Re: [PATCH v3 1/5] v4l: Add new YVU420 multi planar fourcc definition

[Sylwester Nawrocki <sylvester.nawrocki@gmail.com>]

Hi Shaik,

On 07/25/2012 02:26 PM, Shaik Ameer Basha wrote:
> This patch adds the following new fourcc definition.
> For multiplanar YCrCb
>          - V4L2_PIX_FMT_YVU420M - 'YVUM'
>
> Signed-off-by: Shaik Ameer Basha<shaik.ameer@samsung.com>
> ---
>   Documentation/DocBook/media/v4l/pixfmt-yuv420m.xml |   97 +++++++++++++++++---

Can you please add a new xml file for this new format, rather than
modifying this one ? I think it would be more clear this way.

>   include/linux/videodev2.h                          |    1 +
>   2 files changed, 84 insertions(+), 14 deletions(-)
>
> diff --git a/Documentation/DocBook/media/v4l/pixfmt-yuv420m.xml b/Documentation/DocBook/media/v4l/pixfmt-yuv420m.xml
> index 60308f1..9fc9a2e 100644
> --- a/Documentation/DocBook/media/v4l/pixfmt-yuv420m.xml
> +++ b/Documentation/DocBook/media/v4l/pixfmt-yuv420m.xml
> @@ -1,12 +1,14 @@
> -<refentry id="V4L2-PIX-FMT-YUV420M">
> +<refentry>
>         <refmeta>
> -	<refentrytitle>V4L2_PIX_FMT_YUV420M ('YM12')</refentrytitle>
> +	<refentrytitle>V4L2_PIX_FMT_YUV420M ('YM12'), V4L2_PIX_FMT_YVU420M ('YMUM')</refentrytitle>
>   	&manvol;
>         </refmeta>
>         <refnamediv>
> -	<refname>  <constant>V4L2_PIX_FMT_YUV420M</constant></refname>
> -	<refpurpose>Variation of<constant>V4L2_PIX_FMT_YUV420</constant>
> -	  with planes non contiguous in memory.</refpurpose>
> +	<refname id="V4L2_PIX_FMT_YUV420M"><constant>V4L2_PIX_FMT_YUV420M</constant></refname>
> +	<refname id="V4L2_PIX_FMT_YVU420M"><constant>V4L2_PIX_FMT_YVU420M</constant></refname>
> +	<refpurpose>Variation of<constant>V4L2_PIX_FMT_YUV420</constant>,
> +	<constant>V4L2_PIX_FMT_YVU420</constant>  respectively with planes non contiguous in memory.
> +		</refpurpose>
>         </refnamediv>
>
>         <refsect1>
> @@ -16,29 +18,34 @@
>   The three components are separated into three sub- images or planes.
>
>   The Y plane is first. The Y plane has one byte per pixel. The Cb data
> -constitutes the second plane which is half the width and half
> -the height of the Y plane (and of the image). Each Cb belongs to four
> +constitutes the second plane for<constant>V4L2_PIX_FMT_YUV420M</constant>  format
> +and the third plane for<constant>V4L2_PIX_FMT_YVU420M</constant>  format,
> +which is half the width and half the height of the Y plane (and of the image).
> +Each Cb belongs to four
>   pixels, a two-by-two square of the image. For example,
>   Cb<subscript>0</subscript>  belongs to Y'<subscript>00</subscript>,
>   Y'<subscript>01</subscript>, Y'<subscript>10</subscript>, and
> -Y'<subscript>11</subscript>. The Cr data, just like the Cb plane, is
> -in the third plane.</para>
> +Y'<subscript>11</subscript>. The Cr data, just like the Cb data, constitutes
> +the third plane for<constant>V4L2_PIX_FMT_YUV420M</constant>  format and
> +the second plane for<constant>V4L2_PIX_FMT_YVU420M</constant>  format.</para>
>
>   	<para>If the Y plane has pad bytes after each row, then the Cb
>   and Cr planes have half as many pad bytes after their rows. In other
> -words, two Cx rows (including padding) is exactly as long as one Y row
> +words, two Cx rows (including padding) are exactly as long as one Y row
>   (including padding).</para>
>
> -	<para><constant>V4L2_PIX_FMT_NV12M</constant>  is intended to be
> +	<para><constant>V4L2_PIX_FMT_YUV420M</constant>,
> +<constant>V4L2_PIX_FMT_YVU420M</constant>  are intended to be
>   used only in drivers and applications that support the multi-planar API,
>   described in<xref linkend="planar-apis"/>.</para>
>
>   	<example>
> -	<title><constant>V4L2_PIX_FMT_YVU420M</constant>  4&times; 4
> -pixel image</title>
> +	<title><constant>V4L2_PIX_FMT_YUV420M</constant>,
> +		<constant>V4L2_PIX_FMT_YVU420M</constant>  4&times; 4
> +		pixel image</title>
>
>   	<formalpara>
> -	<title>Byte Order.</title>
> +	<title>Byte Order for V4L2_PIX_FMT_YUV420M.</title>
>   	<para>Each cell is one byte.
>   		<informaltable frame="none">
>   		<tgroup cols="5" align="center">
> @@ -101,6 +108,68 @@ pixel image</title>
>   	</formalpara>
>
>   	<formalpara>
> +	<title>Byte Order for V4L2_PIX_FMT_YVU420M.</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>start0&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>start0&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>start0&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>start0&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></entry></row>
> +		<row>
> +		<entry>start1&nbsp;+&nbsp;0:</entry>
> +		<entry>Cr<subscript>00</subscript></entry>
> +		<entry>Cr<subscript>01</subscript></entry>
> +		</row>
> +		<row>
> +		<entry>start1&nbsp;+&nbsp;2:</entry>
> +		<entry>Cr<subscript>10</subscript></entry>
> +		<entry>Cr<subscript>11</subscript></entry>
> +		</row>
> +		<row><entry></entry></row>
> +		<row>
> +		<entry>start2&nbsp;+&nbsp;0:</entry>
> +		<entry>Cb<subscript>00</subscript></entry>
> +		<entry>Cb<subscript>01</subscript></entry>
> +		</row>
> +		<row>
> +		<entry>start2&nbsp;+&nbsp;2:</entry>
> +		<entry>Cb<subscript>10</subscript></entry>
> +		<entry>Cb<subscript>11</subscript></entry>
> +		</row>
> +		</tbody>
> +		</tgroup>
> +		</informaltable>
> +	</para>
> +	</formalpara>
> +	<formalpara>
>   	<title>Color Sample Location.</title>
>   	<para>
>   		<informaltable frame="none">
> diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
> index dbf9d3a..80962b8 100644
> --- a/include/linux/videodev2.h
> +++ b/include/linux/videodev2.h
> @@ -365,6 +365,7 @@ struct v4l2_pix_format {
>
>   /* three non contiguous planes - Y, Cb, Cr */
>   #define V4L2_PIX_FMT_YUV420M v4l2_fourcc('Y', 'M', '1', '2') /* 12  YUV420 planar */
> +#define V4L2_PIX_FMT_YVU420M v4l2_fourcc('Y', 'V', 'U', 'M') /* 12  YVU420 planar */
>
>   /* Bayer formats - see http://www.siliconimaging.com/RGB%20Bayer.htm */
>   #define V4L2_PIX_FMT_SBGGR8  v4l2_fourcc('B', 'A', '8', '1') /*  8  BGBG.. GRGR.. */

--

Thanks,
Sylwester