On Thu, 2009-11-26 at 12:05 -0200, Mauro Carvalho Chehab wrote: > Krzysztof Halasa wrote: > > Andy Walls <awa...@radix.net> 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. I don't know for sure what Microsoft claims to be licensing. I think it is the protocol itself: http://www.microsoft.com/presspass/Press/2002/Apr02/04-16FreestylePhilipsPR.mspx "Under the terms of the agreement, Microsoft and Philips will license to OEMs an IR protocol based on Philips proprietary RC6 IR technology. The patented and globally adopted solution minimizes interference from other remote-control devices in the household. Use of this established protocol will help ensure uniform development of Windows infrared remote-control products, which include infrared remote-control units and remote-control receivers..." http://download.microsoft.com/download/9/8/f/98f3fe47-dfc3-4e74-92a3-088782200fe7/TWEN05007_WinHEC05.ppt See Slide 5, which has the bullet: "How to License RC6" Since the content of the information field in RC-6 Mode 6A is left up to OEMs, I would not be surprised by bogus "innovations" in OEM patents about RC-6 Mode 6A contents. I would not be at all surprised by something like "a bit to indicate a toggled remote key press in the information field" since RC-6's T bits for mode 6 indicate Mode 6A or Mode 6B and not toggles. 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. Regards, Andy > Cheers, > Mauro. -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html