Video display device, terminal device, and method thereof

A method for communicating with at least one server and at least one mobile device in a video display apparatus connected to a set top box (STB), comprising:

• receiving uncompressed audio or video frames through an external input port from the STB;
• extracting fingerprints from the uncompressed audio or video frames;
• transmitting the fingerprints to a first server;
• receiving a first URL from the first server, the first URL being used to retrieve supplementary content from a second server different from the first server;
• retrieving the supplementary content from the second server based on the first URL received from the first server;
• performing a bidirectional communication with the at least one mobile device;
• transmitting a second URL for accessing information related to an application to the at least one mobile device, the second URL being different from the first URL;
• receiving a subscription message from the at least one mobile device, the subscription message comprising service information for identifying a service between the video display apparatus and the at least one mobile device;
• and
• transmitting a notification message to the at least one mobile device when the at least one mobile device is subscribed with the video display apparatus for the identified service between the video display apparatus and the at least one mobile device.