--- /dev/null
+<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. Must be 0 for progressive 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. Must be 0 for progressive 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. Must be 0 for progressive 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 the vertical frontporch
+of field 1 (aka the odd field) is really one half-line longer and the vertical backporch
+of 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>
+ <row>
+ <entry>V4L2_DV_FL_IS_CE_VIDEO</entry>
+ <entry>If set, then this is a Consumer Electronics (CE) video format.
+Such formats differ from other formats (commonly called IT formats) in that if
+R'G'B' encoding is used then by default the R'G'B' values use limited range
+(i.e. 16-235) as opposed to full range (i.e. 0-255). All formats defined in CEA-861
+except for the 640x480p59.94 format are CE formats.
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </refsect1>
+</refentry>
Code Review / kvmfornfv.git / blobdiff