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Topic: Vorbis development, status & patent issues (Read 117239 times) previous topic - next topic
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Vorbis development, status & patent issues

Reply #50
Ok, I asked Xiph's opinion about this specific issue discussed in this thread at Xiph's monthly meeting which is open to public. Here was the answer (the whole Xiphmeeting log can be read here):
Quote
<JohnV> well.. I've gathered here the technical talk in HydrogenAudio regarding speculations whether US 5,214,742 can be avoided in a MDCT codec with window switching: http://www.hydrogenaudio.org/forums/index....showtopic=13531
<xiphmont> JohnV: that patent is not about windows or window switching, it's about the specific method o deciding when to switch.
<JohnV> xiphmont: well, the question is, can it be avoided in a codec which does window switching..
<purple_haese> JohnV: Yes, by using a different method for deciding when to switch.
<JohnV> purple_haese: does Vorbis use "different method"?
<purple_haese> JohnV: xiphmont seems to think so.
<JohnV> seems to think so?
<xiphmont> JohnV: IANAL [I Am Not A Lawyer]
<JohnV> xiphmont: but you base it on what exactly? You are not a lawyer but what is this thinking based on?
<purple_haese> JohnV: In cases you haven't noticed,  the meeting has moved away from the patent discussion. After consultation with the lawyer, we will disclose as much as we possibly can.


Not much explanation there, but later Monty said to me this (outside the meeting): "The patents describe mp3.  We have a different transform path.  For many reasons they don;t pply, but I'm not allowed to say that unless I'm a lawyer."

Xiph is planning somekind of response after consulting with lawyer, but I don't know if it brings any light to this issue.
Juha Laaksonheimo

Vorbis development, status & patent issues

Reply #51
All in all, this is how I perceive the picture... sorta "thinking loud":

Xiph - "We claim Ogg Vorbis is patent free (on the website)"

Q1: "Can you guarantee you are free of patents"

Xiph - "No, nobody can - and you need a expensive lawyer opinion for that"

Q2: "Ok, so how can you claim  "patent free" on the website without applying the same logic?"

Xiph - "We are about to define "patent free" after the meeting"  (analogy with RMS goes here... )

(still, while not defined what actually is, claim "patent free" is key marketing argument for years and the way to disqualify some better codecs as "codecs with patent issues" like somebody said on this forum - see the problem?)

<personal opinion> Maybe it is better to call Vorbis "license free" or "royalty free" since both statements are true even if some patents are infringed  </personal opinion>

Q3: "What is the Xiph's stand on US 5,214,742?"

Xiph: "We cannot comment, you need a professional lawyer opinion"

Q4: "But in-depth technical discussion is presented on HA... c"

Xiph: "We said enough... case closed... meeting moves to... next topic"


IMHO,  one thing is somewhat unclear - Xiph does not want to go into any technical discussion about Vorbis implementation and current patent situation in US and EU,  and especially couple of patents which raise eyebrows - some kind of "no - patent describes THIS WAY, and we did THAT WAY" discussion would be welcome - but unfortunately hard to expect.  I understand that stand, probably every Monty's word has very big legal weight since he is the leader and founder of Xiph - and he probably likes to hear lawyer's opinion before he says something about Ogg in public (but somehow I think technical aspects are of no lawyer's concern)

So, let's wait for the new definition of "patent free" in Vorbis - and, maybe some official lawyer's opinion if it is allowed to be said in public

Vorbis development, status & patent issues

Reply #52
Quote
Ok, I asked Xiph's opinion about this specific issue discussed in this thread at Xiph's monthly meeting which is open to public. Here was the answer (the whole Xiphmeeting log can be read here):

JohnV, your quote is a bit misleading as it doesn't show that the discussion was already over (after we agreed that we should prepare a statement) for a while and at that point, you were just adding noise to the meeting (for those who haven't read the logs, the comments in the quote were interleaved with the "on topic stuff").

Vorbis development, status & patent issues

Reply #53
Quote
Quote
Ok, I asked Xiph's opinion about this specific issue discussed in this thread at Xiph's monthly meeting which is open to public. Here was the answer (the whole Xiphmeeting log can be read here):

JohnV, your quote is a bit misleading as it doesn't show that the discussion was already over (after we agreed that we should prepare a statement) for a while and at that point, you were just adding noise to the meeting (for those who haven't read the logs, the comments in the quote were interleaved with the "on topic stuff").

Discussion already over? In the logs one can see yourself talking about the patent issue with PsyQ (Ivan) in the same minute as I started! And where in the logs it said the patent talk ended? And why did it end so rapidly anyway, before people had really time to ask any questions?
I was just adding noise to the meeting by bringing up this HA thread?? Jeez?? You guys are just incredible...

I urge everybody to read the logs http://xiph.org/~jack/200310.txt and consider themselves if what you said is true...
In case someone doesn't bother I just directly copy lines here which happened before my first comment. Timestamps are from the Xiph log.
Quote
17:24 < xiphmont> Well, I'd have to be the technical side of making such an opinion wit the lawyer.
17:24 < purple_haese> It doesn't have to be elaborate, and it would be a clear sign of good will.
17:24 < derf_> In fact, you're potentially liable for up to triple damages just for reading the thing without consulting your lawyer, for "willful infringement".
17:25 < jack> derf ha sa point here.
17:25 < purple_haese> Yikes.
17:25 < PsyQ> derf: well, how is anyone who is not a lawyer qualified to call something "patent free"?
17:25 < jack> let me ask the lawyer
17:25 < jmspeex> derf_: single/triple damage doesn't change a thing in our case.
17:25 < purple_haese> Well, then the best we can do, unfortunately, is to explain why we can't make specific statements about specific patents.
17:26 < jmspeex> PsyQ: we define "patent-free". It's like free software, RMS decides what qualifies as "free software"
17:26 < jack> purple_haese: that may be the case.  anyway, i'll send an email to tom and we'll figure out where to go from there.
17:26 < xiphmont> yes, we need some sort of statement.
17:27 < PsyQ> jmspeex: free software does not anything to do with "patent free", so I'd leave RMS out of this discussion
17:27 < jack> ok..  stan, you had some changes to libao you wanted to discuss?
17:27 < purple_haese> Businesses that are interested in Vorbis can always take the money they save on licensing and put part of it toward their own patent opinion, or buy some liability insurance
17:28 < PsyQ> ok - so you defined "patent free" as ?  I guess free of your own patents?
17:28 < jmspeex> PsyQ: What I mean is that when the FSF talks about "free software", they also define what they mean exactly by "free software". We should do the same with "patent-free".
17:28 < volsung> Should I jump in now? 
17:28 -!- mackstann [~death@12-217-123-219.client.mchsi.com] has joined #xiphmeet
17:28 < JohnV> well.. I've gathered here the technical talk in HydrogenAudio regarding speculations whether US 5,214,742 can be avoided in a MDCT codec with window switching: http://www.hydrogenaudio.org/forums/index....showtopic=13531


The patent discussion started at 17:14, and you are saying that at 17:28 my comment was already off-topic noise, also considering the direct quote from the discussion above? Nice... Frankly I thought that this topic would have been given more emphasis. I thought I was being polite not to shoot my comment right a way, rather give Xiph some time to first say its general view about the subject. I was not asking or wanting any round statements from a lawyer to my comment, rather some coder opinion and brief technical explanation about the principle of avoiding this patent in code in coder's point of view. Obviously Xiph's tactics was to get rid of this topic as soon as possible before the real questions come.
Juha Laaksonheimo

Vorbis development, status & patent issues

Reply #54
Quote
Discussion already over? In the logs one can see yourself talking about the patent issue with PsyQ (Ivan) in the same minute as I started! And where in the logs it said the patent talk ended? And why did it end so rapidly anyway, before people had really time to ask any questions?
I was just adding noise to the meeting by bringing up this HA thread?? Jeez?? You guys are just incredible...

I said you were adding noise to the meeting because you were the only one left that was talking about that at that point in the meeting (yes, the patent talk ended at the time people started talking about the next point). Besides, it wasn't worth debating much until we at least come up with a draft statement about the patent status. Believe me, I'm one of those that really want to have that. I'll save me tons of explaination.

BTW, when I said you post was misleading, I just meant that by not using "..." (or similar), you made it look like you quoted verbatim, while in fact the comments were more scattered.

Vorbis development, status & patent issues

Reply #55
Quote
I said you were adding noise to the meeting because you were the only one left that was talking about that at that point in the meeting (yes, the patent talk ended at the time people started talking about the next point).

I was the only one who was talking about that? Monty's and Haese's comments just magically appeared on the log. I see. I shouldn't have answered to Monty or Haese because other Xiph members pushed the discussion away from the topic at hand.

I'd rather say some other people added "noise", because there was a discussion going on between me, Monty and Haese, and it started by me when everybody was still talking about the patent issue. You can clearly see that in the logs. And again, I was not asking any "statements" about what is meant with "patent free". I was asking for coder opinion, even on the general principle level about the issue covered in this thread (even forgetting Vorbis, and talking totally in general level, but I was made to shut up there by Xiph before I had a chance to say anything further).

Thank you for letting me know that I only added noise, since after all, this is no important issue at all, right, and I'm just a troll who was adding noise there, when there was "much more important issues" to cover. At least I now know your position what comes to me..

This all makes me wonder why I ever wasted my time bringing up Vorbis quality issues when 1.0 was in the makings, or why I bother keeping up Vorbis forums here, or why I bother asking clarifications to an issue, which might in the end add hughly positive impact on Vorbis. Why should a troll like me do anything for you guys.
Juha Laaksonheimo

Vorbis development, status & patent issues

Reply #56
Quote
I was the only one who was talking about that? Monty's and Haese's comments just magically appeared on the log. I see. I shouldn't have answered to Monty or Haese because other Xiph members pushed the discussion away from the topic at hand.


OK, first my main point was not the noise vs. not noise issue, but just the fact that the way you quoted was misleading. Can you at least acknowledge that?

Quote
I'd rather say some other people added "noise", because there was a discussion going on between me, Monty and Haese, and it started by me when everybody was still talking about the patent issue. You can clearly see that in the logs. And again, I was not asking any "statements" about what is meant with "patent free". I was asking for coder opinion, even on the general principle level about the issue covered in this thread (even forgetting Vorbis, and talking totally in general level, but I was made to shut up there by Xiph before I had a chance to say anything further).


OK, so you were "made to shut up by Xiph". Everyone knows that Xiph is a large, powerful organization with the power to silence people, right?

Quote
Thank you for letting me know that I only added noise, since after all, this is no important issue at all, right, and I'm just a troll who was adding noise there, when there was "much more important issues" to cover. At least I now know your position what comes to me..


I probably want this statement more than you do and probably would have liked to discuss it a bit further... *However*, I realize that going deeper into topics in this kind of *general* meeting just makes the meeting last forever (this one was already 1.5 hours long). That's why we can't stay too long on something. Don't worry, you'll have plenty of time to comment once we at least have something to show.

Quote
This all makes me wonder why I ever wasted my time bringing up Vorbis quality issues when 1.0 was in the makings, or why I bother keeping up Vorbis forums here, or why I bother asking clarifications to an issue, which might in the end add hughly positive impact on Vorbis. Why should a troll like me do anything for you guys.


Don't cry, we love you JohnV 

Vorbis development, status & patent issues

Reply #57
Quote
OK, first my main point was not the noise vs. not noise issue, but just the fact that the way you quoted was misleading. Can you at least acknowledge that?

It was not misleading. I included all the lines which were relevant to issue I brought up and excluded non-relevant lines which had nothing to do with the issue I brought up.

In that above message I said this: "Ok, I asked Xiph's opinion about this specific issue discussed in this thread at Xiph's monthly meeting which is open to public. Here was the answer (the whole Xiphmeeting log can be read here):"

I brought up the issue when the patent discussion was still going on, and quoted the lines which followed from it, excluding Volsung's "off-topic" lines which pushed the discussion away from the topic and had nothing to do with answers to this issue, so if anybody was bringing noise, it was Volsung. I never claimed the quote in this message was full irc log with all the non-issue lines, but I linked to the full log anyway. But the quote in my message here is a direct copy with all the lines and timestamps from a certain section of the log, and it shows the patent discussion was still going on.

Quote
OK, so you were "made to shut up by Xiph". Everyone knows that Xiph is a large, powerful organization with the power to silence people, right?
No, but I was clearly said the discussion is over, and I respected that, since it was the "Monthly Xiph Meeting, open to public".
Juha Laaksonheimo

Vorbis development, status & patent issues

Reply #58
Like I said - if somebody is so sure he avoided patents, and he is the designer of the method which is claimed to be patent free in the same time,  he could certainly say something like:

"No, US Patent XXXXXXX  claims that YYYY is done in THIS way", and our code/product is doing something in THAT way - take a look at ZZZZ.C and page N of the US XXXXXX, thus in my (not professional) opinion ZZZZ.C is not violating the patent.

The issue is pushed to the very limits on "question" side,  and the "answer" side didn't do anything to make issue more clear.

Vorbis development, status & patent issues

Reply #59
I don't want to be boring, but i have to say it again:

US PATENTS ARE NOT WORLD PATENTS !!!     

If Vorbis is illegal in US is an US problem.
Sincerly i don't care; I just wanna remember all of you that HA is mostly composed by European users. 

Some interesting articles follows:

Recent EFF Legal Cases and Efforts

FFII: Software Patents in Europe

...and we won the 1st battle: Parliament Accepts Petitions Against Software Patents 

(note: would this mean that Xiph should move to EU ?)

Vorbis development, status & patent issues

Reply #60
Quote
I don't want to be boring, but i have to say it again:

US PATENTS ARE NOT WORLD PATENTS !!!    

If Vorbis is illegal in US is an US problem.
Sincerly i don't care; I just wanna remember all of you that HA is mostly composed by European users. 

Not only is this off-topic to this thread, but it's irrelevant to the entire discussion.

The issue has never been about US patents being some universal (or even really patents at an essential level themselves), it has been about the meaning behind a claim made by Xiph and about the status of Vorbis technology in relation to other technology.

Please do not continue this off-topic and irrelevant discussion here.

Vorbis development, status & patent issues

Reply #61
JohnV,

It seems to me that Monty's unofficial position on this matter is that patent 5,214,742 is not about Window Switching, but a specific method on when to switch (according to his IRC statement).  To answer the question that you asked on IRC, if a window-switching codec CAN avoid infringment with this patent, then Vorbis is doing so.

The problem is that the wording of that part of the patent is a little vague. I think even you are willing to concede that point. Vorbis doesn't use signal amplitude changes directly to control the window switching.  But since I would dare say that all signals are defined by their amplitude changes, Vorbis is at the very least INDIRECTLY using signal amplitude changes.

So there are two different ways of interpreting this patent, one of them shows Vorbis to be infringing.  Which one is right?  No one is saying officially because no one wants to lose credibility if they're wrong.  I'm betting that Xiph is staying away from it, because they stand to lose no matter how it's cut.

Incidentally, I found two other patents that were interesting:
  • US5,321,729 - which appears to ALSO be a patent for Window Switching... I'm not sure since I find reading patent filings is quite painful.
  • US5,848,391 - which is completely unrelated to Vorbis, but I was wondering whether Musepack infringed on this (I don't know the details of MPC).

Vorbis development, status & patent issues

Reply #62
Quote
I don't want to be boring, but i have to say it again:

US PATENTS ARE NOT WORLD PATENTS !!!    

If Vorbis is illegal in US is an US problem.
Sincerly i don't care; I just wanna remember all of you that HA is mostly composed by European users.  

Some interesting articles follows:

Recent EFF Legal Cases and Efforts

FFII: Software Patents in Europe

...and we won the 1st battle: Parliament Accepts Petitions Against Software Patents 

(note: would this mean that Xiph should move to EU ?)

Yes you are boring - because you do not seem to read whole thread before posting...

Once again,

For example check the US#5,214,742  status:

http://ep.espacenet.com/  (US5214742)

Equivalent patents:

CA2026441,  DD292791,  DE3902948,  EP0414838 (WO9009063),  B1, ES2045902T,  FI101252B, HK55296, HU56473, JP3226537B2, JP3503829T, KR140877, TR24444,  WO9009063

So this patent (like almost all other patents related to audio coding)  is registered worldwide, including USA, EU, Japan, Korea etc.. in 1992.

Once again: audio coding patents ARE NOT SOFTWARE PATENTS (also, they are registered worldwide) and I would like to stay out of that discussion when we discuss implementation issues of particular audio-coding /decoding system

Vorbis development, status & patent issues

Reply #63
Quote
JohnV,

It seems to me that Monty's unofficial position on this matter is that patent 5,214,742 is not about Window Switching, but a specific method on when to switch (according to his IRC statement).  To answer the question that you asked on IRC, if a window-switching codec CAN avoid infringment with this patent, then Vorbis is doing so.

The problem is that the wording of that part of the patent is a little vague. I think even you are willing to concede that point. Vorbis doesn't use signal amplitude changes directly to control the window switching.  But since I would dare say that all signals are defined by their amplitude changes, Vorbis is at the very least INDIRECTLY using signal amplitude changes.

So there are two different ways of interpreting this patent, one of them shows Vorbis to be infringing.  Which one is right?  No one is saying officially because no one wants to lose credibility if they're wrong.  I'm betting that Xiph is staying away from it, because they stand to lose no matter how it's cut.

Incidentally, I found two other patents that were interesting:
  • US5,321,729 - which appears to ALSO be a patent for Window Switching... I'm not sure since I find reading patent filings is quite painful.



  • US5,848,391 - which is completely unrelated to Vorbis, but I was wondering whether Musepack infringed on this (I don't know the details of MPC).

Quote
It seems to me that Monty's unofficial position on this matter is that patent 5,214,742 is not about Window Switching, but a specific method on when to switch (according to his IRC statement). To answer the question that you asked on IRC, if a window-switching codec CAN avoid infringment with this patent, then Vorbis is doing so.


According to my analysis of claims patent is basically claiming this:

1. Improvement consisting of selecting of window length depending on signal amplitude change

2. Window length is a function of signal amplitude change

3. Length of the window is small for large changes, and big for small changes

4, 5, 6 - deal with the forming of transition "overlap/add" windows

7. Tells the spacing between windows changes depending on the amp. chng.

8. Changes are in time

9. Signals are audio signals

Quote
The problem is that the wording of that part of the patent is a little vague. I think even you are willing to concede that point. Vorbis doesn't use signal amplitude changes directly to control the window switching. But since I would dare say that all signals are defined by their amplitude changes, Vorbis is at the very least INDIRECTLY using signal amplitude changes.


Well, defending Xiph position can be done on two basis:

#1 Attacking claim 1 with argument that vorbis do not code spectrum, but residual

#2 Attacking claim 1 with argument that switching criterion is different from "signal amplitude change"


Personally, I think argument #1 can't be very helpful, because the final result before IMDCT in decoder is actual MDCT signal - which is overlapped and added, so the signal is "coded" no matter how the coding representation is done in the encoder/bitstream (LPC+VQ or direct scalar quantization of the coefficients, like in MP3/AAC) - and the patent does not go into the coding implementation at all.

Argument #2 is more serious - and the validity of it is only subject to determining if Parseval's theorem applies - i.e., is checking envelope level change in threshold bands equal to "signal amplitude change"... but we have another problem - patent does not specify whether "signal amplitude change" is in time or frequency domain, or how should checking/triggering be done at all!

It is a very tricky argument I must admit - because, correct me if I wrong, Vorbis triggers to short block if the amplitude level change between consecutive frequency bands in time (meeting claim #8)  - this is ... well... at least looks like "changing of the signal amplitude"

Vorbis development, status & patent issues

Reply #64
Let me try to "preach to the deaf" once again...

Before trying to decide "scientifically" if a codec infringes on a patent, one has to know "scientifically"
what the patent claim means. Unfortunately patent claims are not written by scientists, but they
are written by lawyers with intentional vagueness. The objective is to make it as broad as possible and, eventually, denfend it in court. Hence, any tentative to seriously analyze a patent situation should involve a lawyer to "extract" the precise meaning of the patent claim. Worse, a definitive answer needs a judge.

Otherwise, all of our arguments will have to start with a "According to my analysis of claims patent", as Ivan's post above. The same aspect of possible different interpretations was raised by sthayashi in another post.

Is it clear now why Xiph should avoid to answer this thread without consulting a lawyer?

Considering these arguments, is it technically sound to "ask scientifically if a patent is being infringed"? Hey, I just stated a meta-question  !  I have the opinion that the answer of this question is no. However most people here seems to ignore this aspect and insist on having a pseudo-scientific discussion on a matter that is not solely in the science domain.

Vorbis development, status & patent issues

Reply #65
Quote
Well, defending Xiph position can be done on two basis:

#1 Attacking claim 1 with argument that vorbis do not code spectrum, but residual

#2 Attacking claim 1 with argument that switching criterion is different from "signal amplitude change"

Personally, I think argument #1 can't be very helpful, because the final result before IMDCT in decoder is actual MDCT signal - which is overlapped and added, so the signal is "coded" no matter how the coding representation is done in the encoder/bitstream (LPC+VQ or direct scalar quantization of the coefficients, like in MP3/AAC) - and the patent does not go into the coding implementation at all.

Argument #2 is more serious - and the validity of it is only subject to determining if Parseval's theorem applies - i.e., is checking envelope level change in threshold bands equal to "signal amplitude change"... but we have another problem - patent does not specify whether "signal amplitude change" is in time or frequency domain, or how should checking/triggering be done at all!

It is a very tricky argument I must admit - because, correct me if I wrong, Vorbis triggers to short block if the amplitude level change between consecutive frequency bands in time (meeting claim #8)  - this is ... well... at least looks like "changing of the signal amplitude"

I'm too uneducated to figure out your statement for #1.

As for #2, that spells a big oops for Xiph. I've got a question though. Is there any documentation on how the encoder chooses between short and long window sizes? I mean, I believe you, but I have to see it myself, because that's strong evidence of infringement, IMHO.

Vorbis development, status & patent issues

Reply #66
Quote
Quote
#2 Attacking claim 1 with argument that switching criterion is different from "signal amplitude change"

As for #2, that spells a big oops for Xiph. I've got a question though. Is there any documentation on how the encoder chooses between short and long window sizes? I mean, I believe you, but I have to see it myself, because that's strong evidence of infringement, IMHO.

Here's a page from the Xiph.org developement forum that may shed some light.

Excerpt:
"Vorbis simply normalizes the time-domain envelope before the MDCT.
Each block is scanned for a dynamic range increase over a
predetermined threshhold; the envelope of the time domain signal is
normalized from the point of the change to the end of the block
(current code normalizes to an even =/- 6dB). The envelope is cheap
to compute, easy to encode efficiently (most blocks don't need it, so
we don't encode an envelope in 98% of the blocks) and simple. My
tests with 'castanets.wav' gets better results than with LAME or
Fraunhofer (IMHO ;-) Needless to say, I was a bit surprised."


(Note:  This is from August 1999, but the core functionality of the codec has not changed, has it?)

From what I've studied about the architecture of the Vorbis codec over the past week or so, it seems to be using some variant of signal-amplitude changes to determine window size, but the use of "envelope pre-clamping" has to also be considered before determining whether this is ultimately infringing on the patent in question, if it (if I'm reading this right) normalizes the signal before the MDCT step.  (Does signal = time/domain envelope?)  Also, Monty covers some other points which he believes avoids other MPEG-related patents as well in the linked post.

Everyone's probably already seen this, but it seems relevant right about now.

Edit:  Here's a hopefully more relevant reference to the similarity between Vorbis and MPEG codecs concerning how window size determination is done...

"Vorbis is a hybrid transform domain general purpose audio encoder,
like MPEG in some respects (it is rooted in much of the same basic
theory). For the most part, the similarity comes from the fact that
(like nearly all modern audio compressions), Vorbis codes primarily in
the MDCT domain, using nominal 50% overlap with a y=sin(2PI*sin^2(x))
window (the window is a bit unique). The current Vorbis code and
working spec support switching between two block sizes which must
result in power-of-two sized windowed blocks. From here, the details
diverge." ...

Vorbis development, status & patent issues

Reply #67
Quote
"Vorbis is a hybrid transform domain general purpose audio encoder,
like MPEG in some respects (it is rooted in much of the same basic
theory). For the most part, the similarity comes from the fact that
(like nearly all modern audio compressions), Vorbis codes primarily in
the MDCT domain, using nominal 50% overlap with a y=sin(2PI*sin^2(x))
window (the window is a bit unique). The current Vorbis code and
working spec support switching between two block sizes which must
result in power-of-two sized windowed blocks. From here, the details
diverge." ...


Which is exactly what patent is covering: window-switched MDCT filterbank with variable sized windows depending on a signal statistics - the thing on which Vorbis, MP3, AAC and some other codecs rely - OTOH, how Vorbis codes MDCT coefficients is not relevant for the mentioned patent - it does not have any claim related to coding method of the MDCT spectrum.

Quote
From what I've studied about the architecture of the Vorbis codec over the past week or so, it seems to be using some variant of signal-amplitude changes to determine window size, but the use of "envelope pre-clamping" has to also be considered before determining whether this is ultimately infringing on the patent in question, if it (if I'm reading this right) normalizes the signal before the MDCT step. (Does signal = time/domain envelope?) Also, Monty covers some other points which he believes avoids other MPEG-related patents as well in the linked post.


In my opinion - if it norlalizes it by a constant function over time, it does not release it from the claim - since it is still decision based on amplitude change, but just protected with some kind of pre-echo control mechanism.

But that is just my opinion.

Vorbis development, status & patent issues

Reply #68
Quote

Quote
I'm too uneducated to figure out your statement for #1.


To put it in a simple way - one of the ways to expose Vorbis' "patent-freeness" was the statement that Vorbis does not code MDCT spectrum like MP3 / AAC do. Which is true - the method used in Vorbis is quite different from MP3/AAC.

However, the relevant patent in question does not deal with the MDCT coding at all - what is important is that analysis is done on MDCT windows, and after decoding of the coefficients the result is again - MDCT spectrum which is then passed through IMDCT filterbank to get PCM signal.  And the patent is directed towards filterbank  only - not the coding method.

Quote
As for #2, that spells a big oops for Xiph. I've got a question though. Is there any documentation on how the encoder chooses between short and long window sizes? I mean, I believe you, but I have to see it myself, because that's strong evidence of infringement, IMHO.


Some of the people revealed some ideas how vorbis switches to short blocks  in previous posts, and you can look at envelope.c  in /lib directory of libvorbis package to see how the idea is implemented in the code.

Vorbis development, status & patent issues

Reply #69
From XviD.org website:

Quote
European parliament votes _against_ software patents

This is big news for all users and programmers of XviD in the EU: The european parliament has decided that "inventions" which consist purely of software cannot be protected by patents. This is of course just the way it has always been in europe, but lately there had been much lobby work by "important companies" to have that changed. Until a few weeks ago, it looked like software patents would be introduced in europe within a few month.

The plans would most likely have allowed so-called trivial patents like the famous "one-click-patent" by amazon.com to be possible in europe also. This would have been a serious threat to almost all Open Source development in europe, because there isn't the simplest idea in software development -and in particular in video compression- that isn't under US patent by somebody.
For the experts of you: storing motion vectors relative to a predictor is "protected", MPEG-4's 3dimensional VLCs (run,level,last) aren't free, there even is (or used to be) a patent on YUV as a color space for image compression...

After today's decision, it seems that europe will stay free of such
outgrowth, at least for while...

In you are interested, do have a look at the lots of material at http://www.ffii.org/ or simply search google for "trivial patents".


So video coding differs from audio coding in patent issues ?

Sorry to be so boring... 

Vorbis development, status & patent issues

Reply #70
I don't know what XVid claims (and for what particular technology/algorithm they think software patent might apply), but I have a strong feeling that video coding patents for MPEG-2 and MPEG-4 are also internationally recognized PCT patents registered years ago, and have nothing to do with US pure-software patents (like that amazon crap).

Edit - ok here is the part of the list of "Non-US" patents in MPEG-4 visual :

http://www.mpegla.com/mpeg4v/m4v_patentlist.html

FR 2,599,577
DE 3767919
GB 248,711
IT 248,711
SE 248,711
FR 395,709
GB 395,709
JP 2,790,509
DE 3855203
JP 2,998,741
JP 3,092,610
JP 3,092,613
JP 3,191,935
JP 3,303,869
JP 1,835,550
DE 69031107
FR 424,026
GB 424,026
JP 2,712,645
AT 185663
BE 638,218
CH/LI 638,218
DE 69421135
DK 638,218
ES 2,137,358
FR 638,218
GB 638,218
GR 3,032,133
IE 638,218
IT 638,218
LU 638,218
MC 638,218
NL 638,218
PT 638,218
SE 638,218
DE 69031045
FR 584,840
GB 584,840
JP 2,137,325
NL 584,840
DE 69024235
DE 69030819
FR 379,217
FR 572,046
GB 379,217
GB 572,046
JP 2,072,546

Vorbis development, status & patent issues

Reply #71
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Sorry to be so boring... 


Sorry if I sounded too harsh regarding the issue (and you started with "maybe I am too boring) - consider this as a joke, and nothing else.

You are not boring, but your resoning actually describes the false information from some sources regarding patents - I dont' think it is intentional in most cases,  it just proves that somebody is not informed about patent system.

Most MPEG related patents are not "software patents" in strict term, and they are registered throughout all the world (Sheesh - some SBR patents are now registered even in Yugoslavia - country where I was born,  and I was quite surprised when I saw that in the country list)

So, the typical "we are against software patents" rant (including "It might be illegal in U.S. but it is not in Europe" (which is IMO quite reasonable - and has some logical and phylosophical points) simply does not apply to audio/visual coding algorithms,  and pushing it into the technical discussion like this is simly just adding unwanted noise.

And, even if some patent is idea used in a product without paying a "fee" this does not render product "illegal" or anything like that - some patents are registered with some other ideas in mind, and not all patent holders chase people who use their ideas.

Vorbis development, status & patent issues

Reply #72
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(Note:  This is from August 1999, but the core functionality of the codec has not changed, has it?)

It has. They switched to window-switching. Some things have been massively changed since that time, and the quoted mail is also wrong about how AAC works.

(As far as I understand)

Vorbis development, status & patent issues

Reply #73
Quote
Quote

e.g. if the complete technological details were publicly available more than 20 years ago, then this technology is patent free. If there was a patent before, it has now expired. If there was a (same, similar or encompassing) patent filed more recently, then it doesn't cover this technology.


The thing is,  which is core of this discussion - is that adaptive window switched MDCT filterbanks didn't exist 20 years ago - they were result of work of H.Malvar, J. Princen, A. Bradley and, finally, B. Edler (dynamic switching)  in late 80's.

Do you have the exact text of this patent? What is the property of the MDCT
filter which is patented?


      ................... = const


What is the text for .................. in the patent paper?
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