summaryrefslogtreecommitdiff
path: root/Documentation/DocBook/media/v4l/vidioc-g-output.xml
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/DocBook/media/v4l/vidioc-g-output.xml')
-rw-r--r--Documentation/DocBook/media/v4l/vidioc-g-output.xml84
1 files changed, 84 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-g-output.xml b/Documentation/DocBook/media/v4l/vidioc-g-output.xml
new file mode 100644
index 000000000000..fd45f1c13ccf
--- /dev/null
+++ b/Documentation/DocBook/media/v4l/vidioc-g-output.xml
@@ -0,0 +1,84 @@
+<refentry id="vidioc-g-output">
+ <refmeta>
+ <refentrytitle>ioctl VIDIOC_G_OUTPUT, VIDIOC_S_OUTPUT</refentrytitle>
+ &manvol;
+ </refmeta>
+
+ <refnamediv>
+ <refname>VIDIOC_G_OUTPUT</refname>
+ <refname>VIDIOC_S_OUTPUT</refname>
+ <refpurpose>Query or select the current video 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>int *<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_OUTPUT, VIDIOC_S_OUTPUT</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>argp</parameter></term>
+ <listitem>
+ <para></para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>To query the current video output applications call the
+<constant>VIDIOC_G_OUTPUT</constant> ioctl with a pointer to an integer
+where the driver stores the number of the output, as in the
+&v4l2-output; <structfield>index</structfield> field. This ioctl
+will fail only when there are no video outputs, returning the
+&EINVAL;.</para>
+
+ <para>To select a video output applications store the number of the
+desired output in an integer and call the
+<constant>VIDIOC_S_OUTPUT</constant> ioctl with a pointer to this integer.
+Side effects are possible. For example outputs may support different
+video standards, so the driver may implicitly switch the current
+standard. It is good practice to select an output before querying or
+negotiating any other parameters.</para>
+
+ <para>Information about video outputs is available using the
+&VIDIOC-ENUMOUTPUT; ioctl.</para>
+ </refsect1>
+
+ <refsect1>
+ &return-value;
+
+ <variablelist>
+ <varlistentry>
+ <term><errorcode>EINVAL</errorcode></term>
+ <listitem>
+ <para>The number of the video output is out of bounds, or
+there are no video outputs at all.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+</refentry>