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Diffstat (limited to 'v4l2-spec/dev-rds.sgml')
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diff --git a/v4l2-spec/dev-rds.sgml b/v4l2-spec/dev-rds.sgml deleted file mode 100644 index 0869d701b..000000000 --- a/v4l2-spec/dev-rds.sgml +++ /dev/null @@ -1,168 +0,0 @@ - <title>RDS Interface</title> - - <para>The Radio Data System transmits supplementary -information in binary format, for example the station name or travel -information, on an inaudible audio subcarrier of a radio program. This -interface is aimed at devices capable of receiving and decoding RDS -information.</para> - - <para>For more information see the core RDS standard <xref linkend="en50067" /> -and the RBDS standard <xref linkend="nrsc4" />.</para> - - <para>Note that the RBDS standard as is used in the USA is almost identical -to the RDS standard. Any RDS decoder can also handle RBDS. Only some of the fields -have slightly different meanings. See the RBDS standard for more information.</para> - - <para>The RBDS standard also specifies support for MMBS (Modified Mobile Search). -This is a proprietary format which seems to be discontinued. The RDS interface does not -support this format. Should support for MMBS (or the so-called 'E blocks' in general) -be needed, then please contact the linux-media mailing list: &v4l-ml;.</para> - - <section> - <title>Querying Capabilities</title> - - <para>Devices supporting the RDS capturing API -set the <constant>V4L2_CAP_RDS_CAPTURE</constant> flag in -the <structfield>capabilities</structfield> field of &v4l2-capability; -returned by the &VIDIOC-QUERYCAP; ioctl. -Any tuner that supports RDS will set the -<constant>V4L2_TUNER_CAP_RDS</constant> flag in the <structfield>capability</structfield> -field of &v4l2-tuner;. -Whether an RDS signal is present can be detected by looking at -the <structfield>rxsubchans</structfield> field of &v4l2-tuner;: the -<constant>V4L2_TUNER_SUB_RDS</constant> will be set if RDS data was detected.</para> - - <para>Devices supporting the RDS output API -set the <constant>V4L2_CAP_RDS_OUTPUT</constant> flag in -the <structfield>capabilities</structfield> field of &v4l2-capability; -returned by the &VIDIOC-QUERYCAP; ioctl. -Any modulator that supports RDS will set the -<constant>V4L2_TUNER_CAP_RDS</constant> flag in the <structfield>capability</structfield> -field of &v4l2-modulator;. -In order to enable the RDS transmission one must set the <constant>V4L2_TUNER_SUB_RDS</constant> -bit in the <structfield>txsubchans</structfield> field of &v4l2-modulator;.</para> - - </section> - - <section> - <title>Reading RDS data</title> - - <para>RDS data can be read from the radio device -with the &func-read; function. The data is packed in groups of three bytes, -as follows:</para> - <table frame="none" pgwide="1" id="v4l2-rds-data"> - <title>struct -<structname>v4l2_rds_data</structname></title> - <tgroup cols="3"> - <colspec colname="c1" colwidth="1*" /> - <colspec colname="c2" colwidth="1*" /> - <colspec colname="c3" colwidth="5*" /> - <tbody valign="top"> - <row> - <entry>__u8</entry> - <entry><structfield>lsb</structfield></entry> - <entry>Least Significant Byte of RDS Block</entry> - </row> - <row> - <entry>__u8</entry> - <entry><structfield>msb</structfield></entry> - <entry>Most Significant Byte of RDS Block</entry> - </row> - <row> - <entry>__u8</entry> - <entry><structfield>block</structfield></entry> - <entry>Block description</entry> - </row> - </tbody> - </tgroup> - </table> - <table frame="none" pgwide="1" id="v4l2-rds-block"> - <title>Block description</title> - <tgroup cols="2"> - <colspec colname="c1" colwidth="1*" /> - <colspec colname="c2" colwidth="5*" /> - <tbody valign="top"> - <row> - <entry>Bits 0-2</entry> - <entry>Block (aka offset) of the received data.</entry> - </row> - <row> - <entry>Bits 3-5</entry> - <entry>Deprecated. Currently identical to bits 0-2. Do not use these bits.</entry> - </row> - <row> - <entry>Bit 6</entry> - <entry>Corrected bit. Indicates that an error was corrected for this data block.</entry> - </row> - <row> - <entry>Bit 7</entry> - <entry>Error bit. Indicates that an uncorrectable error occurred during reception of this block.</entry> - </row> - </tbody> - </tgroup> - </table> - - <table frame="none" pgwide="1" id="v4l2-rds-block-codes"> - <title>Block defines</title> - <tgroup cols="3"> - <colspec colname="c1" colwidth="1*" /> - <colspec colname="c2" colwidth="1*" /> - <colspec colname="c3" colwidth="5*" /> - <tbody valign="top"> - <row> - <entry>V4L2_RDS_BLOCK_MSK</entry> - <entry>7</entry> - <entry>Mask for bits 0-2 to get the block ID.</entry> - </row> - <row> - <entry>V4L2_RDS_BLOCK_A</entry> - <entry>0</entry> - <entry>Block A.</entry> - </row> - <row> - <entry>V4L2_RDS_BLOCK_B</entry> - <entry>1</entry> - <entry>Block B.</entry> - </row> - <row> - <entry>V4L2_RDS_BLOCK_C</entry> - <entry>2</entry> - <entry>Block C.</entry> - </row> - <row> - <entry>V4L2_RDS_BLOCK_D</entry> - <entry>3</entry> - <entry>Block D.</entry> - </row> - <row> - <entry>V4L2_RDS_BLOCK_C_ALT</entry> - <entry>4</entry> - <entry>Block C'.</entry> - </row> - <row> - <entry>V4L2_RDS_BLOCK_INVALID</entry> - <entry>7</entry> - <entry>An invalid block.</entry> - </row> - <row> - <entry>V4L2_RDS_BLOCK_CORRECTED</entry> - <entry>0x40</entry> - <entry>A bit error was detected but corrected.</entry> - </row> - <row> - <entry>V4L2_RDS_BLOCK_ERROR</entry> - <entry>0x80</entry> - <entry>An incorrectable error occurred.</entry> - </row> - </tbody> - </tgroup> - </table> - </section> - -<!-- -Local Variables: -mode: sgml -sgml-parent-document: "v4l2.sgml" -indent-tabs-mode: nil -End: - --> |