Look at post #50, you should be able to track down some firmware. MINI PTZ DH_SD-Mao-Rhea_MultiLang_PN_Stream3_IVS_V2.800.0000000.4.R.191105
There was also, I believe, 2 versions of the SD22204T-GN-W with different processors. Each has different firmware. I have the older version and can't find...