.. -*- coding: utf-8; mode: rst -*-

.. _packed-rgb:

******************
Packed RGB formats
******************

Description
===========

These formats are designed to match the pixel formats of typical PC
graphics frame buffers. They occupy 8, 16, 24 or 32 bits per pixel.
These are all packed-pixel formats, meaning all the data for a pixel lie
next to each other in memory.

.. raw:: latex

    \begingroup
    \tiny
    \setlength{\tabcolsep}{2pt}

.. tabularcolumns:: |p{2.3cm}|p{1.6cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|


.. _rgb-formats:

.. flat-table:: Packed RGB Image Formats
    :header-rows:  2
    :stub-columns: 0

    * - Identifier
      - Code
      - :cspan:`7` Byte 0 in memory
      - :cspan:`7` Byte 1
      - :cspan:`7` Byte 2
      - :cspan:`7` Byte 3
    * -
      -
      - 7
      - 6
      - 5
      - 4
      - 3
      - 2
      - 1
      - 0

      - 7
      - 6
      - 5
      - 4
      - 3
      - 2
      - 1
      - 0

      - 7
      - 6
      - 5
      - 4
      - 3
      - 2
      - 1
      - 0

      - 7
      - 6
      - 5
      - 4
      - 3
      - 2
      - 1
      - 0
    * .. _V4L2-PIX-FMT-RGB332:

      - ``V4L2_PIX_FMT_RGB332``
      - 'RGB1'

      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`
      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`
      - b\ :sub:`1`
      - b\ :sub:`0`
      -
    * .. _V4L2-PIX-FMT-ARGB444:

      - ``V4L2_PIX_FMT_ARGB444``
      - 'AR12'

      - g\ :sub:`3`
      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`

      - a\ :sub:`3`
      - a\ :sub:`2`
      - a\ :sub:`1`
      - a\ :sub:`0`
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`
      -
    * .. _V4L2-PIX-FMT-XRGB444:

      - ``V4L2_PIX_FMT_XRGB444``
      - 'XR12'

      - g\ :sub:`3`
      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`

      -
      -
      -
      -
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`
      -
    * .. _V4L2-PIX-FMT-ARGB555:

      - ``V4L2_PIX_FMT_ARGB555``
      - 'AR15'

      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`
      - b\ :sub:`4`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`

      - a
      - r\ :sub:`4`
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`
      - g\ :sub:`4`
      - g\ :sub:`3`
      -
    * .. _V4L2-PIX-FMT-XRGB555:

      - ``V4L2_PIX_FMT_XRGB555``
      - 'XR15'

      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`
      - b\ :sub:`4`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`

      -
      - r\ :sub:`4`
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`
      - g\ :sub:`4`
      - g\ :sub:`3`
      -
    * .. _V4L2-PIX-FMT-RGB565:

      - ``V4L2_PIX_FMT_RGB565``
      - 'RGBP'

      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`
      - b\ :sub:`4`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`

      - r\ :sub:`4`
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`
      - g\ :sub:`5`
      - g\ :sub:`4`
      - g\ :sub:`3`
      -
    * .. _V4L2-PIX-FMT-ARGB555X:

      - ``V4L2_PIX_FMT_ARGB555X``
      - 'AR15' | (1 << 31)

      - a
      - r\ :sub:`4`
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`
      - g\ :sub:`4`
      - g\ :sub:`3`

      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`
      - b\ :sub:`4`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`
      -
    * .. _V4L2-PIX-FMT-XRGB555X:

      - ``V4L2_PIX_FMT_XRGB555X``
      - 'XR15' | (1 << 31)

      -
      - r\ :sub:`4`
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`
      - g\ :sub:`4`
      - g\ :sub:`3`

      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`
      - b\ :sub:`4`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`
      -
    * .. _V4L2-PIX-FMT-RGB565X:

      - ``V4L2_PIX_FMT_RGB565X``
      - 'RGBR'

      - r\ :sub:`4`
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`
      - g\ :sub:`5`
      - g\ :sub:`4`
      - g\ :sub:`3`

      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`
      - b\ :sub:`4`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`
      -
    * .. _V4L2-PIX-FMT-BGR24:

      - ``V4L2_PIX_FMT_BGR24``
      - 'BGR3'

      - b\ :sub:`7`
      - b\ :sub:`6`
      - b\ :sub:`5`
      - b\ :sub:`4`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`

      - g\ :sub:`7`
      - g\ :sub:`6`
      - g\ :sub:`5`
      - g\ :sub:`4`
      - g\ :sub:`3`
      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`

      - r\ :sub:`7`
      - r\ :sub:`6`
      - r\ :sub:`5`
      - r\ :sub:`4`
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`
      -
    * .. _V4L2-PIX-FMT-RGB24:

      - ``V4L2_PIX_FMT_RGB24``
      - 'RGB3'

      - r\ :sub:`7`
      - r\ :sub:`6`
      - r\ :sub:`5`
      - r\ :sub:`4`
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`

      - g\ :sub:`7`
      - g\ :sub:`6`
      - g\ :sub:`5`
      - g\ :sub:`4`
      - g\ :sub:`3`
      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`

      - b\ :sub:`7`
      - b\ :sub:`6`
      - b\ :sub:`5`
      - b\ :sub:`4`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`
      -
    * .. _V4L2-PIX-FMT-BGR666:

      - ``V4L2_PIX_FMT_BGR666``
      - 'BGRH'

      - b\ :sub:`5`
      - b\ :sub:`4`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`
      - g\ :sub:`5`
      - g\ :sub:`4`

      - g\ :sub:`3`
      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`
      - r\ :sub:`5`
      - r\ :sub:`4`
      - r\ :sub:`3`
      - r\ :sub:`2`

      - r\ :sub:`1`
      - r\ :sub:`0`
      -
      -
      -
      -
      -
      -

      -
      -
      -
      -
      -
      -
      -
      -
    * .. _V4L2-PIX-FMT-ABGR32:

      - ``V4L2_PIX_FMT_ABGR32``
      - 'AR24'

      - b\ :sub:`7`
      - b\ :sub:`6`
      - b\ :sub:`5`
      - b\ :sub:`4`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`

      - g\ :sub:`7`
      - g\ :sub:`6`
      - g\ :sub:`5`
      - g\ :sub:`4`
      - g\ :sub:`3`
      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`

      - r\ :sub:`7`
      - r\ :sub:`6`
      - r\ :sub:`5`
      - r\ :sub:`4`
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`

      - a\ :sub:`7`
      - a\ :sub:`6`
      - a\ :sub:`5`
      - a\ :sub:`4`
      - a\ :sub:`3`
      - a\ :sub:`2`
      - a\ :sub:`1`
      - a\ :sub:`0`
    * .. _V4L2-PIX-FMT-XBGR32:

      - ``V4L2_PIX_FMT_XBGR32``
      - 'XR24'

      - b\ :sub:`7`
      - b\ :sub:`6`
      - b\ :sub:`5`
      - b\ :sub:`4`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`

      - g\ :sub:`7`
      - g\ :sub:`6`
      - g\ :sub:`5`
      - g\ :sub:`4`
      - g\ :sub:`3`
      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`

      - r\ :sub:`7`
      - r\ :sub:`6`
      - r\ :sub:`5`
      - r\ :sub:`4`
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`

      -
      -
      -
      -
      -
      -
      -
      -
    * .. _V4L2-PIX-FMT-ARGB32:

      - ``V4L2_PIX_FMT_ARGB32``
      - 'BA24'

      - a\ :sub:`7`
      - a\ :sub:`6`
      - a\ :sub:`5`
      - a\ :sub:`4`
      - a\ :sub:`3`
      - a\ :sub:`2`
      - a\ :sub:`1`
      - a\ :sub:`0`

      - r\ :sub:`7`
      - r\ :sub:`6`
      - r\ :sub:`5`
      - r\ :sub:`4`
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`

      - g\ :sub:`7`
      - g\ :sub:`6`
      - g\ :sub:`5`
      - g\ :sub:`4`
      - g\ :sub:`3`
      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`

      - b\ :sub:`7`
      - b\ :sub:`6`
      - b\ :sub:`5`
      - b\ :sub:`4`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`
    * .. _V4L2-PIX-FMT-XRGB32:

      - ``V4L2_PIX_FMT_XRGB32``
      - 'BX24'

      -
      -
      -
      -
      -
      -
      -
      -

      - r\ :sub:`7`
      - r\ :sub:`6`
      - r\ :sub:`5`
      - r\ :sub:`4`
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`

      - g\ :sub:`7`
      - g\ :sub:`6`
      - g\ :sub:`5`
      - g\ :sub:`4`
      - g\ :sub:`3`
      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`

      - b\ :sub:`7`
      - b\ :sub:`6`
      - b\ :sub:`5`
      - b\ :sub:`4`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`

.. raw:: latex

    \endgroup

.. note:: Bit 7 is the most significant bit.

The usage and value of the alpha bits (a) in the ARGB and ABGR formats
(collectively referred to as alpha formats) depend on the device type
and hardware operation. :ref:`Capture <capture>` devices (including
capture queues of mem-to-mem devices) fill the alpha component in
memory. When the device outputs an alpha channel the alpha component
will have a meaningful value. Otherwise, when the device doesn't output
an alpha channel but can set the alpha bit to a user-configurable value,
the :ref:`V4L2_CID_ALPHA_COMPONENT <v4l2-alpha-component>` control
is used to specify that alpha value, and the alpha component of all
pixels will be set to the value specified by that control. Otherwise a
corresponding format without an alpha component (XRGB or XBGR) must be
used instead of an alpha format.

:ref:`Output <output>` devices (including output queues of mem-to-mem
devices and :ref:`video output overlay <osd>` devices) read the alpha
component from memory. When the device processes the alpha channel the
alpha component must be filled with meaningful values by applications.
Otherwise a corresponding format without an alpha component (XRGB or
XBGR) must be used instead of an alpha format.

The XRGB and XBGR formats contain undefined bits (-). Applications,
devices and drivers must ignore those bits, for both
:ref:`capture` and :ref:`output` devices.

**Byte Order.**
Each cell is one byte.


.. raw:: latex

    \small

.. tabularcolumns:: |p{3.1cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|

.. flat-table:: RGB byte order
    :header-rows:  0
    :stub-columns: 0
    :widths:       11 3 3 3 3 3 3 3 3 3 3 3 3

    * - start + 0:
      - B\ :sub:`00`
      - G\ :sub:`00`
      - R\ :sub:`00`
      - B\ :sub:`01`
      - G\ :sub:`01`
      - R\ :sub:`01`
      - B\ :sub:`02`
      - G\ :sub:`02`
      - R\ :sub:`02`
      - B\ :sub:`03`
      - G\ :sub:`03`
      - R\ :sub:`03`
    * - start + 12:
      - B\ :sub:`10`
      - G\ :sub:`10`
      - R\ :sub:`10`
      - B\ :sub:`11`
      - G\ :sub:`11`
      - R\ :sub:`11`
      - B\ :sub:`12`
      - G\ :sub:`12`
      - R\ :sub:`12`
      - B\ :sub:`13`
      - G\ :sub:`13`
      - R\ :sub:`13`
    * - start + 24:
      - B\ :sub:`20`
      - G\ :sub:`20`
      - R\ :sub:`20`
      - B\ :sub:`21`
      - G\ :sub:`21`
      - R\ :sub:`21`
      - B\ :sub:`22`
      - G\ :sub:`22`
      - R\ :sub:`22`
      - B\ :sub:`23`
      - G\ :sub:`23`
      - R\ :sub:`23`
    * - start + 36:
      - B\ :sub:`30`
      - G\ :sub:`30`
      - R\ :sub:`30`
      - B\ :sub:`31`
      - G\ :sub:`31`
      - R\ :sub:`31`
      - B\ :sub:`32`
      - G\ :sub:`32`
      - R\ :sub:`32`
      - B\ :sub:`33`
      - G\ :sub:`33`
      - R\ :sub:`33`

.. raw:: latex

    \normalsize

Formats defined in :ref:`rgb-formats-deprecated` are deprecated and
must not be used by new drivers. They are documented here for reference.
The meaning of their alpha bits ``(a)`` are ill-defined and interpreted as in
either the corresponding ARGB or XRGB format, depending on the driver.


.. raw:: latex

    \begingroup
    \tiny
    \setlength{\tabcolsep}{2pt}

.. tabularcolumns:: |p{2.2cm}|p{0.60cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|

.. _rgb-formats-deprecated:

.. flat-table:: Deprecated Packed RGB Image Formats
    :header-rows:  2
    :stub-columns: 0

    * - Identifier
      - Code
      - :cspan:`7` Byte 0 in memory

      - :cspan:`7` Byte 1

      - :cspan:`7` Byte 2

      - :cspan:`7` Byte 3
    * -
      -
      - 7
      - 6
      - 5
      - 4
      - 3
      - 2
      - 1
      - 0

      - 7
      - 6
      - 5
      - 4
      - 3
      - 2
      - 1
      - 0

      - 7
      - 6
      - 5
      - 4
      - 3
      - 2
      - 1
      - 0

      - 7
      - 6
      - 5
      - 4
      - 3
      - 2
      - 1
      - 0
    * .. _V4L2-PIX-FMT-RGB444:

      - ``V4L2_PIX_FMT_RGB444``
      - 'R444'

      - g\ :sub:`3`
      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`

      - a\ :sub:`3`
      - a\ :sub:`2`
      - a\ :sub:`1`
      - a\ :sub:`0`
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`
      -
    * .. _V4L2-PIX-FMT-RGB555:

      - ``V4L2_PIX_FMT_RGB555``
      - 'RGBO'

      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`
      - b\ :sub:`4`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`

      - a
      - r\ :sub:`4`
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`
      - g\ :sub:`4`
      - g\ :sub:`3`
      -
    * .. _V4L2-PIX-FMT-RGB555X:

      - ``V4L2_PIX_FMT_RGB555X``
      - 'RGBQ'

      - a
      - r\ :sub:`4`
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`
      - g\ :sub:`4`
      - g\ :sub:`3`

      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`
      - b\ :sub:`4`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`
      -
    * .. _V4L2-PIX-FMT-BGR32:

      - ``V4L2_PIX_FMT_BGR32``
      - 'BGR4'

      - b\ :sub:`7`
      - b\ :sub:`6`
      - b\ :sub:`5`
      - b\ :sub:`4`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`

      - g\ :sub:`7`
      - g\ :sub:`6`
      - g\ :sub:`5`
      - g\ :sub:`4`
      - g\ :sub:`3`
      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`

      - r\ :sub:`7`
      - r\ :sub:`6`
      - r\ :sub:`5`
      - r\ :sub:`4`
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`

      - a\ :sub:`7`
      - a\ :sub:`6`
      - a\ :sub:`5`
      - a\ :sub:`4`
      - a\ :sub:`3`
      - a\ :sub:`2`
      - a\ :sub:`1`
      - a\ :sub:`0`
    * .. _V4L2-PIX-FMT-RGB32:

      - ``V4L2_PIX_FMT_RGB32``
      - 'RGB4'

      - a\ :sub:`7`
      - a\ :sub:`6`
      - a\ :sub:`5`
      - a\ :sub:`4`
      - a\ :sub:`3`
      - a\ :sub:`2`
      - a\ :sub:`1`
      - a\ :sub:`0`

      - r\ :sub:`7`
      - r\ :sub:`6`
      - r\ :sub:`5`
      - r\ :sub:`4`
      - r\ :sub:`3`
      - r\ :sub:`2`
      - r\ :sub:`1`
      - r\ :sub:`0`

      - g\ :sub:`7`
      - g\ :sub:`6`
      - g\ :sub:`5`
      - g\ :sub:`4`
      - g\ :sub:`3`
      - g\ :sub:`2`
      - g\ :sub:`1`
      - g\ :sub:`0`

      - b\ :sub:`7`
      - b\ :sub:`6`
      - b\ :sub:`5`
      - b\ :sub:`4`
      - b\ :sub:`3`
      - b\ :sub:`2`
      - b\ :sub:`1`
      - b\ :sub:`0`

.. raw:: latex

    \endgroup

A test utility to determine which RGB formats a driver actually supports
is available from the LinuxTV v4l-dvb repository. See
`https://linuxtv.org/repo/ <https://linuxtv.org/repo/>`__ for access
instructions.