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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 new file mode 100644 index 000000000..f63120682 --- /dev/null +++ b/v4l2-spec/dev-rds.sgml @@ -0,0 +1,44 @@ + <title>RDS Interface</title> + + <para>The Radio Data System transmits supplementary +information in binary format, for example the station name or travel +information, on a inaudible audio subcarrier of a radio program. This +interface aims at devices capable of receiving and decoding RDS +information.</para> + + <para>The V4L API defines its RDS API as follows.</para> + + <para>From radio devices supporting it, RDS data can be read +with the &func-read; function. The data is packed in groups of three, +as follows:<orderedlist> + <listitem> + <para>First Octet Least Significant Byte of RDS Block</para> + </listitem> + <listitem> + <para>Second Octet Most Significant Byte of RDS Block</para> + </listitem> + <listitem> + <para>Third Octet Bit 7: Error bit. Indicates that an +uncorrectable error occurred during reception of this block. Bit 6: +Corrected bit. Indicates that an error was corrected for this data +block. Bits 5-3: Received Offset. Indicates the offset received by the +sync system. Bits 2-0: Offset Name. Indicates the offset applied to +this data.</para> + </listitem> + </orderedlist></para> + + <para>It was argued <!-- video4linux-list@redhat.com +on 12 Nov 2002, subject "RDS/RBDS" --> the RDS API should be +extended before integration into V4L2, no new API has been devised yet. +Please write to the Video4Linux mailing list for discussion: &v4l-ml;. +Meanwhile no V4L2 driver should set the +<constant>V4L2_CAP_RDS_CAPTURE</constant> capability flag.</para> + + +<!-- +Local Variables: +mode: sgml +sgml-parent-document: "v4l2.sgml" +indent-tabs-mode: nil +End: + --> |