I’ve been reversing these ‘A9’ / ‘X5’ for a few days before finding this thread - my cameras were <$3 and are based on the Taixin TXW817 ; I’ve reversed a part of the P2P UDP communication and have a working (though incomplete) implementation here: GitHub - DavidVentura/cam-reverse
I have video and audio working, but Wifi setup is missing, so I’ve been using them in AP mode.
I’ve not worked into integrating my project anywhere, it should be considered a library that can be used by HA.