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| author | Mauro Carvalho Chehab <mchehab@redhat.com> | 2011-05-31 21:27:44 +0200 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2011-07-27 22:52:05 +0200 |
| commit | 4266129964b8238526936d723de65b419d8069c6 (patch) | |
| tree | 38c6b5cd3dc99b8599391ffad3b87e399bef56a2 /Documentation/DocBook/v4l/pixfmt.xml | |
| parent | [media] DocBook: Add rules to auto-generate some media docbook (diff) | |
| download | linux-4266129964b8238526936d723de65b419d8069c6.tar.xz linux-4266129964b8238526936d723de65b419d8069c6.zip | |
[media] DocBook: Move all media docbook stuff into its own directory
This patch addresses several issues pointed by Randy Dunlap
<rdunlap@xenotime.net> at changeset ece722c:
- In the generated index.html file, "media" is listed first, but it
should be listed in alphabetical order, not first.
- The generated files are (hidden) in .tmpmedia/
- The link from the top-level index.html file to "media" is to
media/index.html, but the file is actually in .tmpmedia/media/index.html
- Please build docs with and without using "O=builddir" and test that.
- Would it be possible for media to have its own Makefile instead of
merging into this one?
Due to the way cleandocs target works, I had to rename the media DocBook
to media_api, otherwise cleandocs would remove the /media directory.
Thanks-to: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'Documentation/DocBook/v4l/pixfmt.xml')
| -rw-r--r-- | Documentation/DocBook/v4l/pixfmt.xml | 951 |
1 files changed, 0 insertions, 951 deletions
diff --git a/Documentation/DocBook/v4l/pixfmt.xml b/Documentation/DocBook/v4l/pixfmt.xml deleted file mode 100644 index deb660207f94..000000000000 --- a/Documentation/DocBook/v4l/pixfmt.xml +++ /dev/null @@ -1,951 +0,0 @@ - <title>Image Formats</title> - - <para>The V4L2 API was primarily designed for devices exchanging -image data with applications. The -<structname>v4l2_pix_format</structname> and <structname>v4l2_pix_format_mplane -</structname> structures define the format and layout of an image in memory. -The former is used with the single-planar API, while the latter is used with the -multi-planar version (see <xref linkend="planar-apis"/>). Image formats are -negotiated with the &VIDIOC-S-FMT; ioctl. (The explanations here focus on video -capturing and output, for overlay frame buffer formats see also -&VIDIOC-G-FBUF;.)</para> - -<section> - <title>Single-planar format structure</title> - <table pgwide="1" frame="none" id="v4l2-pix-format"> - <title>struct <structname>v4l2_pix_format</structname></title> - <tgroup cols="3"> - &cs-str; - <tbody valign="top"> - <row> - <entry>__u32</entry> - <entry><structfield>width</structfield></entry> - <entry>Image width in pixels.</entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>height</structfield></entry> - <entry>Image height in pixels.</entry> - </row> - <row> - <entry spanname="hspan">Applications set these fields to -request an image size, drivers return the closest possible values. In -case of planar formats the <structfield>width</structfield> and -<structfield>height</structfield> applies to the largest plane. To -avoid ambiguities drivers must return values rounded up to a multiple -of the scale factor of any smaller planes. For example when the image -format is YUV 4:2:0, <structfield>width</structfield> and -<structfield>height</structfield> must be multiples of two.</entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>pixelformat</structfield></entry> - <entry>The pixel format or type of compression, set by the -application. This is a little endian <link -linkend="v4l2-fourcc">four character code</link>. V4L2 defines -standard RGB formats in <xref linkend="rgb-formats" />, YUV formats in <xref -linkend="yuv-formats" />, and reserved codes in <xref -linkend="reserved-formats" /></entry> - </row> - <row> - <entry>&v4l2-field;</entry> - <entry><structfield>field</structfield></entry> - <entry>Video images are typically interlaced. Applications -can request to capture or output only the top or bottom field, or both -fields interlaced or sequentially stored in one buffer or alternating -in separate buffers. Drivers return the actual field order selected. -For details see <xref linkend="field-order" />.</entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>bytesperline</structfield></entry> - <entry>Distance in bytes between the leftmost pixels in two -adjacent lines.</entry> - </row> - <row> - <entry spanname="hspan"><para>Both applications and drivers -can set this field to request padding bytes at the end of each line. -Drivers however may ignore the value requested by the application, -returning <structfield>width</structfield> times bytes per pixel or a -larger value required by the hardware. That implies applications can -just set this field to zero to get a reasonable -default.</para><para>Video hardware may access padding bytes, -therefore they must reside in accessible memory. Consider cases where -padding bytes after the last line of an image cross a system page -boundary. Input devices may write padding bytes, the value is -undefined. Output devices ignore the contents of padding -bytes.</para><para>When the image format is planar the -<structfield>bytesperline</structfield> value applies to the largest -plane and is divided by the same factor as the -<structfield>width</structfield> field for any smaller planes. For -example the Cb and Cr planes of a YUV 4:2:0 image have half as many -padding bytes following each line as the Y plane. To avoid ambiguities -drivers must return a <structfield>bytesperline</structfield> value -rounded up to a multiple of the scale factor.</para></entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>sizeimage</structfield></entry> - <entry>Size in bytes of the buffer to hold a complete image, -set by the driver. Usually this is -<structfield>bytesperline</structfield> times -<structfield>height</structfield>. When the image consists of variable -length compressed data this is the maximum number of bytes required to -hold an image.</entry> - </row> - <row> - <entry>&v4l2-colorspace;</entry> - <entry><structfield>colorspace</structfield></entry> - <entry>This information supplements the -<structfield>pixelformat</structfield> and must be set by the driver, -see <xref linkend="colorspaces" />.</entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>priv</structfield></entry> - <entry>Reserved for custom (driver defined) additional -information about formats. When not used drivers and applications must -set this field to zero.</entry> - </row> - </tbody> - </tgroup> - </table> -</section> - -<section> - <title>Multi-planar format structures</title> - <para>The <structname>v4l2_plane_pix_format</structname> structures define - size and layout for each of the planes in a multi-planar format. - The <structname>v4l2_pix_format_mplane</structname> structure contains - information common to all planes (such as image width and height) and - an array of <structname>v4l2_plane_pix_format</structname> structures, - describing all planes of that format.</para> - <table pgwide="1" frame="none" id="v4l2-plane-pix-format"> - <title>struct <structname>vl42_plane_pix_format</structname></title> - <tgroup cols="3"> - &cs-str; - <tbody valign="top"> - <row> - <entry>__u32</entry> - <entry><structfield>sizeimage</structfield></entry> - <entry>Maximum size in bytes required for image data in this plane. - </entry> - </row> - <row> - <entry>__u16</entry> - <entry><structfield>bytesperline</structfield></entry> - <entry>Distance in bytes between the leftmost pixels in two adjacent - lines.</entry> - </row> - <row> - <entry>__u16</entry> - <entry><structfield>reserved[7]</structfield></entry> - <entry>Reserved for future extensions. Should be zeroed by the - application.</entry> - </row> - </tbody> - </tgroup> - </table> - <table pgwide="1" frame="none" id="v4l2-pix-format-mplane"> - <title>struct <structname>v4l2_pix_format_mplane</structname></title> - <tgroup cols="3"> - &cs-str; - <tbody valign="top"> - <row> - <entry>__u32</entry> - <entry><structfield>width</structfield></entry> - <entry>Image width in pixels.</entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>height</structfield></entry> - <entry>Image height in pixels.</entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>pixelformat</structfield></entry> - <entry>The pixel format. Both single- and multi-planar four character -codes can be used.</entry> - </row> - <row> - <entry>&v4l2-field;</entry> - <entry><structfield>field</structfield></entry> - <entry>See &v4l2-pix-format;.</entry> - </row> - <row> - <entry>&v4l2-colorspace;</entry> - <entry><structfield>colorspace</structfield></entry> - <entry>See &v4l2-pix-format;.</entry> - </row> - <row> - <entry>&v4l2-plane-pix-format;</entry> - <entry><structfield>plane_fmt[VIDEO_MAX_PLANES]</structfield></entry> - <entry>An array of structures describing format of each plane this - pixel format consists of. The number of valid entries in this array - has to be put in the <structfield>num_planes</structfield> - field.</entry> - </row> - <row> - <entry>__u8</entry> - <entry><structfield>num_planes</structfield></entry> - <entry>Number of planes (i.e. separate memory buffers) for this format - and the number of valid entries in the - <structfield>plane_fmt</structfield> array.</entry> - </row> - <row> - <entry>__u8</entry> - <entry><structfield>reserved[11]</structfield></entry> - <entry>Reserved for future extensions. Should be zeroed by the - application.</entry> - </row> - </tbody> - </tgroup> - </table> -</section> - - <section> - <title>Standard Image Formats</title> - - <para>In order to exchange images between drivers and -applications, it is necessary to have standard image data formats -which both sides will interpret the same way. V4L2 includes several -such formats, and this section is intended to be an unambiguous -specification of the standard image data formats in V4L2.</para> - - <para>V4L2 drivers are not limited to these formats, however. -Driver-specific formats are possible. In that case the application may -depend on a codec to convert images to one of the standard formats -when needed. But the data can still be stored and retrieved in the -proprietary format. For example, a device may support a proprietary -compressed format. Applications can still capture and save the data in -the compressed format, saving much disk space, and later use a codec -to convert the images to the X Windows screen format when the video is -to be displayed.</para> - - <para>Even so, ultimately, some standard formats are needed, so -the V4L2 specification would not be complete without well-defined -standard formats.</para> - - <para>The V4L2 standard formats are mainly uncompressed formats. The -pixels are always arranged in memory from left to right, and from top -to bottom. The first byte of data in the image buffer is always for -the leftmost pixel of the topmost row. Following that is the pixel -immediately to its right, and so on until the end of the top row of -pixels. Following the rightmost pixel of the row there may be zero or -more bytes of padding to guarantee that each row of pixel data has a -certain alignment. Following the pad bytes, if any, is data for the -leftmost pixel of the second row from the top, and so on. The last row -has just as many pad bytes after it as the other rows.</para> - - <para>In V4L2 each format has an identifier which looks like -<constant>PIX_FMT_XXX</constant>, defined in the <link -linkend="videodev">videodev.h</link> header file. These identifiers -represent <link linkend="v4l2-fourcc">four character (FourCC) codes</link> -which are also listed below, however they are not the same as those -used in the Windows world.</para> - - <para>For some formats, data is stored in separate, discontiguous -memory buffers. Those formats are identified by a separate set of FourCC codes -and are referred to as "multi-planar formats". For example, a YUV422 frame is -normally stored in one memory buffer, but it can also be placed in two or three -separate buffers, with Y component in one buffer and CbCr components in another -in the 2-planar version or with each component in its own buffer in the -3-planar case. Those sub-buffers are referred to as "planes".</para> - </section> - - <section id="colorspaces"> - <title>Colorspaces</title> - - <para>[intro]</para> - - <!-- See proposal by Billy Biggs, video4linux-list@redhat.com -on 11 Oct 2002, subject: "Re: [V4L] Re: v4l2 api", and -http://vektor.theorem.ca/graphics/ycbcr/ and -http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html --> - - <para> - <variablelist> - <varlistentry> - <term>Gamma Correction</term> - <listitem> - <para>[to do]</para> - <para>E'<subscript>R</subscript> = f(R)</para> - <para>E'<subscript>G</subscript> = f(G)</para> - <para>E'<subscript>B</subscript> = f(B)</para> - </listitem> - </varlistentry> - <varlistentry> - <term>Construction of luminance and color-difference -signals</term> - <listitem> - <para>[to do]</para> - <para>E'<subscript>Y</subscript> = -Coeff<subscript>R</subscript> E'<subscript>R</subscript> -+ Coeff<subscript>G</subscript> E'<subscript>G</subscript> -+ Coeff<subscript>B</subscript> E'<subscript>B</subscript></para> - <para>(E'<subscript>R</subscript> - E'<subscript>Y</subscript>) = E'<subscript>R</subscript> -- Coeff<subscript>R</subscript> E'<subscript>R</subscript> -- Coeff<subscript>G</subscript> E'<subscript>G</subscript> -- Coeff<subscript>B</subscript> E'<subscript>B</subscript></para> - <para>(E'<subscript>B</subscript> - E'<subscript>Y</subscript>) = E'<subscript>B</subscript> -- Coeff<subscript>R</subscript> E'<subscript>R</subscript> -- Coeff<subscript>G</subscript> E'<subscript>G</subscript> -- Coeff<subscript>B</subscript> E'<subscript>B</subscript></para> - </listitem> - </varlistentry> - <varlistentry> - <term>Re-normalized color-difference signals</term> - <listitem> - <para>The color-difference signals are scaled back to unity -range [-0.5;+0.5]:</para> - <para>K<subscript>B</subscript> = 0.5 / (1 - Coeff<subscript>B</subscript>)</para> - <para>K<subscript>R</subscript> = 0.5 / (1 - Coeff<subscript>R</subscript>)</para> - <para>P<subscript>B</subscript> = -K<subscript>B</subscript> (E'<subscript>B</subscript> - E'<subscript>Y</subscript>) = - 0.5 (Coeff<subscript>R</subscript> / Coeff<subscript>B</subscript>) E'<subscript>R</subscript> -+ 0.5 (Coeff<subscript>G</subscript> / Coeff<subscript>B</subscript>) E'<subscript>G</subscript> -+ 0.5 E'<subscript>B</subscript></para> - <para>P<subscript>R</subscript> = -K<subscript>R</subscript> (E'<subscript>R</subscript> - E'<subscript>Y</subscript>) = - 0.5 E'<subscript>R</subscript> -+ 0.5 (Coeff<subscript>G</subscript> / Coeff<subscript>R</subscript>) E'<subscript>G</subscript> -+ 0.5 (Coeff<subscript>B</subscript> / Coeff<subscript>R</subscript>) E'<subscript>B</subscript></para> - </listitem> - </varlistentry> - <varlistentry> - <term>Quantization</term> - <listitem> - <para>[to do]</para> - <para>Y' = (Lum. Levels - 1) · E'<subscript>Y</subscript> + Lum. Offset</para> - <para>C<subscript>B</subscript> = (Chrom. Levels - 1) -· P<subscript>B</subscript> + Chrom. Offset</para> - <para>C<subscript>R</subscript> = (Chrom. Levels - 1) -· P<subscript>R</subscript> + Chrom. Offset</para> - <para>Rounding to the nearest integer and clamping to the range -[0;255] finally yields the digital color components Y'CbCr -stored in YUV images.</para> - </listitem> - </varlistentry> - </variablelist> - </para> - - <example> - <title>ITU-R Rec. BT.601 color conversion</title> - - <para>Forward Transformation</para> - - <programlisting> -int ER, EG, EB; /* gamma corrected RGB input [0;255] */ -int Y1, Cb, Cr; /* output [0;255] */ - -double r, g, b; /* temporaries */ -double y1, pb, pr; - -int -clamp (double x) -{ - int r = x; /* round to nearest */ - - if (r < 0) return 0; - else if (r > 255) return 255; - else return r; -} - -r = ER / 255.0; -g = EG / 255.0; -b = EB / 255.0; - -y1 = 0.299 * r + 0.587 * g + 0.114 * b; -pb = -0.169 * r - 0.331 * g + 0.5 * b; -pr = 0.5 * r - 0.419 * g - 0.081 * b; - -Y1 = clamp (219 * y1 + 16); -Cb = clamp (224 * pb + 128); -Cr = clamp (224 * pr + 128); - -/* or shorter */ - -y1 = 0.299 * ER + 0.587 * EG + 0.114 * EB; - -Y1 = clamp ( (219 / 255.0) * y1 + 16); -Cb = clamp (((224 / 255.0) / (2 - 2 * 0.114)) * (EB - y1) + 128); -Cr = clamp (((224 / 255.0) / (2 - 2 * 0.299)) * (ER - y1) + 128); - </programlisting> - - <para>Inverse Transformation</para> - - <programlisting> -int Y1, Cb, Cr; /* gamma pre-corrected input [0;255] */ -int ER, EG, EB; /* output [0;255] */ - -double r, g, b; /* temporaries */ -double y1, pb, pr; - -int -clamp (double x) -{ - int r = x; /* round to nearest */ - - if (r < 0) return 0; - else if (r > 255) return 255; - else return r; -} - -y1 = (255 / 219.0) * (Y1 - 16); -pb = (255 / 224.0) * (Cb - 128); -pr = (255 / 224.0) * (Cr - 128); - -r = 1.0 * y1 + 0 * pb + 1.402 * pr; -g = 1.0 * y1 - 0.344 * pb - 0.714 * pr; -b = 1.0 * y1 + 1.772 * pb + 0 * pr; - -ER = clamp (r * 255); /* [ok? one should prob. limit y1,pb,pr] */ -EG = clamp (g * 255); -EB = clamp (b * 255); - </programlisting> - </example> - - <table pgwide="1" id="v4l2-colorspace" orient="land"> - <title>enum v4l2_colorspace</title> - <tgroup cols="11" align="center"> - <colspec align="left" /> - <colspec align="center" /> - <colspec align="left" /> - <colspec colname="cr" /> - <colspec colname="cg" /> - <colspec colname="cb" /> - <colspec colname="wp" /> - <colspec colname="gc" /> - <colspec colname="lum" /> - <colspec colname="qy" /> - <colspec colname="qc" /> - <spanspec namest="cr" nameend="cb" spanname="chrom" /> - <spanspec namest="qy" nameend="qc" spanname="quant" /> - <spanspec namest="lum" nameend="qc" spanname="spam" /> - <thead> - <row> - <entry morerows="1">Identifier</entry> - <entry morerows="1">Value</entry> - <entry morerows="1">Description</entry> - <entry spanname="chrom">Chromaticities<footnote> - <para>The coordinates of the color primaries are -given in the CIE system (1931)</para> - </footnote></entry> - <entry morerows="1">White Point</entry> - <entry morerows="1">Gamma Correction</entry> - <entry morerows="1">Luminance E'<subscript>Y</subscript></entry> - <entry spanname="quant">Quantization</entry> - </row> - <row> - <entry>Red</entry> - <entry>Green</entry> - <entry>Blue</entry> - <entry>Y'</entry> - <entry>Cb, Cr</entry> - </row> - </thead> - <tbody valign="top"> - <row> - <entry><constant>V4L2_COLORSPACE_SMPTE170M</constant></entry> - <entry>1</entry> - <entry>NTSC/PAL according to <xref linkend="smpte170m" />, -<xref linkend="itu601" /></entry> - <entry>x = 0.630, y = 0.340</entry> - <entry>x = 0.310, y = 0.595</entry> - <entry>x = 0.155, y = 0.070</entry> - <entry>x = 0.3127, y = 0.3290, - Illuminant D<subscript>65</subscript></entry> - <entry>E' = 4.5 I for I ≤0.018, -1.099 I<superscript>0.45</superscript> - 0.099 for 0.018 < I</entry> - <entry>0.299 E'<subscript>R</subscript> -+ 0.587 E'<subscript>G</subscript> -+ 0.114 E'<subscript>B</subscript></entry> - <entry>219 E'<subscript>Y</subscript> + 16</entry> - <entry>224 P<subscript>B,R</subscript> + 128</entry> - </row> - <row> - <entry><constant>V4L2_COLORSPACE_SMPTE240M</constant></entry> - <entry>2</entry> - <entry>1125-Line (US) HDTV, see <xref -linkend="smpte240m" /></entry> - <entry>x = 0.630, y = 0.340</entry> - <entry>x = 0.310, y = 0.595</entry> - <entry>x = 0.155, y = 0.070</entry> - <entry>x = 0.3127, y = 0.3290, - Illuminant D<subscript>65</subscript></entry> - <entry>E' = 4 I for I ≤0.0228, -1.1115 I<superscript>0.45</superscript> - 0.1115 for 0.0228 < I</entry> - <entry>0.212 E'<subscript>R</subscript> -+ 0.701 E'<subscript>G</subscript> -+ 0.087 E'<subscript>B</subscript></entry> - <entry>219 E'<subscript>Y</subscript> + 16</entry> - <entry>224 P<subscript>B,R</subscript> + 128</entry> - </row> - <row> - <entry><constant>V4L2_COLORSPACE_REC709</constant></entry> - <entry>3</entry> - <entry>HDTV and modern devices, see <xref -linkend="itu709" /></entry> - <entry>x = 0.640, y = 0.330</entry> - <entry>x = 0.300, y = 0.600</entry> - <entry>x = 0.150, y = 0.060</entry> - <entry>x = 0.3127, y = 0.3290, - Illuminant D<subscript>65</subscript></entry> - <entry>E' = 4.5 I for I ≤0.018, -1.099 I<superscript>0.45</superscript> - 0.099 for 0.018 < I</entry> - <entry>0.2125 E'<subscript>R</subscript> -+ 0.7154 E'<subscript>G</subscript> -+ 0.0721 E'<subscript>B</subscript></entry> - <entry>219 E'<subscript>Y</subscript> + 16</entry> - <entry>224 P<subscript>B,R</subscript> + 128</entry> - </row> - <row> - <entry><constant>V4L2_COLORSPACE_BT878</constant></entry> - <entry>4</entry> - <entry>Broken Bt878 extents<footnote> - <para>The ubiquitous Bt878 video capture chip -quantizes E'<subscript>Y</subscript> to 238 levels, yielding a range -of Y' = 16 … 253, unlike Rec. 601 Y' = 16 … -235. This is not a typo in the Bt878 documentation, it has been -implemented in silicon. The chroma extents are unclear.</para> - </footnote>, <xref linkend="itu601" /></entry> - <entry>?</entry> - <entry>?</entry> - <entry>?</entry> - <entry>?</entry> - <entry>?</entry> - <entry>0.299 E'<subscript>R</subscript> -+ 0.587 E'<subscript>G</subscript> -+ 0.114 E'<subscript>B</subscript></entry> - <entry><emphasis>237</emphasis> E'<subscript>Y</subscript> + 16</entry> - <entry>224 P<subscript>B,R</subscript> + 128 (probably)</entry> - </row> - <row> - <entry><constant>V4L2_COLORSPACE_470_SYSTEM_M</constant></entry> - <entry>5</entry> - <entry>M/NTSC<footnote> - <para>No identifier exists for M/PAL which uses -the chromaticities of M/NTSC, the remaining parameters are equal to B and -G/PAL.</para> - </footnote> according to <xref linkend="itu470" />, <xref - linkend="itu601" /></entry> - <entry>x = 0.67, y = 0.33</entry> - <entry>x = 0.21, y = 0.71</entry> - <entry>x = 0.14, y = 0.08</entry> - <entry>x = 0.310, y = 0.316, Illuminant C</entry> - <entry>?</entry> - <entry>0.299 E'<subscript>R</subscript> -+ 0.587 E'<subscript>G</subscript> -+ 0.114 E'<subscript>B</subscript></entry> - <entry>219 E'<subscript>Y</subscript> + 16</entry> - <entry>224 P<subscript>B,R</subscript> + 128</entry> - </row> - <row> - <entry><constant>V4L2_COLORSPACE_470_SYSTEM_BG</constant></entry> - <entry>6</entry> - <entry>625-line PAL and SECAM systems according to <xref -linkend="itu470" />, <xref linkend="itu601" /></entry> - <entry>x = 0.64, y = 0.33</entry> - <entry>x = 0.29, y = 0.60</entry> - <entry>x = 0.15, y = 0.06</entry> - <entry>x = 0.313, y = 0.329, -Illuminant D<subscript>65</subscript></entry> - <entry>?</entry> - <entry>0.299 E'<subscript>R</subscript> -+ 0.587 E'<subscript>G</subscript> -+ 0.114 E'<subscript>B</subscript></entry> - <entry>219 E'<subscript>Y</subscript> + 16</entry> - <entry>224 P<subscript>B,R</subscript> + 128</entry> - </row> - <row> - <entry><constant>V4L2_COLORSPACE_JPEG</constant></entry> - <entry>7</entry> - <entry>JPEG Y'CbCr, see <xref linkend="jfif" />, <xref linkend="itu601" /></entry> - <entry>?</entry> - <entry>?</entry> - <entry>?</entry> - <entry>?</entry> - <entry>?</entry> - <entry>0.299 E'<subscript>R</subscript> -+ 0.587 E'<subscript>G</subscript> -+ 0.114 E'<subscript>B</subscript></entry> - <entry>256 E'<subscript>Y</subscript> + 16<footnote> - <para>Note JFIF quantizes -Y'P<subscript>B</subscript>P<subscript>R</subscript> in range [0;+1] and -[-0.5;+0.5] to <emphasis>257</emphasis> levels, however Y'CbCr signals -are still clamped to [0;255].</para> - </footnote></entry> - <entry>256 P<subscript>B,R</subscript> + 128</entry> - </row> - <row> - <entry><constant>V4L2_COLORSPACE_SRGB</constant></entry> - <entry>8</entry> - <entry>[?]</entry> - <entry>x = 0.640, y = 0.330</entry> - <entry>x = 0.300, y = 0.600</entry> - <entry>x = 0.150, y = 0.060</entry> - <entry>x = 0.3127, y = 0.3290, - Illuminant D<subscript>65</subscript></entry> - <entry>E' = 4.5 I for I ≤0.018, -1.099 I<superscript>0.45</superscript> - 0.099 for 0.018 < I</entry> - <entry spanname="spam">n/a</entry> - </row> - </tbody> - </tgroup> - </table> - </section> - - <section id="pixfmt-indexed"> - <title>Indexed Format</title> - - <para>In this format each pixel is represented by an 8 bit index -into a 256 entry ARGB palette. It is intended for <link -linkend="osd">Video Output Overlays</link> only. There are no ioctls to -access the palette, this must be done with ioctls of the Linux framebuffer API.</para> - - <table pgwide="0" frame="none"> - <title>Indexed Image Format</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" /> - - <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</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> - </row> - </thead> - <tbody valign="top"> - <row id="V4L2-PIX-FMT-PAL8"> - <entry><constant>V4L2_PIX_FMT_PAL8</constant></entry> - <entry>'PAL8'</entry> - <entry></entry> - <entry>i<subscript>7</subscript></entry> - <entry>i<subscript>6</subscript></entry> - <entry>i<subscript>5</subscript></entry> - <entry>i<subscript>4</subscript></entry> - <entry>i<subscript>3</subscript></entry> - <entry>i<subscript>2</subscript></entry> - <entry>i<subscript>1</subscript></entry> - <entry>i<subscript>0</subscript></entry> - </row> - </tbody> - </tgroup> - </table> - </section> - - <section id="pixfmt-rgb"> - <title>RGB Formats</title> - - &sub-packed-rgb; - &sub-sbggr8; - &sub-sgbrg8; - &sub-sgrbg8; - &sub-srggb8; - &sub-sbggr16; - &sub-srggb10; - &sub-srggb12; - </section> - - <section id="yuv-formats"> - <title>YUV Formats</title> - - <para>YUV is the format native to TV broadcast and composite video -signals. It separates the brightness information (Y) from the color -information (U and V or Cb and Cr). The color information consists of -red and blue <emphasis>color difference</emphasis> signals, this way -the green component can be reconstructed by subtracting from the -brightness component. See <xref linkend="colorspaces" /> for conversion -examples. YUV was chosen because early television would only transmit -brightness information. To add color in a way compatible with existing -receivers a new signal carrier was added to transmit the color -difference signals. Secondary in the YUV format the U and V components -usually have lower resolution than the Y component. This is an analog -video compression technique taking advantage of a property of the -human visual system, being more sensitive to brightness -information.</para> - - &sub-packed-yuv; - &sub-grey; - &sub-y10; - &sub-y12; - &sub-y10b; - &sub-y16; - &sub-yuyv; - &sub-uyvy; - &sub-yvyu; - &sub-vyuy; - &sub-y41p; - &sub-yuv420; - &sub-yuv420m; - &sub-yuv410; - &sub-yuv422p; - &sub-yuv411p; - &sub-nv12; - &sub-nv12m; - &sub-nv12mt; - &sub-nv16; - &sub-m420; - </section> - - <section> - <title>Compressed Formats</title> - - <table pgwide="1" frame="none" id="compressed-formats"> - <title>Compressed Image Formats</title> - <tgroup cols="3" align="left"> - &cs-def; - <thead> - <row> - <entry>Identifier</entry> - <entry>Code</entry> - <entry>Details</entry> - </row> - </thead> - <tbody valign="top"> - <row id="V4L2-PIX-FMT-JPEG"> - <entry><constant>V4L2_PIX_FMT_JPEG</constant></entry> - <entry>'JPEG'</entry> - <entry>TBD. See also &VIDIOC-G-JPEGCOMP;, - &VIDIOC-S-JPEGCOMP;.</entry> - </row> - <row id="V4L2-PIX-FMT-MPEG"> - <entry><constant>V4L2_PIX_FMT_MPEG</constant></entry> - <entry>'MPEG'</entry> - <entry>MPEG stream. The actual format is determined by -extended control <constant>V4L2_CID_MPEG_STREAM_TYPE</constant>, see -<xref linkend="mpeg-control-id" />.</entry> - </row> - </tbody> - </tgroup> - </table> - </section> - - <section id="pixfmt-reserved"> - <title>Reserved Format Identifiers</title> - - <para>These formats are not defined by this specification, they -are just listed for reference and to avoid naming conflicts. If you -want to register your own format, send an e-mail to the linux-media mailing -list &v4l-ml; for inclusion in the <filename>videodev2.h</filename> -file. If you want to share your format with other developers add a -link to your documentation and send a copy to the linux-media mailing list -for inclusion in this section. If you think your format should be listed -in a standard format section please make a proposal on the linux-media mailing -list.</para> - - <table pgwide="1" frame="none" id="reserved-formats"> - <title>Reserved Image Formats</title> - <tgroup cols="3" align="left"> - &cs-def; - <thead> - <row> - <entry>Identifier</entry> - <entry>Code</entry> - <entry>Details</entry> - </row> - </thead> - <tbody valign="top"> - <row id="V4L2-PIX-FMT-DV"> - <entry><constant>V4L2_PIX_FMT_DV</constant></entry> - <entry>'dvsd'</entry> - <entry>unknown</entry> - </row> - <row id="V4L2-PIX-FMT-ET61X251"> - <entry><constant>V4L2_PIX_FMT_ET61X251</constant></entry> - <entry>'E625'</entry> - <entry>Compressed format of the ET61X251 driver.</entry> - </row> - <row id="V4L2-PIX-FMT-HI240"> - <entry><constant>V4L2_PIX_FMT_HI240</constant></entry> - <entry>'HI24'</entry> - <entry><para>8 bit RGB format used by the BTTV driver.</para></entry> - </row> - <row id="V4L2-PIX-FMT-HM12"> - <entry><constant>V4L2_PIX_FMT_HM12</constant></entry> - <entry>'HM12'</entry> - <entry><para>YUV 4:2:0 format used by the -IVTV driver, <ulink url="http://www.ivtvdriver.org/"> -http://www.ivtvdriver.org/</ulink></para><para>The format is documented in the -kernel sources in the file <filename>Documentation/video4linux/cx2341x/README.hm12</filename> -</para></entry> - </row> - <row id="V4L2-PIX-FMT-CPIA1"> - <entry><constant>V4L2_PIX_FMT_CPIA1</constant></entry> - <entry>'CPIA'</entry> - <entry>YUV format used by the gspca cpia1 driver.</entry> - </row> - <row id="V4L2-PIX-FMT-SPCA501"> - <entry><constant>V4L2_PIX_FMT_SPCA501</constant></entry> - <entry>'S501'</entry> - <entry>YUYV per line used by the gspca driver.</entry> - </row> - <row id="V4L2-PIX-FMT-SPCA505"> - <entry><constant>V4L2_PIX_FMT_SPCA505</constant></entry> - <entry>'S505'</entry> - <entry>YYUV per line used by the gspca driver.</entry> - </row> - <row id="V4L2-PIX-FMT-SPCA508"> - <entry><constant>V4L2_PIX_FMT_SPCA508</constant></entry> - <entry>'S508'</entry> - <entry>YUVY per line used by the gspca driver.</entry> - </row> - <row id="V4L2-PIX-FMT-SPCA561"> - <entry><constant>V4L2_PIX_FMT_SPCA561</constant></entry> - <entry>'S561'</entry> - <entry>Compressed GBRG Bayer format used by the gspca driver.</entry> - </row> - <row id="V4L2-PIX-FMT-SGRBG10DPCM8"> - <entry><constant>V4L2_PIX_FMT_SGRBG10DPCM8</constant></entry> - <entry>'DB10'</entry> - <entry>10 bit raw Bayer DPCM compressed to 8 bits.</entry> - </row> - <row id="V4L2-PIX-FMT-PAC207"> - <entry><constant>V4L2_PIX_FMT_PAC207</constant></entry> - <entry>'P207'</entry> - <entry>Compressed BGGR Bayer format used by the gspca driver.</entry> - </row> - <row id="V4L2-PIX-FMT-MR97310A"> - <entry><constant>V4L2_PIX_FMT_MR97310A</constant></entry> - <entry>'M310'</entry> - <entry>Compressed BGGR Bayer format used by the gspca driver.</entry> - </row> - <row id="V4L2-PIX-FMT-OV511"> - <entry><constant>V4L2_PIX_FMT_OV511</constant></entry> - <entry>'O511'</entry> - <entry>OV511 JPEG format used by the gspca driver.</entry> - </row> - <row id="V4L2-PIX-FMT-OV518"> - <entry><constant>V4L2_PIX_FMT_OV518</constant></entry> - <entry>'O518'</entry> - <entry>OV518 JPEG format used by the gspca driver.</entry> - </row> - <row id="V4L2-PIX-FMT-PJPG"> - <entry><constant>V4L2_PIX_FMT_PJPG</constant></entry> - <entry>'PJPG'</entry> - <entry>Pixart 73xx JPEG format used by the gspca driver.</entry> - </row> - <row id="V4L2-PIX-FMT-SQ905C"> - <entry><constant>V4L2_PIX_FMT_SQ905C</constant></entry> - <entry>'905C'</entry> - <entry>Compressed RGGB bayer format used by the gspca driver.</entry> - </row> - <row id="V4L2-PIX-FMT-MJPEG"> - <entry><constant>V4L2_PIX_FMT_MJPEG</constant></entry> - <entry>'MJPG'</entry> - <entry>Compressed format used by the Zoran driver</entry> - </row> - <row id="V4L2-PIX-FMT-PWC1"> - <entry><constant>V4L2_PIX_FMT_PWC1</constant></entry> - <entry>'PWC1'</entry> - <entry>Compressed format of the PWC driver.</entry> - </row> - <row id="V4L2-PIX-FMT-PWC2"> - <entry><constant>V4L2_PIX_FMT_PWC2</constant></entry> - <entry>'PWC2'</entry> - <entry>Compressed format of the PWC driver.</entry> - </row> - <row id="V4L2-PIX-FMT-SN9C10X"> - <entry><constant>V4L2_PIX_FMT_SN9C10X</constant></entry> - <entry>'S910'</entry> - <entry>Compressed format of the SN9C102 driver.</entry> - </row> - <row id="V4L2-PIX-FMT-SN9C20X-I420"> - <entry><constant>V4L2_PIX_FMT_SN9C20X_I420</constant></entry> - <entry>'S920'</entry> - <entry>YUV 4:2:0 format of the gspca sn9c20x driver.</entry> - </row> - <row id="V4L2-PIX-FMT-SN9C2028"> - <entry><constant>V4L2_PIX_FMT_SN9C2028</constant></entry> - <entry>'SONX'</entry> - <entry>Compressed GBRG bayer format of the gspca sn9c2028 driver.</entry> - </row> - <row id="V4L2-PIX-FMT-STV0680"> - <entry><constant>V4L2_PIX_FMT_STV0680</constant></entry> - <entry>'S680'</entry> - <entry>Bayer format of the gspca stv0680 driver.</entry> - </row> - <row id="V4L2-PIX-FMT-WNVA"> - <entry><constant>V4L2_PIX_FMT_WNVA</constant></entry> - <entry>'WNVA'</entry> - <entry><para>Used by the Winnov Videum driver, <ulink -url="http://www.thedirks.org/winnov/"> -http://www.thedirks.org/winnov/</ulink></para></entry> - </row> - <row id="V4L2-PIX-FMT-TM6000"> - <entry><constant>V4L2_PIX_FMT_TM6000</constant></entry> - <entry>'TM60'</entry> - <entry><para>Used by Trident tm6000</para></entry> - </row> - <row id="V4L2-PIX-FMT-CIT-YYVYUY"> - <entry><constant>V4L2_PIX_FMT_CIT_YYVYUY</constant></entry> - <entry>'CITV'</entry> - <entry><para>Used by xirlink CIT, found at IBM webcams.</para> - <para>Uses one line of Y then 1 line of VYUY</para> - </entry> - </row> - <row id="V4L2-PIX-FMT-KONICA420"> - <entry><constant>V4L2_PIX_FMT_KONICA420</constant></entry> - <entry>'KONI'</entry> - <entry><para>Used by Konica webcams.</para> - <para>YUV420 planar in blocks of 256 pixels.</para> - </entry> - </row> - <row id="V4L2-PIX-FMT-YYUV"> - <entry><constant>V4L2_PIX_FMT_YYUV</constant></entry> - <entry>'YYUV'</entry> - <entry>unknown</entry> - </row> - <row id="V4L2-PIX-FMT-Y4"> - <entry><constant>V4L2_PIX_FMT_Y4</constant></entry> - <entry>'Y04 '</entry> - <entry>Old 4-bit greyscale format. Only the least significant 4 bits of each byte are used, -the other bits are set to 0.</entry> - </row> - <row id="V4L2-PIX-FMT-Y6"> - <entry><constant>V4L2_PIX_FMT_Y6</constant></entry> - <entry>'Y06 '</entry> - <entry>Old 6-bit greyscale format. Only the least significant 6 bits of each byte are used, -the other bits are set to 0.</entry> - </row> - </tbody> - </tgroup> - </table> - </section> - - <!-- -Local Variables: -mode: sgml -sgml-parent-document: "v4l2.sgml" -indent-tabs-mode: nil -End: - --> |