diff options
| -rw-r--r-- | Documentation/DocBook/media/v4l/controls.xml | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/Documentation/DocBook/media/v4l/controls.xml b/Documentation/DocBook/media/v4l/controls.xml index 282f0a50433a..8c62ead889e4 100644 --- a/Documentation/DocBook/media/v4l/controls.xml +++ b/Documentation/DocBook/media/v4l/controls.xml @@ -5013,8 +5013,27 @@ defines possible values for de-emphasis. Here they are:</entry> <section id="rf-tuner-controls"> <title>RF Tuner Control Reference</title> - <para>The RF Tuner (RF_TUNER) class includes controls for common features -of devices having RF tuner.</para> + <para> +The RF Tuner (RF_TUNER) class includes controls for common features of devices +having RF tuner. + </para> + <para> +In this context, RF tuner is radio receiver circuit between antenna and +demodulator. It receives radio frequency (RF) from the antenna and converts that +received signal to lower intermediate frequency (IF) or baseband frequency (BB). +Tuners that could do baseband output are often called Zero-IF tuners. Older +tuners were typically simple PLL tuners inside a metal box, whilst newer ones +are highly integrated chips without a metal box "silicon tuners". These controls +are mostly applicable for new feature rich silicon tuners, just because older +tuners does not have much adjustable features. + </para> + <para> +For more information about RF tuners see +<ulink url="http://en.wikipedia.org/wiki/Tuner_%28radio%29">Tuner (radio)</ulink> +and +<ulink url="http://en.wikipedia.org/wiki/RF_front_end">RF front end</ulink> +from Wikipedia. + </para> <table pgwide="1" frame="none" id="rf-tuner-control-id"> <title>RF_TUNER Control IDs</title> |