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Diffstat (limited to 'Documentation/DocBook/media/v4l/vidioc-querystd.xml')
-rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-querystd.xml | 85 |
1 files changed, 0 insertions, 85 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-querystd.xml b/Documentation/DocBook/media/v4l/vidioc-querystd.xml deleted file mode 100644 index 3ceae35fab03..000000000000 --- a/Documentation/DocBook/media/v4l/vidioc-querystd.xml +++ /dev/null @@ -1,85 +0,0 @@ -<refentry id="vidioc-querystd"> - <refmeta> - <refentrytitle>ioctl VIDIOC_QUERYSTD</refentrytitle> - &manvol; - </refmeta> - - <refnamediv> - <refname>VIDIOC_QUERYSTD</refname> - <refpurpose>Sense the video standard received by the current -input</refpurpose> - </refnamediv> - - <refsynopsisdiv> - <funcsynopsis> - <funcprototype> - <funcdef>int <function>ioctl</function></funcdef> - <paramdef>int <parameter>fd</parameter></paramdef> - <paramdef>int <parameter>request</parameter></paramdef> - <paramdef>v4l2_std_id *<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_QUERYSTD</para> - </listitem> - </varlistentry> - <varlistentry> - <term><parameter>argp</parameter></term> - <listitem> - <para></para> - </listitem> - </varlistentry> - </variablelist> - </refsect1> - - <refsect1> - <title>Description</title> - - <para>The hardware may be able to detect the current video -standard automatically. To do so, applications call <constant> -VIDIOC_QUERYSTD</constant> with a pointer to a &v4l2-std-id; type. The -driver stores here a set of candidates, this can be a single flag or a -set of supported standards if for example the hardware can only -distinguish between 50 and 60 Hz systems. If no signal was detected, -then the driver will return V4L2_STD_UNKNOWN. When detection is not -possible or fails, the set must contain all standards supported by the -current video input or output.</para> - -<para>Please note that drivers shall <emphasis>not</emphasis> switch the video standard -automatically if a new video standard is detected. Instead, drivers should send the -<constant>V4L2_EVENT_SOURCE_CHANGE</constant> event (if they support this) and expect -that userspace will take action by calling <constant>VIDIOC_QUERYSTD</constant>. -The reason is that a new video standard can mean different buffer sizes as well, and you -cannot change buffer sizes on the fly. In general, applications that receive the -Source Change event will have to call <constant>VIDIOC_QUERYSTD</constant>, -and if the detected video standard is valid they will have to stop streaming, set the new -standard, allocate new buffers and start streaming again.</para> - - </refsect1> - - <refsect1> - &return-value; - <variablelist> - <varlistentry> - <term><errorcode>ENODATA</errorcode></term> - <listitem> - <para>Standard video timings are not supported for this input or output.</para> - </listitem> - </varlistentry> - </variablelist> - </refsect1> -</refentry> |