========= CVBS Video Output =======

===== Hardware Example =====

The below picture is a sample guide.

You can find **cvbs** test point by header J7 near HDMI connector.

We recommend to use board backside point as the following picture. **Pin 1 of header J7** can be used as Ground point.

{{:en:c2_cvbs1.png?700|}} {{:en:c2_cvbs2.png?700|}}


==== Software Guide (1) - Ubuntu ====

<WRAP center round important>
  * Ubuntu : Available with 3.14.79-89 (Oct 13, 2016) or higher version
</WRAP>

There are two modes of CVBS, **480cvbs** and **576cvbs** on C2.

You need to modify boot.ini to set CVBS output.
<code>
setenv m "480cvbs"
setenv cvbsmode "480cvbs"

setenv bootargs ${bootargs} cvbsmode=${cvbsmode}
</code>

And make sure the **vout** mode is set as **hdmi** mode.
<code>
setenv vout "hdmi"
</code>
== Overscan ==
Please refer to the following article.

http://magazine.odroid.com/wp-content/uploads/ODROID-Magazine-201602.pdf#page=9

As we tested cvbs mode with our monitors, overscan setting is needed.

For example, in case of 480cvbs mode, the following values can be used.
<code>
# echo 20 20 695 478 > /sys/class/graphics/fb0/window_axis                                                                                             
# echo 0x10001 > /sys/class/graphics/fb0/free_scale
</code>

==== Software Guide (2) - Android ====

<WRAP center round important>
  * We're planning to release CVBS functionality soon. The version will be specified here after new release.
</WRAP>

Please refer to the following example.
<code>
setenv hdmimode "480cvbs"
showlogo "hdmimode"
</code>
And make sure the **vout** mode is set as **hdmi** mode.
<code>
setenv vout "hdmi"
</code>

== Overscan ==
As we tested cvbs mode with our monitors, overscan setting is needed.
For example, the following values can be used.
<code>
### 480cvbs
$ wm overscan 30,25,30,10

### 576cvbs
$ wm overscan 40,10,50,110
</code>