Hi Takam,
Please refer to the ADV7181C_Configuring_the_ADV7181C_for_RGB_with_external_CSync.pdf document in
the support files (https://ez.analog.com/docs/DOC-1621).
Using the configuration described in the document sounds more appropriate. You could just use the evaluation board configuration for
AIN6, AIN5, AIN4 and SOG/SOY, with the G component connected to the SOG/SOY pin through a 1nF capacitor.
Because the embedded sync is on the G component in your case, you wouldn’t need to set the gain manually, so you could remove the writes to reg 0x73, 0x74, 0x75 and 0x76 from the script in the doc.
Dave