[deliverable/linux.git] / Documentation / DocBook / media / v4l / pixfmt-nv16.xml

    <refentry>
      <refmeta>
	<refentrytitle>V4L2_PIX_FMT_NV16 ('NV16'), V4L2_PIX_FMT_NV61 ('NV61')</refentrytitle>
	&manvol;
      </refmeta>
      <refnamediv>
	<refname id="V4L2-PIX-FMT-NV16"><constant>V4L2_PIX_FMT_NV16</constant></refname>
	<refname id="V4L2-PIX-FMT-NV61"><constant>V4L2_PIX_FMT_NV61</constant></refname>
	<refpurpose>Formats with &frac12; horizontal
chroma resolution, also known as YUV 4:2:2. One luminance and one
chrominance plane with alternating chroma samples as opposed to
<constant>V4L2_PIX_FMT_YVU420</constant></refpurpose>
      </refnamediv>
      <refsect1>
	<title>Description</title>

	<para>These are two-plane versions of the YUV 4:2:2 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
<constant>V4L2_PIX_FMT_NV16</constant>, a combined CbCr plane
immediately follows the Y plane in memory.  The CbCr plane is the same
width and height, in bytes, as the Y plane (and of the image).
Each CbCr pair belongs to two pixels. For example,
Cb<subscript>0</subscript>/Cr<subscript>0</subscript> belongs to
Y'<subscript>00</subscript>, Y'<subscript>01</subscript>.
<constant>V4L2_PIX_FMT_NV61</constant> is the same except the Cb and
Cr bytes are swapped, the CrCb plane starts with a Cr byte.</para>

	<para>If the Y plane has pad bytes after each row, then the
CbCr plane has as many pad bytes after its rows.</para>

	<example>
	  <title><constant>V4L2_PIX_FMT_NV16</constant> 4 &times; 4
pixel image</title>

	  <formalpara>
	    <title>Byte Order.</title>
	    <para>Each cell is one byte.
		<informaltable frame="none">
		<tgroup cols="5" align="center">
		  <colspec align="left" colwidth="2*" />
		  <tbody valign="top">
		    <row>
		      <entry>start&nbsp;+&nbsp;0:</entry>
		      <entry>Y'<subscript>00</subscript></entry>
		      <entry>Y'<subscript>01</subscript></entry>
		      <entry>Y'<subscript>02</subscript></entry>
		      <entry>Y'<subscript>03</subscript></entry>
		    </row>
		    <row>
		      <entry>start&nbsp;+&nbsp;4:</entry>
		      <entry>Y'<subscript>10</subscript></entry>
		      <entry>Y'<subscript>11</subscript></entry>
		      <entry>Y'<subscript>12</subscript></entry>
		      <entry>Y'<subscript>13</subscript></entry>
		    </row>
		    <row>
		      <entry>start&nbsp;+&nbsp;8:</entry>
		      <entry>Y'<subscript>20</subscript></entry>
		      <entry>Y'<subscript>21</subscript></entry>
		      <entry>Y'<subscript>22</subscript></entry>
		      <entry>Y'<subscript>23</subscript></entry>
		    </row>
		    <row>
		      <entry>start&nbsp;+&nbsp;12:</entry>
		      <entry>Y'<subscript>30</subscript></entry>
		      <entry>Y'<subscript>31</subscript></entry>
		      <entry>Y'<subscript>32</subscript></entry>
		      <entry>Y'<subscript>33</subscript></entry>
		    </row>
		    <row>
		      <entry>start&nbsp;+&nbsp;16:</entry>
		      <entry>Cb<subscript>00</subscript></entry>
		      <entry>Cr<subscript>00</subscript></entry>
		      <entry>Cb<subscript>01</subscript></entry>
		      <entry>Cr<subscript>01</subscript></entry>
		    </row>
		    <row>
		      <entry>start&nbsp;+&nbsp;20:</entry>
		      <entry>Cb<subscript>10</subscript></entry>
		      <entry>Cr<subscript>10</subscript></entry>
		      <entry>Cb<subscript>11</subscript></entry>
		      <entry>Cr<subscript>11</subscript></entry>
		    </row>
		    <row>
		      <entry>start&nbsp;+&nbsp;24:</entry>
		      <entry>Cb<subscript>20</subscript></entry>
		      <entry>Cr<subscript>20</subscript></entry>
		      <entry>Cb<subscript>21</subscript></entry>
		      <entry>Cr<subscript>21</subscript></entry>
		    </row>
		    <row>
		      <entry>start&nbsp;+&nbsp;28:</entry>
		      <entry>Cb<subscript>30</subscript></entry>
		      <entry>Cr<subscript>30</subscript></entry>
		      <entry>Cb<subscript>31</subscript></entry>
		      <entry>Cr<subscript>31</subscript></entry>
		    </row>
		  </tbody>
		</tgroup>
		</informaltable>
	      </para>
	  </formalpara>

	  <formalpara>
	    <title>Color Sample Location.</title>
	    <para>
		<informaltable frame="none">
		<tgroup cols="7" align="center">
		  <tbody valign="top">
		    <row>
		      <entry></entry>
		      <entry>0</entry><entry></entry><entry>1</entry><entry></entry>
		      <entry>2</entry><entry></entry><entry>3</entry>
		    </row>
		    <row>
		      <entry>0</entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry>
		    </row>
		    <row>
		      <entry></entry>
		      <entry></entry><entry>C</entry><entry></entry><entry></entry>
		      <entry></entry><entry>C</entry><entry></entry>
		    </row>
		    <row>
		      <entry>1</entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry>
		    </row>
		    <row>
		      <entry></entry>
		      <entry></entry><entry>C</entry><entry></entry><entry></entry>
		      <entry></entry><entry>C</entry><entry></entry>
		    </row>
		    <row>
		      <entry></entry>
		    </row>
		    <row>
		      <entry>2</entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry>
		    </row>
		    <row>
		      <entry></entry>
		      <entry></entry><entry>C</entry><entry></entry><entry></entry>
		      <entry></entry><entry>C</entry><entry></entry>
		    </row>
		    <row>
		      <entry>3</entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry>
		    </row>
		    <row>
		      <entry></entry>
		      <entry></entry><entry>C</entry><entry></entry><entry></entry>
		      <entry></entry><entry>C</entry><entry></entry>
		    </row>
		  </tbody>
		</tgroup>
		</informaltable>
	      </para>
	  </formalpara>
	</example>
      </refsect1>
    </refentry>
Commit	Line	Data
8e080c2e MCC	1	<refentry>
	2	<refmeta>
	3	<refentrytitle>V4L2_PIX_FMT_NV16 ('NV16'), V4L2_PIX_FMT_NV61 ('NV61')</refentrytitle>
	4	&manvol;
	5	</refmeta>
	6	<refnamediv>
	7	<refname id="V4L2-PIX-FMT-NV16"><constant>V4L2_PIX_FMT_NV16</constant></refname>
	8	<refname id="V4L2-PIX-FMT-NV61"><constant>V4L2_PIX_FMT_NV61</constant></refname>
	9	<refpurpose>Formats with ½ horizontal
	10	chroma resolution, also known as YUV 4:2:2. One luminance and one
	11	chrominance plane with alternating chroma samples as opposed to
	12	<constant>V4L2_PIX_FMT_YVU420</constant></refpurpose>
	13	</refnamediv>
	14	<refsect1>
	15	<title>Description</title>
	16
	17	<para>These are two-plane versions of the YUV 4:2:2 format.
	18	The three components are separated into two sub-images or planes. The
	19	Y plane is first. The Y plane has one byte per pixel. For
	20	<constant>V4L2_PIX_FMT_NV16</constant>, a combined CbCr plane
	21	immediately follows the Y plane in memory. The CbCr plane is the same
	22	width and height, in bytes, as the Y plane (and of the image).
	23	Each CbCr pair belongs to two pixels. For example,
	24	Cb<subscript>0</subscript>/Cr<subscript>0</subscript> belongs to
	25	Y'<subscript>00</subscript>, Y'<subscript>01</subscript>.
	26	<constant>V4L2_PIX_FMT_NV61</constant> is the same except the Cb and
	27	Cr bytes are swapped, the CrCb plane starts with a Cr byte.</para>
	28
	29	<para>If the Y plane has pad bytes after each row, then the
	30	CbCr plane has as many pad bytes after its rows.</para>
	31
	32	<example>
	33	<title><constant>V4L2_PIX_FMT_NV16</constant> 4 × 4
	34	pixel image</title>
	35
	36	<formalpara>
	37	<title>Byte Order.</title>
	38	<para>Each cell is one byte.
	39	<informaltable frame="none">
	40	<tgroup cols="5" align="center">
	41	<colspec align="left" colwidth="2*" />
	42	<tbody valign="top">
	43	<row>
	44	<entry>start + 0:</entry>
	45	<entry>Y'<subscript>00</subscript></entry>
	46	<entry>Y'<subscript>01</subscript></entry>
	47	<entry>Y'<subscript>02</subscript></entry>
	48	<entry>Y'<subscript>03</subscript></entry>
	49	</row>
	50	<row>
	51	<entry>start + 4:</entry>
	52	<entry>Y'<subscript>10</subscript></entry>
	53	<entry>Y'<subscript>11</subscript></entry>
	54	<entry>Y'<subscript>12</subscript></entry>
	55	<entry>Y'<subscript>13</subscript></entry>
	56	</row>
	57	<row>
	58	<entry>start + 8:</entry>
	59	<entry>Y'<subscript>20</subscript></entry>
	60	<entry>Y'<subscript>21</subscript></entry>
	61	<entry>Y'<subscript>22</subscript></entry>
	62	<entry>Y'<subscript>23</subscript></entry>
	63	</row>
	64	<row>
65	<entry>start + 12:</entry>
66	<entry>Y'<subscript>30</subscript></entry>
67	<entry>Y'<subscript>31</subscript></entry>
68	<entry>Y'<subscript>32</subscript></entry>
69	<entry>Y'<subscript>33</subscript></entry>
70	</row>
71	<row>
72	<entry>start + 16:</entry>
73	<entry>Cb<subscript>00</subscript></entry>
74	<entry>Cr<subscript>00</subscript></entry>
75	<entry>Cb<subscript>01</subscript></entry>
76	<entry>Cr<subscript>01</subscript></entry>
77	</row>
78	<row>
79	<entry>start + 20:</entry>
80	<entry>Cb<subscript>10</subscript></entry>
81	<entry>Cr<subscript>10</subscript></entry>
82	<entry>Cb<subscript>11</subscript></entry>
83	<entry>Cr<subscript>11</subscript></entry>
84	</row>
85	<row>
86	<entry>start + 24:</entry>
87	<entry>Cb<subscript>20</subscript></entry>
88	<entry>Cr<subscript>20</subscript></entry>
89	<entry>Cb<subscript>21</subscript></entry>
90	<entry>Cr<subscript>21</subscript></entry>
91	</row>
92	<row>
93	<entry>start + 28:</entry>
94	<entry>Cb<subscript>30</subscript></entry>
95	<entry>Cr<subscript>30</subscript></entry>
96	<entry>Cb<subscript>31</subscript></entry>
97	<entry>Cr<subscript>31</subscript></entry>
98	</row>
99	</tbody>
100	</tgroup>
101	</informaltable>
102	</para>
103	</formalpara>
104
105	<formalpara>
106	<title>Color Sample Location.</title>
107	<para>
108	<informaltable frame="none">
109	<tgroup cols="7" align="center">
110	<tbody valign="top">
111	<row>
112	<entry></entry>
113	<entry>0</entry><entry></entry><entry>1</entry><entry></entry>
114	<entry>2</entry><entry></entry><entry>3</entry>
115	</row>
116	<row>
117	<entry>0</entry>
118	<entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
119	<entry>Y</entry><entry></entry><entry>Y</entry>
120	</row>
121	<row>
122	<entry></entry>
123	<entry></entry><entry>C</entry><entry></entry><entry></entry>
124	<entry></entry><entry>C</entry><entry></entry>
125	</row>
126	<row>
127	<entry>1</entry>
128	<entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
129	<entry>Y</entry><entry></entry><entry>Y</entry>
130	</row>
131	<row>
132	<entry></entry>
133	<entry></entry><entry>C</entry><entry></entry><entry></entry>
134	<entry></entry><entry>C</entry><entry></entry>
135	</row>
136	<row>
137	<entry></entry>
138	</row>
139	<row>
140	<entry>2</entry>
141	<entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
142	<entry>Y</entry><entry></entry><entry>Y</entry>
143	</row>
144	<row>
145	<entry></entry>
146	<entry></entry><entry>C</entry><entry></entry><entry></entry>
147	<entry></entry><entry>C</entry><entry></entry>
148	</row>
149	<row>
150	<entry>3</entry>
151	<entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
152	<entry>Y</entry><entry></entry><entry>Y</entry>
153	</row>
154	<row>
155	<entry></entry>
156	<entry></entry><entry>C</entry><entry></entry><entry></entry>
157	<entry></entry><entry>C</entry><entry></entry>
158	</row>
159	</tbody>
160	</tgroup>
161	</informaltable>
162	</para>
163	</formalpara>
164	</example>
165	</refsect1>
166	</refentry>