OpenCloudOS-Kernel/Documentation/media/uapi/v4l/pixfmt-sdr-pcu20be.rst

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.. document under the terms of the GNU Free Documentation License,
.. Version 1.1 or any later version published by the Free Software
.. Foundation, with no Invariant Sections, no Front-Cover Texts
.. and no Back-Cover Texts. A copy of the license is included at
.. Documentation/media/uapi/fdl-appendix.rst.
..
.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections

.. _V4L2-SDR-FMT-PCU20BE:

******************************
V4L2_SDR_FMT_PCU20BE ('PC20')
******************************

Planar complex unsigned 20-bit big endian IQ sample

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

This format contains a sequence of complex number samples. Each complex
number consist of two parts called In-phase and Quadrature (IQ). Both I
and Q are represented as a 20 bit unsigned big endian number stored in
32 bit space. The remaining unused bits within the 32 bit space will be
padded with 0. I value starts first and Q value starts at an offset
equalling half of the buffer size (i.e.) offset = buffersize/2. Out of
the 20 bits, bit 19:2 (18 bit) is data and bit 1:0 (2 bit) can be any
value.

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

.. flat-table::
    :header-rows:  1
    :stub-columns: 0

    * -  Offset:
      -  Byte B0
      -  Byte B1
      -  Byte B2
      -  Byte B3
    * -  start + 0:
      -  I'\ :sub:`0[19:12]`
      -  I'\ :sub:`0[11:4]`
      -  I'\ :sub:`0[3:0]; B2[3:0]=pad`
      -  pad
    * -  start + 4:
      -  I'\ :sub:`1[19:12]`
      -  I'\ :sub:`1[11:4]`
      -  I'\ :sub:`1[3:0]; B2[3:0]=pad`
      -  pad
    * -  ...
    * - start + offset:
      -  Q'\ :sub:`0[19:12]`
      -  Q'\ :sub:`0[11:4]`
      -  Q'\ :sub:`0[3:0]; B2[3:0]=pad`
      -  pad
    * - start + offset + 4:
      -  Q'\ :sub:`1[19:12]`
      -  Q'\ :sub:`1[11:4]`
      -  Q'\ :sub:`1[3:0]; B2[3:0]=pad`
      -  pad