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.. -*- coding: utf-8; mode: rst -*-
.. _V4L2-PIX-FMT-NV12M:
.. _v4l2-pix-fmt-nv12mt-16x16:
.. _V4L2-PIX-FMT-NV21M:
***********************************************************************************
V4L2_PIX_FMT_NV12M ('NM12'), V4L2_PIX_FMT_NV21M ('NM21'), V4L2_PIX_FMT_NV12MT_16X16
***********************************************************************************
V4L2_PIX_FMT_NV21M
V4L2_PIX_FMT_NV12MT_16X16
Variation of ``V4L2_PIX_FMT_NV12`` and ``V4L2_PIX_FMT_NV21`` with planes
non contiguous in memory.
Description
===========
This is a multi-planar, two-plane version of the YUV 4:2:0 format. The
three components are separated into two sub-images or planes.
``V4L2_PIX_FMT_NV12M`` differs from ``V4L2_PIX_FMT_NV12`` in that the
two planes are non-contiguous in memory, i.e. the chroma plane do not
necessarily immediately follows the luma plane. The luminance data
occupies the first plane. The Y plane has one byte per pixel. In the
second plane there is a chrominance data with alternating chroma
samples. The CbCr plane is the same width, in bytes, as the Y plane (and
of the image), but is half as tall in pixels. Each CbCr pair belongs to
four pixels. For example, Cb\ :sub:`0`/Cr\ :sub:`0` belongs to
Y'\ :sub:`00`, Y'\ :sub:`01`, Y'\ :sub:`10`, Y'\ :sub:`11`.
``V4L2_PIX_FMT_NV12MT_16X16`` is the tiled version of
``V4L2_PIX_FMT_NV12M`` with 16x16 macroblock tiles. Here pixels are
arranged in 16x16 2D tiles and tiles are arranged in linear order in
memory. ``V4L2_PIX_FMT_NV21M`` is the same as ``V4L2_PIX_FMT_NV12M``
except the Cb and Cr bytes are swapped, the CrCb plane starts with a Cr
byte.
``V4L2_PIX_FMT_NV12M`` is intended to be used only in drivers and
applications that support the multi-planar API, described in
:ref:`planar-apis`.
If the Y plane has pad bytes after each row, then the CbCr plane has as
many pad bytes after its rows.
**Byte Order.**
Each cell is one byte.
.. flat-table::
:header-rows: 0
:stub-columns: 0
* - start0 + 0:
- Y'\ :sub:`00`
- Y'\ :sub:`01`
- Y'\ :sub:`02`
- Y'\ :sub:`03`
* - start0 + 4:
- Y'\ :sub:`10`
- Y'\ :sub:`11`
- Y'\ :sub:`12`
- Y'\ :sub:`13`
* - start0 + 8:
- Y'\ :sub:`20`
- Y'\ :sub:`21`
- Y'\ :sub:`22`
- Y'\ :sub:`23`
* - start0 + 12:
- Y'\ :sub:`30`
- Y'\ :sub:`31`
- Y'\ :sub:`32`
- Y'\ :sub:`33`
* -
* - start1 + 0:
- Cb\ :sub:`00`
- Cr\ :sub:`00`
- Cb\ :sub:`01`
- Cr\ :sub:`01`
* - start1 + 4:
- Cb\ :sub:`10`
- Cr\ :sub:`10`
- Cb\ :sub:`11`
- Cr\ :sub:`11`
**Color Sample Location:**
.. flat-table::
:header-rows: 0
:stub-columns: 0
* -
- 0
-
- 1
- 2
-
- 3
* - 0
- Y
-
- Y
- Y
-
- Y
* -
-
- C
-
-
- C
-
* - 1
- Y
-
- Y
- Y
-
- Y
* -
* - 2
- Y
-
- Y
- Y
-
- Y
* -
-
- C
-
-
-
- C
-
* - 3
- Y
-
- Y
- Y
-
- Y
|
