We're no longer updating This wiki!!

This is an old revision of the document!


HDMI Force RGB Option

Issue Brief

With some TV monitors, there is a bug in their HDMI implementation that sometimes trigger the selection of the wrong colorspace in a magenta/green display.
It looks TV reports that is capable of YUV422 or YUV444 but it's not indeed.
To avoid this situation, you can use forcergb option to set COLORSPACE_SPACE_RGB444 forcely.

Here are the more investigations and discussions in ODROID Forum.

http://forum.odroid.com/viewtopic.php?f=141&t=20697#p137351

How to set boot.ini to activate forcergb

To activate it, add hdmitx=forcergb in bootargs.

setenv bootargs ${bootargs} hdmitx=forcergb

Here is the catch.
The env hdmitx has other parameters related to HDMI CEC Control.
If you use CEC options, the env format can be hdmitx=cecf,forcergb or hdmitx=cec0,forcergb.

The ODROID Forum user, wrxtasy already implemented a good guide for this case.
https://github.com/wrxtasy/LibreELEC.tv.7.0/blob/libreelec-7.1/projects/Odroid_C2/bootloader/boot.ini

# Enable | Disable HDMI CEC Control                 
setenv hdmi_cec  "0"            # Disabled                      
# setenv hdmi_cec  "1"          # Enabled                       
# setenv hdmi_cec  "2"          # Enabled but disable auto TV switching ON
                                                  
# Force HDMI to use RGB colorspace regardless of TV request
# setenv hdmi_forcergb "0"      # Disabled         
setenv hdmi_forcergb "1"        # Enabled          

if test "${hdmi_cec}" = "0"; then setenv hdmitx "hdmitx=cec0"; fi
if test "${hdmi_cec}" = "1"; then setenv hdmitx "hdmitx=cecf"; fi
if test "${hdmi_cec}" = "2"; then setenv hdmitx "hdmitx=cec7"; fi

if test "${hdmi_forcergb}" = "1"; then setenv hdmitx "${hdmitx},forcergb"; fi

setenv bootargs "${rootopt} ${consoleopt} hdmimode=${hdmimode} ${hdmitx} vout=${vout_mode} ............"
en/c2_forcergb.1481789297.txt.gz · Last modified: 2016/12/15 16:38 by joy.cho
CC Attribution-Share Alike 3.0 Unported
Driven by DokuWiki Recent changes RSS feed Valid CSS Valid XHTML 1.0