diff options
Diffstat (limited to 'Documentation/DocBook/v4l/vidioc-enuminput.xml')
| -rw-r--r-- | Documentation/DocBook/v4l/vidioc-enuminput.xml | 287 |
1 files changed, 287 insertions, 0 deletions
diff --git a/Documentation/DocBook/v4l/vidioc-enuminput.xml b/Documentation/DocBook/v4l/vidioc-enuminput.xml new file mode 100644 index 00000000000..414856b8247 --- /dev/null +++ b/Documentation/DocBook/v4l/vidioc-enuminput.xml @@ -0,0 +1,287 @@ +<refentry id="vidioc-enuminput"> + <refmeta> + <refentrytitle>ioctl VIDIOC_ENUMINPUT</refentrytitle> + &manvol; + </refmeta> + + <refnamediv> + <refname>VIDIOC_ENUMINPUT</refname> + <refpurpose>Enumerate video inputs</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_input +*<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_ENUMINPUT</para> + </listitem> + </varlistentry> + <varlistentry> + <term><parameter>argp</parameter></term> + <listitem> + <para></para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Description</title> + + <para>To query the attributes of a video input applications +initialize the <structfield>index</structfield> field of &v4l2-input; +and call the <constant>VIDIOC_ENUMINPUT</constant> ioctl with a +pointer to this structure. Drivers fill the rest of the structure or +return an &EINVAL; when the index is out of bounds. To enumerate all +inputs applications shall begin at index zero, incrementing by one +until the driver returns <errorcode>EINVAL</errorcode>.</para> + + <table frame="none" pgwide="1" id="v4l2-input"> + <title>struct <structname>v4l2_input</structname></title> + <tgroup cols="3"> + &cs-str; + <tbody valign="top"> + <row> + <entry>__u32</entry> + <entry><structfield>index</structfield></entry> + <entry>Identifies the input, set by the +application.</entry> + </row> + <row> + <entry>__u8</entry> + <entry><structfield>name</structfield>[32]</entry> + <entry>Name of the video input, a NUL-terminated ASCII +string, for example: "Vin (Composite 2)". This information is intended +for the user, preferably the connector label on the device itself.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>type</structfield></entry> + <entry>Type of the input, see <xref + linkend="input-type" />.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>audioset</structfield></entry> + <entry><para>Drivers can enumerate up to 32 video and +audio inputs. This field shows which audio inputs were selectable as +audio source if this was the currently selected video input. It is a +bit mask. The LSB corresponds to audio input 0, the MSB to input 31. +Any number of bits can be set, or none.</para><para>When the driver +does not enumerate audio inputs no bits must be set. Applications +shall not interpret this as lack of audio support. Some drivers +automatically select audio sources and do not enumerate them since +there is no choice anyway.</para><para>For details on audio inputs and +how to select the current input see <xref + linkend="audio" />.</para></entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>tuner</structfield></entry> + <entry>Capture devices can have zero or more tuners (RF +demodulators). When the <structfield>type</structfield> is set to +<constant>V4L2_INPUT_TYPE_TUNER</constant> this is an RF connector and +this field identifies the tuner. It corresponds to +&v4l2-tuner; field <structfield>index</structfield>. For details on +tuners see <xref linkend="tuner" />.</entry> + </row> + <row> + <entry>&v4l2-std-id;</entry> + <entry><structfield>std</structfield></entry> + <entry>Every video input supports one or more different +video standards. This field is a set of all supported standards. For +details on video standards and how to switch see <xref +linkend="standard" />.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>status</structfield></entry> + <entry>This field provides status information about the +input. See <xref linkend="input-status" /> for flags. +With the exception of the sensor orientation bits <structfield>status</structfield> is only valid when this is the +current input.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>reserved</structfield>[4]</entry> + <entry>Reserved for future extensions. Drivers must set +the array to zero.</entry> + </row> + </tbody> + </tgroup> + </table> + + <table frame="none" pgwide="1" id="input-type"> + <title>Input Types</title> + <tgroup cols="3"> + &cs-def; + <tbody valign="top"> + <row> + <entry><constant>V4L2_INPUT_TYPE_TUNER</constant></entry> + <entry>1</entry> + <entry>This input uses a tuner (RF demodulator).</entry> + </row> + <row> + <entry><constant>V4L2_INPUT_TYPE_CAMERA</constant></entry> + <entry>2</entry> + <entry>Analog baseband input, for example CVBS / +Composite Video, S-Video, RGB.</entry> + </row> + </tbody> + </tgroup> + </table> + + <!-- Status flags based on proposal by Mark McClelland, +video4linux-list@redhat.com on 18 Oct 2002, subject "Re: [V4L] Re: +v4l2 api". "Why are some of them inverted? So that the driver doesn't +have to lie about the status in cases where it can't tell one way or +the other. Plus, a status of zero would generally mean that everything +is OK." --> + + <table frame="none" pgwide="1" id="input-status"> + <title>Input Status Flags</title> + <tgroup cols="3"> + <colspec colname="c1" /> + <colspec colname="c2" align="center" /> + <colspec colname="c3" /> + <spanspec namest="c1" nameend="c3" spanname="hspan" + align="left" /> + <tbody valign="top"> + <row> + <entry spanname="hspan">General</entry> + </row> + <row> + <entry><constant>V4L2_IN_ST_NO_POWER</constant></entry> + <entry>0x00000001</entry> + <entry>Attached device is off.</entry> + </row> + <row> + <entry><constant>V4L2_IN_ST_NO_SIGNAL</constant></entry> + <entry>0x00000002</entry> + <entry></entry> + </row> + <row> + <entry><constant>V4L2_IN_ST_NO_COLOR</constant></entry> + <entry>0x00000004</entry> + <entry>The hardware supports color decoding, but does not +detect color modulation in the signal.</entry> + </row> + <row> + <entry spanname="hspan">Sensor Orientation</entry> + </row> + <row> + <entry><constant>V4L2_IN_ST_HFLIP</constant></entry> + <entry>0x00000010</entry> + <entry>The input is connected to a device that produces a signal +that is flipped horizontally and does not correct this before passing the +signal to userspace.</entry> + </row> + <row> + <entry><constant>V4L2_IN_ST_VFLIP</constant></entry> + <entry>0x00000020</entry> + <entry>The input is connected to a device that produces a signal +that is flipped vertically and does not correct this before passing the +signal to userspace. Note that a 180 degree rotation is the same as HFLIP | VFLIP</entry> + </row> + <row> + <entry spanname="hspan">Analog Video</entry> + </row> + <row> + <entry><constant>V4L2_IN_ST_NO_H_LOCK</constant></entry> + <entry>0x00000100</entry> + <entry>No horizontal sync lock.</entry> + </row> + <row> + <entry><constant>V4L2_IN_ST_COLOR_KILL</constant></entry> + <entry>0x00000200</entry> + <entry>A color killer circuit automatically disables color +decoding when it detects no color modulation. When this flag is set +the color killer is enabled <emphasis>and</emphasis> has shut off +color decoding.</entry> + </row> + <row> + <entry spanname="hspan">Digital Video</entry> + </row> + <row> + <entry><constant>V4L2_IN_ST_NO_SYNC</constant></entry> + <entry>0x00010000</entry> + <entry>No synchronization lock.</entry> + </row> + <row> + <entry><constant>V4L2_IN_ST_NO_EQU</constant></entry> + <entry>0x00020000</entry> + <entry>No equalizer lock.</entry> + </row> + <row> + <entry><constant>V4L2_IN_ST_NO_CARRIER</constant></entry> + <entry>0x00040000</entry> + <entry>Carrier recovery failed.</entry> + </row> + <row> + <entry spanname="hspan">VCR and Set-Top Box</entry> + </row> + <row> + <entry><constant>V4L2_IN_ST_MACROVISION</constant></entry> + <entry>0x01000000</entry> + <entry>Macrovision is an analog copy prevention system +mangling the video signal to confuse video recorders. When this +flag is set Macrovision has been detected.</entry> + </row> + <row> + <entry><constant>V4L2_IN_ST_NO_ACCESS</constant></entry> + <entry>0x02000000</entry> + <entry>Conditional access denied.</entry> + </row> + <row> + <entry><constant>V4L2_IN_ST_VTR</constant></entry> + <entry>0x04000000</entry> + <entry>VTR time constant. [?]</entry> + </row> + </tbody> + </tgroup> + </table> + </refsect1> + + <refsect1> + &return-value; + + <variablelist> + <varlistentry> + <term><errorcode>EINVAL</errorcode></term> + <listitem> + <para>The &v4l2-input; <structfield>index</structfield> is +out of bounds.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> +</refentry> + +<!-- +Local Variables: +mode: sgml +sgml-parent-document: "v4l2.sgml" +indent-tabs-mode: nil +End: +--> |