xref: /OK3568_Linux_fs/kernel/Documentation/userspace-api/media/v4l/pixfmt-yuv420m.rst (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2*4882a593Smuzhiyun
3*4882a593Smuzhiyun.. _V4L2-PIX-FMT-YUV420M:
4*4882a593Smuzhiyun.. _v4l2-pix-fmt-yvu420m:
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun************************************************************
7*4882a593SmuzhiyunV4L2_PIX_FMT_YUV420M ('YM12'), V4L2_PIX_FMT_YVU420M ('YM21')
8*4882a593Smuzhiyun************************************************************
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun
11*4882a593SmuzhiyunV4L2_PIX_FMT_YVU420M
12*4882a593SmuzhiyunVariation of ``V4L2_PIX_FMT_YUV420`` and ``V4L2_PIX_FMT_YVU420`` with
13*4882a593Smuzhiyunplanes non contiguous in memory.
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun
16*4882a593SmuzhiyunDescription
17*4882a593Smuzhiyun===========
18*4882a593Smuzhiyun
19*4882a593SmuzhiyunThis is a multi-planar format, as opposed to a packed format. The three
20*4882a593Smuzhiyuncomponents are separated into three sub-images or planes.
21*4882a593Smuzhiyun
22*4882a593SmuzhiyunThe Y plane is first. The Y plane has one byte per pixel. For
23*4882a593Smuzhiyun``V4L2_PIX_FMT_YUV420M`` the Cb data constitutes the second plane which
24*4882a593Smuzhiyunis half the width and half the height of the Y plane (and of the image).
25*4882a593SmuzhiyunEach Cb belongs to four pixels, a two-by-two square of the image. For
26*4882a593Smuzhiyunexample, Cb\ :sub:`0` belongs to Y'\ :sub:`00`, Y'\ :sub:`01`,
27*4882a593SmuzhiyunY'\ :sub:`10`, and Y'\ :sub:`11`. The Cr data, just like the Cb plane,
28*4882a593Smuzhiyunis in the third plane.
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun``V4L2_PIX_FMT_YVU420M`` is the same except the Cr data is stored in the
31*4882a593Smuzhiyunsecond plane and the Cb data in the third plane.
32*4882a593Smuzhiyun
33*4882a593SmuzhiyunIf the Y plane has pad bytes after each row, then the Cb and Cr planes
34*4882a593Smuzhiyunhave half as many pad bytes after their rows. In other words, two Cx
35*4882a593Smuzhiyunrows (including padding) is exactly as long as one Y row (including
36*4882a593Smuzhiyunpadding).
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun``V4L2_PIX_FMT_YUV420M`` and ``V4L2_PIX_FMT_YVU420M`` are intended to be
39*4882a593Smuzhiyunused only in drivers and applications that support the multi-planar API,
40*4882a593Smuzhiyundescribed in :ref:`planar-apis`.
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun**Byte Order.**
43*4882a593SmuzhiyunEach cell is one byte.
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun.. flat-table::
49*4882a593Smuzhiyun    :header-rows:  0
50*4882a593Smuzhiyun    :stub-columns: 0
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun    * - start0 + 0:
53*4882a593Smuzhiyun      - Y'\ :sub:`00`
54*4882a593Smuzhiyun      - Y'\ :sub:`01`
55*4882a593Smuzhiyun      - Y'\ :sub:`02`
56*4882a593Smuzhiyun      - Y'\ :sub:`03`
57*4882a593Smuzhiyun    * - start0 + 4:
58*4882a593Smuzhiyun      - Y'\ :sub:`10`
59*4882a593Smuzhiyun      - Y'\ :sub:`11`
60*4882a593Smuzhiyun      - Y'\ :sub:`12`
61*4882a593Smuzhiyun      - Y'\ :sub:`13`
62*4882a593Smuzhiyun    * - start0 + 8:
63*4882a593Smuzhiyun      - Y'\ :sub:`20`
64*4882a593Smuzhiyun      - Y'\ :sub:`21`
65*4882a593Smuzhiyun      - Y'\ :sub:`22`
66*4882a593Smuzhiyun      - Y'\ :sub:`23`
67*4882a593Smuzhiyun    * - start0 + 12:
68*4882a593Smuzhiyun      - Y'\ :sub:`30`
69*4882a593Smuzhiyun      - Y'\ :sub:`31`
70*4882a593Smuzhiyun      - Y'\ :sub:`32`
71*4882a593Smuzhiyun      - Y'\ :sub:`33`
72*4882a593Smuzhiyun    * -
73*4882a593Smuzhiyun    * - start1 + 0:
74*4882a593Smuzhiyun      - Cb\ :sub:`00`
75*4882a593Smuzhiyun      - Cb\ :sub:`01`
76*4882a593Smuzhiyun    * - start1 + 2:
77*4882a593Smuzhiyun      - Cb\ :sub:`10`
78*4882a593Smuzhiyun      - Cb\ :sub:`11`
79*4882a593Smuzhiyun    * -
80*4882a593Smuzhiyun    * - start2 + 0:
81*4882a593Smuzhiyun      - Cr\ :sub:`00`
82*4882a593Smuzhiyun      - Cr\ :sub:`01`
83*4882a593Smuzhiyun    * - start2 + 2:
84*4882a593Smuzhiyun      - Cr\ :sub:`10`
85*4882a593Smuzhiyun      - Cr\ :sub:`11`
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun
88*4882a593Smuzhiyun**Color Sample Location:**
89*4882a593Smuzhiyun
90*4882a593Smuzhiyun
91*4882a593Smuzhiyun
92*4882a593Smuzhiyun.. flat-table::
93*4882a593Smuzhiyun    :header-rows:  0
94*4882a593Smuzhiyun    :stub-columns: 0
95*4882a593Smuzhiyun
96*4882a593Smuzhiyun    * -
97*4882a593Smuzhiyun      - 0
98*4882a593Smuzhiyun      -
99*4882a593Smuzhiyun      - 1
100*4882a593Smuzhiyun      -
101*4882a593Smuzhiyun      - 2
102*4882a593Smuzhiyun      -
103*4882a593Smuzhiyun      - 3
104*4882a593Smuzhiyun    * - 0
105*4882a593Smuzhiyun      - Y
106*4882a593Smuzhiyun      -
107*4882a593Smuzhiyun      - Y
108*4882a593Smuzhiyun      -
109*4882a593Smuzhiyun      - Y
110*4882a593Smuzhiyun      -
111*4882a593Smuzhiyun      - Y
112*4882a593Smuzhiyun    * -
113*4882a593Smuzhiyun      -
114*4882a593Smuzhiyun      - C
115*4882a593Smuzhiyun      -
116*4882a593Smuzhiyun      -
117*4882a593Smuzhiyun      -
118*4882a593Smuzhiyun      - C
119*4882a593Smuzhiyun      -
120*4882a593Smuzhiyun    * - 1
121*4882a593Smuzhiyun      - Y
122*4882a593Smuzhiyun      -
123*4882a593Smuzhiyun      - Y
124*4882a593Smuzhiyun      -
125*4882a593Smuzhiyun      - Y
126*4882a593Smuzhiyun      -
127*4882a593Smuzhiyun      - Y
128*4882a593Smuzhiyun    * -
129*4882a593Smuzhiyun    * - 2
130*4882a593Smuzhiyun      - Y
131*4882a593Smuzhiyun      -
132*4882a593Smuzhiyun      - Y
133*4882a593Smuzhiyun      -
134*4882a593Smuzhiyun      - Y
135*4882a593Smuzhiyun      -
136*4882a593Smuzhiyun      - Y
137*4882a593Smuzhiyun    * -
138*4882a593Smuzhiyun      -
139*4882a593Smuzhiyun      - C
140*4882a593Smuzhiyun      -
141*4882a593Smuzhiyun      -
142*4882a593Smuzhiyun      -
143*4882a593Smuzhiyun      - C
144*4882a593Smuzhiyun      -
145*4882a593Smuzhiyun    * - 3
146*4882a593Smuzhiyun      - Y
147*4882a593Smuzhiyun      -
148*4882a593Smuzhiyun      - Y
149*4882a593Smuzhiyun      -
150*4882a593Smuzhiyun      - Y
151*4882a593Smuzhiyun      -
152*4882a593Smuzhiyun      - Y
153