[media] v4l: Add ARGB and XRGB pixel formats

The existing RGB pixel formats are ill-defined in respect to their alpha
bits and their meaning is driver dependent. Create new standard ARGB and
XRGB variants with clearly defined meanings and make the existing
variants deprecated.

The new pixel formats 4CC values have been selected to match the DRM
4CCs for the same in-memory formats.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

1 files changed, 395 insertions, 20 deletions

diff --git a/Documentation/DocBook/media/v4l/pixfmt-packed-rgb.xml b/Documentation/DocBook/media/v4l/pixfmt-packed-rgb.xml
index e1c4f8b4c0b3..5f1602fe5494 100644
--- a/Documentation/DocBook/media/v4l/pixfmt-packed-rgb.xml
+++ b/Documentation/DocBook/media/v4l/pixfmt-packed-rgb.xml
@@ -130,9 +130,9 @@ colorspace <constant>V4L2_COLORSPACE_SRGB</constant>.</para>
 	    <entry>b<subscript>1</subscript></entry>
 	    <entry>b<subscript>0</subscript></entry>
 	  </row>
-	  <row id="V4L2-PIX-FMT-RGB444">
-	    <entry><constant>V4L2_PIX_FMT_RGB444</constant></entry>
-	    <entry>'R444'</entry>
+	  <row id="V4L2-PIX-FMT-ARGB444">
+	    <entry><constant>V4L2_PIX_FMT_ARGB444</constant></entry>
+	    <entry>'AR12'</entry>
 	    <entry></entry>
 	    <entry>g<subscript>3</subscript></entry>
 	    <entry>g<subscript>2</subscript></entry>
@@ -152,9 +152,31 @@ colorspace <constant>V4L2_COLORSPACE_SRGB</constant>.</para>
 	    <entry>r<subscript>1</subscript></entry>
 	    <entry>r<subscript>0</subscript></entry>
 	  </row>
-	  <row id="V4L2-PIX-FMT-RGB555">
-	    <entry><constant>V4L2_PIX_FMT_RGB555</constant></entry>
-	    <entry>'RGBO'</entry>
+	  <row id="V4L2-PIX-FMT-XRGB444">
+	    <entry><constant>V4L2_PIX_FMT_XRGB444</constant></entry>
+	    <entry>'XR12'</entry>
+	    <entry></entry>
+	    <entry>g<subscript>3</subscript></entry>
+	    <entry>g<subscript>2</subscript></entry>
+	    <entry>g<subscript>1</subscript></entry>
+	    <entry>g<subscript>0</subscript></entry>
+	    <entry>b<subscript>3</subscript></entry>
+	    <entry>b<subscript>2</subscript></entry>
+	    <entry>b<subscript>1</subscript></entry>
+	    <entry>b<subscript>0</subscript></entry>
+	    <entry></entry>
+	    <entry>-</entry>
+	    <entry>-</entry>
+	    <entry>-</entry>
+	    <entry>-</entry>
+	    <entry>r<subscript>3</subscript></entry>
+	    <entry>r<subscript>2</subscript></entry>
+	    <entry>r<subscript>1</subscript></entry>
+	    <entry>r<subscript>0</subscript></entry>
+	  </row>
+	  <row id="V4L2-PIX-FMT-ARGB555">
+	    <entry><constant>V4L2_PIX_FMT_ARGB555</constant></entry>
+	    <entry>'AR15'</entry>
 	    <entry></entry>
 	    <entry>g<subscript>2</subscript></entry>
 	    <entry>g<subscript>1</subscript></entry>
@@ -174,6 +196,28 @@ colorspace <constant>V4L2_COLORSPACE_SRGB</constant>.</para>
 	    <entry>g<subscript>4</subscript></entry>
 	    <entry>g<subscript>3</subscript></entry>
 	  </row>
+	  <row id="V4L2-PIX-FMT-XRGB555">
+	    <entry><constant>V4L2_PIX_FMT_XRGB555</constant></entry>
+	    <entry>'XR15'</entry>
+	    <entry></entry>
+	    <entry>g<subscript>2</subscript></entry>
+	    <entry>g<subscript>1</subscript></entry>
+	    <entry>g<subscript>0</subscript></entry>
+	    <entry>b<subscript>4</subscript></entry>
+	    <entry>b<subscript>3</subscript></entry>
+	    <entry>b<subscript>2</subscript></entry>
+	    <entry>b<subscript>1</subscript></entry>
+	    <entry>b<subscript>0</subscript></entry>
+	    <entry></entry>
+	    <entry>-</entry>
+	    <entry>r<subscript>4</subscript></entry>
+	    <entry>r<subscript>3</subscript></entry>
+	    <entry>r<subscript>2</subscript></entry>
+	    <entry>r<subscript>1</subscript></entry>
+	    <entry>r<subscript>0</subscript></entry>
+	    <entry>g<subscript>4</subscript></entry>
+	    <entry>g<subscript>3</subscript></entry>
+	  </row>
 	  <row id="V4L2-PIX-FMT-RGB565">
 	    <entry><constant>V4L2_PIX_FMT_RGB565</constant></entry>
 	    <entry>'RGBP'</entry>
@@ -341,9 +385,9 @@ colorspace <constant>V4L2_COLORSPACE_SRGB</constant>.</para>
 	    <entry>b<subscript>1</subscript></entry>
 	    <entry>b<subscript>0</subscript></entry>
 	  </row>
-	  <row id="V4L2-PIX-FMT-BGR32">
-	    <entry><constant>V4L2_PIX_FMT_BGR32</constant></entry>
-	    <entry>'BGR4'</entry>
+	  <row id="V4L2-PIX-FMT-ABGR32">
+	    <entry><constant>V4L2_PIX_FMT_ABGR32</constant></entry>
+	    <entry>'AR24'</entry>
 	    <entry></entry>
 	    <entry>b<subscript>7</subscript></entry>
 	    <entry>b<subscript>6</subscript></entry>
@@ -381,9 +425,49 @@ colorspace <constant>V4L2_COLORSPACE_SRGB</constant>.</para>
 	    <entry>a<subscript>1</subscript></entry>
 	    <entry>a<subscript>0</subscript></entry>
 	  </row>
-	  <row id="V4L2-PIX-FMT-RGB32">
-	    <entry><constant>V4L2_PIX_FMT_RGB32</constant></entry>
-	    <entry>'RGB4'</entry>
+	  <row id="V4L2-PIX-FMT-XBGR32">
+	    <entry><constant>V4L2_PIX_FMT_XBGR32</constant></entry>
+	    <entry>'XR24'</entry>
+	    <entry></entry>
+	    <entry>b<subscript>7</subscript></entry>
+	    <entry>b<subscript>6</subscript></entry>
+	    <entry>b<subscript>5</subscript></entry>
+	    <entry>b<subscript>4</subscript></entry>
+	    <entry>b<subscript>3</subscript></entry>
+	    <entry>b<subscript>2</subscript></entry>
+	    <entry>b<subscript>1</subscript></entry>
+	    <entry>b<subscript>0</subscript></entry>
+	    <entry></entry>
+	    <entry>g<subscript>7</subscript></entry>
+	    <entry>g<subscript>6</subscript></entry>
+	    <entry>g<subscript>5</subscript></entry>
+	    <entry>g<subscript>4</subscript></entry>
+	    <entry>g<subscript>3</subscript></entry>
+	    <entry>g<subscript>2</subscript></entry>
+	    <entry>g<subscript>1</subscript></entry>
+	    <entry>g<subscript>0</subscript></entry>
+	    <entry></entry>
+	    <entry>r<subscript>7</subscript></entry>
+	    <entry>r<subscript>6</subscript></entry>
+	    <entry>r<subscript>5</subscript></entry>
+	    <entry>r<subscript>4</subscript></entry>
+	    <entry>r<subscript>3</subscript></entry>
+	    <entry>r<subscript>2</subscript></entry>
+	    <entry>r<subscript>1</subscript></entry>
+	    <entry>r<subscript>0</subscript></entry>
+	    <entry></entry>
+	    <entry>-</entry>
+	    <entry>-</entry>
+	    <entry>-</entry>
+	    <entry>-</entry>
+	    <entry>-</entry>
+	    <entry>-</entry>
+	    <entry>-</entry>
+	    <entry>-</entry>
+	  </row>
+	  <row id="V4L2-PIX-FMT-ARGB32">
+	    <entry><constant>V4L2_PIX_FMT_ARGB32</constant></entry>
+	    <entry>'AX24'</entry>
 	    <entry></entry>
 	    <entry>a<subscript>7</subscript></entry>
 	    <entry>a<subscript>6</subscript></entry>
@@ -421,18 +505,76 @@ colorspace <constant>V4L2_COLORSPACE_SRGB</constant>.</para>
 	    <entry>b<subscript>1</subscript></entry>
 	    <entry>b<subscript>0</subscript></entry>
 	  </row>
+	  <row id="V4L2-PIX-FMT-XRGB32">
+	    <entry><constant>V4L2_PIX_FMT_XRGB32</constant></entry>
+	    <entry>'BX24'</entry>
+	    <entry></entry>
+	    <entry>-</entry>
+	    <entry>-</entry>
+	    <entry>-</entry>
+	    <entry>-</entry>
+	    <entry>-</entry>
+	    <entry>-</entry>
+	    <entry>-</entry>
+	    <entry>-</entry>
+	    <entry></entry>
+	    <entry>r<subscript>7</subscript></entry>
+	    <entry>r<subscript>6</subscript></entry>
+	    <entry>r<subscript>5</subscript></entry>
+	    <entry>r<subscript>4</subscript></entry>
+	    <entry>r<subscript>3</subscript></entry>
+	    <entry>r<subscript>2</subscript></entry>
+	    <entry>r<subscript>1</subscript></entry>
+	    <entry>r<subscript>0</subscript></entry>
+	    <entry></entry>
+	    <entry>g<subscript>7</subscript></entry>
+	    <entry>g<subscript>6</subscript></entry>
+	    <entry>g<subscript>5</subscript></entry>
+	    <entry>g<subscript>4</subscript></entry>
+	    <entry>g<subscript>3</subscript></entry>
+	    <entry>g<subscript>2</subscript></entry>
+	    <entry>g<subscript>1</subscript></entry>
+	    <entry>g<subscript>0</subscript></entry>
+	    <entry></entry>
+	    <entry>b<subscript>7</subscript></entry>
+	    <entry>b<subscript>6</subscript></entry>
+	    <entry>b<subscript>5</subscript></entry>
+	    <entry>b<subscript>4</subscript></entry>
+	    <entry>b<subscript>3</subscript></entry>
+	    <entry>b<subscript>2</subscript></entry>
+	    <entry>b<subscript>1</subscript></entry>
+	    <entry>b<subscript>0</subscript></entry>
+	  </row>
 	</tbody>
       </tgroup>
     </table>
 
-    <para>Bit 7 is the most significant bit. The value of the 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> or when the 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>
+    <para>Bit 7 is the most significant bit.</para>
+
+    <para>The usage and value of the alpha bits (a) in the ARGB and ABGR formats
+    (collectively referred to as alpha formats) depend on the device type and
+    hardware operation. <link linkend="capture">Capture</link> devices
+    (including capture queues of mem-to-mem devices) fill the alpha component in
+    memory. When the device outputs an alpha channel the alpha component will
+    have a meaningful value. Otherwise, when the device doesn't output an alpha
+    channel but can set the alpha bit to a user-configurable value, the <link
+    linkend="v4l2-alpha-component"><constant>V4L2_CID_ALPHA_COMPONENT</constant>
+    </link> control is used to specify that alpha value, and the alpha component
+    of all pixels will be set to the value specified by that control. Otherwise
+    a corresponding format without an alpha component (XRGB or XBGR) must be
+    used instead of an alpha format.</para>
+
+    <para><link linkend="output">Output</link> devices (including output queues
+    of mem-to-mem devices and <link linkend="osd">video output overlay</link>
+    devices) read the alpha component from memory. When the device processes the
+    alpha channel the alpha component must be filled with meaningful values by
+    applications. Otherwise a corresponding format without an alpha component
+    (XRGB or XBGR) must be used instead of an alpha format.</para>
+
+    <para>The XRGB and XBGR formats contain undefined bits (-). Applications,
+    devices and drivers must ignore those bits, for both <link
+    linkend="capture">capture</link> and <link linkend="output">output</link>
+    devices.</para>
 
     <example>
       <title><constant>V4L2_PIX_FMT_BGR24</constant> 4 &times; 4 pixel
@@ -512,6 +654,239 @@ image</title>
       </formalpara>
     </example>
 
+    <para>Formats defined in <xref linkend="rgb-formats-deprecated"/> are
+    deprecated and must not be used by new drivers. They are documented here for
+    reference. The meaning of their alpha bits (a) is ill-defined and
+    interpreted as in either the corresponding ARGB or XRGB format, depending on
+    the driver.</para>
+
+    <table pgwide="1" frame="none" id="rgb-formats-deprecated">
+      <title>Deprecated Packed RGB Image Formats</title>
+      <tgroup cols="37" align="center">
+	<colspec colname="id" align="left" />
+	<colspec colname="fourcc" />
+	<colspec colname="bit" />
+
+	<colspec colnum="4" colname="b07" align="center" />
+	<colspec colnum="5" colname="b06" align="center" />
+	<colspec colnum="6" colname="b05" align="center" />
+	<colspec colnum="7" colname="b04" align="center" />
+	<colspec colnum="8" colname="b03" align="center" />
+	<colspec colnum="9" colname="b02" align="center" />
+	<colspec colnum="10" colname="b01" align="center" />
+	<colspec colnum="11" colname="b00" align="center" />
+
+	<colspec colnum="13" colname="b17" align="center" />
+	<colspec colnum="14" colname="b16" align="center" />
+	<colspec colnum="15" colname="b15" align="center" />
+	<colspec colnum="16" colname="b14" align="center" />
+	<colspec colnum="17" colname="b13" align="center" />
+	<colspec colnum="18" colname="b12" align="center" />
+	<colspec colnum="19" colname="b11" align="center" />
+	<colspec colnum="20" colname="b10" align="center" />
+
+	<colspec colnum="22" colname="b27" align="center" />
+	<colspec colnum="23" colname="b26" align="center" />
+	<colspec colnum="24" colname="b25" align="center" />
+	<colspec colnum="25" colname="b24" align="center" />
+	<colspec colnum="26" colname="b23" align="center" />
+	<colspec colnum="27" colname="b22" align="center" />
+	<colspec colnum="28" colname="b21" align="center" />
+	<colspec colnum="29" colname="b20" align="center" />
+
+	<colspec colnum="31" colname="b37" align="center" />
+	<colspec colnum="32" colname="b36" align="center" />
+	<colspec colnum="33" colname="b35" align="center" />
+	<colspec colnum="34" colname="b34" align="center" />
+	<colspec colnum="35" colname="b33" align="center" />
+	<colspec colnum="36" colname="b32" align="center" />
+	<colspec colnum="37" colname="b31" align="center" />
+	<colspec colnum="38" colname="b30" align="center" />
+
+	<spanspec namest="b07" nameend="b00" spanname="b0" />
+	<spanspec namest="b17" nameend="b10" spanname="b1" />
+	<spanspec namest="b27" nameend="b20" spanname="b2" />
+	<spanspec namest="b37" nameend="b30" spanname="b3" />
+	<thead>
+	  <row>
+	    <entry>Identifier</entry>
+	    <entry>Code</entry>
+	    <entry>&nbsp;</entry>
+	    <entry spanname="b0">Byte&nbsp;0 in memory</entry>
+	    <entry spanname="b1">Byte&nbsp;1</entry>
+	    <entry spanname="b2">Byte&nbsp;2</entry>
+	    <entry spanname="b3">Byte&nbsp;3</entry>
+	  </row>
+	  <row>
+	    <entry>&nbsp;</entry>
+	    <entry>&nbsp;</entry>
+	    <entry>Bit</entry>
+	    <entry>7</entry>
+	    <entry>6</entry>
+	    <entry>5</entry>
+	    <entry>4</entry>
+	    <entry>3</entry>
+	    <entry>2</entry>
+	    <entry>1</entry>
+	    <entry>0</entry>
+	    <entry>&nbsp;</entry>
+	    <entry>7</entry>
+	    <entry>6</entry>
+	    <entry>5</entry>
+	    <entry>4</entry>
+	    <entry>3</entry>
+	    <entry>2</entry>
+	    <entry>1</entry>
+	    <entry>0</entry>
+	    <entry>&nbsp;</entry>
+	    <entry>7</entry>
+	    <entry>6</entry>
+	    <entry>5</entry>
+	    <entry>4</entry>
+	    <entry>3</entry>
+	    <entry>2</entry>
+	    <entry>1</entry>
+	    <entry>0</entry>
+	    <entry>&nbsp;</entry>
+	    <entry>7</entry>
+	    <entry>6</entry>
+	    <entry>5</entry>
+	    <entry>4</entry>
+	    <entry>3</entry>
+	    <entry>2</entry>
+	    <entry>1</entry>
+	    <entry>0</entry>
+	  </row>
+	</thead>
+	<tbody>
+	  <row id="V4L2-PIX-FMT-RGB444">
+	    <entry><constant>V4L2_PIX_FMT_RGB444</constant></entry>
+	    <entry>'R444'</entry>
+	    <entry></entry>
+	    <entry>g<subscript>3</subscript></entry>
+	    <entry>g<subscript>2</subscript></entry>
+	    <entry>g<subscript>1</subscript></entry>
+	    <entry>g<subscript>0</subscript></entry>
+	    <entry>b<subscript>3</subscript></entry>
+	    <entry>b<subscript>2</subscript></entry>
+	    <entry>b<subscript>1</subscript></entry>
+	    <entry>b<subscript>0</subscript></entry>
+	    <entry></entry>
+	    <entry>a<subscript>3</subscript></entry>
+	    <entry>a<subscript>2</subscript></entry>
+	    <entry>a<subscript>1</subscript></entry>
+	    <entry>a<subscript>0</subscript></entry>
+	    <entry>r<subscript>3</subscript></entry>
+	    <entry>r<subscript>2</subscript></entry>
+	    <entry>r<subscript>1</subscript></entry>
+	    <entry>r<subscript>0</subscript></entry>
+	  </row>
+	  <row id="V4L2-PIX-FMT-RGB555">
+	    <entry><constant>V4L2_PIX_FMT_RGB555</constant></entry>
+	    <entry>'RGBO'</entry>
+	    <entry></entry>
+	    <entry>g<subscript>2</subscript></entry>
+	    <entry>g<subscript>1</subscript></entry>
+	    <entry>g<subscript>0</subscript></entry>
+	    <entry>b<subscript>4</subscript></entry>
+	    <entry>b<subscript>3</subscript></entry>
+	    <entry>b<subscript>2</subscript></entry>
+	    <entry>b<subscript>1</subscript></entry>
+	    <entry>b<subscript>0</subscript></entry>
+	    <entry></entry>
+	    <entry>a</entry>
+	    <entry>r<subscript>4</subscript></entry>
+	    <entry>r<subscript>3</subscript></entry>
+	    <entry>r<subscript>2</subscript></entry>
+	    <entry>r<subscript>1</subscript></entry>
+	    <entry>r<subscript>0</subscript></entry>
+	    <entry>g<subscript>4</subscript></entry>
+	    <entry>g<subscript>3</subscript></entry>
+	  </row>
+	  <row id="V4L2-PIX-FMT-BGR32">
+	    <entry><constant>V4L2_PIX_FMT_BGR32</constant></entry>
+	    <entry>'BGR4'</entry>
+	    <entry></entry>
+	    <entry>b<subscript>7</subscript></entry>
+	    <entry>b<subscript>6</subscript></entry>
+	    <entry>b<subscript>5</subscript></entry>
+	    <entry>b<subscript>4</subscript></entry>
+	    <entry>b<subscript>3</subscript></entry>
+	    <entry>b<subscript>2</subscript></entry>
+	    <entry>b<subscript>1</subscript></entry>
+	    <entry>b<subscript>0</subscript></entry>
+	    <entry></entry>
+	    <entry>g<subscript>7</subscript></entry>
+	    <entry>g<subscript>6</subscript></entry>
+	    <entry>g<subscript>5</subscript></entry>
+	    <entry>g<subscript>4</subscript></entry>
+	    <entry>g<subscript>3</subscript></entry>
+	    <entry>g<subscript>2</subscript></entry>
+	    <entry>g<subscript>1</subscript></entry>
+	    <entry>g<subscript>0</subscript></entry>
+	    <entry></entry>
+	    <entry>r<subscript>7</subscript></entry>
+	    <entry>r<subscript>6</subscript></entry>
+	    <entry>r<subscript>5</subscript></entry>
+	    <entry>r<subscript>4</subscript></entry>
+	    <entry>r<subscript>3</subscript></entry>
+	    <entry>r<subscript>2</subscript></entry>
+	    <entry>r<subscript>1</subscript></entry>
+	    <entry>r<subscript>0</subscript></entry>
+	    <entry></entry>
+	    <entry>a<subscript>7</subscript></entry>
+	    <entry>a<subscript>6</subscript></entry>
+	    <entry>a<subscript>5</subscript></entry>
+	    <entry>a<subscript>4</subscript></entry>
+	    <entry>a<subscript>3</subscript></entry>
+	    <entry>a<subscript>2</subscript></entry>
+	    <entry>a<subscript>1</subscript></entry>
+	    <entry>a<subscript>0</subscript></entry>
+	  </row>
+	  <row id="V4L2-PIX-FMT-RGB32">
+	    <entry><constant>V4L2_PIX_FMT_RGB32</constant></entry>
+	    <entry>'RGB4'</entry>
+	    <entry></entry>
+	    <entry>a<subscript>7</subscript></entry>
+	    <entry>a<subscript>6</subscript></entry>
+	    <entry>a<subscript>5</subscript></entry>
+	    <entry>a<subscript>4</subscript></entry>
+	    <entry>a<subscript>3</subscript></entry>
+	    <entry>a<subscript>2</subscript></entry>
+	    <entry>a<subscript>1</subscript></entry>
+	    <entry>a<subscript>0</subscript></entry>
+	    <entry></entry>
+	    <entry>r<subscript>7</subscript></entry>
+	    <entry>r<subscript>6</subscript></entry>
+	    <entry>r<subscript>5</subscript></entry>
+	    <entry>r<subscript>4</subscript></entry>
+	    <entry>r<subscript>3</subscript></entry>
+	    <entry>r<subscript>2</subscript></entry>
+	    <entry>r<subscript>1</subscript></entry>
+	    <entry>r<subscript>0</subscript></entry>
+	    <entry></entry>
+	    <entry>g<subscript>7</subscript></entry>
+	    <entry>g<subscript>6</subscript></entry>
+	    <entry>g<subscript>5</subscript></entry>
+	    <entry>g<subscript>4</subscript></entry>
+	    <entry>g<subscript>3</subscript></entry>
+	    <entry>g<subscript>2</subscript></entry>
+	    <entry>g<subscript>1</subscript></entry>
+	    <entry>g<subscript>0</subscript></entry>
+	    <entry></entry>
+	    <entry>b<subscript>7</subscript></entry>
+	    <entry>b<subscript>6</subscript></entry>
+	    <entry>b<subscript>5</subscript></entry>
+	    <entry>b<subscript>4</subscript></entry>
+	    <entry>b<subscript>3</subscript></entry>
+	    <entry>b<subscript>2</subscript></entry>
+	    <entry>b<subscript>1</subscript></entry>
+	    <entry>b<subscript>0</subscript></entry>
+	  </row>
+	</tbody>
+      </tgroup>
+    </table>
+
     <para>A test utility to determine which RGB formats a driver
 actually supports is available from the LinuxTV v4l-dvb repository.
 See &v4l-dvb; for access instructions.</para>