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+ <refentry>
+ <refmeta>
+ <refentrytitle>V4L2_PIX_FMT_NV12MT ('TM12')</refentrytitle>
+ &manvol;
+ </refmeta>
+ <refnamediv>
+ <refname id="V4L2-PIX-FMT-NV12MT"><constant>V4L2_PIX_FMT_NV12MT
+ <refpurpose>Formats with &frac12; horizontal and vertical
+chroma resolution. This format has two planes - one for luminance and one for
+chrominance. Chroma samples are interleaved. The difference to
+<constant>V4L2_PIX_FMT_NV12</constant> is the memory layout. Pixels are
+grouped in macroblocks of 64x32 size. The order of macroblocks in memory is
+also not standard.
+ </refpurpose>
+ </refnamediv>
+ <refsect1>
+ <title>Description</title>
+ <para>This is the two-plane versions of the YUV 4:2:0 format where data
+is grouped into 64x32 macroblocks. The three components are separated into two
+sub-images or planes. The Y plane has one byte per pixel and pixels are grouped
+into 64x32 macroblocks. The CbCr plane has the same width, in bytes, as the Y
+plane (and the image), but is half as tall in pixels. The chroma plane is also
+grouped into 64x32 macroblocks.</para>
+ <para>Width of the buffer has to be aligned to the multiple of 128, and
+height alignment is 32. Every four adjactent buffers - two horizontally and two
+vertically are grouped together and are located in memory in Z or flipped Z
+order. </para>
+ <para>Layout of macroblocks in memory is presented in the following
+ <para><figure id="nv12mt">
+ <title><constant>V4L2_PIX_FMT_NV12MT</constant> macroblock Z shape
+memory layout</title>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="nv12mt.gif" format="GIF" />
+ </imageobject>
+ </mediaobject>
+ </figure>
+ The requirement that width is multiple of 128 is implemented because,
+the Z shape cannot be cut in half horizontally. In case the vertical resolution
+of macroblocks is odd then the last row of macroblocks is arranged in a linear
+order. </para>
+ <para>In case of chroma the layout is identical. Cb and Cr samples are
+interleaved. Height of the buffer is aligned to 32.
+ </para>
+ <example>
+ <title>Memory layout of macroblocks in <constant>V4L2_PIX_FMT_NV12
+</constant> format pixel image - extreme case</title>
+ <para>
+ <figure id="nv12mt_ex">
+ <title>Example <constant>V4L2_PIX_FMT_NV12MT</constant> memory
+layout of macroblocks</title>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="nv12mt_example.gif" format="GIF" />
+ </imageobject>
+ </mediaobject>
+ </figure>
+ Memory layout of macroblocks of <constant>V4L2_PIX_FMT_NV12MT
+</constant> format in most extreme case.
+ </para>
+ </example>
+ </refsect1>
+ </refentry>
+ <!--
+Local Variables:
+mode: sgml
+sgml-parent-document: "pixfmt.sgml"
+indent-tabs-mode: nil
+ -->