# HG changeset patch
# User Eduardo Valentin <eduardo.valentin@xxxxxxxxx>
# Date 1242209424 -10800
# Branch export
# Node ID 2dd45d3736ae1952dfa98e65b072eb08157fb19d
# Parent fadf1cddf504609cdb4889f4aa3305ca8d15323a
From: Eduardo Valentin <eduardo.valentin@xxxxxxxxx>
This single patch adds documentation description for FM Transmitter (FMTX)
Extended Control Class and its Control IDs. The text was added under
"Extended Controls" section.
Priority: normal
Signed-off-by: Eduardo Valentin <eduardo.valentin@xxxxxxxxx>
diff -r fadf1cddf504 -r 2dd45d3736ae v4l2-spec/controls.sgml
--- a/v4l2-spec/controls.sgml Wed May 27 11:56:47 2009 +0300
+++ b/v4l2-spec/controls.sgml Wed May 13 13:10:24 2009 +0300
@@ -458,6 +458,12 @@
<para>Unfortunately, the original control API lacked some
features needed for these new uses and so it was extended into the
(not terribly originally named) extended control API.</para>
+
+ <para>Even though the MPEG encoding API was the first effort
+to use the Extended Control API, nowadays there are also other classes
+of Extended Controls, such as Camera Controls and FM Transmitter Controls.
+The Extended Controls API as well as all Extended Controls classes are
+described in the following text.</para>
</section>
<section>
@@ -1816,6 +1822,200 @@
</tgroup>
</table>
</section>
+
+ <section id="fmtx-controls">
+ <title>FM Transmitter Control Reference</title>
+
+ <para>The FM Transmitter (FMTX) class includes controls for common features of
+FM transmissions capable devices. Currently this class include parameters for audio
+compression, pilot tone generation, audio deviation limiter, RDS transmission and
+tuning power features.</para>
+
+ <table pgwide="1" frame="none" id="fmtx-control-id">
+ <title>FMTX Control IDs</title>
+
+ <tgroup cols="4">
+ <colspec colname="c1" colwidth="1*">
+ <colspec colname="c2" colwidth="6*">
+ <colspec colname="c3" colwidth="2*">
+ <colspec colname="c4" colwidth="6*">
+ <spanspec namest="c1" nameend="c2" spanname="id">
+ <spanspec namest="c2" nameend="c4" spanname="descr">
+ <thead>
+ <row>
+ <entry spanname="id" align="left">ID</entry>
+ <entry align="left">Type</entry>
+ </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
+ </row>
+ </thead>
+ <tbody valign="top">
+ <row><entry></entry></row>
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_FMTX_CLASS</constant> </entry>
+ <entry>class</entry>
+ </row><row><entry spanname="descr">The FMTX class
+descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
+description of this control class.</entry>
+ </row>
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_RDS_ENABLED</constant> </entry>
+ <entry>boolean</entry>
+ </row>
+ <row><entry spanname="descr">Enables or disables the RDS transmission feature.</entry>
+ </row>
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_RDS_PI</constant> </entry>
+ <entry>integer</entry>
+ </row>
+ <row><entry spanname="descr">Sets the RDS Programme Identification field
+for transmission.</entry>
+ </row>
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_RDS_PTY</constant> </entry>
+ <entry>integer</entry>
+ </row>
+ <row><entry spanname="descr">iSets the RDS Programme Type field for transmission.
+This coding of up to 31 pre-defined programme types.</entry>
+ </row>
+<!--
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_RDS_PS_NAME</constant> </entry>
+ <entry>integer</entry>
+ </row>
+ <row><entry spanname="descr">.</entry>
+ </row>
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_RDS_RADIO_TEXT</constant> </entry>
+ <entry>integer</entry>
+ </row>
+ <row><entry spanname="descr">.</entry>
+ </row>
+-->
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_ENABLED</constant> </entry>
+ <entry>boolean</entry>
+ </row>
+ <row><entry spanname="descr">Enables or disables the audio deviation limiter feature.
+The limiter is useful when trying to maximize the audio volume, minimize receiver-generated
+distortion and prevent overmodulation.
+</entry>
+ </row>
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_RELEASE_TIME</constant> </entry>
+ <entry>integer</entry>
+ </row>
+ <row><entry spanname="descr">Sets the audio deviation limiter feature release time.
+The unit, step and range are driver-specific.</entry>
+ </row>
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_DEVIATION</constant> </entry>
+ <entry>integer</entry>
+ </row>
+ <row><entry spanname="descr">Configures audio frequency deviation level in Hz.
+The range and step are driver-specific.</entry>
+ </row>
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ENABLED</constant> </entry>
+ <entry>boolean</entry>
+ </row>
+ <row><entry spanname="descr">Enables or disables the audio compression feature.
+This feature amplifies signals below the threshold by a fixed gain and compresses audio
+signals above the threshold by the ratio of Threshold/(Gain + Threshold).</entry>
+ </row>
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_GAIN</constant> </entry>
+ <entry>integer</entry>
+ </row>
+ <row><entry spanname="descr">Sets the gain for audio compression feature. It is
+a dB value. The range and step are driver-specific.</entry>
+ </row>
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_THRESHOLD</constant> </entry>
+ <entry>integer</entry>
+ </row>
+ <row><entry spanname="descr">Sets the threshold level for audio compression freature.
+It is a dB value. The range and step are driver-specific.</entry>
+ </row>
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ATTACK_TIME</constant> </entry>
+ <entry>integer</entry>
+ </row>
+ <row><entry spanname="descr">Sets the attack time for audio compression feature.
+It is a useconds value. The range and step are driver-specific.</entry>
+ </row>
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_RELEASE_TIME</constant> </entry>
+ <entry>integer</entry>
+ </row>
+ <row><entry spanname="descr">Sets the release time for audio compression feature.
+It is a useconds value. The range and step are driver-specific.</entry>
+ </row>
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_ENABLED</constant> </entry>
+ <entry>boolean</entry>
+ </row>
+ <row><entry spanname="descr">Enables or disables the pilot tone generation feature.</entry>
+ </row>
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_DEVIATION</constant> </entry>
+ <entry>integer</entry>
+ </row>
+ <row><entry spanname="descr">Configures pilot tone frequency deviation level. Unit is
+in Hz. The range and step are driver-specific.</entry>
+ </row>
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_FREQUENCY</constant> </entry>
+ <entry>integer</entry>
+ </row>
+ <row><entry spanname="descr">Configures pilot tone frequency value. Unit is
+in Hz. The range and step are driver-specific.</entry>
+ </row>
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_PREEMPHASIS</constant> </entry>
+ <entry>integer</entry>
+ </row>
+ <row><entry spanname="descr">Configures the pre-emphasis value for broadcasting.
+A pre-emphasis filter is applied to the broadcast to accentuate the high audio frequencies.
+Depending on the region, a time constant of either 50 or 75 useconds is used. Possible values
+are:</entry>
+ </row><row>
+ <entrytbl spanname="descr" cols="2">
+ <tbody valign="top">
+ <row>
+ <entry><constant>V4L2_FMTX_PREEMPHASIS_DISABLED</constant> </entry>
+ <entry>No pre-emphasis is applied.</entry>
+ </row>
+ <row>
+ <entry><constant>V4L2_FMTX_PREEMPHASIS_50_uS</constant> </entry>
+ <entry>A pre-emphasis of 50 uS is used.</entry>
+ </row>
+ <row>
+ <entry><constant>V4L2_FMTX_PREEMPHASIS_75_uS</constant> </entry>
+ <entry>A pre-emphasis of 75 uS is used.</entry>
+ </row>
+ </tbody>
+ </entrytbl>
+
+ </row>
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_TUNE_POWER_LEVEL</constant> </entry>
+ <entry>integer</entry>
+ </row>
+ <row><entry spanname="descr">Sets the output power level for signal transmission.
+Unit is in dBuV. Range and step are driver-specific.</entry>
+ </row>
+ <row>
+ <entry spanname="id"><constant>V4L2_CID_TUNE_ANTENNA_CAPACITOR</constant> </entry>
+ <entry>integer</entry>
+ </row>
+ <row><entry spanname="descr">This selects the value of antenna tuning capacitor
+manually or automatically if set to zero. Unit, range and step are driver-specific.</entry>
+ </row>
+ <row><entry></entry></row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
</section>
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