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Diffstat (limited to 'Documentation/DocBook/v4l/vidioc-g-enc-index.xml')
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diff --git a/Documentation/DocBook/v4l/vidioc-g-enc-index.xml b/Documentation/DocBook/v4l/vidioc-g-enc-index.xml deleted file mode 100644 index 9f242e4..0000000 --- a/Documentation/DocBook/v4l/vidioc-g-enc-index.xml +++ /dev/null @@ -1,213 +0,0 @@ -<refentry id="vidioc-g-enc-index"> - <refmeta> - <refentrytitle>ioctl VIDIOC_G_ENC_INDEX</refentrytitle> - &manvol; - </refmeta> - - <refnamediv> - <refname>VIDIOC_G_ENC_INDEX</refname> - <refpurpose>Get meta data about a compressed video stream</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_enc_idx *<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_ENC_INDEX</para> - </listitem> - </varlistentry> - <varlistentry> - <term><parameter>argp</parameter></term> - <listitem> - <para></para> - </listitem> - </varlistentry> - </variablelist> - </refsect1> - - <refsect1> - <title>Description</title> - - <note> - <title>Experimental</title> - - <para>This is an <link linkend="experimental">experimental</link> -interface and may change in the future.</para> - </note> - - <para>The <constant>VIDIOC_G_ENC_INDEX</constant> ioctl provides -meta data about a compressed video stream the same or another -application currently reads from the driver, which is useful for -random access into the stream without decoding it.</para> - - <para>To read the data applications must call -<constant>VIDIOC_G_ENC_INDEX</constant> with a pointer to a -&v4l2-enc-idx;. On success the driver fills the -<structfield>entry</structfield> array, stores the number of elements -written in the <structfield>entries</structfield> field, and -initializes the <structfield>entries_cap</structfield> field.</para> - - <para>Each element of the <structfield>entry</structfield> array -contains meta data about one picture. A -<constant>VIDIOC_G_ENC_INDEX</constant> call reads up to -<constant>V4L2_ENC_IDX_ENTRIES</constant> entries from a driver -buffer, which can hold up to <structfield>entries_cap</structfield> -entries. This number can be lower or higher than -<constant>V4L2_ENC_IDX_ENTRIES</constant>, but not zero. When the -application fails to read the meta data in time the oldest entries -will be lost. When the buffer is empty or no capturing/encoding is in -progress, <structfield>entries</structfield> will be zero.</para> - - <para>Currently this ioctl is only defined for MPEG-2 program -streams and video elementary streams.</para> - - <table pgwide="1" frame="none" id="v4l2-enc-idx"> - <title>struct <structname>v4l2_enc_idx</structname></title> - <tgroup cols="3"> - &cs-str; - <tbody valign="top"> - <row> - <entry>__u32</entry> - <entry><structfield>entries</structfield></entry> - <entry>The number of entries the driver stored in the -<structfield>entry</structfield> array.</entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>entries_cap</structfield></entry> - <entry>The number of entries the driver can -buffer. Must be greater than zero.</entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>reserved</structfield>[4]</entry> - <entry spanname="hspan">Reserved for future extensions. -Drivers must set the array to zero.</entry> - </row> - <row> - <entry>&v4l2-enc-idx-entry;</entry> - <entry><structfield>entry</structfield>[<constant>V4L2_ENC_IDX_ENTRIES</constant>]</entry> - <entry>Meta data about a compressed video stream. Each -element of the array corresponds to one picture, sorted in ascending -order by their <structfield>offset</structfield>.</entry> - </row> - </tbody> - </tgroup> - </table> - - <table pgwide="1" frame="none" id="v4l2-enc-idx-entry"> - <title>struct <structname>v4l2_enc_idx_entry</structname></title> - <tgroup cols="3"> - &cs-str; - <tbody valign="top"> - <row> - <entry>__u64</entry> - <entry><structfield>offset</structfield></entry> - <entry>The offset in bytes from the beginning of the -compressed video stream to the beginning of this picture, that is a -<wordasword>PES packet header</wordasword> as defined in <xref - linkend="mpeg2part1" /> or a <wordasword>picture -header</wordasword> as defined in <xref linkend="mpeg2part2" />. When -the encoder is stopped, the driver resets the offset to zero.</entry> - </row> - <row> - <entry>__u64</entry> - <entry><structfield>pts</structfield></entry> - <entry>The 33 bit <wordasword>Presentation Time -Stamp</wordasword> of this picture as defined in <xref - linkend="mpeg2part1" />.</entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>length</structfield></entry> - <entry>The length of this picture in bytes.</entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>flags</structfield></entry> - <entry>Flags containing the coding type of this picture, see <xref - linkend="enc-idx-flags" />.</entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>reserved</structfield>[2]</entry> - <entry>Reserved for future extensions. -Drivers must set the array to zero.</entry> - </row> - </tbody> - </tgroup> - </table> - - <table pgwide="1" frame="none" id="enc-idx-flags"> - <title>Index Entry Flags</title> - <tgroup cols="3"> - &cs-def; - <tbody valign="top"> - <row> - <entry><constant>V4L2_ENC_IDX_FRAME_I</constant></entry> - <entry>0x00</entry> - <entry>This is an Intra-coded picture.</entry> - </row> - <row> - <entry><constant>V4L2_ENC_IDX_FRAME_P</constant></entry> - <entry>0x01</entry> - <entry>This is a Predictive-coded picture.</entry> - </row> - <row> - <entry><constant>V4L2_ENC_IDX_FRAME_B</constant></entry> - <entry>0x02</entry> - <entry>This is a Bidirectionally predictive-coded -picture.</entry> - </row> - <row> - <entry><constant>V4L2_ENC_IDX_FRAME_MASK</constant></entry> - <entry>0x0F</entry> - <entry><wordasword>AND</wordasword> the flags field with -this mask to obtain the picture coding type.</entry> - </row> - </tbody> - </tgroup> - </table> - </refsect1> - - <refsect1> - &return-value; - - <variablelist> - <varlistentry> - <term><errorcode>EINVAL</errorcode></term> - <listitem> - <para>The driver does not support this ioctl.</para> - </listitem> - </varlistentry> - </variablelist> - </refsect1> -</refentry> - -<!-- -Local Variables: -mode: sgml -sgml-parent-document: "v4l2.sgml" -indent-tabs-mode: nil -End: ---> |