Hi Sylwester,
On Friday 25 November 2011 16:39:31 Sylwester Nawrocki wrote:
> This control is intended for the video capture or memory-to-memory devices
> that are capable of setting up a per-pixel alpha component to some
> arbitrary value. The V4L2_CID_ALPHA_COMPONENT control allows to set the
> alpha component for all pixels to a value in range from 0 to 255.
>
> Signed-off-by: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> ---
> Documentation/DocBook/media/v4l/compat.xml | 11 ++++++++
> Documentation/DocBook/media/v4l/controls.xml | 25
> +++++++++++++++---- .../DocBook/media/v4l/pixfmt-packed-rgb.xml |
> 7 ++++-
> drivers/media/video/v4l2-ctrls.c | 7 +++++
> include/linux/videodev2.h | 6 ++--
> 5 files changed, 45 insertions(+), 11 deletions(-)
>
> diff --git a/Documentation/DocBook/media/v4l/compat.xml
> b/Documentation/DocBook/media/v4l/compat.xml index b68698f..0adda43 100644
> --- a/Documentation/DocBook/media/v4l/compat.xml
> +++ b/Documentation/DocBook/media/v4l/compat.xml
> @@ -2379,6 +2379,17 @@ that used it. It was originally scheduled for
> removal in 2.6.35. </orderedlist>
> </section>
>
> + <section>
> + <title>V4L2 in Linux 3.3</title>
> + <orderedlist>
> + <listitem>
> + <para>Added <constant>V4L2_CID_ALPHA_COMPONENT</constant> control
> + to the <link linkend="control">User controls class</link>.
> + </para>
> + </listitem>
> + </orderedlist>
> + </section>
> +
> <section id="other">
> <title>Relation of V4L2 to other Linux multimedia APIs</title>
>
> diff --git a/Documentation/DocBook/media/v4l/controls.xml
> b/Documentation/DocBook/media/v4l/controls.xml index 3bc5ee8..4fd83c0
> 100644
> --- a/Documentation/DocBook/media/v4l/controls.xml
> +++ b/Documentation/DocBook/media/v4l/controls.xml
> @@ -324,12 +324,6 @@ minimum value disables backlight compensation.</entry>
> (usually a microscope).</entry>
> </row>
> <row>
> - <entry><constant>V4L2_CID_LASTP1</constant></entry>
> - <entry></entry>
> - <entry>End of the predefined control IDs (currently
> -<constant>V4L2_CID_ILLUMINATORS_2</constant> + 1).</entry>
> - </row>
> - <row>
> <entry><constant>V4L2_CID_MIN_BUFFERS_FOR_CAPTURE</constant></entry>
> <entry>integer</entry>
> <entry>This is a read-only control that can be read by the
> application @@ -345,6 +339,25 @@ and used as a hint to determine the
> number of OUTPUT buffers to pass to REQBUFS. The value is the minimum
> number of OUTPUT buffers that is necessary for hardware to work.</entry>
> </row>
> + <row id="v4l2-alpha-component">
> + <entry><constant>V4L2_CID_ALPHA_COMPONENT</constant></entry>
> + <entry>integer</entry>
> + <entry> Sets the alpha color component on the capture device or on
> + the capture buffer queue of a mem-to-mem device. When a mem-to-mem
> + device produces frame format that includes an alpha component
> + (e.g. <link linkend="rgb-formats">packed RGB image formats</link>)
> + and the alpha value is not defined by the mem-to-mem input data
> + this control lets you select the alpha component value of all
> + pixels. It is applicable to any pixel format that contains an alpha
> + component.
> + </entry>
> + </row>
> + <row>
> + <entry><constant>V4L2_CID_LASTP1</constant></entry>
> + <entry></entry>
> + <entry>End of the predefined control IDs (currently
> + <constant>V4L2_CID_ALPHA_COMPONENT</constant> + 1).</entry>
> + </row>
> <row>
> <entry><constant>V4L2_CID_PRIVATE_BASE</constant></entry>
> <entry></entry>
> diff --git a/Documentation/DocBook/media/v4l/pixfmt-packed-rgb.xml
> b/Documentation/DocBook/media/v4l/pixfmt-packed-rgb.xml index
> 4db272b..c13278b 100644
> --- a/Documentation/DocBook/media/v4l/pixfmt-packed-rgb.xml
> +++ b/Documentation/DocBook/media/v4l/pixfmt-packed-rgb.xml
> @@ -428,8 +428,11 @@ colorspace
> <constant>V4L2_COLORSPACE_SRGB</constant>.</para> <para>Bit 7 is the most
> significant bit. The value of a = alpha bits is undefined when reading
> from the driver, ignored when writing to the driver, except when alpha
> blending has been negotiated for a -<link linkend="overlay">Video
> Overlay</link> or <link
> -linkend="osd">Video Output Overlay</link>.</para>
> +<link linkend="overlay">Video Overlay</link> or <link linkend="osd">
> +Video Output Overlay</link> or when alpha component has been configured
> +for a <link linkend="capture">Video Capture</link> by means of <link
> +linkend="v4l2-alpha-component"> <constant>V4L2_CID_ALPHA_COMPONENT
> +</constant> </link> control.</para>
>
> <example>
> <title><constant>V4L2_PIX_FMT_BGR24</constant> 4 × 4 pixel
> diff --git a/drivers/media/video/v4l2-ctrls.c
> b/drivers/media/video/v4l2-ctrls.c index 5552f81..882cc84 100644
> --- a/drivers/media/video/v4l2-ctrls.c
> +++ b/drivers/media/video/v4l2-ctrls.c
> @@ -466,6 +466,7 @@ const char *v4l2_ctrl_get_name(u32 id)
> case V4L2_CID_ILLUMINATORS_2: return "Illuminator 2";
> case V4L2_CID_MIN_BUFFERS_FOR_CAPTURE: return "Minimum Number of Capture
> Buffers"; case V4L2_CID_MIN_BUFFERS_FOR_OUTPUT: return "Minimum Number of
> Output Buffers"; + case V4L2_CID_ALPHA_COMPONENT: return "Alpha
> Component";
>
> /* MPEG controls */
> /* Keep the order of the 'case's the same as in videodev2.h! */
> @@ -714,6 +715,12 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum
> v4l2_ctrl_type *type, /* Max is calculated as RGB888 that is 2^24 */
> *max = 0xFFFFFF;
> break;
> + case V4L2_CID_ALPHA_COMPONENT:
> + *type = V4L2_CTRL_TYPE_INTEGER;
> + *step = 1;
> + *min = 0;
> + *max = 0xff;
> + break;
> case V4L2_CID_FLASH_FAULT:
> *type = V4L2_CTRL_TYPE_BITMASK;
> break;
> diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
> index 4b752d5..fdda200 100644
> --- a/include/linux/videodev2.h
> +++ b/include/linux/videodev2.h
> @@ -1204,10 +1204,10 @@ enum v4l2_colorfx {
> #define V4L2_CID_MIN_BUFFERS_FOR_CAPTURE (V4L2_CID_BASE+39)
> #define V4L2_CID_MIN_BUFFERS_FOR_OUTPUT (V4L2_CID_BASE+40)
>
> -/* last CID + 1 */
> -#define V4L2_CID_LASTP1 (V4L2_CID_BASE+41)
> +#define V4L2_CID_ALPHA_COMPONENT (V4L2_CID_BASE+41)
>
> -/* Minimum number of buffer neede by the device */
> +/* last CID + 1 */
> +#define V4L2_CID_LASTP1 (V4L2_CID_BASE+42)
>
> /* MPEG-class control IDs defined by V4L2 */
> #define V4L2_CID_MPEG_BASE (V4L2_CTRL_CLASS_MPEG | 0x900)
--
Regards,
Laurent Pinchart
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