Device and method for processing and transmitting image data in wireless AV system

A device for processing and transmitting a picture in a wireless audio/video, AV, system, the device comprising:

• an external device interface unit being configured to receive an externally inputted signal including an actual picture;
• a controller being connected to the external device interface unit so as to detect the externally inputted signal and being configured to generate information related to the externally inputted signal;
• a picture processor being connected to the controller so as to receive at least one of the externally inputted signal and the information related to the externally inputted signal from the controller, determine a picture compression rate based on the information related to the externally inputted signal, and output a compressed picture based on the determined picture compression rate;
• and
• a communication unit transmitting the compressed picture through a wireless channel, wherein the information related to the externally inputted signal includes a presence or absence of the externally inputted signal, wherein, when the controller detects the externally inputted signal, the controller configures the information related to the externally inputted signal so as to indicate the presence of the externally inputted signal, the determined picture compression rate is set to a first picture compression rate which is no compression, a visually lossless compression rate, or a compression rate that is lower than a visually lossless compression rate, and
• wherein, when the controller fails to detect the externally inputted signal, the controller configures the information related to the externally inputted signal so as to indicate the absence of the externally inputted signal, the determined picture compression rate is set to a second picture compression rate relatively higher than the first picture compression rate, which has a compression ratio that is equal to or greater than a multiple of ⅙ to 1/10.