说明：  蓝牙协议This specification describes the Audio/Video Control Transport Protocol (AVCTP), which is used to transport command and response messages for controlling Audio Video features in conformant devices. This protocol enables a device to support more than one control profile at the same time each supported profile shall define its own message formatting and/or usage rules.
(Bluetooth protocol This specification describes the Aud io/Video Control Transport Protocol (AVRCP). which is used to transport command and response messages for controlling Audio Video features in conformant devices. This protocol enables a device to support more than one control profile at the same time each supported profile shall de fine its own message formatting and/or usage ru les.)