On Nov 26, 2009, at 2:43 PM, Andy Walls wrote: > On Thu, 2009-11-26 at 12:05 -0200, Mauro Carvalho Chehab wrote: >> Krzysztof Halasa wrote: >>> Andy Walls <awalls@xxxxxxxxx> writes: >>> >>>> I would also note that RC-6 Mode 6A, used by most MCE remotes, was >>>> developed by Philips, but Microsoft has some sort of licensing interest >>>> in it and it is almost surely encumbered somwhow: >>> >>> I don't know about legal problems in some countries but from the >>> technical POV handling the protocol in the kernel is more efficient >>> or (/and) simpler. >> >> A software licensing from Microsoft won't apply to Linux kernel, so I'm >> assuming that you're referring to some patent that they could be filled >> about RC6 mode 6A. >> >> I don't know if is there any US patent pending about it (AFAIK, only US >> accepts software patents), but there are some prior-art for IR key >> decoding. So, I don't see what "innovation" RC6 would be adding. >> If it is some new way to transmit waves, the patent issues >> aren't related to software, and the device manufacturer had already handled >> it when they made their devices. >> >> If it is just a new keytable, this issue >> could be easily solved by loading the keytable via userspace. >> >> Also, assuming that you can use the driver only with a hardware that comes >> with a licensed software, the user has already the license for using it. >> >> Do you have any details on what patents they are claiming? > > The US Philips RC-6 patent is US Patent 5,877,702 > > http://www.google.com/patents?vid=USPAT5877702 > > Click on download PDF to get a copy of the whole patent. > > I am not a lawyer. Philips claims' all appear to tie to a transmitter > or receiver as part of a system, but most of the claims are about > information and bit positions and lengths. ... > IMO, given > > a. the dearth of public information about RC-6, indicating someone > thinks it's their trade secret or intellectual property > > b. Microsoft claiming to license something related to the MCE remote > protocols (which are obviously RC-6 Mode 6A), > > c. my inability to draw a "clear, bright line" that RC-6 Mode 6A > encoding and decoding, as needed by MCE remotes, implemented in software > doesn't violate anyone's government granted rights to exclusivity. > > I think it's much better to implement software RC-6 Mode 6A encoding and > decoding in user space, doing only the minimum needed to get the > hardware setup and going in the kernel. > > Encoding/decoding of RC-6 by microcontrollers with firmware doesn't > worry me. > > > Maybe I'm being too conservative here, but I have a personal interest in > keeping Linux free and unencumbered even in the US which, I cannot deny, > has a patent system that is screwed up. So I had one of the people who does all the license and patent audits for Fedora packages look at the Philips patent on RC-6. He's 100% positive that the patent *only* covers hardware, there should be no problem whatsoever writing a software decoder for RC-6. -- Jarod Wilson jarod@xxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
