mirror of https://gitee.com/openkylin/linux.git
63 lines
1.8 KiB
ReStructuredText
63 lines
1.8 KiB
ReStructuredText
.. Permission is granted to copy, distribute and/or modify this
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.. document under the terms of the GNU Free Documentation License,
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.. Version 1.1 or any later version published by the Free Software
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.. Foundation, with no Invariant Sections, no Front-Cover Texts
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.. and no Back-Cover Texts. A copy of the license is included at
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.. Documentation/media/uapi/fdl-appendix.rst.
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..
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.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
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.. _V4L2-SDR-FMT-PCU20BE:
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******************************
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V4L2_SDR_FMT_PCU20BE ('PC20')
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******************************
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Planar complex unsigned 20-bit big endian IQ sample
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Description
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===========
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This format contains a sequence of complex number samples. Each complex
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number consist of two parts called In-phase and Quadrature (IQ). Both I
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and Q are represented as a 20 bit unsigned big endian number stored in
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32 bit space. The remaining unused bits within the 32 bit space will be
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padded with 0. I value starts first and Q value starts at an offset
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equalling half of the buffer size (i.e.) offset = buffersize/2. Out of
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the 20 bits, bit 19:2 (18 bit) is data and bit 1:0 (2 bit) can be any
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value.
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**Byte Order.**
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Each cell is one byte.
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.. flat-table::
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:header-rows: 1
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:stub-columns: 0
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* - Offset:
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- Byte B0
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- Byte B1
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- Byte B2
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- Byte B3
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* - start + 0:
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- I'\ :sub:`0[19:12]`
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- I'\ :sub:`0[11:4]`
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- I'\ :sub:`0[3:0]; B2[3:0]=pad`
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- pad
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* - start + 4:
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- I'\ :sub:`1[19:12]`
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- I'\ :sub:`1[11:4]`
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- I'\ :sub:`1[3:0]; B2[3:0]=pad`
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- pad
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* - ...
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* - start + offset:
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- Q'\ :sub:`0[19:12]`
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- Q'\ :sub:`0[11:4]`
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- Q'\ :sub:`0[3:0]; B2[3:0]=pad`
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- pad
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* - start + offset + 4:
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- Q'\ :sub:`1[19:12]`
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- Q'\ :sub:`1[11:4]`
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- Q'\ :sub:`1[3:0]; B2[3:0]=pad`
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- pad
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