Documentation/DocBook/media/v4l/pixfmt.xml

   1   <title>Image Formats</title>
   2
   3   <para>The V4L2 API was primarily designed for devices exchanging
   4 image data with applications. The
   5 <structname>v4l2_pix_format</structname> and <structname>v4l2_pix_format_mplane
   6 </structname> structures define the format and layout of an image in memory.
   7 The former is used with the single-planar API, while the latter is used with the
   8 multi-planar version (see <xref linkend="planar-apis"/>). Image formats are
   9 negotiated with the &VIDIOC-S-FMT; ioctl. (The explanations here focus on video
  10 capturing and output, for overlay frame buffer formats see also
  11 &VIDIOC-G-FBUF;.)</para>
  12
  13 <section>
  14   <title>Single-planar format structure</title>
  15   <table pgwide="1" frame="none" id="v4l2-pix-format">
  16     <title>struct <structname>v4l2_pix_format</structname></title>
  17     <tgroup cols="3">
  18       &cs-str;
  19       <tbody valign="top">
  20         <row>
  21           <entry>__u32</entry>
  22           <entry><structfield>width</structfield></entry>
  23           <entry>Image width in pixels.</entry>
  24         </row>
  25         <row>
  26           <entry>__u32</entry>
  27           <entry><structfield>height</structfield></entry>
  28           <entry>Image height in pixels. If <structfield>field</structfield> is
  29           one of <constant>V4L2_FIELD_TOP</constant>, <constant>V4L2_FIELD_BOTTOM</constant>
  30           or <constant>V4L2_FIELD_ALTERNATE</constant> then height refers to the
  31           number of lines in the field, otherwise it refers to the number of
  32           lines in the frame (which is twice the field height for interlaced
  33           formats).</entry>
  34         </row>
  35         <row>
  36           <entry spanname="hspan">Applications set these fields to
  37 request an image size, drivers return the closest possible values. In
  38 case of planar formats the <structfield>width</structfield> and
  39 <structfield>height</structfield> applies to the largest plane. To
  40 avoid ambiguities drivers must return values rounded up to a multiple
  41 of the scale factor of any smaller planes. For example when the image
  42 format is YUV 4:2:0, <structfield>width</structfield> and
  43 <structfield>height</structfield> must be multiples of two.</entry>
  44         </row>
  45         <row>
  46           <entry>__u32</entry>
  47           <entry><structfield>pixelformat</structfield></entry>
  48           <entry>The pixel format or type of compression, set by the
  49 application. This is a little endian <link
  50 linkend="v4l2-fourcc">four character code</link>. V4L2 defines
  51 standard RGB formats in <xref linkend="rgb-formats" />, YUV formats in <xref
  52 linkend="yuv-formats" />, and reserved codes in <xref
  53 linkend="reserved-formats" /></entry>
  54         </row>
  55         <row>
  56           <entry>&v4l2-field;</entry>
  57           <entry><structfield>field</structfield></entry>
  58           <entry>Video images are typically interlaced. Applications
  59 can request to capture or output only the top or bottom field, or both
  60 fields interlaced or sequentially stored in one buffer or alternating
  61 in separate buffers. Drivers return the actual field order selected.
  62 For more details on fields see <xref linkend="field-order" />.</entry>
  63         </row>
  64         <row>
  65           <entry>__u32</entry>
  66           <entry><structfield>bytesperline</structfield></entry>
  67           <entry>Distance in bytes between the leftmost pixels in two
  68 adjacent lines.</entry>
  69         </row>
  70         <row>
  71           <entry spanname="hspan"><para>Both applications and drivers
  72 can set this field to request padding bytes at the end of each line.
  73 Drivers however may ignore the value requested by the application,
  74 returning <structfield>width</structfield> times bytes per pixel or a
  75 larger value required by the hardware. That implies applications can
  76 just set this field to zero to get a reasonable
  77 default.</para><para>Video hardware may access padding bytes,
  78 therefore they must reside in accessible memory. Consider cases where
  79 padding bytes after the last line of an image cross a system page
  80 boundary. Input devices may write padding bytes, the value is
  81 undefined. Output devices ignore the contents of padding
  82 bytes.</para><para>When the image format is planar the
  83 <structfield>bytesperline</structfield> value applies to the largest
  84 plane and is divided by the same factor as the
  85 <structfield>width</structfield> field for any smaller planes. For
  86 example the Cb and Cr planes of a YUV 4:2:0 image have half as many
  87 padding bytes following each line as the Y plane. To avoid ambiguities
  88 drivers must return a <structfield>bytesperline</structfield> value
  89 rounded up to a multiple of the scale factor.</para>
  90 <para>For compressed formats the <structfield>bytesperline</structfield>
  91 value makes no sense. Applications and drivers must set this to 0 in
  92 that case.</para></entry>
  93         </row>
  94         <row>
  95           <entry>__u32</entry>
  96           <entry><structfield>sizeimage</structfield></entry>
  97           <entry>Size in bytes of the buffer to hold a complete image,
  98 set by the driver. Usually this is
  99 <structfield>bytesperline</structfield> times
 100 <structfield>height</structfield>. When the image consists of variable
 101 length compressed data this is the maximum number of bytes required to
 102 hold an image.</entry>
 103         </row>
 104         <row>
 105           <entry>&v4l2-colorspace;</entry>
 106           <entry><structfield>colorspace</structfield></entry>
 107           <entry>This information supplements the
 108 <structfield>pixelformat</structfield> and must be set by the driver for
 109 capture streams and by the application for output streams,
 110 see <xref linkend="colorspaces" />.</entry>
 111         </row>
 112         <row>
 113           <entry>__u32</entry>
 114           <entry><structfield>priv</structfield></entry>
 115           <entry>Reserved for custom (driver defined) additional
 116 information about formats. When not used drivers and applications must
 117 set this field to zero.</entry>
 118         </row>
 119       </tbody>
 120     </tgroup>
 121   </table>
 122 </section>
 123
 124 <section>
 125   <title>Multi-planar format structures</title>
 126   <para>The <structname>v4l2_plane_pix_format</structname> structures define
 127     size and layout for each of the planes in a multi-planar format.
 128     The <structname>v4l2_pix_format_mplane</structname> structure contains
 129     information common to all planes (such as image width and height) and
 130     an array of <structname>v4l2_plane_pix_format</structname> structures,
 131     describing all planes of that format.</para>
 132   <table pgwide="1" frame="none" id="v4l2-plane-pix-format">
 133     <title>struct <structname>v4l2_plane_pix_format</structname></title>
 134     <tgroup cols="3">
 135       &cs-str;
 136       <tbody valign="top">
 137         <row>
 138           <entry>__u32</entry>
 139           <entry><structfield>sizeimage</structfield></entry>
 140           <entry>Maximum size in bytes required for image data in this plane.
 141           </entry>
 142         </row>
 143         <row>
 144           <entry>__u16</entry>
 145           <entry><structfield>bytesperline</structfield></entry>
 146           <entry>Distance in bytes between the leftmost pixels in two adjacent
 147             lines. See &v4l2-pix-format;.</entry>
 148         </row>
 149         <row>
 150           <entry>__u16</entry>
 151           <entry><structfield>reserved[7]</structfield></entry>
 152           <entry>Reserved for future extensions. Should be zeroed by the
 153            application.</entry>
 154         </row>
 155       </tbody>
 156     </tgroup>
 157   </table>
 158   <table pgwide="1" frame="none" id="v4l2-pix-format-mplane">
 159     <title>struct <structname>v4l2_pix_format_mplane</structname></title>
 160     <tgroup cols="3">
 161       &cs-str;
 162       <tbody valign="top">
 163         <row>
 164           <entry>__u32</entry>
 165           <entry><structfield>width</structfield></entry>
 166           <entry>Image width in pixels. See &v4l2-pix-format;.</entry>
 167         </row>
 168         <row>
 169           <entry>__u32</entry>
 170           <entry><structfield>height</structfield></entry>
 171           <entry>Image height in pixels. See &v4l2-pix-format;.</entry>
 172         </row>
 173         <row>
 174           <entry>__u32</entry>
 175           <entry><structfield>pixelformat</structfield></entry>
 176           <entry>The pixel format. Both single- and multi-planar four character
 177 codes can be used.</entry>
 178         </row>
 179         <row>
 180           <entry>&v4l2-field;</entry>
 181           <entry><structfield>field</structfield></entry>
 182           <entry>See &v4l2-pix-format;.</entry>
 183         </row>
 184         <row>
 185           <entry>&v4l2-colorspace;</entry>
 186           <entry><structfield>colorspace</structfield></entry>
 187           <entry>See &v4l2-pix-format;.</entry>
 188         </row>
 189         <row>
 190           <entry>&v4l2-plane-pix-format;</entry>
 191           <entry><structfield>plane_fmt[VIDEO_MAX_PLANES]</structfield></entry>
 192           <entry>An array of structures describing format of each plane this
 193           pixel format consists of. The number of valid entries in this array
 194           has to be put in the <structfield>num_planes</structfield>
 195           field.</entry>
 196         </row>
 197         <row>
 198           <entry>__u8</entry>
 199           <entry><structfield>num_planes</structfield></entry>
 200           <entry>Number of planes (i.e. separate memory buffers) for this format
 201           and the number of valid entries in the
 202           <structfield>plane_fmt</structfield> array.</entry>
 203         </row>
 204         <row>
 205           <entry>__u8</entry>
 206           <entry><structfield>reserved[11]</structfield></entry>
 207           <entry>Reserved for future extensions. Should be zeroed by the
 208            application.</entry>
 209         </row>
 210       </tbody>
 211     </tgroup>
 212   </table>
 213 </section>
 214
 215   <section>
 216     <title>Standard Image Formats</title>
 217
 218     <para>In order to exchange images between drivers and
 219 applications, it is necessary to have standard image data formats
 220 which both sides will interpret the same way. V4L2 includes several
 221 such formats, and this section is intended to be an unambiguous
 222 specification of the standard image data formats in V4L2.</para>
 223
 224     <para>V4L2 drivers are not limited to these formats, however.
 225 Driver-specific formats are possible. In that case the application may
 226 depend on a codec to convert images to one of the standard formats
 227 when needed. But the data can still be stored and retrieved in the
 228 proprietary format. For example, a device may support a proprietary
 229 compressed format. Applications can still capture and save the data in
 230 the compressed format, saving much disk space, and later use a codec
 231 to convert the images to the X Windows screen format when the video is
 232 to be displayed.</para>
 233
 234     <para>Even so, ultimately, some standard formats are needed, so
 235 the V4L2 specification would not be complete without well-defined
 236 standard formats.</para>
 237
 238     <para>The V4L2 standard formats are mainly uncompressed formats. The
 239 pixels are always arranged in memory from left to right, and from top
 240 to bottom. The first byte of data in the image buffer is always for
 241 the leftmost pixel of the topmost row. Following that is the pixel
 242 immediately to its right, and so on until the end of the top row of
 243 pixels. Following the rightmost pixel of the row there may be zero or
 244 more bytes of padding to guarantee that each row of pixel data has a
 245 certain alignment. Following the pad bytes, if any, is data for the
 246 leftmost pixel of the second row from the top, and so on. The last row
 247 has just as many pad bytes after it as the other rows.</para>
 248
 249     <para>In V4L2 each format has an identifier which looks like
 250 <constant>PIX_FMT_XXX</constant>, defined in the <link
 251 linkend="videodev">videodev.h</link> header file. These identifiers
 252 represent <link linkend="v4l2-fourcc">four character (FourCC) codes</link>
 253 which are also listed below, however they are not the same as those
 254 used in the Windows world.</para>
 255
 256     <para>For some formats, data is stored in separate, discontiguous
 257 memory buffers. Those formats are identified by a separate set of FourCC codes
 258 and are referred to as "multi-planar formats". For example, a YUV422 frame is
 259 normally stored in one memory buffer, but it can also be placed in two or three
 260 separate buffers, with Y component in one buffer and CbCr components in another
 261 in the 2-planar version or with each component in its own buffer in the
 262 3-planar case. Those sub-buffers are referred to as "planes".</para>
 263   </section>
 264
 265   <section id="colorspaces">
 266     <title>Colorspaces</title>
 267
 268     <para>[intro]</para>
 269
 270     <!-- See proposal by Billy Biggs, video4linux-list@redhat.com
 271 on 11 Oct 2002, subject: "Re: [V4L] Re: v4l2 api", and
 272 http://vektor.theorem.ca/graphics/ycbcr/ and
 273 http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html -->
 274
 275     <para>
 276       <variablelist>
 277         <varlistentry>
 278           <term>Gamma Correction</term>
 279           <listitem>
 280             <para>[to do]</para>
 281             <para>E'<subscript>R</subscript> = f(R)</para>
 282             <para>E'<subscript>G</subscript> = f(G)</para>
 283             <para>E'<subscript>B</subscript> = f(B)</para>
 284           </listitem>
 285         </varlistentry>
 286         <varlistentry>
 287           <term>Construction of luminance and color-difference
 288 signals</term>
 289           <listitem>
 290             <para>[to do]</para>
 291             <para>E'<subscript>Y</subscript> =
 292 Coeff<subscript>R</subscript> E'<subscript>R</subscript>
 293 + Coeff<subscript>G</subscript> E'<subscript>G</subscript>
 294 + Coeff<subscript>B</subscript> E'<subscript>B</subscript></para>
 295             <para>(E'<subscript>R</subscript> - E'<subscript>Y</subscript>) = E'<subscript>R</subscript>
 296 - Coeff<subscript>R</subscript> E'<subscript>R</subscript>
 297 - Coeff<subscript>G</subscript> E'<subscript>G</subscript>
 298 - Coeff<subscript>B</subscript> E'<subscript>B</subscript></para>
 299             <para>(E'<subscript>B</subscript> - E'<subscript>Y</subscript>) = E'<subscript>B</subscript>
 300 - Coeff<subscript>R</subscript> E'<subscript>R</subscript>
 301 - Coeff<subscript>G</subscript> E'<subscript>G</subscript>
 302 - Coeff<subscript>B</subscript> E'<subscript>B</subscript></para>
 303           </listitem>
 304         </varlistentry>
 305         <varlistentry>
 306           <term>Re-normalized color-difference signals</term>
 307           <listitem>
 308             <para>The color-difference signals are scaled back to unity
 309 range [-0.5;+0.5]:</para>
 310             <para>K<subscript>B</subscript> = 0.5 / (1 - Coeff<subscript>B</subscript>)</para>
 311             <para>K<subscript>R</subscript> = 0.5 / (1 - Coeff<subscript>R</subscript>)</para>
 312             <para>P<subscript>B</subscript> =
 313 K<subscript>B</subscript> (E'<subscript>B</subscript> - E'<subscript>Y</subscript>) =
 314   0.5 (Coeff<subscript>R</subscript> / Coeff<subscript>B</subscript>) E'<subscript>R</subscript>
 315 + 0.5 (Coeff<subscript>G</subscript> / Coeff<subscript>B</subscript>) E'<subscript>G</subscript>
 316 + 0.5 E'<subscript>B</subscript></para>
 317             <para>P<subscript>R</subscript> =
 318 K<subscript>R</subscript> (E'<subscript>R</subscript> - E'<subscript>Y</subscript>) =
 319   0.5 E'<subscript>R</subscript>
 320 + 0.5 (Coeff<subscript>G</subscript> / Coeff<subscript>R</subscript>) E'<subscript>G</subscript>
 321 + 0.5 (Coeff<subscript>B</subscript> / Coeff<subscript>R</subscript>) E'<subscript>B</subscript></para>
 322           </listitem>
 323         </varlistentry>
 324         <varlistentry>
 325           <term>Quantization</term>
 326           <listitem>
 327             <para>[to do]</para>
 328             <para>Y' = (Lum. Levels - 1) &middot; E'<subscript>Y</subscript> + Lum. Offset</para>
 329             <para>C<subscript>B</subscript> = (Chrom. Levels - 1)
 330 &middot; P<subscript>B</subscript> + Chrom. Offset</para>
 331             <para>C<subscript>R</subscript> = (Chrom. Levels - 1)
 332 &middot; P<subscript>R</subscript> + Chrom. Offset</para>
 333             <para>Rounding to the nearest integer and clamping to the range
 334 [0;255] finally yields the digital color components Y'CbCr
 335 stored in YUV images.</para>
 336           </listitem>
 337         </varlistentry>
 338       </variablelist>
 339     </para>
 340
 341     <example>
 342       <title>ITU-R Rec. BT.601 color conversion</title>
 343
 344       <para>Forward Transformation</para>
 345
 346       <programlisting>
 347 int ER, EG, EB;         /* gamma corrected RGB input [0;255] */
 348 int Y1, Cb, Cr;         /* output [0;255] */
 349
 350 double r, g, b;         /* temporaries */
 351 double y1, pb, pr;
 352
 353 int
 354 clamp (double x)
 355 {
 356         int r = x;      /* round to nearest */
 357
 358         if (r &lt; 0)         return 0;
 359         else if (r &gt; 255)  return 255;
 360         else               return r;
 361 }
 362
 363 r = ER / 255.0;
 364 g = EG / 255.0;
 365 b = EB / 255.0;
 366
 367 y1  =  0.299  * r + 0.587 * g + 0.114  * b;
 368 pb  = -0.169  * r - 0.331 * g + 0.5    * b;
 369 pr  =  0.5    * r - 0.419 * g - 0.081  * b;
 370
 371 Y1 = clamp (219 * y1 + 16);
 372 Cb = clamp (224 * pb + 128);
 373 Cr = clamp (224 * pr + 128);
 374
 375 /* or shorter */
 376
 377 y1 = 0.299 * ER + 0.587 * EG + 0.114 * EB;
 378
 379 Y1 = clamp ( (219 / 255.0)                    *       y1  + 16);
 380 Cb = clamp (((224 / 255.0) / (2 - 2 * 0.114)) * (EB - y1) + 128);
 381 Cr = clamp (((224 / 255.0) / (2 - 2 * 0.299)) * (ER - y1) + 128);
 382       </programlisting>
 383
 384       <para>Inverse Transformation</para>
 385
 386       <programlisting>
 387 int Y1, Cb, Cr;         /* gamma pre-corrected input [0;255] */
 388 int ER, EG, EB;         /* output [0;255] */
 389
 390 double r, g, b;         /* temporaries */
 391 double y1, pb, pr;
 392
 393 int
 394 clamp (double x)
 395 {
 396         int r = x;      /* round to nearest */
 397
 398         if (r &lt; 0)         return 0;
 399         else if (r &gt; 255)  return 255;
 400         else               return r;
 401 }
 402
 403 y1 = (Y1 - 16) / 219.0;
 404 pb = (Cb - 128) / 224.0;
 405 pr = (Cr - 128) / 224.0;
 406
 407 r = 1.0 * y1 + 0     * pb + 1.402 * pr;
 408 g = 1.0 * y1 - 0.344 * pb - 0.714 * pr;
 409 b = 1.0 * y1 + 1.772 * pb + 0     * pr;
 410
 411 ER = clamp (r * 255); /* [ok? one should prob. limit y1,pb,pr] */
 412 EG = clamp (g * 255);
 413 EB = clamp (b * 255);
 414       </programlisting>
 415     </example>
 416
 417     <table pgwide="1" id="v4l2-colorspace" orient="land">
 418       <title>enum v4l2_colorspace</title>
 419       <tgroup cols="11" align="center">
 420         <colspec align="left" />
 421         <colspec align="center" />
 422         <colspec align="left" />
 423         <colspec colname="cr" />
 424         <colspec colname="cg" />
 425         <colspec colname="cb" />
 426         <colspec colname="wp" />
 427         <colspec colname="gc" />
 428         <colspec colname="lum" />
 429         <colspec colname="qy" />
 430         <colspec colname="qc" />
 431         <spanspec namest="cr" nameend="cb" spanname="chrom" />
 432         <spanspec namest="qy" nameend="qc" spanname="quant" />
 433         <spanspec namest="lum" nameend="qc" spanname="spam" />
 434         <thead>
 435           <row>
 436             <entry morerows="1">Identifier</entry>
 437             <entry morerows="1">Value</entry>
 438             <entry morerows="1">Description</entry>
 439             <entry spanname="chrom">Chromaticities<footnote>
 440                 <para>The coordinates of the color primaries are
 441 given in the CIE system (1931)</para>
 442               </footnote></entry>
 443             <entry morerows="1">White Point</entry>
 444             <entry morerows="1">Gamma Correction</entry>
 445             <entry morerows="1">Luminance E'<subscript>Y</subscript></entry>
 446             <entry spanname="quant">Quantization</entry>
 447           </row>
 448           <row>
 449             <entry>Red</entry>
 450             <entry>Green</entry>
 451             <entry>Blue</entry>
 452             <entry>Y'</entry>
 453             <entry>Cb, Cr</entry>
 454           </row>
 455         </thead>
 456         <tbody valign="top">
 457           <row>
 458             <entry><constant>V4L2_COLORSPACE_SMPTE170M</constant></entry>
 459             <entry>1</entry>
 460             <entry>NTSC/PAL according to <xref linkend="smpte170m" />,
 461 <xref linkend="itu601" /></entry>
 462             <entry>x&nbsp;=&nbsp;0.630, y&nbsp;=&nbsp;0.340</entry>
 463             <entry>x&nbsp;=&nbsp;0.310, y&nbsp;=&nbsp;0.595</entry>
 464             <entry>x&nbsp;=&nbsp;0.155, y&nbsp;=&nbsp;0.070</entry>
 465             <entry>x&nbsp;=&nbsp;0.3127, y&nbsp;=&nbsp;0.3290,
 466             Illuminant D<subscript>65</subscript></entry>
 467             <entry>E' = 4.5&nbsp;I&nbsp;for&nbsp;I&nbsp;&le;0.018,
 468 1.099&nbsp;I<superscript>0.45</superscript>&nbsp;-&nbsp;0.099&nbsp;for&nbsp;0.018&nbsp;&lt;&nbsp;I</entry>
 469             <entry>0.299&nbsp;E'<subscript>R</subscript>
 470 +&nbsp;0.587&nbsp;E'<subscript>G</subscript>
 471 +&nbsp;0.114&nbsp;E'<subscript>B</subscript></entry>
 472             <entry>219&nbsp;E'<subscript>Y</subscript>&nbsp;+&nbsp;16</entry>
 473             <entry>224&nbsp;P<subscript>B,R</subscript>&nbsp;+&nbsp;128</entry>
 474           </row>
 475           <row>
 476             <entry><constant>V4L2_COLORSPACE_SMPTE240M</constant></entry>
 477             <entry>2</entry>
 478             <entry>1125-Line (US) HDTV, see <xref
 479 linkend="smpte240m" /></entry>
 480             <entry>x&nbsp;=&nbsp;0.630, y&nbsp;=&nbsp;0.340</entry>
 481             <entry>x&nbsp;=&nbsp;0.310, y&nbsp;=&nbsp;0.595</entry>
 482             <entry>x&nbsp;=&nbsp;0.155, y&nbsp;=&nbsp;0.070</entry>
 483             <entry>x&nbsp;=&nbsp;0.3127, y&nbsp;=&nbsp;0.3290,
 484             Illuminant D<subscript>65</subscript></entry>
 485             <entry>E' = 4&nbsp;I&nbsp;for&nbsp;I&nbsp;&le;0.0228,
 486 1.1115&nbsp;I<superscript>0.45</superscript>&nbsp;-&nbsp;0.1115&nbsp;for&nbsp;0.0228&nbsp;&lt;&nbsp;I</entry>
 487             <entry>0.212&nbsp;E'<subscript>R</subscript>
 488 +&nbsp;0.701&nbsp;E'<subscript>G</subscript>
 489 +&nbsp;0.087&nbsp;E'<subscript>B</subscript></entry>
 490             <entry>219&nbsp;E'<subscript>Y</subscript>&nbsp;+&nbsp;16</entry>
 491             <entry>224&nbsp;P<subscript>B,R</subscript>&nbsp;+&nbsp;128</entry>
 492           </row>
 493           <row>
 494             <entry><constant>V4L2_COLORSPACE_REC709</constant></entry>
 495             <entry>3</entry>
 496             <entry>HDTV and modern devices, see <xref
 497 linkend="itu709" /></entry>
 498             <entry>x&nbsp;=&nbsp;0.640, y&nbsp;=&nbsp;0.330</entry>
 499             <entry>x&nbsp;=&nbsp;0.300, y&nbsp;=&nbsp;0.600</entry>
 500             <entry>x&nbsp;=&nbsp;0.150, y&nbsp;=&nbsp;0.060</entry>
 501             <entry>x&nbsp;=&nbsp;0.3127, y&nbsp;=&nbsp;0.3290,
 502             Illuminant D<subscript>65</subscript></entry>
 503             <entry>E' = 4.5&nbsp;I&nbsp;for&nbsp;I&nbsp;&le;0.018,
 504 1.099&nbsp;I<superscript>0.45</superscript>&nbsp;-&nbsp;0.099&nbsp;for&nbsp;0.018&nbsp;&lt;&nbsp;I</entry>
 505             <entry>0.2125&nbsp;E'<subscript>R</subscript>
 506 +&nbsp;0.7154&nbsp;E'<subscript>G</subscript>
 507 +&nbsp;0.0721&nbsp;E'<subscript>B</subscript></entry>
 508             <entry>219&nbsp;E'<subscript>Y</subscript>&nbsp;+&nbsp;16</entry>
 509             <entry>224&nbsp;P<subscript>B,R</subscript>&nbsp;+&nbsp;128</entry>
 510           </row>
 511           <row>
 512             <entry><constant>V4L2_COLORSPACE_BT878</constant></entry>
 513             <entry>4</entry>
 514             <entry>Broken Bt878 extents<footnote>
 515                 <para>The ubiquitous Bt878 video capture chip
 516 quantizes E'<subscript>Y</subscript> to 238 levels, yielding a range
 517 of Y' = 16 &hellip; 253, unlike Rec. 601 Y' = 16 &hellip;
 518 235. This is not a typo in the Bt878 documentation, it has been
 519 implemented in silicon. The chroma extents are unclear.</para>
 520               </footnote>, <xref linkend="itu601" /></entry>
 521             <entry>?</entry>
 522             <entry>?</entry>
 523             <entry>?</entry>
 524             <entry>?</entry>
 525             <entry>?</entry>
 526             <entry>0.299&nbsp;E'<subscript>R</subscript>
 527 +&nbsp;0.587&nbsp;E'<subscript>G</subscript>
 528 +&nbsp;0.114&nbsp;E'<subscript>B</subscript></entry>
 529             <entry><emphasis>237</emphasis>&nbsp;E'<subscript>Y</subscript>&nbsp;+&nbsp;16</entry>
 530             <entry>224&nbsp;P<subscript>B,R</subscript>&nbsp;+&nbsp;128 (probably)</entry>
 531           </row>
 532           <row>
 533             <entry><constant>V4L2_COLORSPACE_470_SYSTEM_M</constant></entry>
 534             <entry>5</entry>
 535             <entry>M/NTSC<footnote>
 536                 <para>No identifier exists for M/PAL which uses
 537 the chromaticities of M/NTSC, the remaining parameters are equal to B and
 538 G/PAL.</para>
 539               </footnote> according to <xref linkend="itu470" />, <xref
 540                 linkend="itu601" /></entry>
 541             <entry>x&nbsp;=&nbsp;0.67, y&nbsp;=&nbsp;0.33</entry>
 542             <entry>x&nbsp;=&nbsp;0.21, y&nbsp;=&nbsp;0.71</entry>
 543             <entry>x&nbsp;=&nbsp;0.14, y&nbsp;=&nbsp;0.08</entry>
 544             <entry>x&nbsp;=&nbsp;0.310, y&nbsp;=&nbsp;0.316, Illuminant C</entry>
 545             <entry>?</entry>
 546             <entry>0.299&nbsp;E'<subscript>R</subscript>
 547 +&nbsp;0.587&nbsp;E'<subscript>G</subscript>
 548 +&nbsp;0.114&nbsp;E'<subscript>B</subscript></entry>
 549             <entry>219&nbsp;E'<subscript>Y</subscript>&nbsp;+&nbsp;16</entry>
 550             <entry>224&nbsp;P<subscript>B,R</subscript>&nbsp;+&nbsp;128</entry>
 551           </row>
 552           <row>
 553             <entry><constant>V4L2_COLORSPACE_470_SYSTEM_BG</constant></entry>
 554             <entry>6</entry>
 555             <entry>625-line PAL and SECAM systems according to <xref
 556 linkend="itu470" />, <xref linkend="itu601" /></entry>
 557             <entry>x&nbsp;=&nbsp;0.64, y&nbsp;=&nbsp;0.33</entry>
 558             <entry>x&nbsp;=&nbsp;0.29, y&nbsp;=&nbsp;0.60</entry>
 559             <entry>x&nbsp;=&nbsp;0.15, y&nbsp;=&nbsp;0.06</entry>
 560             <entry>x&nbsp;=&nbsp;0.313, y&nbsp;=&nbsp;0.329,
 561 Illuminant D<subscript>65</subscript></entry>
 562             <entry>?</entry>
 563             <entry>0.299&nbsp;E'<subscript>R</subscript>
 564 +&nbsp;0.587&nbsp;E'<subscript>G</subscript>
 565 +&nbsp;0.114&nbsp;E'<subscript>B</subscript></entry>
 566             <entry>219&nbsp;E'<subscript>Y</subscript>&nbsp;+&nbsp;16</entry>
 567             <entry>224&nbsp;P<subscript>B,R</subscript>&nbsp;+&nbsp;128</entry>
 568           </row>
 569           <row>
 570             <entry><constant>V4L2_COLORSPACE_JPEG</constant></entry>
 571             <entry>7</entry>
 572             <entry>JPEG Y'CbCr, see <xref linkend="jfif" />, <xref linkend="itu601" /></entry>
 573             <entry>?</entry>
 574             <entry>?</entry>
 575             <entry>?</entry>
 576             <entry>?</entry>
 577             <entry>?</entry>
 578             <entry>0.299&nbsp;E'<subscript>R</subscript>
 579 +&nbsp;0.587&nbsp;E'<subscript>G</subscript>
 580 +&nbsp;0.114&nbsp;E'<subscript>B</subscript></entry>
 581             <entry>256&nbsp;E'<subscript>Y</subscript>&nbsp;+&nbsp;16<footnote>
 582                 <para>Note JFIF quantizes
 583 Y'P<subscript>B</subscript>P<subscript>R</subscript> in range [0;+1] and
 584 [-0.5;+0.5] to <emphasis>257</emphasis> levels, however Y'CbCr signals
 585 are still clamped to [0;255].</para>
 586               </footnote></entry>
 587             <entry>256&nbsp;P<subscript>B,R</subscript>&nbsp;+&nbsp;128</entry>
 588           </row>
 589           <row>
 590             <entry><constant>V4L2_COLORSPACE_SRGB</constant></entry>
 591             <entry>8</entry>
 592             <entry>[?]</entry>
 593             <entry>x&nbsp;=&nbsp;0.640, y&nbsp;=&nbsp;0.330</entry>
 594             <entry>x&nbsp;=&nbsp;0.300, y&nbsp;=&nbsp;0.600</entry>
 595             <entry>x&nbsp;=&nbsp;0.150, y&nbsp;=&nbsp;0.060</entry>
 596             <entry>x&nbsp;=&nbsp;0.3127, y&nbsp;=&nbsp;0.3290,
 597             Illuminant D<subscript>65</subscript></entry>
 598             <entry>E' = 4.5&nbsp;I&nbsp;for&nbsp;I&nbsp;&le;0.018,
 599 1.099&nbsp;I<superscript>0.45</superscript>&nbsp;-&nbsp;0.099&nbsp;for&nbsp;0.018&nbsp;&lt;&nbsp;I</entry>
 600             <entry spanname="spam">n/a</entry>
 601           </row>
 602         </tbody>
 603       </tgroup>
 604     </table>
 605   </section>
 606
 607   <section id="pixfmt-indexed">
 608     <title>Indexed Format</title>
 609
 610     <para>In this format each pixel is represented by an 8 bit index
 611 into a 256 entry ARGB palette. It is intended for <link
 612 linkend="osd">Video Output Overlays</link> only. There are no ioctls to
 613 access the palette, this must be done with ioctls of the Linux framebuffer API.</para>
 614
 615     <table pgwide="0" frame="none">
 616       <title>Indexed Image Format</title>
 617       <tgroup cols="37" align="center">
 618         <colspec colname="id" align="left" />
 619         <colspec colname="fourcc" />
 620         <colspec colname="bit" />
 621
 622         <colspec colnum="4" colname="b07" align="center" />
 623         <colspec colnum="5" colname="b06" align="center" />
 624         <colspec colnum="6" colname="b05" align="center" />
 625         <colspec colnum="7" colname="b04" align="center" />
 626         <colspec colnum="8" colname="b03" align="center" />
 627         <colspec colnum="9" colname="b02" align="center" />
 628         <colspec colnum="10" colname="b01" align="center" />
 629         <colspec colnum="11" colname="b00" align="center" />
 630
 631         <spanspec namest="b07" nameend="b00" spanname="b0" />
 632         <spanspec namest="b17" nameend="b10" spanname="b1" />
 633         <spanspec namest="b27" nameend="b20" spanname="b2" />
 634         <spanspec namest="b37" nameend="b30" spanname="b3" />
 635         <thead>
 636           <row>
 637             <entry>Identifier</entry>
 638             <entry>Code</entry>
 639             <entry>&nbsp;</entry>
 640             <entry spanname="b0">Byte&nbsp;0</entry>
 641           </row>
 642           <row>
 643             <entry>&nbsp;</entry>
 644             <entry>&nbsp;</entry>
 645             <entry>Bit</entry>
 646             <entry>7</entry>
 647             <entry>6</entry>
 648             <entry>5</entry>
 649             <entry>4</entry>
 650             <entry>3</entry>
 651             <entry>2</entry>
 652             <entry>1</entry>
 653             <entry>0</entry>
 654           </row>
 655         </thead>
 656         <tbody valign="top">
 657           <row id="V4L2-PIX-FMT-PAL8">
 658             <entry><constant>V4L2_PIX_FMT_PAL8</constant></entry>
 659             <entry>'PAL8'</entry>
 660             <entry></entry>
 661             <entry>i<subscript>7</subscript></entry>
 662             <entry>i<subscript>6</subscript></entry>
 663             <entry>i<subscript>5</subscript></entry>
 664             <entry>i<subscript>4</subscript></entry>
 665             <entry>i<subscript>3</subscript></entry>
 666             <entry>i<subscript>2</subscript></entry>
 667             <entry>i<subscript>1</subscript></entry>
 668             <entry>i<subscript>0</subscript></entry>
 669           </row>
 670         </tbody>
 671       </tgroup>
 672     </table>
 673   </section>
 674
 675   <section id="pixfmt-rgb">
 676     <title>RGB Formats</title>
 677
 678     &sub-packed-rgb;
 679     &sub-sbggr8;
 680     &sub-sgbrg8;
 681     &sub-sgrbg8;
 682     &sub-srggb8;
 683     &sub-sbggr16;
 684     &sub-srggb10;
 685     &sub-srggb10alaw8;
 686     &sub-srggb10dpcm8;
 687     &sub-srggb12;
 688   </section>
 689
 690   <section id="yuv-formats">
 691     <title>YUV Formats</title>
 692
 693     <para>YUV is the format native to TV broadcast and composite video
 694 signals. It separates the brightness information (Y) from the color
 695 information (U and V or Cb and Cr). The color information consists of
 696 red and blue <emphasis>color difference</emphasis> signals, this way
 697 the green component can be reconstructed by subtracting from the
 698 brightness component. See <xref linkend="colorspaces" /> for conversion
 699 examples. YUV was chosen because early television would only transmit
 700 brightness information. To add color in a way compatible with existing
 701 receivers a new signal carrier was added to transmit the color
 702 difference signals. Secondary in the YUV format the U and V components
 703 usually have lower resolution than the Y component. This is an analog
 704 video compression technique taking advantage of a property of the
 705 human visual system, being more sensitive to brightness
 706 information.</para>
 707
 708     &sub-packed-yuv;
 709     &sub-grey;
 710     &sub-y10;
 711     &sub-y12;
 712     &sub-y10b;
 713     &sub-y16;
 714     &sub-uv8;
 715     &sub-yuyv;
 716     &sub-uyvy;
 717     &sub-yvyu;
 718     &sub-vyuy;
 719     &sub-y41p;
 720     &sub-yuv420;
 721     &sub-yuv420m;
 722     &sub-yvu420m;
 723     &sub-yuv410;
 724     &sub-yuv422p;
 725     &sub-yuv411p;
 726     &sub-nv12;
 727     &sub-nv12m;
 728     &sub-nv12mt;
 729     &sub-nv16;
 730     &sub-nv16m;
 731     &sub-nv24;
 732     &sub-m420;
 733   </section>
 734
 735   <section>
 736     <title>Compressed Formats</title>
 737
 738     <table pgwide="1" frame="none" id="compressed-formats">
 739       <title>Compressed Image Formats</title>
 740       <tgroup cols="3" align="left">
 741         &cs-def;
 742         <thead>
 743           <row>
 744             <entry>Identifier</entry>
 745             <entry>Code</entry>
 746             <entry>Details</entry>
 747           </row>
 748         </thead>
 749         <tbody valign="top">
 750          <row id="V4L2-PIX-FMT-JPEG">
 751             <entry><constant>V4L2_PIX_FMT_JPEG</constant></entry>
 752             <entry>'JPEG'</entry>
 753             <entry>TBD. See also &VIDIOC-G-JPEGCOMP;,
 754             &VIDIOC-S-JPEGCOMP;.</entry>
 755           </row>
 756           <row id="V4L2-PIX-FMT-MPEG">
 757             <entry><constant>V4L2_PIX_FMT_MPEG</constant></entry>
 758             <entry>'MPEG'</entry>
 759             <entry>MPEG multiplexed stream. The actual format is determined by
 760 extended control <constant>V4L2_CID_MPEG_STREAM_TYPE</constant>, see
 761 <xref linkend="mpeg-control-id" />.</entry>
 762           </row>
 763           <row id="V4L2-PIX-FMT-H264">
 764                 <entry><constant>V4L2_PIX_FMT_H264</constant></entry>
 765                 <entry>'H264'</entry>
 766                 <entry>H264 video elementary stream with start codes.</entry>
 767           </row>
 768           <row id="V4L2-PIX-FMT-H264-NO-SC">
 769                 <entry><constant>V4L2_PIX_FMT_H264_NO_SC</constant></entry>
 770                 <entry>'AVC1'</entry>
 771                 <entry>H264 video elementary stream without start codes.</entry>
 772           </row>
 773           <row id="V4L2-PIX-FMT-H264-MVC">
 774                 <entry><constant>V4L2_PIX_FMT_H264_MVC</constant></entry>
 775                 <entry>'MVC'</entry>
 776                 <entry>H264 MVC video elementary stream.</entry>
 777           </row>
 778           <row id="V4L2-PIX-FMT-H263">
 779                 <entry><constant>V4L2_PIX_FMT_H263</constant></entry>
 780                 <entry>'H263'</entry>
 781                 <entry>H263 video elementary stream.</entry>
 782           </row>
 783           <row id="V4L2-PIX-FMT-MPEG1">
 784                 <entry><constant>V4L2_PIX_FMT_MPEG1</constant></entry>
 785                 <entry>'MPG1'</entry>
 786                 <entry>MPEG1 video elementary stream.</entry>
 787           </row>
 788           <row id="V4L2-PIX-FMT-MPEG2">
 789                 <entry><constant>V4L2_PIX_FMT_MPEG2</constant></entry>
 790                 <entry>'MPG2'</entry>
 791                 <entry>MPEG2 video elementary stream.</entry>
 792           </row>
 793           <row id="V4L2-PIX-FMT-MPEG4">
 794                 <entry><constant>V4L2_PIX_FMT_MPEG4</constant></entry>
 795                 <entry>'MPG4'</entry>
 796                 <entry>MPEG4 video elementary stream.</entry>
 797           </row>
 798           <row id="V4L2-PIX-FMT-XVID">
 799                 <entry><constant>V4L2_PIX_FMT_XVID</constant></entry>
 800                 <entry>'XVID'</entry>
 801                 <entry>Xvid video elementary stream.</entry>
 802           </row>
 803           <row id="V4L2-PIX-FMT-VC1-ANNEX-G">
 804                 <entry><constant>V4L2_PIX_FMT_VC1_ANNEX_G</constant></entry>
 805                 <entry>'VC1G'</entry>
 806                 <entry>VC1, SMPTE 421M Annex G compliant stream.</entry>
 807           </row>
 808           <row id="V4L2-PIX-FMT-VC1-ANNEX-L">
 809                 <entry><constant>V4L2_PIX_FMT_VC1_ANNEX_L</constant></entry>
 810                 <entry>'VC1L'</entry>
 811                 <entry>VC1, SMPTE 421M Annex L compliant stream.</entry>
 812           </row>
 813           <row id="V4L2-PIX-FMT-VP8">
 814                 <entry><constant>V4L2_PIX_FMT_VP8</constant></entry>
 815                 <entry>'VP8'</entry>
 816                 <entry>VP8 video elementary stream.</entry>
 817           </row>
 818         </tbody>
 819       </tgroup>
 820     </table>
 821   </section>
 822
 823   <section id="sdr-formats">
 824     <title>SDR Formats</title>
 825
 826     <para>These formats are used for <link linkend="sdr">SDR Capture</link>
 827 interface only.</para>
 828
 829     &sub-sdr-cu08;
 830     &sub-sdr-cu16le;
 831
 832   </section>
 833
 834   <section id="pixfmt-reserved">
 835     <title>Reserved Format Identifiers</title>
 836
 837     <para>These formats are not defined by this specification, they
 838 are just listed for reference and to avoid naming conflicts. If you
 839 want to register your own format, send an e-mail to the linux-media mailing
 840 list &v4l-ml; for inclusion in the <filename>videodev2.h</filename>
 841 file. If you want to share your format with other developers add a
 842 link to your documentation and send a copy to the linux-media mailing list
 843 for inclusion in this section. If you think your format should be listed
 844 in a standard format section please make a proposal on the linux-media mailing
 845 list.</para>
 846
 847     <table pgwide="1" frame="none" id="reserved-formats">
 848       <title>Reserved Image Formats</title>
 849       <tgroup cols="3" align="left">
 850         &cs-def;
 851         <thead>
 852           <row>
 853             <entry>Identifier</entry>
 854             <entry>Code</entry>
 855             <entry>Details</entry>
 856           </row>
 857         </thead>
 858         <tbody valign="top">
 859           <row id="V4L2-PIX-FMT-DV">
 860             <entry><constant>V4L2_PIX_FMT_DV</constant></entry>
 861             <entry>'dvsd'</entry>
 862             <entry>unknown</entry>
 863           </row>
 864           <row id="V4L2-PIX-FMT-ET61X251">
 865             <entry><constant>V4L2_PIX_FMT_ET61X251</constant></entry>
 866             <entry>'E625'</entry>
 867             <entry>Compressed format of the ET61X251 driver.</entry>
 868           </row>
 869           <row id="V4L2-PIX-FMT-HI240">
 870             <entry><constant>V4L2_PIX_FMT_HI240</constant></entry>
 871             <entry>'HI24'</entry>
 872             <entry><para>8 bit RGB format used by the BTTV driver.</para></entry>
 873           </row>
 874           <row id="V4L2-PIX-FMT-HM12">
 875             <entry><constant>V4L2_PIX_FMT_HM12</constant></entry>
 876             <entry>'HM12'</entry>
 877             <entry><para>YUV 4:2:0 format used by the
 878 IVTV driver, <ulink url="http://www.ivtvdriver.org/">
 879 http://www.ivtvdriver.org/</ulink></para><para>The format is documented in the
 880 kernel sources in the file <filename>Documentation/video4linux/cx2341x/README.hm12</filename>
 881 </para></entry>
 882           </row>
 883           <row id="V4L2-PIX-FMT-CPIA1">
 884             <entry><constant>V4L2_PIX_FMT_CPIA1</constant></entry>
 885             <entry>'CPIA'</entry>
 886             <entry>YUV format used by the gspca cpia1 driver.</entry>
 887           </row>
 888           <row id="V4L2-PIX-FMT-JPGL">
 889             <entry><constant>V4L2_PIX_FMT_JPGL</constant></entry>
 890             <entry>'JPGL'</entry>
 891             <entry>JPEG-Light format (Pegasus Lossless JPEG)
 892                         used in Divio webcams NW 80x.</entry>
 893           </row>
 894           <row id="V4L2-PIX-FMT-SPCA501">
 895             <entry><constant>V4L2_PIX_FMT_SPCA501</constant></entry>
 896             <entry>'S501'</entry>
 897             <entry>YUYV per line used by the gspca driver.</entry>
 898           </row>
 899           <row id="V4L2-PIX-FMT-SPCA505">
 900             <entry><constant>V4L2_PIX_FMT_SPCA505</constant></entry>
 901             <entry>'S505'</entry>
 902             <entry>YYUV per line used by the gspca driver.</entry>
 903           </row>
 904           <row id="V4L2-PIX-FMT-SPCA508">
 905             <entry><constant>V4L2_PIX_FMT_SPCA508</constant></entry>
 906             <entry>'S508'</entry>
 907             <entry>YUVY per line used by the gspca driver.</entry>
 908           </row>
 909           <row id="V4L2-PIX-FMT-SPCA561">
 910             <entry><constant>V4L2_PIX_FMT_SPCA561</constant></entry>
 911             <entry>'S561'</entry>
 912             <entry>Compressed GBRG Bayer format used by the gspca driver.</entry>
 913           </row>
 914           <row id="V4L2-PIX-FMT-PAC207">
 915             <entry><constant>V4L2_PIX_FMT_PAC207</constant></entry>
 916             <entry>'P207'</entry>
 917             <entry>Compressed BGGR Bayer format used by the gspca driver.</entry>
 918           </row>
 919           <row id="V4L2-PIX-FMT-MR97310A">
 920             <entry><constant>V4L2_PIX_FMT_MR97310A</constant></entry>
 921             <entry>'M310'</entry>
 922             <entry>Compressed BGGR Bayer format used by the gspca driver.</entry>
 923           </row>
 924           <row id="V4L2-PIX-FMT-JL2005BCD">
 925             <entry><constant>V4L2_PIX_FMT_JL2005BCD</constant></entry>
 926             <entry>'JL20'</entry>
 927             <entry>JPEG compressed RGGB Bayer format used by the gspca driver.</entry>
 928           </row>
 929           <row id="V4L2-PIX-FMT-OV511">
 930             <entry><constant>V4L2_PIX_FMT_OV511</constant></entry>
 931             <entry>'O511'</entry>
 932             <entry>OV511 JPEG format used by the gspca driver.</entry>
 933           </row>
 934           <row id="V4L2-PIX-FMT-OV518">
 935             <entry><constant>V4L2_PIX_FMT_OV518</constant></entry>
 936             <entry>'O518'</entry>
 937             <entry>OV518 JPEG format used by the gspca driver.</entry>
 938           </row>
 939           <row id="V4L2-PIX-FMT-PJPG">
 940             <entry><constant>V4L2_PIX_FMT_PJPG</constant></entry>
 941             <entry>'PJPG'</entry>
 942             <entry>Pixart 73xx JPEG format used by the gspca driver.</entry>
 943           </row>
 944           <row id="V4L2-PIX-FMT-SE401">
 945             <entry><constant>V4L2_PIX_FMT_SE401</constant></entry>
 946             <entry>'S401'</entry>
 947             <entry>Compressed RGB format used by the gspca se401 driver</entry>
 948           </row>
 949           <row id="V4L2-PIX-FMT-SQ905C">
 950             <entry><constant>V4L2_PIX_FMT_SQ905C</constant></entry>
 951             <entry>'905C'</entry>
 952             <entry>Compressed RGGB bayer format used by the gspca driver.</entry>
 953           </row>
 954           <row id="V4L2-PIX-FMT-MJPEG">
 955             <entry><constant>V4L2_PIX_FMT_MJPEG</constant></entry>
 956             <entry>'MJPG'</entry>
 957             <entry>Compressed format used by the Zoran driver</entry>
 958           </row>
 959           <row id="V4L2-PIX-FMT-PWC1">
 960             <entry><constant>V4L2_PIX_FMT_PWC1</constant></entry>
 961             <entry>'PWC1'</entry>
 962             <entry>Compressed format of the PWC driver.</entry>
 963           </row>
 964           <row id="V4L2-PIX-FMT-PWC2">
 965             <entry><constant>V4L2_PIX_FMT_PWC2</constant></entry>
 966             <entry>'PWC2'</entry>
 967             <entry>Compressed format of the PWC driver.</entry>
 968           </row>
 969           <row id="V4L2-PIX-FMT-SN9C10X">
 970             <entry><constant>V4L2_PIX_FMT_SN9C10X</constant></entry>
 971             <entry>'S910'</entry>
 972             <entry>Compressed format of the SN9C102 driver.</entry>
 973           </row>
 974           <row id="V4L2-PIX-FMT-SN9C20X-I420">
 975             <entry><constant>V4L2_PIX_FMT_SN9C20X_I420</constant></entry>
 976             <entry>'S920'</entry>
 977             <entry>YUV 4:2:0 format of the gspca sn9c20x driver.</entry>
 978           </row>
 979           <row id="V4L2-PIX-FMT-SN9C2028">
 980             <entry><constant>V4L2_PIX_FMT_SN9C2028</constant></entry>
 981             <entry>'SONX'</entry>
 982             <entry>Compressed GBRG bayer format of the gspca sn9c2028 driver.</entry>
 983           </row>
 984           <row id="V4L2-PIX-FMT-STV0680">
 985             <entry><constant>V4L2_PIX_FMT_STV0680</constant></entry>
 986             <entry>'S680'</entry>
 987             <entry>Bayer format of the gspca stv0680 driver.</entry>
 988           </row>
 989           <row id="V4L2-PIX-FMT-WNVA">
 990             <entry><constant>V4L2_PIX_FMT_WNVA</constant></entry>
 991             <entry>'WNVA'</entry>
 992             <entry><para>Used by the Winnov Videum driver, <ulink
 993 url="http://www.thedirks.org/winnov/">
 994 http://www.thedirks.org/winnov/</ulink></para></entry>
 995           </row>
 996           <row id="V4L2-PIX-FMT-TM6000">
 997             <entry><constant>V4L2_PIX_FMT_TM6000</constant></entry>
 998             <entry>'TM60'</entry>
 999             <entry><para>Used by Trident tm6000</para></entry>
1000           </row>
1001           <row id="V4L2-PIX-FMT-CIT-YYVYUY">
1002             <entry><constant>V4L2_PIX_FMT_CIT_YYVYUY</constant></entry>
1003             <entry>'CITV'</entry>
1004             <entry><para>Used by xirlink CIT, found at IBM webcams.</para>
1005                    <para>Uses one line of Y then 1 line of VYUY</para>
1006             </entry>
1007           </row>
1008           <row id="V4L2-PIX-FMT-KONICA420">
1009             <entry><constant>V4L2_PIX_FMT_KONICA420</constant></entry>
1010             <entry>'KONI'</entry>
1011             <entry><para>Used by Konica webcams.</para>
1012                    <para>YUV420 planar in blocks of 256 pixels.</para>
1013             </entry>
1014           </row>
1015           <row id="V4L2-PIX-FMT-YYUV">
1016             <entry><constant>V4L2_PIX_FMT_YYUV</constant></entry>
1017             <entry>'YYUV'</entry>
1018             <entry>unknown</entry>
1019           </row>
1020           <row id="V4L2-PIX-FMT-Y4">
1021             <entry><constant>V4L2_PIX_FMT_Y4</constant></entry>
1022             <entry>'Y04 '</entry>
1023             <entry>Old 4-bit greyscale format. Only the most significant 4 bits of each byte are used,
1024 the other bits are set to 0.</entry>
1025           </row>
1026           <row id="V4L2-PIX-FMT-Y6">
1027             <entry><constant>V4L2_PIX_FMT_Y6</constant></entry>
1028             <entry>'Y06 '</entry>
1029             <entry>Old 6-bit greyscale format. Only the most significant 6 bits of each byte are used,
1030 the other bits are set to 0.</entry>
1031           </row>
1032           <row id="V4L2-PIX-FMT-S5C-UYVY-JPG">
1033             <entry><constant>V4L2_PIX_FMT_S5C_UYVY_JPG</constant></entry>
1034             <entry>'S5CI'</entry>
1035             <entry>Two-planar format used by Samsung S5C73MX cameras. The
1036 first plane contains interleaved JPEG and UYVY image data, followed by meta data
1037 in form of an array of offsets to the UYVY data blocks. The actual pointer array
1038 follows immediately the interleaved JPEG/UYVY data, the number of entries in
1039 this array equals the height of the UYVY image. Each entry is a 4-byte unsigned
1040 integer in big endian order and it's an offset to a single pixel line of the
1041 UYVY image. The first plane can start either with JPEG or UYVY data chunk. The
1042 size of a single UYVY block equals the UYVY image's width multiplied by 2. The
1043 size of a JPEG chunk depends on the image and can vary with each line.
1044 <para>The second plane, at an offset of 4084 bytes, contains a 4-byte offset to
1045 the pointer array in the first plane. This offset is followed by a 4-byte value
1046 indicating size of the pointer array. All numbers in the second plane are also
1047 in big endian order. Remaining data in the second plane is undefined. The
1048 information in the second plane allows to easily find location of the pointer
1049 array, which can be different for each frame. The size of the pointer array is
1050 constant for given UYVY image height.</para>
1051 <para>In order to extract UYVY and JPEG frames an application can initially set
1052 a data pointer to the start of first plane and then add an offset from the first
1053 entry of the pointers table. Such a pointer indicates start of an UYVY image
1054 pixel line. Whole UYVY line can be copied to a separate buffer. These steps
1055 should be repeated for each line, i.e. the number of entries in the pointer
1056 array. Anything what's in between the UYVY lines is JPEG data and should be
1057 concatenated to form the JPEG stream. </para>
1058 </entry>
1059           </row>
1060         </tbody>
1061       </tgroup>
1062     </table>
1063   </section>