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en:c2_forcergb [2016/12/15 15:18] joy.cho created |
en:c2_forcergb [2016/12/15 16:56] joy.cho [HDMI Force RGB Option] |
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- | (under construction) | + | ========= HDMI Force RGB Option ======= |
+ | <WRAP center round important> | ||
+ | * Ubuntu : The available version should be the one released after Jun 20, 2016. | ||
+ | * Android : New version will be released soon. | ||
+ | </WRAP> | ||
+ | ===== 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.\\ | ||
+ | |||
+ | {{:en:c2_forcergb_1.png?600}} \\ | ||
+ | http://forum.odroid.com/viewtopic.php?f=141&t=20697#p137351 | ||
+ | |||
+ | 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 forcibly. | ||
+ | |||
+ | Here are more investigations and discussions in ODROID Forum. | ||
+ | * http://forum.odroid.com/viewtopic.php?f=144&t=21780&hilit=forcergb | ||
+ | * http://forum.odroid.com/viewtopic.php?f=141&t=21737 | ||
+ | * http://forum.odroid.com/viewtopic.php?f=144&t=20415&p=145208#p145208 | ||
+ | |||
+ | ===== How to set boot.ini to activate forcergb ===== | ||
+ | To activate it, add **hdmitx=forcergb** in bootargs. | ||
+ | <code> | ||
+ | setenv bootargs ${bootargs} hdmitx=forcergb | ||
+ | </code> | ||
+ | |||
+ | Here is the catch.\\ | ||
+ | The env **hdmitx** has other parameters related to HDMI CEC control.\\ | ||
+ | If you use CEC options, the env format can be **hdmitx=cecf,forcergb** or **hdmitx=cec0,forcergb**.\\ | ||
+ | |||
+ | The ODROID Forum user, wrxtasy from LibreELEC already implemented a good guide for this case.\\ | ||
+ | |||
+ | https://github.com/wrxtasy/LibreELEC.tv.7.0/blob/libreelec-7.1/projects/Odroid_C2/bootloader/boot.ini | ||
+ | |||
+ | <code> | ||
+ | # Enable | Disable HDMI CEC Control | ||
+ | setenv hdmi_cec "0" # Disabled | ||
+ | # setenv hdmi_cec "1" # Enabled | ||
+ | # setenv hdmi_cec "2" # Enabled but disable auto TV switching ON | ||
+ | | ||
+ | # Force HDMI to use RGB colorspace regardless of TV request | ||
+ | # setenv hdmi_forcergb "0" # Disabled | ||
+ | setenv hdmi_forcergb "1" # Enabled | ||
+ | |||
+ | if test "${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} ............" | ||
+ | </code> |