xref: /kernel/linux/linux-6.6/Documentation/userspace-api/media/v4l/pixfmt-yuv-luma.rst

.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later

.. _yuv-luma-only:

*****************
Luma-Only Formats
*****************

This family of formats only store the luma component of a Y'CbCr image. They
are often referred to as greyscale formats.

.. note::

   - In all the tables that follow, bit 7 is the most significant bit in a byte.
   - Formats are described with the minimum number of pixels needed to create a
     byte-aligned repeating pattern. `...` indicates repetition of the pattern.
   - Y'\ :sub:`x`\ [9:2] denotes bits 9 to 2 of the Y' value for pixel at column
     `x`.
   - `0` denotes padding bits set to 0.


.. raw:: latex

    \scriptsize

.. tabularcolumns:: |p{3.6cm}|p{3.0cm}|p{1.3cm}|p{2.6cm}|p{1.3cm}|p{1.3cm}|p{1.3cm}|

.. flat-table:: Luma-Only Image Formats
    :header-rows: 1
    :stub-columns: 0

    * - Identifier
      - Code
      - Byte 0
      - Byte 1
      - Byte 2
      - Byte 3
      - Byte 4

    * .. _V4L2-PIX-FMT-GREY:

      - ``V4L2_PIX_FMT_GREY``
      - 'GREY'

      - Y'\ :sub:`0`\ [7:0]
      - ...
      - ...
      - ...
      - ...

    * .. _V4L2-PIX-FMT-IPU3-Y10:

      - ``V4L2_PIX_FMT_IPU3_Y10``
      - 'ip3y'

      - Y'\ :sub:`0`\ [7:0]
      - Y'\ :sub:`1`\ [5:0] Y'\ :sub:`0`\ [9:8]
      - Y'\ :sub:`2`\ [3:0] Y'\ :sub:`1`\ [9:6]
      - Y'\ :sub:`3`\ [1:0] Y'\ :sub:`2`\ [9:4]
      - Y'\ :sub:`3`\ [9:2]

    * .. _V4L2-PIX-FMT-Y10:

      - ``V4L2_PIX_FMT_Y10``
      - 'Y10 '

      - Y'\ :sub:`0`\ [7:0]
      - `000000` Y'\ :sub:`0`\ [9:8]
      - ...
      - ...
      - ...

    * .. _V4L2-PIX-FMT-Y10BPACK:

      - ``V4L2_PIX_FMT_Y10BPACK``
      - 'Y10B'

      - Y'\ :sub:`0`\ [9:2]
      - Y'\ :sub:`0`\ [1:0] Y'\ :sub:`1`\ [9:4]
      - Y'\ :sub:`1`\ [3:0] Y'\ :sub:`2`\ [9:6]
      - Y'\ :sub:`2`\ [5:0] Y'\ :sub:`3`\ [9:8]
      - Y'\ :sub:`3`\ [7:0]

    * .. _V4L2-PIX-FMT-Y10P:

      - ``V4L2_PIX_FMT_Y10P``
      - 'Y10P'

      - Y'\ :sub:`0`\ [9:2]
      - Y'\ :sub:`1`\ [9:2]
      - Y'\ :sub:`2`\ [9:2]
      - Y'\ :sub:`3`\ [9:2]
      - Y'\ :sub:`3`\ [1:0] Y'\ :sub:`2`\ [1:0] Y'\ :sub:`1`\ [1:0] Y'\ :sub:`0`\ [1:0]

    * .. _V4L2-PIX-FMT-Y12:

      - ``V4L2_PIX_FMT_Y12``
      - 'Y12 '

      - Y'\ :sub:`0`\ [7:0]
      - `0000` Y'\ :sub:`0`\ [11:8]
      - ...
      - ...
      - ...

    * .. _V4L2-PIX-FMT-Y012:

      - ``V4L2_PIX_FMT_Y012``
      - 'Y012'

      - Y'\ :sub:`0`\ [3:0] `0000`
      - Y'\ :sub:`0`\ [11:4]
      - ...
      - ...
      - ...

    * .. _V4L2-PIX-FMT-Y14:

      - ``V4L2_PIX_FMT_Y14``
      - 'Y14 '

      - Y'\ :sub:`0`\ [7:0]
      - `00` Y'\ :sub:`0`\ [13:8]
      - ...
      - ...
      - ...

    * .. _V4L2-PIX-FMT-Y16:

      - ``V4L2_PIX_FMT_Y16``
      - 'Y16 '

      - Y'\ :sub:`0`\ [7:0]
      - Y'\ :sub:`0`\ [15:8]
      - ...
      - ...
      - ...

    * .. _V4L2-PIX-FMT-Y16-BE:

      - ``V4L2_PIX_FMT_Y16_BE``
      - 'Y16 ' | (1U << 31)

      - Y'\ :sub:`0`\ [15:8]
      - Y'\ :sub:`0`\ [7:0]
      - ...
      - ...
      - ...

.. raw:: latex

    \normalsize

.. note::

    For the Y16 and Y16_BE formats, the actual sampling precision may be lower
    than 16 bits. For example, 10 bits per pixel uses values in the range 0 to
    1023. For the IPU3_Y10 format 25 pixels are packed into 32 bytes, which
    leaves the 6 most significant bits of the last byte padded with 0.

    For Y012 and Y12 formats, Y012 places its data in the 12 high bits, with
    padding zeros in the 4 low bits, in contrast to the Y12 format, which has
    its padding located in the most significant bits of the 16 bit word.