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[v2,2/6,media] Documentation: Add HSV format

Message ID CAPybu_2N+gKU4=qRfxHhEurTvUqT0f8Pup55C8KKTT_jEwf2nw@mail.gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Ricardo Ribalda Delgado July 16, 2016, 2:32 p.m. UTC
Hi

On Sat, Jul 16, 2016 at 4:12 PM, Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:

> I'd still like to know about it for my personal information :-)

Maybe it is just a very cheap gamma.

>
>> Anyway, I am inclined to use ycbcr_enc as well.
>
> I'm glad we agree.
>

Are you thinking about something like this:


v4l2_rgb_encoding */
+       };
        __u32                   quantization;   /* enum v4l2_quantization */
        __u32                   xfer_func;      /* enum v4l2_xfer_func */
 };
@@ -1988,7 +2002,11 @@ struct v4l2_pix_format_mplane {
        struct v4l2_plane_pix_format    plane_fmt[VIDEO_MAX_PLANES];
        __u8                            num_planes;
        __u8                            flags;
-       __u8                            ycbcr_enc;
+       union {
+               __u8                    ycbcr_enc;      /* enum
v4l2_ycbcr_encoding */
+               __u8                    hsv_enc;        /* enum
v4l2_hsv_encoding */
+               __u8                    rgb_enc;        /* enum
v4l2_rgb_encoding */
+       };
        __u8                            quantization;
        __u8                            xfer_func;
        __u8                            reserved[7];

> --


Best regards!

Comments

Hans Verkuil July 16, 2016, 3:28 p.m. UTC | #1
On 07/16/2016 04:32 PM, Ricardo Ribalda Delgado wrote:
> Hi
> 
> On Sat, Jul 16, 2016 at 4:12 PM, Laurent Pinchart
> <laurent.pinchart@ideasonboard.com> wrote:
> 
>> I'd still like to know about it for my personal information :-)
> 
> Maybe it is just a very cheap gamma.
> 
>>
>>> Anyway, I am inclined to use ycbcr_enc as well.
>>
>> I'm glad we agree.
>>
> 
> Are you thinking about something like this:
> 
> 
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index c7fb760386cf..3e613fba1b20 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -330,6 +330,16 @@ enum v4l2_ycbcr_encoding {
>         V4L2_YCBCR_ENC_SMPTE240M      = 8,
>  };
> 
> +enum v4l2_hsv_encoding {
> +       V4L2_HSV_ENC_180        = 16,
> +       V4L2_HSV_ENC_256        = 17,
> +};

Yes.

> +
> +enum v4l2_rgb_encoding {
> +       V4L2_RGB_ENC_FULL       = 32,
> +       V4L2_HSV_ENC_16_235     = 33,
> +};

No.

The starting point is RGB, so there is nothing to encode. YCbCr and HSV
are transformations from RGB (or R'G'B' to be precise).

The basic chain is:

XYZ -> colorspace conversion -> RGB -> transfer function -> R'G'B'

and after this there is an optional step that converts R'G'B' to
Y'CbCr or HSV (ycbcr_enc or hsv_enc). The final step is the quantization
step where you end up with the actual color component values.

There doesn't seem to be something like limited range HSV, so I'd say it's
full range only.

Regards,

	Hans

> +
>  /*
>   * Determine how YCBCR_ENC_DEFAULT should map to a proper Y'CbCr encoding.
>   * This depends on the colorspace.
> @@ -455,7 +465,11 @@ struct v4l2_pix_format {
>         __u32                   colorspace;     /* enum v4l2_colorspace */
>         __u32                   priv;           /* private data,
> depends on pixelformat */
>         __u32                   flags;          /* format flags
> (V4L2_PIX_FMT_FLAG_*) */
> -       __u32                   ycbcr_enc;      /* enum v4l2_ycbcr_encoding */
> +       union {
> +               __u32                   ycbcr_enc;      /* enum
> v4l2_ycbcr_encoding */
> +               __u32                   hsv_enc;        /* enum
> v4l2_hsv_encoding */
> +               __u32                   rgb_enc;        /* enum
> v4l2_rgb_encoding */
> +       };
>         __u32                   quantization;   /* enum v4l2_quantization */
>         __u32                   xfer_func;      /* enum v4l2_xfer_func */
>  };
> @@ -1988,7 +2002,11 @@ struct v4l2_pix_format_mplane {
>         struct v4l2_plane_pix_format    plane_fmt[VIDEO_MAX_PLANES];
>         __u8                            num_planes;
>         __u8                            flags;
> -       __u8                            ycbcr_enc;
> +       union {
> +               __u8                    ycbcr_enc;      /* enum
> v4l2_ycbcr_encoding */
> +               __u8                    hsv_enc;        /* enum
> v4l2_hsv_encoding */
> +               __u8                    rgb_enc;        /* enum
> v4l2_rgb_encoding */
> +       };
>         __u8                            quantization;
>         __u8                            xfer_func;
>         __u8                            reserved[7];
> 
>> --
> 
> 
> Best regards!
> 
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Ricardo Ribalda Delgado July 16, 2016, 3:57 p.m. UTC | #2
Hi Hans

On Sat, Jul 16, 2016 at 5:28 PM, Hans Verkuil <hverkuil@xs4all.nl> wrote:

>
>> +
>> +enum v4l2_rgb_encoding {
>> +       V4L2_RGB_ENC_FULL       = 32,
>> +       V4L2_HSV_ENC_16_235     = 33,
>> +};
>
> No.

I was trying to fit also Laurent special 16-235 RGB format. I will
remove it on future versions.


Can I make this change as 2 new patches on my vivid-hsv patchset?

1) Add hsv_encoding
2) Add support for vivid hsv_encoding


?


Best Regards
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Hans Verkuil July 16, 2016, 4:14 p.m. UTC | #3
On 07/16/2016 05:57 PM, Ricardo Ribalda Delgado wrote:
> Hi Hans
> 
> On Sat, Jul 16, 2016 at 5:28 PM, Hans Verkuil <hverkuil@xs4all.nl> wrote:
> 
>>
>>> +
>>> +enum v4l2_rgb_encoding {
>>> +       V4L2_RGB_ENC_FULL       = 32,
>>> +       V4L2_HSV_ENC_16_235     = 33,
>>> +};
>>
>> No.
> 
> I was trying to fit also Laurent special 16-235 RGB format. I will
> remove it on future versions.
> 
> 
> Can I make this change as 2 new patches on my vivid-hsv patchset?
> 
> 1) Add hsv_encoding
> 2) Add support for vivid hsv_encoding

Yes. I prefer them last in the series, since I am not quite 100% certain yet.

Regards,

	Hans
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diff mbox

Patch

diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index c7fb760386cf..3e613fba1b20 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -330,6 +330,16 @@  enum v4l2_ycbcr_encoding {
        V4L2_YCBCR_ENC_SMPTE240M      = 8,
 };

+enum v4l2_hsv_encoding {
+       V4L2_HSV_ENC_180        = 16,
+       V4L2_HSV_ENC_256        = 17,
+};
+
+enum v4l2_rgb_encoding {
+       V4L2_RGB_ENC_FULL       = 32,
+       V4L2_HSV_ENC_16_235     = 33,
+};
+
 /*
  * Determine how YCBCR_ENC_DEFAULT should map to a proper Y'CbCr encoding.
  * This depends on the colorspace.
@@ -455,7 +465,11 @@  struct v4l2_pix_format {
        __u32                   colorspace;     /* enum v4l2_colorspace */
        __u32                   priv;           /* private data,
depends on pixelformat */
        __u32                   flags;          /* format flags
(V4L2_PIX_FMT_FLAG_*) */
-       __u32                   ycbcr_enc;      /* enum v4l2_ycbcr_encoding */
+       union {
+               __u32                   ycbcr_enc;      /* enum
v4l2_ycbcr_encoding */
+               __u32                   hsv_enc;        /* enum
v4l2_hsv_encoding */
+               __u32                   rgb_enc;        /* enum