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54f38fcae5
Since 2017, there is an space reserved for userspace API,
created by changeset 1d596dee38 ("docs: Create a user-space API guide").
As the media subsystem was one of the first subsystems to use
Sphinx, until this patch, we were keeping things on a separate
place.
Let's just use the new location, as having all uAPI altogether
will likely make things easier for developers.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
134 lines
2.5 KiB
ReStructuredText
134 lines
2.5 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/userspace-api/media/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-PIX-FMT-M420:
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**************************
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V4L2_PIX_FMT_M420 ('M420')
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**************************
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Format with ½ horizontal and vertical chroma resolution, also known as
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YUV 4:2:0. Hybrid plane line-interleaved layout.
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Description
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===========
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M420 is a YUV format with ½ horizontal and vertical chroma subsampling
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(YUV 4:2:0). Pixels are organized as interleaved luma and chroma planes.
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Two lines of luma data are followed by one line of chroma data.
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The luma plane has one byte per pixel. The chroma plane contains
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interleaved CbCr pixels subsampled by ½ in the horizontal and vertical
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directions. Each CbCr pair belongs to four pixels. For example,
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Cb\ :sub:`0`/Cr\ :sub:`0` belongs to Y'\ :sub:`00`, Y'\ :sub:`01`,
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Y'\ :sub:`10`, Y'\ :sub:`11`.
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All line lengths are identical: if the Y lines include pad bytes so do
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the CbCr lines.
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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: 0
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:stub-columns: 0
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* - start + 0:
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- Y'\ :sub:`00`
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- Y'\ :sub:`01`
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- Y'\ :sub:`02`
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- Y'\ :sub:`03`
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* - start + 4:
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- Y'\ :sub:`10`
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- Y'\ :sub:`11`
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- Y'\ :sub:`12`
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- Y'\ :sub:`13`
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* - start + 8:
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- Cb\ :sub:`00`
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- Cr\ :sub:`00`
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- Cb\ :sub:`01`
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- Cr\ :sub:`01`
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* - start + 16:
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- Y'\ :sub:`20`
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- Y'\ :sub:`21`
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- Y'\ :sub:`22`
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- Y'\ :sub:`23`
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* - start + 20:
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- Y'\ :sub:`30`
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- Y'\ :sub:`31`
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- Y'\ :sub:`32`
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- Y'\ :sub:`33`
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* - start + 24:
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- Cb\ :sub:`10`
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- Cr\ :sub:`10`
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- Cb\ :sub:`11`
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- Cr\ :sub:`11`
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**Color Sample Location:**
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.. flat-table::
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:header-rows: 0
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:stub-columns: 0
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* -
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- 0
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- 1
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* - 0
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- Y
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- Y
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- Y
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* -
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- C
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* - 1
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- Y
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- Y
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- C
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* - 3
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- Y
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- Y
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