Hi Sylwester, On Sat, Jan 28, 2012 at 06:01:59PM +0100, Sylwester Nawrocki wrote: > On 01/04/2012 10:07 PM, Sakari Ailus wrote: > > On Fri, Dec 30, 2011 at 12:18:40PM +0100, Sylwester Nawrocki wrote: > >> Thus we would three levels of controls for camera, > >> 1) image source class (lowest possible level), dealing mostly with hardware > >> registers; > > > > I intended the image source class for controls which only deal with the a/d > > conversion itself. Other controls would be elsewhere. > > > > There hasn't been a final decision on this yet, but an alternative which has > > been also discussed is just to call this a "low level" control class. > > > >> 2) "normal" camera controls (V4L2_CID_CAMERA_CLASS) [2]; > >> 3) high level camera controls (for camera software algorithms) > ... > > > >> I'm afraid a little it might be hard to distinguish if some control should > >> belong to 2) or 3), as sensors' logic complexity and advancement varies. > > > > I can see two main use cases: > > > > 1. V4L2 / V4L2 subdev / MC as the low level API for camera control and > > > > 2. Regular V4L2 applications. > > > > For most controls it's clear which of the two classes they belong to. > > Have you any ideas on what the class' name could be ? I thought about > V4L2_CTRL_CLASS_HIGH_LEVEL_CAMERA or V4L2_CTRL_CLASS_CAMERA_USER although > I'm not too happy with any of them and it seems hard to make up some > reasonable name, when we already have V4L2_CTRL_CLASS_CAMERA. I might continue to use the current V4L2_CTRL_CLASS_CAMERA to that --- as far I understand most are quite high level controls. We could create a new class for the low level controls instead. Should the new class be for camera controls only or for any low level controls? I'd perhaps vote for a camera, or even sensor low level class. (I actually call it image source class in the patchset.) Another question is how should we call the class for low level controls which may or may not be implemented in sensor. Digital gain, for example. > >> Although I can see an advantage of logically separating controls which have > >> influence on one or more other (lower level) controls. And separate control > >> class would be helpful in that. > >> > >> The candidates to such control class might be: > >> > >> * V4L2_CID_METERING_MODE, > >> * V4L2_CID_EXPOSURE_BIAS, > >> * V4L2_CID_ISO, > >> * V4L2_CID_WHITE_BALANCE_PRESET, > >> * V4L2_CID_SCENEMODE, > >> * V4L2_CID_WDR, > >> * V4L2_CID_ANTISHAKE, > > > > The list looks good to me. Cheers, -- Sakari Ailus e-mail: sakari.ailus@xxxxxx jabber/XMPP/Gmail: sailus@xxxxxxxxxxxxxx -- 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
