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authorKamil Debski <k.debski@samsung.com>2011-03-11 06:16:22 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2011-03-22 04:54:22 -0300
commitbd08a0cd5f546916a9454ae2c35756ed77957458 (patch)
tree887ec84169ae57ef697458c3f845adf06937b9e0 /Documentation
parent91707b8b27a785c42949ba55b65f084027962afa (diff)
[media] v4l: Documentation for the NV12MT format
Added documentation for V4L2_PIX_FMT_NV12MT format. This is a YUV 4:2:0 format with macro block size of 64x32 and specific order of macro blocks in the memory. Signed-off-by: Kamil Debski <k.debski@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/DocBook/media-entities.tmpl1
-rw-r--r--Documentation/DocBook/v4l/nv12mt.gifbin0 -> 2108 bytes
-rw-r--r--Documentation/DocBook/v4l/nv12mt_example.gifbin0 -> 6858 bytes
-rw-r--r--Documentation/DocBook/v4l/pixfmt-nv12mt.xml74
-rw-r--r--Documentation/DocBook/v4l/pixfmt.xml1
5 files changed, 76 insertions, 0 deletions
diff --git a/Documentation/DocBook/media-entities.tmpl b/Documentation/DocBook/media-entities.tmpl
index 40158ee3d369..5d259c632cdf 100644
--- a/Documentation/DocBook/media-entities.tmpl
+++ b/Documentation/DocBook/media-entities.tmpl
@@ -272,6 +272,7 @@
<!ENTITY sub-grey SYSTEM "v4l/pixfmt-grey.xml">
<!ENTITY sub-nv12 SYSTEM "v4l/pixfmt-nv12.xml">
<!ENTITY sub-nv12m SYSTEM "v4l/pixfmt-nv12m.xml">
+<!ENTITY sub-nv12mt SYSTEM "v4l/pixfmt-nv12mt.xml">
<!ENTITY sub-nv16 SYSTEM "v4l/pixfmt-nv16.xml">
<!ENTITY sub-packed-rgb SYSTEM "v4l/pixfmt-packed-rgb.xml">
<!ENTITY sub-packed-yuv SYSTEM "v4l/pixfmt-packed-yuv.xml">
diff --git a/Documentation/DocBook/v4l/nv12mt.gif b/Documentation/DocBook/v4l/nv12mt.gif
new file mode 100644
index 000000000000..ef2d4cf8367b
--- /dev/null
+++ b/Documentation/DocBook/v4l/nv12mt.gif
Binary files differ
diff --git a/Documentation/DocBook/v4l/nv12mt_example.gif b/Documentation/DocBook/v4l/nv12mt_example.gif
new file mode 100644
index 000000000000..df81d68108ee
--- /dev/null
+++ b/Documentation/DocBook/v4l/nv12mt_example.gif
Binary files differ
diff --git a/Documentation/DocBook/v4l/pixfmt-nv12mt.xml b/Documentation/DocBook/v4l/pixfmt-nv12mt.xml
new file mode 100644
index 000000000000..5cb5bec8b653
--- /dev/null
+++ b/Documentation/DocBook/v4l/pixfmt-nv12mt.xml
@@ -0,0 +1,74 @@
+ <refentry>
+ <refmeta>
+ <refentrytitle>V4L2_PIX_FMT_NV12MT ('TM12')</refentrytitle>
+ &manvol;
+ </refmeta>
+ <refnamediv>
+ <refname id="V4L2-PIX-FMT-NV12MT"><constant>V4L2_PIX_FMT_NV12MT
+</constant></refname>
+ <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
+figure.</para>
+ <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">
+ <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
+End:
+ -->
diff --git a/Documentation/DocBook/v4l/pixfmt.xml b/Documentation/DocBook/v4l/pixfmt.xml
index f8436dcb7414..c6fdcbbd1b41 100644
--- a/Documentation/DocBook/v4l/pixfmt.xml
+++ b/Documentation/DocBook/v4l/pixfmt.xml
@@ -709,6 +709,7 @@ information.</para>
&sub-yuv411p;
&sub-nv12;
&sub-nv12m;
+ &sub-nv12mt;
&sub-nv16;
</section>