Proposal to extend V4L2 Control ID for advanced imaging processing features.

Proposal to extend V4L2 Control ID for advanced imaging processing features.

[Wang, Wen W]

Hi all,

We are developing a V4L2 device driver which the ISP has many advanced features such as manual exposure setting, GDC (Geometric Distortion Correction), CAC (Chromatic Aberration Correction), video stabilization, false color correction, shading correction, etc. But to control those features, we find current v4l2 framework has limited CIDs and cannot support these advanced features in normal way . 

So we propose to extend the V4L2 CIDs and add the below CIDs. Can you please review and feel free to give your comments?

V4L2_CID_ISO_ABSOLUTE -- This CID is used to set up manual ISO speed value. This CID has integer type and with as valid range or limited valid value, depending on the hardware. If the target value is not supported by hardware, a closest value will be set
V4L2_CID_APERTURE_ABSOLUTE -- This CID is used to set up manual aperture value. This CID has integer type and with as valid range or limited valid value, depending on the hardware. If the target value is not supported by hardware, a closest value will be set
V4L2_CID_ATOMISP_FIXED_PATTERN_NR - This CID is used to enable/disable Fixed pattern noise reduction. This CID has Boolean type and 0 indicate to disable fixed pattern NR and 1 indicate to enable it.
V4L2_CID_ATOMISP_POSTPROCESS_XNR - This CID is used to enable/disable XNR. This CID has Boolean type and 0 indicate to disable XNR and 1 indicate to enable it.
V4L2_CID_ATOMISP_POSTPROCESS_GDC_CAC - Our ISP combined GDC and CAC together. This CID is used to enable/disable GDC and CAC. This CID has Boolean type and 0 indicate to disable it and 1 indicate to enable it.
V4L2_CID_ATOMISP_VIDEO_STABILIZATION -- This CID is used to enable/disable video stabilization capability. This CID has Boolean type and 0 indicate to disable it and 1 indicate to enable it.
V4L2_CID_ATOMISP_FALSE_COLOR_CORRECTION - This CID is used to enable color correction capability. This CID has Boolean type and 0 indicate to disable it and 1 indicate to enable it.

Thanks,
Wen

Re: Proposal to extend V4L2 Control ID for advanced imaging processing features.

[Sakari Ailus]

Wang, Wen W wrote:
> Hi all,

Hi Wang,

Thanks for the proposal!

(Cc'ing Hans Verkuil.)

> We are developing a V4L2 device driver which the ISP has many
> advanced features such as manual exposure setting, GDC (Geometric
> Distortion Correction), CAC (Chromatic Aberration Correction), video
> stabilization, false color correction, shading correction, etc. But
> to control those features, we find current v4l2 framework has limited
> CIDs and cannot support these advanced features in normal way .

Manual exposure sounds like a sensor property, not ISP's. Are the rest
implemented in the ISP or is there a user space library to support them?
I think in either case the definition will be in kernel headers.

These controls appear quite high level to me. What about the specific
parameters for the functionality, I suppose shading correction for
example has a lot more parameters than just disable/enable?

> So we propose to extend the V4L2 CIDs and add the below CIDs. Can you
> please review and feel free to give your comments?
> 
> V4L2_CID_ISO_ABSOLUTE -- This CID is used to set up manual ISO speed
> value. This CID has integer type and with as valid range or limited
> valid value, depending on the hardware. If the target value is not
> supported by hardware, a closest value will be set 
> V4L2_CID_APERTURE_ABSOLUTE -- This CID is used to set up manual
> aperture value. This CID has integer type and with as valid range or
> limited valid value, depending on the hardware. If the target value
> is not supported by hardware, a closest value will be set 

The above look like image sensor properties.

I wonder if it would make sense to create a new control class for these.

> V4L2_CID_ATOMISP_FIXED_PATTERN_NR - This CID is used to
> enable/disable Fixed pattern noise reduction. This CID has Boolean
> type and 0 indicate to disable fixed pattern NR and 1 indicate to
> enable it. V4L2_CID_ATOMISP_POSTPROCESS_XNR - This CID is used to
> enable/disable XNR. This CID has Boolean type and 0 indicate to
> disable XNR and 1 indicate to enable it. 
> V4L2_CID_ATOMISP_POSTPROCESS_GDC_CAC - Our ISP combined GDC and CAC
> together. This CID is used to enable/disable GDC and CAC. This CID
> has Boolean type and 0 indicate to disable it and 1 indicate to

What are GDC and CAC?

> enable it. V4L2_CID_ATOMISP_VIDEO_STABILIZATION -- This CID is used
> to enable/disable video stabilization capability. This CID has
> Boolean type and 0 indicate to disable it and 1 indicate to enable
> it. V4L2_CID_ATOMISP_FALSE_COLOR_CORRECTION - This CID is used to
> enable color correction capability. This CID has Boolean type and 0
> indicate to disable it and 1 indicate to enable it.

Ps. Could you wrap your lines to 80 characters, please? That makes your
messages easier to read and reply. Thank you.

Regards,

-- 
Sakari Ailus
sakari.ailus@maxwell.research.nokia.com