Volume Control Protocol Reversing Documentation

Volume related commands such as muting and setting absolute volume level are sent to the receiver over TCP via port 33335 in what appears to be a proprietary binary protocol.

Payload

Packet

The packet is composed of 7-9 bytes of binary data. It appears that every odd byte is constant across all commands. The second and fourth byte appear to be command opcodes, with the sixth and eighth being parameters for said command opcode.

• Set Absolute Volume Payload:

    0x02, 0x06, 0xA0, 0x52, 0x00, 0x03, 0x00, *0xXX*, 0x00
    
    _0xXX is a byte between 0x00 and 0x4A
  

• Set Mute Value Payload:

    0x02, 0x04, 0xA0, 0x53, 0x00, *0xXX*, 0x00
  
    _0xXX is 0x01 to Mute and 0x00 to Unmute