecting pins to it and sending information that will be written to it. The clever part is that it is totally secure in that it is impossible for an intruder to have access to the data.
... In general any object that doesn't allow to read the information you write to it is considered WOM and should be licensed by me.
Examples of WOM are wooden sticks, raw pieces of plastics, glass, or other material,