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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-22 20:23:57 +08:00
linux-next/Documentation/media/uapi/v4l/pixfmt-nv12.rst
Laurent Pinchart c2b66cafdf [media] v4l: doc: Remove row numbers from tables
Shorten the tables by removing row numbers in comments, allowing for
later insertion of rows with minimal diffs.

All changes have been generated by the following script.

import io
import re
import sys

def process_table(fname, data):
	if fname.endswith('hist-v4l2.rst'):
		data = re.sub(u'\n{1,2}\t( ?)  -( ?) ?', u'\n\t\\1 -\\2', data, flags = re.MULTILINE)
		data = re.sub(u'\n(\t|       )-  \.\. row [0-9]+\n\t  ?-( ?) ?', u'\\1* -\\2', data, flags = re.MULTILINE)
	else:
		data = re.sub(u'\n{1,2}       -( ?) ?', u'\n      -\\1', data, flags = re.MULTILINE)
		data = re.sub(u'(\n?)(\n\n    -  \.\. row 1\n)', u'\n\\2', data, flags = re.MULTILINE)
		data = re.sub(u'\n    -  \.\. row [0-9]+\n      -( ?) ?', u'    * -\\1', data, flags = re.MULTILINE)
		data = re.sub(u'\n    -  \.\. row [0-9]+\n       \.\. (_[A-Z0-9_`-]*:)', u'\n    -  .. \\1', data, flags = re.MULTILINE)
		data = re.sub(u'\n    -  \.\. (_[A-Z0-9_`-]*:)\n      -', u'    * .. \\1\n\n      -', data, flags = re.MULTILINE)
		data = re.sub(u'^       - ', u'      -', data, flags = re.MULTILINE)
		data = re.sub(u'^(\t{1,2})  ', u'\\1', data, flags = re.MULTILINE)

	return data

def process_file(fname, data):
	buf = io.StringIO(data)
	output = ''
	in_table = False
	table_separator = 0

	for line in buf.readlines():
		if line.find('.. flat-table::') != -1:
			in_table = True
			table = ''
		elif in_table and not re.match('^[\t\n]|(    )', line):
			in_table = False
			output += process_table(fname, table)

		if in_table:
			table += line
		else:
			output += line

	if in_table:
		in_table = False
		output += process_table(fname, table)

	return output

fname = sys.argv[1]

data = file(fname, 'rb').read().decode('utf-8')
data = process_file(fname, data)
file(fname, 'wb').write(data.encode('utf-8'))

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2016-09-22 07:03:14 -03:00

130 lines
2.5 KiB
ReStructuredText

.. -*- coding: utf-8; mode: rst -*-
.. _V4L2-PIX-FMT-NV12:
.. _V4L2-PIX-FMT-NV21:
******************************************************
V4L2_PIX_FMT_NV12 ('NV12'), V4L2_PIX_FMT_NV21 ('NV21')
******************************************************
V4L2_PIX_FMT_NV21
Formats with ½ horizontal and vertical chroma resolution, also known as
YUV 4:2:0. One luminance and one chrominance plane with alternating
chroma samples as opposed to ``V4L2_PIX_FMT_YVU420``
Description
===========
These are two-plane versions of the YUV 4:2:0 format. The three
components are separated into two sub-images or planes. The Y plane is
first. The Y plane has one byte per pixel. For ``V4L2_PIX_FMT_NV12``, a
combined CbCr plane immediately follows the Y plane in memory. 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_NV21`` is
the same except the Cb and Cr bytes are swapped, the CrCb plane starts
with a Cr byte.
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
* - start + 0:
- Y'\ :sub:`00`
- Y'\ :sub:`01`
- Y'\ :sub:`02`
- Y'\ :sub:`03`
* - start + 4:
- Y'\ :sub:`10`
- Y'\ :sub:`11`
- Y'\ :sub:`12`
- Y'\ :sub:`13`
* - start + 8:
- Y'\ :sub:`20`
- Y'\ :sub:`21`
- Y'\ :sub:`22`
- Y'\ :sub:`23`
* - start + 12:
- Y'\ :sub:`30`
- Y'\ :sub:`31`
- Y'\ :sub:`32`
- Y'\ :sub:`33`
* - start + 16:
- Cb\ :sub:`00`
- Cr\ :sub:`00`
- Cb\ :sub:`01`
- Cr\ :sub:`01`
* - start + 20:
- 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