Vorbis development, status & patent issues, PART 2 - Technical discussion Options

[Gabriel]

Moderator comment
Currently the Vorbis patent issue covers these threads:
Vorbis development, status & patent issues PART 1 - NON-technical discussion
Vorbis development, status & patent issues PART 2 - Technical discussion (This thread)
/Moderator comment

By looking at this:
http://www.xiph.org/archives/vorbis-dev/20...2/index.html#83
it seems that Xiph (at least in 2000) was open to the idea of disclosing the patent research.
Is this position changed now, or does it still stand?

[Ivan Dimkovic]

Consider this like a pure technical question called:

How can you avoid US Patent #5,214,742 in a MDCT window-switched codec?

...

So - we are getting down to elementary technical level, ok?

I hope that we can get back to meaningful discussion which could have some scientific importance.

The only technical answer to this question is in Monty's code (envelope.c pointed to by c_haese). Anything more (debating the exact meaning of the words in the patents) is not a technical/scientific discussion but rather a legal one, which I don't think can be answered (without just stating opinions) by anyone on HA (including me). That is, unless you're a patent attorney?

Ah ... so Monty speaks through source code only

Well, the code does not explain how they avoided patent. In fact, cheching the spectral envelope level is analog to checking signal amplitude level in my books (just in frequency instead of time domain) - However it does not violate, one other patent where the change in perceptual entropy (PE) is proposed as a switching mechanism - but the thing with window-switched filterbanks is still in place, IMHO.

Furthermore, this might not be the reason why they claim they avoided the patent at all - but for all of that, we need to hear technical opinion from someone who actually invented Vorbis, because he is the only one who knows how did they avoid patents, right?

Like Danchr said - that is purely a technical discussion, because he used technical (his digital signal processing proficiency), not legal (employing DSP experts and DSP and patent expers + hell load of lawyers), means to avoid the patents.

This post has been edited by Ivan Dimkovic: Oct 2 2003, 11:43