> Hi Hans, > > On Wednesday 15 December 2010 08:57:29 Hans Verkuil wrote: >> On Wednesday, December 15, 2010 01:19:43 Laurent Pinchart wrote: >> > On Tuesday 14 December 2010 12:27:32 Kim, HeungJun wrote: >> > > Hi Laurent and Hans, >> > > >> > > I am working on V4L2 subdev for M5MOLS by Fujitsu. >> > > and I wanna listen your comments about Auto Focus mode of my ideas. >> > > the details is in the following link discussed at the past. >> > > Although the situation(adding the more various functions at the >> M5MOLS >> > > or any other MEGA camera sensor, I worked.)is changed, >> > > so I wanna continue this threads for now. >> > > >> > > http://www.mail-archive.com/linux-media@xxxxxxxxxxxxxxx/msg03543.html >> > > >> > > First of all, the at least two more mode of auto-focus exists in the >> > > M5MOLS camera sensor. So, considering defined V4L2 controls and the >> > > controls in the M5MOLS, I suggest like this: >> > > >> > > +enum v4l2_focus_auto_type { >> > > + V4L2_FOCUS_AUTO_NORMAL = 0, >> > > + V4L2_FOCUS_AUTO_MACRO = 1, >> > > + V4L2_FOCUS_AUTO_POSITION = 2, >> > > +}; >> > > +#define V4L2_CID_FOCUS_POSITION (V4L2_CID_CAMERA_CLASS_BASE+13) >> > > >> > > -#define V4L2_CID_ZOOM_ABSOLUTE (V4L2_CID_CAMERA_CLASS_BASE+13) >> > > -#define V4L2_CID_ZOOM_RELATIVE (V4L2_CID_CAMERA_CLASS_BASE+14) >> > > +#define V4L2_CID_ZOOM_ABSOLUTE (V4L2_CID_CAMERA_CLASS_BASE+14) >> > > +#define V4L2_CID_ZOOM_RELATIVE (V4L2_CID_CAMERA_CLASS_BASE+15) >> > > >> > > >> > > The M5MOLS(or other recent camera sensor) can have at least 2 mode >> > > although in any cases : *MACRO* and *NORMAL* mode. plus, M5MOLS >> > > supports positioning focus mode, AKA. POSITION AF mode. >> > > >> > > The MACRO mode scan short range, and this mode can be used at the >> > > circumstance in the short distance with object and camera lens. So, >> It >> > > has fast lens movement, but the command FOCUSING dosen't works well >> at >> > > the long distance object. >> > > >> > > On the other hand, NORMAL mode can this. As the words, It's general >> and >> > > normal focus mode. The M5MOLS scan fully in the mode. >> > > >> > > In the Position AF mode, the position(expressed x,y) is given at the >> > > M5MOLS, and then the M5MOLS focus this area. But, the time given the >> > > position, is normally touch the lcd screen at the mobile device, in >> my >> > > case. If the time is given from button, it's no big problem *when*. >> > > But, in touch-lcd screen case, the position is read at the touch >> > > screen driver, before command FOCUS to camera sensor. It's the why I >> > > add another CID(V4L2_CID_FOCUS_POSITION). >> > >> > I'm pretty sure that some devices would require a rectangle instead of >> > coordinates to define the focus point. Even a rectangle might not be >> > enough. It would help if we could get feedback from camera designers >> > here. >> > >> > Hans, should we add a new control type to pass coordinates/rectangles >> ? >> > :-) >> >> It's a bit tricky actually since QUERYCTRL can return only one set of >> min/max values. For coordinates/rectangles we need two sets (horizontal >> and vertical). >> >> And I think it is important to know the min/max values. > > Hence my question, should we add a way to pass rectangles (basically a > struct > v4l2_rect) through the control ioctls ? It would make sense. I thought it over and came to the conclusion that we should not do that. Instead we can create four separate controls. The problem we run into when adding more complex types is that we can no longer communicate min and max values (something that we definitely want when dealing with coordinates). Another reason is how the control mechanism is designed: they only support the basic types (int, bool, string, enum, int64 and a 'button' aka action). And the controls are grouped into classes which are named through the 'ctrl_class' control. So effectively controls represent a field in a class (or struct) and each class can be presented as a tab page in a control panel. Simple and straightforward. If we start to add complex types, then it becomes really hard to define the meta data of the control since you are really defining a 'mini-class'. It sounds nice initially, but we really should not do this since I believe it will lead to chaos later on. You want complex types, then use ioctls, not controls. Or split up the complex type into multiple simple types. Regards, Hans -- Hans Verkuil - video4linux developer - sponsored by Cisco -- 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
