Re: [Patch v4 12/12] Documention: v4l: Documentation for HEVC CIDs

[Sylwester Nawrocki]

On 04/07/2017 12:03 PM, Smitha T Murthy wrote:
> > > +``V4L2_CID_MPEG_VIDEO_HEVC_LF``
> > > +    Indicates loop filtering. Control ID 0 indicates loop filtering
> > > +    is enabled and when set to 1 indicates no filter.
>>
> > "Setting this control to 0 enables loop filtering, setting this control
> > to 1 disables loop filtering." ?
> >
> > Couldn't the meaning be inverted, so setting the control to 0 disables
> > the loop filtering?
> >
> > From register point of view, this control value needs be 0 to enable
> loop filtering.

OK, this is true for our specific hardware/firmware implementation.

In general, for this user space interface I would rather define that
boolean control so value 1 enables LF and value 0 disables LF.
The driver could simply negate the value when writing registers.

BTW we might need to specify type of the control here as Hans suggested
commenting on other control.

--
Regards,
Sylwester