On Tue, Sep 06, 2011 at 09:35:24AM +0000, Bastian Hecht wrote: > Hello Sakari, > > 2011/9/6 Sakari Ailus <sakari.ailus@xxxxxx>: > > On Tue, Sep 06, 2011 at 09:01:15AM +0000, Bastian Hecht wrote: > >> 2011/9/6 Sakari Ailus <sakari.ailus@xxxxxx>: > >> > On Tue, Sep 06, 2011 at 07:56:40AM +0000, Bastian Hecht wrote: > >> >> Hello Sakari! > >> > > >> > Hi Bastian, > >> > > >> >> 2011/9/6 Sakari Ailus <sakari.ailus@xxxxxx>: > >> >> > Hi Bastian, > >> >> > > >> >> > On Mon, Sep 05, 2011 at 09:32:55AM +0000, Bastian Hecht wrote: > >> >> >> 2011/9/1 Sakari Ailus <sakari.ailus@xxxxxx>: > >> >> >> > On Thu, Sep 01, 2011 at 11:14:08AM +0200, Sylwester Nawrocki wrote: > >> >> >> >> Hi Sakari, > >> >> >> >> > >> >> >> >> On 09/01/2011 10:47 AM, Sakari Ailus wrote: > >> >> >> >> > On Thu, Sep 01, 2011 at 09:15:20AM +0200, Guennadi Liakhovetski wrote: > >> >> >> >> >> On Thu, 1 Sep 2011, Sakari Ailus wrote: > >> >> >> >> >> > >> >> >> >> >>> On Wed, Aug 31, 2011 at 03:27:49PM +0000, Bastian Hecht wrote: > >> >> >> >> >>>> 2011/8/28 Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>: > >> >> >> >> >>> [clip] > >> >> >> >> >>>>> If I'm not mistaken V4L2_CID_PRIVATE_BASE is deprecated. > >> >> >> >> >>>> > >> >> >> >> >>>> I checked at http://v4l2spec.bytesex.org/spec/x542.htm, googled > >> >> >> >> >>>> "V4L2_CID_PRIVATE_BASE deprecated" and read > >> >> >> >> >>>> Documentation/feature-removal-schedule.txt. I couldn't find anything. > >> >> >> >> >>> > >> >> >> >> >>> Hmm. Did you happen to check when that has been written? :) > >> >> >> >> >>> > >> >> >> >> >>> Please use this one instead: > >> >> >> >> >>> > >> >> >> >> >>> <URL:http://hverkuil.home.xs4all.nl/spec/media.html> > >> >> >> >> >> > >> >> >> >> >> "Drivers can also implement their own custom controls using > >> >> >> >> >> V4L2_CID_PRIVATE_BASE and higher values." > >> >> >> >> >> > >> >> >> >> >> Which specific location describes V4L2_CID_PRIVATE_BASE differently there? > >> >> >> >> > > >> >> >> >> > That was a general comment, not related to the private base. There's no > >> >> >> >> > use for a three-year-old spec as a reference! > >> >> >> >> > > >> >> >> >> > The control framework does not support private controls, for example. The > >> >> >> >> > controls should be put to their own class in videodev2.h nowadays, that's my > >> >> >> >> > understanding. Cc Hans. > >> >> >> >> > >> >> >> >> Is this really the case that we close the door for private controls in > >> >> >> >> the mainline kernel ? Or am I misunderstanding something ? > >> >> >> >> How about v4l2_ctrl_new_custom() ? > >> >> >> >> > >> >> >> >> What if there are controls applicable to single driver only ? > >> >> >> >> Do we really want to have plenty of such in videodev2.h ? > >> >> >> > > >> >> >> > We have some of those already in videodev2.h. I'm not certain if I'm happy > >> >> >> > with this myself, considering e.g. that we could get a few truckloads of > >> >> >> > only camera lens hardware specific controls in the near future. > >> >> >> > >> >> >> So in my case (as these are controls that might be used by others too) > >> >> >> I should add something like > >> >> >> > >> >> >> #define V4L2_CID_BLUE_SATURATION (V4L2_CID_CAMERA_CLASS_BASE+19) > >> >> >> #define V4L2_CID_RED_SATURATION (V4L2_CID_CAMERA_CLASS_BASE+20) > >> >> > > >> >> > What do these two controls do? Do they control gain or something else? > >> >> > >> >> Hmm. Maybe I named them a bit unsharp. It is the U Saturation and V > >> >> Saturation. To me it looks like turning up the saturation in HSV > >> >> space, but only for either the blue or the red channel. This would > >> >> correspond to V4L2_CID_{RED,BLUE}_BALANCE when I read the docs. They > >> >> say it is "{Red,Blue} chroma balance". > >> >> > >> >> I have other controls for that I used V4L2_CID_{RED,BLUE}_BALANCE. > >> >> These are gains. So in fact I should swap them in my code and the > >> >> remaining question is, how to name the red and blue gain controls. > >> > > >> > I think Laurent had a similar issue in his Aptina sensor driver. In my > >> > opinion we need a class for low level controls such as the gain ones. Do I > >> > understand correctly they control the red and blue pixel gain in the sensor > >> > pixel matrix? Do you also have gain controls for the two greens? > >> > >> Yes, I assume that this is done there. Either in the analog circuit by > >> decreasing the preload or digitally then. Don't know exactly. There > >> are registers for the green pixels as well. As I used the > >> V4L2_CID_{RED,BLUE}_BALANCE controls and there was no > >> V4L2_CID_GREEN_BALANCE, I just skipped green as one can > >> increase/decrease the global gain and get an arbitrary mix as well. > >> > >> So for these gain settings we should add these? > >> V4L2_CID_RED_GAIN > >> V4L2_CID_BLUE_GAIN > >> V4L2_CID_GREEN_GAIN > > > > Do you have two or just one green gains? In all sensors I've seen there are > > two. > > No, here is only one. It is a raw bayer sensor, isn't it? > > I think I could send an RFC on this to the list and cc you and Laurent. > > Ok fine, thanks! But hmmm - what do I do with my driver in the > meantime actually? Stall the upstream process or remove my controls > temporarily - or is there a better way? It is also possible to expose these controls just for this sensor, but I would wait a little bit if that's okay for you. Your sensor driver isn't the only one depending on these new controls --- Laurent also has one. I don't think this should take too long, but I can't promise that. :-) If you want the driver to mainline fast, then you could also submit it without these controls implemented, and implement them in another patch when the controls have been standardised. > >> >> >> #define V4L2_CID_GRAY_SCALE_IMAGE (V4L2_CID_CAMERA_CLASS_BASE+21) > >> >> > > >> >> > V4L2_CID_COLOR_KILLER looks like something which would fit for the purpose. > >> >> > >> >> Oh great! So I just take this. > >> >> > >> >> >> #define V4L2_CID_SOLARIZE_EFFECT (V4L2_CID_CAMERA_CLASS_BASE+22) > >> >> > > >> >> > Sounds interesting for a sensor. I wonder if this would fall under a menu > >> >> > control, V4L2_CID_COLORFX. > >> >> > >> >> When I read the the possible enums for V4L2_CID_COLORFX, it indeed > >> >> sounds very much like my solarize effect should be added there too. I > >> >> found V4L2_COLORFX_BW there, too. Isn't that a duplicate of the color > >> >> killer control then? > >> > > >> > In my opinion V4L2_CID_COLORFX should never be implemented in drivers for > >> > which the hardware doesn't implement these effects in a non-parametrisable > >> > way. This control was originally added for the OMAP 3 ISP driver but the > >> > driver never implemented it. > >> > >> Your triple negation (never, doesn't, non-) is quite tricky xD > >> If I get it right, you say that one should not use V4L2_CID_COLORFX > >> for hardware with parametrisable effects. > > > > Yes. I could have written that in a more clear way. ;-) > > After starring dazzled for 2 minutes on it, I realized at some point > that formal logic is your friend ;) > > >> My BW and Solarize effects are non-parametrisable and they can be > >> turned on together (which makes not so much sense though - but these > >> fun-effects like "solarize" aren't here to make sense, I guess :-) ). > > > > Good. > > > > The OMAP 3 ISP actually provides a way to set gamma tables, any effects > > implemented using them are more or less use case specific. There are also > > other uses for those same gamma tables, making a driver implementation for > > effects using them non-functional in practice. > > Ok I see. Luckily (for me) in my sensor it is binary on/off only. > > >> > I think you have a valid case using this control. I think the main > >> > difference between the two is that V4L2_COLORFX_BW is something that you > >> > can't use with other effects while V4L2_CID_COLOR_KILLER can be used with > >> > any of the effects. > >> > >> > Based on your original proposal the black/white should stay as a separate > >> > control but the solarise should be configurable through V4L2_CID_COLORFX > >> > menu control. So it boils down to the question whether you can use them at > >> > the same time. > >> > >> I can - so it is still working to enable V4L2_COLORFX_BW and > >> V4L2_CID_COLORFX with a new enum value, right? Is that the way to go > >> now? > > > > That's my opinion, yes. > > So I will post an additional patch for videodev2.h with > enum v4l2_colorfx { > ... > V4L2_COLORFX_SOLARIZE = 10, > }; That's correct. I think the COLORFX hasn't been very well documented so far, but it should be. I don't think many know what the solarize effect would do. :-) I think the patch should also add that. The user control documentation may be found in Documentation/DocBook/media/v4l/controls.xml . 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
