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Diffstat (limited to 'kernel/Documentation/DocBook/media/v4l/pixfmt-packed-rgb.xml')
| -rw-r--r-- | kernel/Documentation/DocBook/media/v4l/pixfmt-packed-rgb.xml | 937 |
1 files changed, 937 insertions, 0 deletions
diff --git a/kernel/Documentation/DocBook/media/v4l/pixfmt-packed-rgb.xml b/kernel/Documentation/DocBook/media/v4l/pixfmt-packed-rgb.xml new file mode 100644 index 000000000..b60fb935b --- /dev/null +++ b/kernel/Documentation/DocBook/media/v4l/pixfmt-packed-rgb.xml @@ -0,0 +1,937 @@ +<refentry id="packed-rgb"> + <refmeta> + <refentrytitle>Packed RGB formats</refentrytitle> + &manvol; + </refmeta> + <refnamediv> + <refname>Packed RGB formats</refname> + <refpurpose>Packed RGB formats</refpurpose> + </refnamediv> + <refsect1> + <title>Description</title> + + <para>These formats are designed to match the pixel formats of +typical PC graphics frame buffers. They occupy 8, 16, 24 or 32 bits +per pixel. These are all packed-pixel formats, meaning all the data +for a pixel lie next to each other in memory.</para> + + <table pgwide="1" frame="none" id="rgb-formats"> + <title>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> </entry> + <entry spanname="b0">Byte 0 in memory</entry> + <entry spanname="b1">Byte 1</entry> + <entry spanname="b2">Byte 2</entry> + <entry spanname="b3">Byte 3</entry> + </row> + <row> + <entry> </entry> + <entry> </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> </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> </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> </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 valign="top"> + <row id="V4L2-PIX-FMT-RGB332"> + <entry><constant>V4L2_PIX_FMT_RGB332</constant></entry> + <entry>'RGB1'</entry> + <entry></entry> + <entry>r<subscript>2</subscript></entry> + <entry>r<subscript>1</subscript></entry> + <entry>r<subscript>0</subscript></entry> + <entry>g<subscript>2</subscript></entry> + <entry>g<subscript>1</subscript></entry> + <entry>g<subscript>0</subscript></entry> + <entry>b<subscript>1</subscript></entry> + <entry>b<subscript>0</subscript></entry> + </row> + <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> + <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-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> + <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-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> + <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>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>5</subscript></entry> + <entry>g<subscript>4</subscript></entry> + <entry>g<subscript>3</subscript></entry> + </row> + <row id="V4L2-PIX-FMT-ARGB555X"> + <entry><constant>V4L2_PIX_FMT_ARGB555X</constant></entry> + <entry>'AR15' | (1 << 31)</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> + <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> + </row> + <row id="V4L2-PIX-FMT-XRGB555X"> + <entry><constant>V4L2_PIX_FMT_XRGB555X</constant></entry> + <entry>'XR15' | (1 << 31)</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> + <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> + </row> + <row id="V4L2-PIX-FMT-RGB565X"> + <entry><constant>V4L2_PIX_FMT_RGB565X</constant></entry> + <entry>'RGBR'</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>5</subscript></entry> + <entry>g<subscript>4</subscript></entry> + <entry>g<subscript>3</subscript></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> + </row> + <row id="V4L2-PIX-FMT-BGR24"> + <entry><constant>V4L2_PIX_FMT_BGR24</constant></entry> + <entry>'BGR3'</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> + </row> + <row id="V4L2-PIX-FMT-RGB24"> + <entry><constant>V4L2_PIX_FMT_RGB24</constant></entry> + <entry>'RGB3'</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> + <row id="V4L2-PIX-FMT-BGR666"> + <entry><constant>V4L2_PIX_FMT_BGR666</constant></entry> + <entry>'BGRH'</entry> + <entry></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>g<subscript>5</subscript></entry> + <entry>g<subscript>4</subscript></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>r<subscript>5</subscript></entry> + <entry>r<subscript>4</subscript></entry> + <entry>r<subscript>3</subscript></entry> + <entry>r<subscript>2</subscript></entry> + <entry></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> + <entry>-</entry> + <entry>-</entry> + <entry>-</entry> + <entry>-</entry> + <entry>-</entry> + <entry>-</entry> + </row> + <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> + <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-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>'BA24'</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> + <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.</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 × 4 pixel +image</title> + + <formalpara> + <title>Byte Order.</title> + <para>Each cell is one byte. + <informaltable frame="none"> + <tgroup cols="13" align="center"> + <colspec align="left" colwidth="2*" /> + <tbody valign="top"> + <row> + <entry>start + 0:</entry> + <entry>B<subscript>00</subscript></entry> + <entry>G<subscript>00</subscript></entry> + <entry>R<subscript>00</subscript></entry> + <entry>B<subscript>01</subscript></entry> + <entry>G<subscript>01</subscript></entry> + <entry>R<subscript>01</subscript></entry> + <entry>B<subscript>02</subscript></entry> + <entry>G<subscript>02</subscript></entry> + <entry>R<subscript>02</subscript></entry> + <entry>B<subscript>03</subscript></entry> + <entry>G<subscript>03</subscript></entry> + <entry>R<subscript>03</subscript></entry> + </row> + <row> + <entry>start + 12:</entry> + <entry>B<subscript>10</subscript></entry> + <entry>G<subscript>10</subscript></entry> + <entry>R<subscript>10</subscript></entry> + <entry>B<subscript>11</subscript></entry> + <entry>G<subscript>11</subscript></entry> + <entry>R<subscript>11</subscript></entry> + <entry>B<subscript>12</subscript></entry> + <entry>G<subscript>12</subscript></entry> + <entry>R<subscript>12</subscript></entry> + <entry>B<subscript>13</subscript></entry> + <entry>G<subscript>13</subscript></entry> + <entry>R<subscript>13</subscript></entry> + </row> + <row> + <entry>start + 24:</entry> + <entry>B<subscript>20</subscript></entry> + <entry>G<subscript>20</subscript></entry> + <entry>R<subscript>20</subscript></entry> + <entry>B<subscript>21</subscript></entry> + <entry>G<subscript>21</subscript></entry> + <entry>R<subscript>21</subscript></entry> + <entry>B<subscript>22</subscript></entry> + <entry>G<subscript>22</subscript></entry> + <entry>R<subscript>22</subscript></entry> + <entry>B<subscript>23</subscript></entry> + <entry>G<subscript>23</subscript></entry> + <entry>R<subscript>23</subscript></entry> + </row> + <row> + <entry>start + 36:</entry> + <entry>B<subscript>30</subscript></entry> + <entry>G<subscript>30</subscript></entry> + <entry>R<subscript>30</subscript></entry> + <entry>B<subscript>31</subscript></entry> + <entry>G<subscript>31</subscript></entry> + <entry>R<subscript>31</subscript></entry> + <entry>B<subscript>32</subscript></entry> + <entry>G<subscript>32</subscript></entry> + <entry>R<subscript>32</subscript></entry> + <entry>B<subscript>33</subscript></entry> + <entry>G<subscript>33</subscript></entry> + <entry>R<subscript>33</subscript></entry> + </row> + </tbody> + </tgroup> + </informaltable> + </para> + </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> </entry> + <entry spanname="b0">Byte 0 in memory</entry> + <entry spanname="b1">Byte 1</entry> + <entry spanname="b2">Byte 2</entry> + <entry spanname="b3">Byte 3</entry> + </row> + <row> + <entry> </entry> + <entry> </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> </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> </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> </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-RGB555X"> + <entry><constant>V4L2_PIX_FMT_RGB555X</constant></entry> + <entry>'RGBQ'</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> + <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> + </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> + + </refsect1> + </refentry> |