Hello, On Sun, Apr 13, 2008 at 11:25:38PM +0200, Laurent Pinchart wrote: > On Saturday 12 April 2008, Richard Atterer wrote: > > IMHO, the kernel driver could even provide the mapping 0x0000200e => > > "Exposure, Auto Priority" without any maintenance problems. [...] > I'm not sure what you mean by a "mapping 0x0000200e => Exposure, Auto > Priority". The driver can be queried to enumerate controls. For each of > them it will return the control ID and name. This is part of the V4L2 API.
I was thinking of additional, vendor-specific controls that are not part of V4L2 (pan/tilt etc.) and how the driver makes them available. Basically, I'm not a fan of the concept of having a userspace tool set up the mapping. From the experiences of the last months, I think it might be less hassle to maintain extra controls in the driver. The userspace solution requires Linux distributions to ensure their uvcdynctrl setups work with multiple kernel driver versions, and it also means that if two different vendors implement e.g. pan/tilt differently, the application will have to know about which IDs correspond to which control - but the driver should abstract away from this and provide a generic pan/tilt API. Hmm, if it really *has* to be a userspace solution, the still-non-existent generic v4l2 userspace library would be the place to set up the controls. :-/ In <http://lists.berlios.de/pipermail/linux-uvc-devel/2007-October/002257.html>, you wrote: > Hardcoding all vendor-specific controls in the driver would soon become a > maintenance nightmare. As most controls are quite simple, I decided to go > for a userspace API that allows vendors to register new controls are > runtime. This is what my "pleeease" was referring to - please change your mind, I don't want to live with focus etc. controls on my Quickcam 9000 which break at regular intervals! ;) Cheers, Richard -- __ _ |_) /| Richard Atterer | GnuPG key: 888354F7 | \/¯| http://atterer.net | 08A9 7B7D 3D13 3EF2 3D25 D157 79E6 F6DC 8883 54F7 ¯ '` ¯ _______________________________________________ Linux-uvc-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
