A transmitter device adapted to be coupled to an image providing device and a receiver device includes first and second conversion units, a wireless module, and a processing unit. The first conversion unit and the second conversion unit are configured to be coupled to the image providing device through an HDMI transmission cable and a Type-C transmission cable, respectively, so as to respectively receive a first video and audio stream and a second video and audio stream provided by the image providing device. The wireless module is connected to the receiver device through wireless communication. The processing unit preferentially selects the first conversion unit to receive a first video and audio signal output by converting the first video and audio stream by the first conversion unit and transmits the first video and audio signal to the receiver device through the wireless module.