[linux-2.6-block.git] / Documentation / DocBook / media / v4l / vidioc-g-dv-timings.xml

<refentry id="vidioc-g-dv-timings">
  <refmeta>
    <refentrytitle>ioctl VIDIOC_G_DV_TIMINGS, VIDIOC_S_DV_TIMINGS</refentrytitle>
    &manvol;
  </refmeta>

  <refnamediv>
    <refname>VIDIOC_G_DV_TIMINGS</refname>
    <refname>VIDIOC_S_DV_TIMINGS</refname>
    <refpurpose>Get or set DV timings for input or output</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <funcsynopsis>
      <funcprototype>
	<funcdef>int <function>ioctl</function></funcdef>
	<paramdef>int <parameter>fd</parameter></paramdef>
	<paramdef>int <parameter>request</parameter></paramdef>
	<paramdef>struct v4l2_dv_timings *<parameter>argp</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Arguments</title>

    <variablelist>
      <varlistentry>
	<term><parameter>fd</parameter></term>
	<listitem>
	  <para>&fd;</para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><parameter>request</parameter></term>
	<listitem>
	  <para>VIDIOC_G_DV_TIMINGS, VIDIOC_S_DV_TIMINGS</para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><parameter>argp</parameter></term>
	<listitem>
	  <para></para>
	</listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>Description</title>
    <para>To set DV timings for the input or output, applications use the
<constant>VIDIOC_S_DV_TIMINGS</constant> ioctl and to get the current timings,
applications use the <constant>VIDIOC_G_DV_TIMINGS</constant> ioctl. The detailed timing
information is filled in using the structure &v4l2-dv-timings;. These ioctls take
a pointer to the &v4l2-dv-timings; structure as argument. If the ioctl is not supported
or the timing values are not correct, the driver returns &EINVAL;.</para>
<para>The <filename>linux/v4l2-dv-timings.h</filename> header can be used to get the
timings of the formats in the <xref linkend="cea861" /> and <xref linkend="vesadmt" />
standards. If the current input or output does not support DV timings (e.g. if
&VIDIOC-ENUMINPUT; does not set the <constant>V4L2_IN_CAP_DV_TIMINGS</constant> flag), then
&ENODATA; is returned.</para>
  </refsect1>

  <refsect1>
    &return-value;

    <variablelist>
      <varlistentry>
	<term><errorcode>EINVAL</errorcode></term>
	<listitem>
	  <para>This ioctl is not supported, or the
<constant>VIDIOC_S_DV_TIMINGS</constant> parameter was unsuitable.</para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><errorcode>ENODATA</errorcode></term>
	<listitem>
	  <para>Digital video timings are not supported for this input or output.</para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><errorcode>EBUSY</errorcode></term>
	<listitem>
	  <para>The device is busy and therefore can not change the timings.</para>
	</listitem>
      </varlistentry>
    </variablelist>

    <table pgwide="1" frame="none" id="v4l2-bt-timings">
      <title>struct <structname>v4l2_bt_timings</structname></title>
      <tgroup cols="3">
	&cs-str;
	<tbody valign="top">
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>width</structfield></entry>
	    <entry>Width of the active video in pixels.</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>height</structfield></entry>
	    <entry>Height of the active video frame in lines. So for interlaced formats the
	    height of the active video in each field is <structfield>height</structfield>/2.</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>interlaced</structfield></entry>
	    <entry>Progressive (0) or interlaced (1)</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>polarities</structfield></entry>
	    <entry>This is a bit mask that defines polarities of sync signals.
bit 0 (V4L2_DV_VSYNC_POS_POL) is for vertical sync polarity and bit 1 (V4L2_DV_HSYNC_POS_POL) is for horizontal sync polarity. If the bit is set
(1) it is positive polarity and if is cleared (0), it is negative polarity.</entry>
	  </row>
	  <row>
	    <entry>__u64</entry>
	    <entry><structfield>pixelclock</structfield></entry>
	    <entry>Pixel clock in Hz. Ex. 74.25MHz->74250000</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>hfrontporch</structfield></entry>
	    <entry>Horizontal front porch in pixels</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>hsync</structfield></entry>
	    <entry>Horizontal sync length in pixels</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>hbackporch</structfield></entry>
	    <entry>Horizontal back porch in pixels</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>vfrontporch</structfield></entry>
	    <entry>Vertical front porch in lines. For interlaced formats this refers to the
	    odd field (aka field 1).</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>vsync</structfield></entry>
	    <entry>Vertical sync length in lines. For interlaced formats this refers to the
	    odd field (aka field 1).</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>vbackporch</structfield></entry>
	    <entry>Vertical back porch in lines. For interlaced formats this refers to the
	    odd field (aka field 1).</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>il_vfrontporch</structfield></entry>
	    <entry>Vertical front porch in lines for the even field (aka field 2) of
	    interlaced field formats.</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>il_vsync</structfield></entry>
	    <entry>Vertical sync length in lines for the even field (aka field 2) of
	    interlaced field formats.</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>il_vbackporch</structfield></entry>
	    <entry>Vertical back porch in lines for the even field (aka field 2) of
	    interlaced field formats.</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>standards</structfield></entry>
	    <entry>The video standard(s) this format belongs to. This will be filled in by
	    the driver. Applications must set this to 0. See <xref linkend="dv-bt-standards"/>
	    for a list of standards.</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>flags</structfield></entry>
	    <entry>Several flags giving more information about the format.
	    See <xref linkend="dv-bt-flags"/> for a description of the flags.
	    </entry>
	  </row>
	</tbody>
      </tgroup>
    </table>

    <table pgwide="1" frame="none" id="v4l2-dv-timings">
      <title>struct <structname>v4l2_dv_timings</structname></title>
      <tgroup cols="4">
	&cs-str;
	<tbody valign="top">
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>type</structfield></entry>
	    <entry></entry>
	    <entry>Type of DV timings as listed in <xref linkend="dv-timing-types"/>.</entry>
	  </row>
	  <row>
	    <entry>union</entry>
	    <entry><structfield></structfield></entry>
	    <entry></entry>
	  </row>
	  <row>
	    <entry></entry>
	    <entry>&v4l2-bt-timings;</entry>
	    <entry><structfield>bt</structfield></entry>
	    <entry>Timings defined by BT.656/1120 specifications</entry>
	  </row>
	  <row>
	    <entry></entry>
	    <entry>__u32</entry>
	    <entry><structfield>reserved</structfield>[32]</entry>
	    <entry></entry>
	  </row>
	</tbody>
      </tgroup>
    </table>

    <table pgwide="1" frame="none" id="dv-timing-types">
      <title>DV Timing types</title>
      <tgroup cols="3">
	&cs-str;
	<tbody valign="top">
	  <row>
	    <entry>Timing type</entry>
	    <entry>value</entry>
	    <entry>Description</entry>
	  </row>
	  <row>
	    <entry></entry>
	    <entry></entry>
	    <entry></entry>
	  </row>
	  <row>
	    <entry>V4L2_DV_BT_656_1120</entry>
	    <entry>0</entry>
	    <entry>BT.656/1120 timings</entry>
	  </row>
	</tbody>
      </tgroup>
    </table>
    <table pgwide="1" frame="none" id="dv-bt-standards">
      <title>DV BT Timing standards</title>
      <tgroup cols="2">
	&cs-str;
	<tbody valign="top">
	  <row>
	    <entry>Timing standard</entry>
	    <entry>Description</entry>
	  </row>
	  <row>
	    <entry></entry>
	    <entry></entry>
	  </row>
	  <row>
	    <entry>V4L2_DV_BT_STD_CEA861</entry>
	    <entry>The timings follow the CEA-861 Digital TV Profile standard</entry>
	  </row>
	  <row>
	    <entry>V4L2_DV_BT_STD_DMT</entry>
	    <entry>The timings follow the VESA Discrete Monitor Timings standard</entry>
	  </row>
	  <row>
	    <entry>V4L2_DV_BT_STD_CVT</entry>
	    <entry>The timings follow the VESA Coordinated Video Timings standard</entry>
	  </row>
	  <row>
	    <entry>V4L2_DV_BT_STD_GTF</entry>
	    <entry>The timings follow the VESA Generalized Timings Formula standard</entry>
	  </row>
	</tbody>
      </tgroup>
    </table>
    <table pgwide="1" frame="none" id="dv-bt-flags">
      <title>DV BT Timing flags</title>
      <tgroup cols="2">
	&cs-str;
	<tbody valign="top">
	  <row>
	    <entry>Flag</entry>
	    <entry>Description</entry>
	  </row>
	  <row>
	    <entry></entry>
	    <entry></entry>
	  </row>
	  <row>
	    <entry>V4L2_DV_FL_REDUCED_BLANKING</entry>
	    <entry>CVT/GTF specific: the timings use reduced blanking (CVT) or the 'Secondary
GTF' curve (GTF). In both cases the horizontal and/or vertical blanking
intervals are reduced, allowing a higher resolution over the same
bandwidth. This is a read-only flag, applications must not set this.
	    </entry>
	  </row>
	  <row>
	    <entry>V4L2_DV_FL_CAN_REDUCE_FPS</entry>
	    <entry>CEA-861 specific: set for CEA-861 formats with a framerate that is a multiple
of six. These formats can be optionally played at 1 / 1.001 speed to
be compatible with 60 Hz based standards such as NTSC and PAL-M that use a framerate of
29.97 frames per second. If the transmitter can't generate such frequencies, then the
flag will also be cleared. This is a read-only flag, applications must not set this.
	    </entry>
	  </row>
	  <row>
	    <entry>V4L2_DV_FL_REDUCED_FPS</entry>
	    <entry>CEA-861 specific: only valid for video transmitters, the flag is cleared
by receivers. It is also only valid for formats with the V4L2_DV_FL_CAN_REDUCE_FPS flag
set, for other formats the flag will be cleared by the driver.

If the application sets this flag, then the pixelclock used to set up the transmitter is
divided by 1.001 to make it compatible with NTSC framerates. If the transmitter
can't generate such frequencies, then the flag will also be cleared.
	    </entry>
	  </row>
	  <row>
	    <entry>V4L2_DV_FL_HALF_LINE</entry>
	    <entry>Specific to interlaced formats: if set, then field 1 (aka the odd field)
is really one half-line longer and field 2 (aka the even field) is really one half-line
shorter, so each field has exactly the same number of half-lines. Whether half-lines can be
detected or used depends on the hardware.
	    </entry>
	  </row>
	</tbody>
      </tgroup>
    </table>
  </refsect1>
</refentry>
Commit	Line	Data
007701e2 MK	1	<refentry id="vidioc-g-dv-timings">
	2	<refmeta>
	3	<refentrytitle>ioctl VIDIOC_G_DV_TIMINGS, VIDIOC_S_DV_TIMINGS</refentrytitle>
	4	&manvol;
	5	</refmeta>
	6
	7	<refnamediv>
	8	<refname>VIDIOC_G_DV_TIMINGS</refname>
	9	<refname>VIDIOC_S_DV_TIMINGS</refname>
7dcc606b	10	<refpurpose>Get or set DV timings for input or output</refpurpose>
007701e2 MK	11	</refnamediv>
	12
	13	<refsynopsisdiv>
	14	<funcsynopsis>
	15	<funcprototype>
	16	<funcdef>int <function>ioctl</function></funcdef>
	17	<paramdef>int <parameter>fd</parameter></paramdef>
	18	<paramdef>int <parameter>request</parameter></paramdef>
5e765c6e	19	<paramdef>struct v4l2_dv_timings *<parameter>argp</parameter></paramdef>
007701e2 MK	20	</funcprototype>
	21	</funcsynopsis>
	22	</refsynopsisdiv>
	23
	24	<refsect1>
	25	<title>Arguments</title>
	26
	27	<variablelist>
	28	<varlistentry>
	29	<term><parameter>fd</parameter></term>
	30	<listitem>
	31	<para>&fd;</para>
	32	</listitem>
	33	</varlistentry>
	34	<varlistentry>
	35	<term><parameter>request</parameter></term>
	36	<listitem>
	37	<para>VIDIOC_G_DV_TIMINGS, VIDIOC_S_DV_TIMINGS</para>
	38	</listitem>
	39	</varlistentry>
	40	<varlistentry>
	41	<term><parameter>argp</parameter></term>
	42	<listitem>
	43	<para></para>
	44	</listitem>
	45	</varlistentry>
	46	</variablelist>
	47	</refsect1>
	48
	49	<refsect1>
	50	<title>Description</title>
7dcc606b HV	51	<para>To set DV timings for the input or output, applications use the
7dcc606b HV	52	<constant>VIDIOC_S_DV_TIMINGS</constant> ioctl and to get the current timings,
007701e2 MK	53	applications use the <constant>VIDIOC_G_DV_TIMINGS</constant> ioctl. The detailed timing
	54	information is filled in using the structure &v4l2-dv-timings;. These ioctls take
	55	a pointer to the &v4l2-dv-timings; structure as argument. If the ioctl is not supported
	56	or the timing values are not correct, the driver returns &EINVAL;.</para>
7dcc606b HV	57	<para>The <filename>linux/v4l2-dv-timings.h</filename> header can be used to get the
7dcc606b HV	58	timings of the formats in the <xref linkend="cea861" /> and <xref linkend="vesadmt" />
663dc7f3	59	standards. If the current input or output does not support DV timings (e.g. if
1c4f3c98	60	&VIDIOC-ENUMINPUT; does not set the <constant>V4L2_IN_CAP_DV_TIMINGS</constant> flag), then
663dc7f3	61	&ENODATA; is returned.</para>
007701e2 MK	62	</refsect1>
	63
	64	<refsect1>
	65	&return-value;
	66
	67	<variablelist>
	68	<varlistentry>
	69	<term><errorcode>EINVAL</errorcode></term>
	70	<listitem>
	71	<para>This ioctl is not supported, or the
	72	<constant>VIDIOC_S_DV_TIMINGS</constant> parameter was unsuitable.</para>
	73	</listitem>
	74	</varlistentry>
663dc7f3 HV	75	<varlistentry>
	76	<term><errorcode>ENODATA</errorcode></term>
	77	<listitem>
	78	<para>Digital video timings are not supported for this input or output.</para>
	79	</listitem>
	80	</varlistentry>
007701e2 MK	81	<varlistentry>
	82	<term><errorcode>EBUSY</errorcode></term>
	83	<listitem>
	84	<para>The device is busy and therefore can not change the timings.</para>
	85	</listitem>
	86	</varlistentry>
	87	</variablelist>
	88
	89	<table pgwide="1" frame="none" id="v4l2-bt-timings">
	90	<title>struct <structname>v4l2_bt_timings</structname></title>
	91	<tgroup cols="3">
	92	&cs-str;
	93	<tbody valign="top">
	94	<row>
	95	<entry>__u32</entry>
	96	<entry><structfield>width</structfield></entry>
7dcc606b	97	<entry>Width of the active video in pixels.</entry>
007701e2 MK	98	</row>
	99	<row>
	100	<entry>__u32</entry>
	101	<entry><structfield>height</structfield></entry>
7dcc606b HV	102	<entry>Height of the active video frame in lines. So for interlaced formats the
7dcc606b HV	103	height of the active video in each field is <structfield>height</structfield>/2.</entry>
007701e2 MK	104	</row>
	105	<row>
	106	<entry>__u32</entry>
	107	<entry><structfield>interlaced</structfield></entry>
	108	<entry>Progressive (0) or interlaced (1)</entry>
	109	</row>
	110	<row>
	111	<entry>__u32</entry>
	112	<entry><structfield>polarities</structfield></entry>
	113	<entry>This is a bit mask that defines polarities of sync signals.
	114	bit 0 (V4L2_DV_VSYNC_POS_POL) is for vertical sync polarity and bit 1 (V4L2_DV_HSYNC_POS_POL) is for horizontal sync polarity. If the bit is set
	115	(1) it is positive polarity and if is cleared (0), it is negative polarity.</entry>
	116	</row>
	117	<row>
	118	<entry>__u64</entry>
	119	<entry><structfield>pixelclock</structfield></entry>
	120	<entry>Pixel clock in Hz. Ex. 74.25MHz->74250000</entry>
	121	</row>
	122	<row>
	123	<entry>__u32</entry>
	124	<entry><structfield>hfrontporch</structfield></entry>
	125	<entry>Horizontal front porch in pixels</entry>
	126	</row>
	127	<row>
	128	<entry>__u32</entry>
	129	<entry><structfield>hsync</structfield></entry>
	130	<entry>Horizontal sync length in pixels</entry>
	131	</row>
	132	<row>
	133	<entry>__u32</entry>
	134	<entry><structfield>hbackporch</structfield></entry>
	135	<entry>Horizontal back porch in pixels</entry>
	136	</row>
	137	<row>
	138	<entry>__u32</entry>
	139	<entry><structfield>vfrontporch</structfield></entry>
7dcc606b HV	140	<entry>Vertical front porch in lines. For interlaced formats this refers to the
7dcc606b HV	141	odd field (aka field 1).</entry>
007701e2 MK	142	</row>
	143	<row>
	144	<entry>__u32</entry>
	145	<entry><structfield>vsync</structfield></entry>
7dcc606b HV	146	<entry>Vertical sync length in lines. For interlaced formats this refers to the
7dcc606b HV	147	odd field (aka field 1).</entry>
007701e2 MK	148	</row>
	149	<row>
	150	<entry>__u32</entry>
	151	<entry><structfield>vbackporch</structfield></entry>
7dcc606b HV	152	<entry>Vertical back porch in lines. For interlaced formats this refers to the
7dcc606b HV	153	odd field (aka field 1).</entry>
007701e2 MK	154	</row>
	155	<row>
	156	<entry>__u32</entry>
	157	<entry><structfield>il_vfrontporch</structfield></entry>
7dcc606b HV	158	<entry>Vertical front porch in lines for the even field (aka field 2) of
7dcc606b HV	159	interlaced field formats.</entry>
007701e2 MK	160	</row>
	161	<row>
	162	<entry>__u32</entry>
	163	<entry><structfield>il_vsync</structfield></entry>
7dcc606b HV	164	<entry>Vertical sync length in lines for the even field (aka field 2) of
7dcc606b HV	165	interlaced field formats.</entry>
007701e2 MK	166	</row>
	167	<row>
	168	<entry>__u32</entry>
	169	<entry><structfield>il_vbackporch</structfield></entry>
7dcc606b HV	170	<entry>Vertical back porch in lines for the even field (aka field 2) of
	171	interlaced field formats.</entry>
	172	</row>
	173	<row>
	174	<entry>__u32</entry>
	175	<entry><structfield>standards</structfield></entry>
	176	<entry>The video standard(s) this format belongs to. This will be filled in by
	177	the driver. Applications must set this to 0. See <xref linkend="dv-bt-standards"/>
	178	for a list of standards.</entry>
	179	</row>
	180	<row>
	181	<entry>__u32</entry>
	182	<entry><structfield>flags</structfield></entry>
	183	<entry>Several flags giving more information about the format.
	184	See <xref linkend="dv-bt-flags"/> for a description of the flags.
	185	</entry>
007701e2 MK	186	</row>
	187	</tbody>
	188	</tgroup>
	189	</table>
	190
	191	<table pgwide="1" frame="none" id="v4l2-dv-timings">
	192	<title>struct <structname>v4l2_dv_timings</structname></title>
	193	<tgroup cols="4">
	194	&cs-str;
	195	<tbody valign="top">
	196	<row>
	197	<entry>__u32</entry>
	198	<entry><structfield>type</structfield></entry>
	199	<entry></entry>
	200	<entry>Type of DV timings as listed in <xref linkend="dv-timing-types"/>.</entry>
	201	</row>
	202	<row>
	203	<entry>union</entry>
	204	<entry><structfield></structfield></entry>
	205	<entry></entry>
	206	</row>
	207	<row>
	208	<entry></entry>
	209	<entry>&v4l2-bt-timings;</entry>
	210	<entry><structfield>bt</structfield></entry>
	211	<entry>Timings defined by BT.656/1120 specifications</entry>
	212	</row>
	213	<row>
	214	<entry></entry>
	215	<entry>__u32</entry>
	216	<entry><structfield>reserved</structfield>[32]</entry>
	217	<entry></entry>
	218	</row>
	219	</tbody>
	220	</tgroup>
	221	</table>
	222
	223	<table pgwide="1" frame="none" id="dv-timing-types">
	224	<title>DV Timing types</title>
	225	<tgroup cols="3">
	226	&cs-str;
	227	<tbody valign="top">
	228	<row>
	229	<entry>Timing type</entry>
	230	<entry>value</entry>
	231	<entry>Description</entry>
	232	</row>
	233	<row>
	234	<entry></entry>
	235	<entry></entry>
	236	<entry></entry>
	237	</row>
	238	<row>
	239	<entry>V4L2_DV_BT_656_1120</entry>
	240	<entry>0</entry>
	241	<entry>BT.656/1120 timings</entry>
	242	</row>
	243	</tbody>
	244	</tgroup>
	245	</table>
7dcc606b HV	246	<table pgwide="1" frame="none" id="dv-bt-standards">
	247	<title>DV BT Timing standards</title>
	248	<tgroup cols="2">
	249	&cs-str;
	250	<tbody valign="top">
	251	<row>
	252	<entry>Timing standard</entry>
	253	<entry>Description</entry>
	254	</row>
	255	<row>
	256	<entry></entry>
	257	<entry></entry>
	258	</row>
	259	<row>
	260	<entry>V4L2_DV_BT_STD_CEA861</entry>
	261	<entry>The timings follow the CEA-861 Digital TV Profile standard</entry>
	262	</row>
	263	<row>
	264	<entry>V4L2_DV_BT_STD_DMT</entry>
	265	<entry>The timings follow the VESA Discrete Monitor Timings standard</entry>
	266	</row>
	267	<row>
	268	<entry>V4L2_DV_BT_STD_CVT</entry>
	269	<entry>The timings follow the VESA Coordinated Video Timings standard</entry>
	270	</row>
	271	<row>
	272	<entry>V4L2_DV_BT_STD_GTF</entry>
	273	<entry>The timings follow the VESA Generalized Timings Formula standard</entry>
	274	</row>
	275	</tbody>
	276	</tgroup>
	277	</table>
	278	<table pgwide="1" frame="none" id="dv-bt-flags">
	279	<title>DV BT Timing flags</title>
	280	<tgroup cols="2">
	281	&cs-str;
	282	<tbody valign="top">
	283	<row>
	284	<entry>Flag</entry>
	285	<entry>Description</entry>
	286	</row>
	287	<row>
	288	<entry></entry>
	289	<entry></entry>
	290	</row>
	291	<row>
	292	<entry>V4L2_DV_FL_REDUCED_BLANKING</entry>
	293	<entry>CVT/GTF specific: the timings use reduced blanking (CVT) or the 'Secondary
	294	GTF' curve (GTF). In both cases the horizontal and/or vertical blanking
	295	intervals are reduced, allowing a higher resolution over the same
	296	bandwidth. This is a read-only flag, applications must not set this.
	297	</entry>
	298	</row>
	299	<row>
	300	<entry>V4L2_DV_FL_CAN_REDUCE_FPS</entry>
	301	<entry>CEA-861 specific: set for CEA-861 formats with a framerate that is a multiple
	302	of six. These formats can be optionally played at 1 / 1.001 speed to
	303	be compatible with 60 Hz based standards such as NTSC and PAL-M that use a framerate of
	304	29.97 frames per second. If the transmitter can't generate such frequencies, then the
	305	flag will also be cleared. This is a read-only flag, applications must not set this.
	306	</entry>
	307	</row>
	308	<row>
	309	<entry>V4L2_DV_FL_REDUCED_FPS</entry>
310	<entry>CEA-861 specific: only valid for video transmitters, the flag is cleared
311	by receivers. It is also only valid for formats with the V4L2_DV_FL_CAN_REDUCE_FPS flag
312	set, for other formats the flag will be cleared by the driver.
313
314	If the application sets this flag, then the pixelclock used to set up the transmitter is
315	divided by 1.001 to make it compatible with NTSC framerates. If the transmitter
316	can't generate such frequencies, then the flag will also be cleared.
317	</entry>
318	</row>
319	<row>
320	<entry>V4L2_DV_FL_HALF_LINE</entry>
321	<entry>Specific to interlaced formats: if set, then field 1 (aka the odd field)
322	is really one half-line longer and field 2 (aka the even field) is really one half-line
323	shorter, so each field has exactly the same number of half-lines. Whether half-lines can be
324	detected or used depends on the hardware.
325	</entry>
326	</row>
327	</tbody>
328	</tgroup>
329	</table>
007701e2 MK	330	</refsect1>
007701e2 MK	331	</refentry>