Re: Extended driver private controls?

[Sakari Ailus <sakari.ailus@nokia.com>]

ext Hans Verkuil wrote:
> Hi Sakari,

Hello,

...
> What I did to support private controls is to allow drivers to add their own 
> controls to the various classes, as long as the low 16 bits are >= 0x1000.
> 
> You add them to videodev2.h (see the CX2341X private controls), and you just 
> pick a starting base such as 'V4L2_CTRL_CLASS_MPEG | 0x1100'.
> 
> This way the controls are together in one header, they have unique IDs, and 
> you can assign them to a specific class.
...
> So, to summarize: for new drivers I recommend using V4L2_CTRL_FLAG_NEXT_CTRL 
> and adding the private controls to videodev2.h and to prepare documentation 
> for inclusion with the v4l2 spec. If you really must support old apps, then 
> you might have to make duplicate PRIVATE_BASE controls (yuck!), but I hope 
> that won't be necessary.

Thanks, Hans, for the definitive answer. This is what we'll do then.

Cheers,

-- 
Sakari Ailus
sakari.ailus@nokia.com