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Commit 5f3d32ec authored by Ricardo Ribalda Delgado's avatar Ricardo Ribalda Delgado Committed by Mauro Carvalho Chehab
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[media] Documentation: Add HSV encodings 



Describe the hsv_enc field and its use.

Signed-off-by: default avatarRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Acked-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 8a0d62af

Documentation/media/uapi/v4l/pixfmt-002.rst

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@@ -121,6 +121,11 @@ Single-planar format structure 
      - This information supplements the ``colorspace`` and must be set by

	the driver for capture streams and by the application for output

	streams, see :ref:`colorspaces`.

    * - enum :c:type:`v4l2_hsv_encoding`

      - ``hsv_enc``

      - This information supplements the ``colorspace`` and must be set by

	the driver for capture streams and by the application for output

	streams, see :ref:`colorspaces`.

    * - enum :c:type:`v4l2_quantization`

      - ``quantization``

      - This information supplements the ``colorspace`` and must be set by

Documentation/media/uapi/v4l/pixfmt-003.rst

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@@ -78,6 +78,11 @@ describing all planes of that format. 
      - This information supplements the ``colorspace`` and must be set by

	the driver for capture streams and by the application for output

	streams, see :ref:`colorspaces`.

    * - enum :c:type:`v4l2_hsv_encoding`

      - ``hsv_enc``

      - This information supplements the ``colorspace`` and must be set by

	the driver for capture streams and by the application for output

	streams, see :ref:`colorspaces`.

    * - enum :c:type:`v4l2_quantization`

      - ``quantization``

      - This information supplements the ``colorspace`` and must be set by

Documentation/media/uapi/v4l/pixfmt-006.rst

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@@ -19,9 +19,16 @@ colorspace field of struct :c:type:`v4l2_pix_format` 
or struct :c:type:`v4l2_pix_format_mplane`

needs to be filled in.



.. note::

.. _hsv-colorspace:



   The default R'G'B' quantization is full range for all

On :ref:`HSV formats <hsv-formats>` the *Hue* is defined as the angle on

the cylindrical color representation. Usually this angle is measured in

degrees, i.e. 0-360. When we map this angle value into 8 bits, there are

two basic ways to do it: Divide the angular value by 2 (0-179), or use the

whole range, 0-255, dividing the angular value by 1.41. The enum

:c:type:`v4l2_hsv_encoding` specifies which encoding is used.



.. note:: The default R'G'B' quantization is full range for all

   colorspaces except for BT.2020 which uses limited range R'G'B'

   quantization.
@@ -123,6 +130,24 @@ needs to be filled in. 






.. c:type:: v4l2_hsv_encoding



.. tabularcolumns:: |p{6.5cm}|p{11.0cm}|



.. flat-table:: V4L2 HSV Encodings

    :header-rows:  1

    :stub-columns: 0



    * - Identifier

      - Details

    * - ``V4L2_HSV_ENC_180``

      - For the Hue, each LSB is two degrees.

    * - ``V4L2_HSV_ENC_256``

      - For the Hue, the 360 degrees are mapped into 8 bits, i.e. each

	LSB is roughly 1.41 degrees.







.. c:type:: v4l2_quantization



.. tabularcolumns:: |p{6.5cm}|p{11.0cm}|
@@ -136,7 +161,7 @@ needs to be filled in. 
    * - ``V4L2_QUANTIZATION_DEFAULT``

      - Use the default quantization encoding as defined by the

	colorspace. This is always full range for R'G'B' (except for the

	BT.2020 colorspace) and usually limited range for Y'CbCr.

	BT.2020 colorspace) and HSV. It is usually limited range for Y'CbCr.

    * - ``V4L2_QUANTIZATION_FULL_RANGE``

      - Use the full range quantization encoding. I.e. the range [0…1] is

	mapped to [0…255] (with possible clipping to [1…254] to avoid the

Documentation/media/uapi/v4l/pixfmt-packed-hsv.rst

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@@ -9,7 +9,8 @@ Packed HSV formats 
Description

===========



The *hue* (h) is measured in degrees, one LSB represents two degrees.

The *hue* (h) is measured in degrees, the equivalence between degrees and LSBs

depends on the hsv-encoding used, see :ref:`colorspaces`.

The *saturation* (s) and the *value* (v) are measured in percentage of the

cylinder: 0 being the smallest value and 255 the maximum.

Documentation/media/videodev2.h.rst.exceptions

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@@ -87,6 +87,10 @@ replace symbol V4L2_YCBCR_ENC_XV601 :c:type:`v4l2_ycbcr_encoding` 
replace symbol V4L2_YCBCR_ENC_XV709 :c:type:`v4l2_ycbcr_encoding`

replace symbol V4L2_YCBCR_ENC_SMPTE240M :c:type:`v4l2_ycbcr_encoding`



# Documented enum v4l2_hsv_encoding

replace symbol V4L2_HSV_ENC_180 :c:type:`v4l2_hsv_encoding`

replace symbol V4L2_HSV_ENC_256 :c:type:`v4l2_hsv_encoding`



# Documented enum v4l2_quantization

replace symbol V4L2_QUANTIZATION_DEFAULT :c:type:`v4l2_quantization`

replace symbol V4L2_QUANTIZATION_FULL_RANGE :c:type:`v4l2_quantization`