Protocol conversion circuit and protocol conversion method

A protocol conversion circuit, comprising:

• a display port (DP) signal receiver receiving a DP signal from a first electronic device, wherein the DP signal receiver is configured to analyze the DP signal to obtain video data and packet information;
• a control analysis circuit configured to determine whether the packet information indicates to activate a live function or a panel replay (PR) function;
• a downstream transmitter connected to a second electronic device;
• and
• a frame buffer receiving the video data, wherein, in response to determining that the live function is activated, the control analysis circuit is configured to execute a preset live process to control the frame buffer to store current video data received by the frame buffer, and simultaneously send the current video data to the downstream transmitter;
• wherein, in response to determining that the PR function is activated, the control analysis circuit is configured to execute a preset PR process, including:
• controlling the frame buffer to discard the received current video data, or to update the previous video data stored in the frame buffer with content within a specified range of the current video data;
• and
• controlling the frame buffer to transmit latest video data stored therein to the downstream transmitter;
• wherein, when the live broadcast function is activated, the downstream transmitter is configured to convert the current video data from the frame buffer into a target signal in a target format and outputs the target signal to the second electronic device, and when the PR function is activated, the downstream transmitter is configured to convert the latest video data from the frame buffer into the target signal in the target format and output the target signal to the second electronic device.