CVBS Video Output

The below picture is a sample guide.

You can find CVBS test point by header J7 near the HDMI connector.

We recommend using the board's backside point as shown in the picture. Pin 1 of header J7 can be used as a Ground point.

  • Ubuntu : Available with 3.14.79-89 (Oct 13, 2016) or higher version

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

You need to modify boot.ini to set CVBS output.

setenv m "480cvbs"
setenv cvbsmode "480cvbs"
setenv bootargs ${bootargs} cvbsmode=${cvbsmode}

And make sure the vout mode is set as hdmi mode.

setenv vout "hdmi"

Please refer to the following article.


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.

# echo 20 20 695 478 > /sys/class/graphics/fb0/window_axis                                                                                             
# echo 0x10001 > /sys/class/graphics/fb0/free_scale
  • We're planning to release CVBS functionality soon. The version will be specified here after new release.

Please refer to the following example.

setenv hdmimode "480cvbs"
setenv cvbs "480cvbs"
# Display Auto Detection                          
# "false" or "true"                                
setenv display_autodetect "false"   
setenv bootargs "${rootopt} ${consoleopt} hdmimode=${hdmimode} cvbs=${cvbs} ${cmode} ${hdmitx} vout=${vout_mode} disablehpd=${disablehpd} logo=${logoopt} ${androidopt} ${selinuxopt} suspend_hdmiphy=${suspend_hdmiphy} led_onoff=${led_onoff} max_freq=${max_freq} maxcpus=${maxcpus} disable_vu7=${disable_vu7} touch_invert_x=${touch_invert_x} touch_invert_y=${touch_invert_y} usbmulticam=${usbmulticam} gpiopower=${gpiopower} backlight_pwm=${backlight_pwm} ddrclock=${ddrclock} test_mt_pid=${test_mt_pid} test_mt_vid=${test_mt_vid}"

As we tested cvbs mode with our monitors, overscan setting is needed. For example, the following values can be used.

### 480cvbs
$ wm overscan 30,25,30,10
### 576cvbs
$ wm overscan 40,10,50,110
  • odroid-c2/application_note/external_connector/cvbs.txt
  • Last modified: 2020/03/31 11:11
  • by codewalker