xref: /OK3568_Linux_fs/kernel/Documentation/userspace-api/media/v4l/pixfmt-nv12.rst (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2*4882a593Smuzhiyun
3*4882a593Smuzhiyun.. _V4L2-PIX-FMT-NV12:
4*4882a593Smuzhiyun.. _V4L2-PIX-FMT-NV21:
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun******************************************************
7*4882a593SmuzhiyunV4L2_PIX_FMT_NV12 ('NV12'), V4L2_PIX_FMT_NV21 ('NV21')
8*4882a593Smuzhiyun******************************************************
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun
11*4882a593SmuzhiyunV4L2_PIX_FMT_NV21
12*4882a593SmuzhiyunFormats with ½ horizontal and vertical chroma resolution, also known as
13*4882a593SmuzhiyunYUV 4:2:0. One luminance and one chrominance plane with alternating
14*4882a593Smuzhiyunchroma samples as opposed to ``V4L2_PIX_FMT_YVU420``
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun
17*4882a593SmuzhiyunDescription
18*4882a593Smuzhiyun===========
19*4882a593Smuzhiyun
20*4882a593SmuzhiyunThese are two-plane versions of the YUV 4:2:0 format. The three
21*4882a593Smuzhiyuncomponents are separated into two sub-images or planes. The Y plane is
22*4882a593Smuzhiyunfirst. The Y plane has one byte per pixel. For ``V4L2_PIX_FMT_NV12``, a
23*4882a593Smuzhiyuncombined CbCr plane immediately follows the Y plane in memory. The CbCr
24*4882a593Smuzhiyunplane is the same width, in bytes, as the Y plane (and of the image),
25*4882a593Smuzhiyunbut is half as tall in pixels. Each CbCr pair belongs to four pixels.
26*4882a593SmuzhiyunFor example, Cb\ :sub:`0`/Cr\ :sub:`0` belongs to Y'\ :sub:`00`,
27*4882a593SmuzhiyunY'\ :sub:`01`, Y'\ :sub:`10`, Y'\ :sub:`11`. ``V4L2_PIX_FMT_NV21`` is
28*4882a593Smuzhiyunthe same except the Cb and Cr bytes are swapped, the CrCb plane starts
29*4882a593Smuzhiyunwith a Cr byte.
30*4882a593Smuzhiyun
31*4882a593SmuzhiyunIf the Y plane has pad bytes after each row, then the CbCr plane has as
32*4882a593Smuzhiyunmany pad bytes after its rows.
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun**Byte Order.**
35*4882a593SmuzhiyunEach cell is one byte.
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun.. flat-table::
39*4882a593Smuzhiyun    :header-rows:  0
40*4882a593Smuzhiyun    :stub-columns: 0
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun    * - start + 0:
43*4882a593Smuzhiyun      - Y'\ :sub:`00`
44*4882a593Smuzhiyun      - Y'\ :sub:`01`
45*4882a593Smuzhiyun      - Y'\ :sub:`02`
46*4882a593Smuzhiyun      - Y'\ :sub:`03`
47*4882a593Smuzhiyun    * - start + 4:
48*4882a593Smuzhiyun      - Y'\ :sub:`10`
49*4882a593Smuzhiyun      - Y'\ :sub:`11`
50*4882a593Smuzhiyun      - Y'\ :sub:`12`
51*4882a593Smuzhiyun      - Y'\ :sub:`13`
52*4882a593Smuzhiyun    * - start + 8:
53*4882a593Smuzhiyun      - Y'\ :sub:`20`
54*4882a593Smuzhiyun      - Y'\ :sub:`21`
55*4882a593Smuzhiyun      - Y'\ :sub:`22`
56*4882a593Smuzhiyun      - Y'\ :sub:`23`
57*4882a593Smuzhiyun    * - start + 12:
58*4882a593Smuzhiyun      - Y'\ :sub:`30`
59*4882a593Smuzhiyun      - Y'\ :sub:`31`
60*4882a593Smuzhiyun      - Y'\ :sub:`32`
61*4882a593Smuzhiyun      - Y'\ :sub:`33`
62*4882a593Smuzhiyun    * - start + 16:
63*4882a593Smuzhiyun      - Cb\ :sub:`00`
64*4882a593Smuzhiyun      - Cr\ :sub:`00`
65*4882a593Smuzhiyun      - Cb\ :sub:`01`
66*4882a593Smuzhiyun      - Cr\ :sub:`01`
67*4882a593Smuzhiyun    * - start + 20:
68*4882a593Smuzhiyun      - Cb\ :sub:`10`
69*4882a593Smuzhiyun      - Cr\ :sub:`10`
70*4882a593Smuzhiyun      - Cb\ :sub:`11`
71*4882a593Smuzhiyun      - Cr\ :sub:`11`
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun
74*4882a593Smuzhiyun**Color Sample Location:**
75*4882a593Smuzhiyun
76*4882a593Smuzhiyun.. flat-table::
77*4882a593Smuzhiyun    :header-rows:  0
78*4882a593Smuzhiyun    :stub-columns: 0
79*4882a593Smuzhiyun
80*4882a593Smuzhiyun    * -
81*4882a593Smuzhiyun      - 0
82*4882a593Smuzhiyun      -
83*4882a593Smuzhiyun      - 1
84*4882a593Smuzhiyun      - 2
85*4882a593Smuzhiyun      -
86*4882a593Smuzhiyun      - 3
87*4882a593Smuzhiyun    * - 0
88*4882a593Smuzhiyun      - Y
89*4882a593Smuzhiyun      -
90*4882a593Smuzhiyun      - Y
91*4882a593Smuzhiyun      - Y
92*4882a593Smuzhiyun      -
93*4882a593Smuzhiyun      - Y
94*4882a593Smuzhiyun    * -
95*4882a593Smuzhiyun      -
96*4882a593Smuzhiyun      - C
97*4882a593Smuzhiyun      -
98*4882a593Smuzhiyun      -
99*4882a593Smuzhiyun      - C
100*4882a593Smuzhiyun      -
101*4882a593Smuzhiyun    * - 1
102*4882a593Smuzhiyun      - Y
103*4882a593Smuzhiyun      -
104*4882a593Smuzhiyun      - Y
105*4882a593Smuzhiyun      - Y
106*4882a593Smuzhiyun      -
107*4882a593Smuzhiyun      - Y
108*4882a593Smuzhiyun    * -
109*4882a593Smuzhiyun    * - 2
110*4882a593Smuzhiyun      - Y
111*4882a593Smuzhiyun      -
112*4882a593Smuzhiyun      - Y
113*4882a593Smuzhiyun      - Y
114*4882a593Smuzhiyun      -
115*4882a593Smuzhiyun      - Y
116*4882a593Smuzhiyun    * -
117*4882a593Smuzhiyun      -
118*4882a593Smuzhiyun      - C
119*4882a593Smuzhiyun      -
120*4882a593Smuzhiyun      -
121*4882a593Smuzhiyun      - C
122*4882a593Smuzhiyun      -
123*4882a593Smuzhiyun    * - 3
124*4882a593Smuzhiyun      - Y
125*4882a593Smuzhiyun      -
126*4882a593Smuzhiyun      - Y
127*4882a593Smuzhiyun      - Y
128*4882a593Smuzhiyun      -
129*4882a593Smuzhiyun      - Y
130