Re: [PATCH v4 6/8] media: v4l2-ctrls: Add RGB color effects control

[Hans Verkuil]

On 14/10/2021 12:53, Dillon Min wrote:
> Hi Hans
> 
> Thanks for quick reply
> 
> On Thu, 14 Oct 2021 at 18:44, Hans Verkuil <hverkuil-cisco@xxxxxxxxx> wrote:
>>
>> On 14/10/2021 12:25, dillon.minfei@xxxxxxxxx wrote:
>>> From: Dillon Min <dillon.minfei@xxxxxxxxx>
>>>
>>> Add V4L2_COLORFX_SET_RGB color effects control, V4L2_CID_COLORFX_RGB
>>> for RGB color setting.
>>>
>>> Signed-off-by: Dillon Min <dillon.minfei@xxxxxxxxx>
>>> ---
>>> v4:
>>> - replace V4L2_COLORFX_SET_ARGB, V4L2_CID_COLORFX_ARGB to
>>>   V4L2_COLORFX_SET_RGB, V4L2_CID_COLORFX_RGB since Alpha paramter not used
>>>   in current. thanks Hans.
>>>
>>>  Documentation/userspace-api/media/v4l/control.rst | 9 +++++++++
>>>  drivers/media/v4l2-core/v4l2-ctrls-defs.c         | 2 ++
>>>  include/uapi/linux/v4l2-controls.h                | 4 +++-
>>>  3 files changed, 14 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/Documentation/userspace-api/media/v4l/control.rst b/Documentation/userspace-api/media/v4l/control.rst
>>> index f8d0b923da20..3eec65174260 100644
>>> --- a/Documentation/userspace-api/media/v4l/control.rst
>>> +++ b/Documentation/userspace-api/media/v4l/control.rst
>>> @@ -242,8 +242,17 @@ Control IDs
>>>      * - ``V4L2_COLORFX_SET_CBCR``
>>>        - The Cb and Cr chroma components are replaced by fixed coefficients
>>>       determined by ``V4L2_CID_COLORFX_CBCR`` control.
>>> +    * - ``V4L2_COLORFX_SET_RGB``
>>> +      - The RGB components are replaced by the fixed RGB components determined
>>> +        by ``V4L2_CID_COLORFX_RGB`` control.
>>>
>>>
>>> +``V4L2_CID_COLORFX_RGB`` ``(integer)``
>>> +    Determines the Red, Green, and Blue coefficients for
>>> +    ``V4L2_COLORFX_SET_RGB`` color effect.
>>> +    Bits [7:0] of the supplied 32 bit value are interpreted as Blue component,
>>> +    bits [15:8] as Green component, bits [23:16] as Red component, and
>>> +    bits [31:24] must be zero.
>>>
>>>  ``V4L2_CID_COLORFX_CBCR`` ``(integer)``
>>>      Determines the Cb and Cr coefficients for ``V4L2_COLORFX_SET_CBCR``
>>> diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
>>> index 421300e13a41..f4bd90170105 100644
>>> --- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
>>> +++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
>>> @@ -785,6 +785,7 @@ const char *v4l2_ctrl_get_name(u32 id)
>>>       case V4L2_CID_MIN_BUFFERS_FOR_OUTPUT:   return "Min Number of Output Buffers";
>>>       case V4L2_CID_ALPHA_COMPONENT:          return "Alpha Component";
>>>       case V4L2_CID_COLORFX_CBCR:             return "Color Effects, CbCr";
>>> +     case V4L2_CID_COLORFX_RGB:              return "Color Effects, RGB";
>>>
>>>       /*
>>>        * Codec controls
>>> @@ -1392,6 +1393,7 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
>>>               *min = *max = *step = *def = 0;
>>>               break;
>>>       case V4L2_CID_BG_COLOR:
>>> +     case V4L2_CID_COLORFX_RGB:
>>>               *type = V4L2_CTRL_TYPE_INTEGER;
>>>               *step = 1;
>>>               *min = 0;
>>
>> Can you make another small change here? Please change:
>>
>>         *max = 0xFFFFFF;
>>
>> to:
>>
>>         *max = 0xffffff;
>>
>> to keep in line with the coding standard for hex values.
> 
> Sure, do it right now.
> 
>>
>> Also, can you add a separate patch that adds an entry here for V4L2_CID_COLORFX_CBCR
>> that sets *max to 0xffff? I noticed that that was missing. While adding V4L2_CID_COLORFX_RGB
>> it's good to fix V4L2_CID_COLORFX_CBCR as well.
> 
> Sure, you mean the final code like this? first patch to fix cbcr 0xFFFFFF,

For cbcr max should be 0xffff.

> another one to add V4L2_CID_COLORFX_RGB entry.
> 
> 1395         case V4L2_CID_BG_COLOR:
> 1396         case V4L2_CID_COLORFX_RGB:
> 1397                 *type = V4L2_CTRL_TYPE_INTEGER;
> 1398                 *step = 1;
> 1399                 *min = 0;
> 1400                 /* Max is calculated as RGB888 that is 2^24 */

Actually, the comment is wrong: it should be 2^24-1. Let's fix that too.

> 1401                 *max = 0xffffff;

Yes, that's what I am looking for.

Regards,

	Hans

> 1402                 break;
> 
> Best Regards
> Dillon
> 
>>
>> Regards,
>>
>>         Hans
>>
>>> diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
>>> index 5532b5f68493..9aa3fd368383 100644
>>> --- a/include/uapi/linux/v4l2-controls.h
>>> +++ b/include/uapi/linux/v4l2-controls.h
>>> @@ -128,6 +128,7 @@ enum v4l2_colorfx {
>>>       V4L2_COLORFX_SOLARIZATION               = 13,
>>>       V4L2_COLORFX_ANTIQUE                    = 14,
>>>       V4L2_COLORFX_SET_CBCR                   = 15,
>>> +     V4L2_COLORFX_SET_RGB                    = 16,
>>>  };
>>>  #define V4L2_CID_AUTOBRIGHTNESS                      (V4L2_CID_BASE+32)
>>>  #define V4L2_CID_BAND_STOP_FILTER            (V4L2_CID_BASE+33)
>>> @@ -145,9 +146,10 @@ enum v4l2_colorfx {
>>>
>>>  #define V4L2_CID_ALPHA_COMPONENT             (V4L2_CID_BASE+41)
>>>  #define V4L2_CID_COLORFX_CBCR                        (V4L2_CID_BASE+42)
>>> +#define V4L2_CID_COLORFX_RGB                 (V4L2_CID_BASE+43)
>>>
>>>  /* last CID + 1 */
>>> -#define V4L2_CID_LASTP1                         (V4L2_CID_BASE+43)
>>> +#define V4L2_CID_LASTP1                         (V4L2_CID_BASE+44)
>>>
>>>  /* USER-class private control IDs */
>>>
>>>
>>