xref: /OK3568_Linux_fs/kernel/Documentation/userspace-api/media/v4l/pixfmt-yuv420.rst (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2*4882a593Smuzhiyun
3*4882a593Smuzhiyun.. _V4L2-PIX-FMT-YVU420:
4*4882a593Smuzhiyun.. _V4L2-PIX-FMT-YUV420:
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun**********************************************************
7*4882a593SmuzhiyunV4L2_PIX_FMT_YVU420 ('YV12'), V4L2_PIX_FMT_YUV420 ('YU12')
8*4882a593Smuzhiyun**********************************************************
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun
11*4882a593SmuzhiyunV4L2_PIX_FMT_YUV420
12*4882a593SmuzhiyunPlanar formats with ½ horizontal and vertical chroma resolution, also
13*4882a593Smuzhiyunknown as YUV 4:2:0
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun
16*4882a593SmuzhiyunDescription
17*4882a593Smuzhiyun===========
18*4882a593Smuzhiyun
19*4882a593SmuzhiyunThese are planar formats, as opposed to a packed format. The three
20*4882a593Smuzhiyuncomponents are separated into three sub- images or planes. The Y plane
21*4882a593Smuzhiyunis first. The Y plane has one byte per pixel. For
22*4882a593Smuzhiyun``V4L2_PIX_FMT_YVU420``, the Cr plane immediately follows the Y plane in
23*4882a593Smuzhiyunmemory. The Cr plane is half the width and half the height of the Y
24*4882a593Smuzhiyunplane (and of the image). Each Cr belongs to four pixels, a two-by-two
25*4882a593Smuzhiyunsquare of the image. For example, Cr\ :sub:`0` belongs to Y'\ :sub:`00`,
26*4882a593SmuzhiyunY'\ :sub:`01`, Y'\ :sub:`10`, and Y'\ :sub:`11`. Following the Cr plane
27*4882a593Smuzhiyunis the Cb plane, just like the Cr plane. ``V4L2_PIX_FMT_YUV420`` is the
28*4882a593Smuzhiyunsame except the Cb plane comes first, then the Cr plane.
29*4882a593Smuzhiyun
30*4882a593SmuzhiyunIf the Y plane has pad bytes after each row, then the Cr and Cb planes
31*4882a593Smuzhiyunhave half as many pad bytes after their rows. In other words, two Cx
32*4882a593Smuzhiyunrows (including padding) is exactly as long as one Y row (including
33*4882a593Smuzhiyunpadding).
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun**Byte Order.**
36*4882a593SmuzhiyunEach cell is one byte.
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun.. flat-table::
42*4882a593Smuzhiyun    :header-rows:  0
43*4882a593Smuzhiyun    :stub-columns: 0
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun    * - start + 0:
46*4882a593Smuzhiyun      - Y'\ :sub:`00`
47*4882a593Smuzhiyun      - Y'\ :sub:`01`
48*4882a593Smuzhiyun      - Y'\ :sub:`02`
49*4882a593Smuzhiyun      - Y'\ :sub:`03`
50*4882a593Smuzhiyun    * - start + 4:
51*4882a593Smuzhiyun      - Y'\ :sub:`10`
52*4882a593Smuzhiyun      - Y'\ :sub:`11`
53*4882a593Smuzhiyun      - Y'\ :sub:`12`
54*4882a593Smuzhiyun      - Y'\ :sub:`13`
55*4882a593Smuzhiyun    * - start + 8:
56*4882a593Smuzhiyun      - Y'\ :sub:`20`
57*4882a593Smuzhiyun      - Y'\ :sub:`21`
58*4882a593Smuzhiyun      - Y'\ :sub:`22`
59*4882a593Smuzhiyun      - Y'\ :sub:`23`
60*4882a593Smuzhiyun    * - start + 12:
61*4882a593Smuzhiyun      - Y'\ :sub:`30`
62*4882a593Smuzhiyun      - Y'\ :sub:`31`
63*4882a593Smuzhiyun      - Y'\ :sub:`32`
64*4882a593Smuzhiyun      - Y'\ :sub:`33`
65*4882a593Smuzhiyun    * - start + 16:
66*4882a593Smuzhiyun      - Cr\ :sub:`00`
67*4882a593Smuzhiyun      - Cr\ :sub:`01`
68*4882a593Smuzhiyun    * - start + 18:
69*4882a593Smuzhiyun      - Cr\ :sub:`10`
70*4882a593Smuzhiyun      - Cr\ :sub:`11`
71*4882a593Smuzhiyun    * - start + 20:
72*4882a593Smuzhiyun      - Cb\ :sub:`00`
73*4882a593Smuzhiyun      - Cb\ :sub:`01`
74*4882a593Smuzhiyun    * - start + 22:
75*4882a593Smuzhiyun      - Cb\ :sub:`10`
76*4882a593Smuzhiyun      - Cb\ :sub:`11`
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun
79*4882a593Smuzhiyun**Color Sample Location:**
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun
82*4882a593Smuzhiyun
83*4882a593Smuzhiyun.. flat-table::
84*4882a593Smuzhiyun    :header-rows:  0
85*4882a593Smuzhiyun    :stub-columns: 0
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun    * -
88*4882a593Smuzhiyun      - 0
89*4882a593Smuzhiyun      -
90*4882a593Smuzhiyun      - 1
91*4882a593Smuzhiyun      -
92*4882a593Smuzhiyun      - 2
93*4882a593Smuzhiyun      -
94*4882a593Smuzhiyun      - 3
95*4882a593Smuzhiyun    * - 0
96*4882a593Smuzhiyun      - Y
97*4882a593Smuzhiyun      -
98*4882a593Smuzhiyun      - Y
99*4882a593Smuzhiyun      -
100*4882a593Smuzhiyun      - Y
101*4882a593Smuzhiyun      -
102*4882a593Smuzhiyun      - Y
103*4882a593Smuzhiyun    * -
104*4882a593Smuzhiyun      -
105*4882a593Smuzhiyun      - C
106*4882a593Smuzhiyun      -
107*4882a593Smuzhiyun      -
108*4882a593Smuzhiyun      -
109*4882a593Smuzhiyun      - C
110*4882a593Smuzhiyun      -
111*4882a593Smuzhiyun    * - 1
112*4882a593Smuzhiyun      - Y
113*4882a593Smuzhiyun      -
114*4882a593Smuzhiyun      - Y
115*4882a593Smuzhiyun      -
116*4882a593Smuzhiyun      - Y
117*4882a593Smuzhiyun      -
118*4882a593Smuzhiyun      - Y
119*4882a593Smuzhiyun    * -
120*4882a593Smuzhiyun    * - 2
121*4882a593Smuzhiyun      - Y
122*4882a593Smuzhiyun      -
123*4882a593Smuzhiyun      - Y
124*4882a593Smuzhiyun      -
125*4882a593Smuzhiyun      - Y
126*4882a593Smuzhiyun      -
127*4882a593Smuzhiyun      - Y
128*4882a593Smuzhiyun    * -
129*4882a593Smuzhiyun      -
130*4882a593Smuzhiyun      - C
131*4882a593Smuzhiyun      -
132*4882a593Smuzhiyun      -
133*4882a593Smuzhiyun      -
134*4882a593Smuzhiyun      - C
135*4882a593Smuzhiyun      -
136*4882a593Smuzhiyun    * - 3
137*4882a593Smuzhiyun      - Y
138*4882a593Smuzhiyun      -
139*4882a593Smuzhiyun      - Y
140*4882a593Smuzhiyun      -
141*4882a593Smuzhiyun      - Y
142*4882a593Smuzhiyun      -
143*4882a593Smuzhiyun      - Y
144