Abstract: A copyright protection method is applied to an electronic device. The method includes: obtaining digital data of an audio file via Video on Demand (VOD); determining whether or not the audio file is free to use; determining whether or not the accessing of the audio file is legal if the audio file is not free. Upon a condition that the audio file is free, or the accessing of the audio file is legal and not free, decoding the audio file into analog signals. Upon a condition that digital copyright information is not included in the audio file, inserting into the analog signals the digital copyright information; outputting the analog signals of the audio file along with digital copyright information of the audio file. Upon a condition that the audio file is not free and not legally permitted, indicating the accessing of the audio file is illegal. The electronic device is also provided.

Abstract: A copyright protection method is applied to an electronic device. The method includes: obtaining digital data of an audio file via Video on Demand (VOD); determining whether or not the audio file is free to use; determining whether or not the accessing of the audio file is legal if the audio file is not free. Upon a condition that the audio file is free, or the accessing of the audio file is legal and not free, decoding the audio file into analog signals. Upon a condition that digital copyright information is not included in the audio file, inserting into the analog signals the digital copyright information; outputting the analog signals of the audio file along with digital copyright information of the audio file. Upon a condition that the audio file is not free and not legally permitted, indicating the accessing of the audio file is illegal. The electronic device is also provided.

Abstract: A video device includes a signal generating circuit configured for generating video signals; an internal resistor connected to the output port of the signal generating circuit and matching with an external resistor of an external device; a detecting circuit connected to two ends of the internal resistor through two input ports thereof, and configured for detecting voltages of the two ends of the internal resistor and outputting a voltage difference therebetween; a controlling circuit connected to the output port of the detecting circuit, and configured for determining whether or not the external device is connected to the video device according to the voltage deference, and outputting a controlling signal to the signal generating circuit; an auxiliary detecting circuit connected to the output port of the controlling circuit, and configured for generating an auxiliary detecting signal transmitted to the internal resistor.

Abstract: A video device includes a signal generating circuit configured for generating video signals; an internal resistor connected to the output port of the signal generating circuit and matching with an external resistor of an external device; a detecting circuit connected to two ends of the internal resistor through two input ports thereof, and configured for detecting voltages of the two ends of the internal resistor and outputting a voltage difference therebetween; a controlling circuit connected to the output port of the detecting circuit, and configured for determining whether or not the external device is connected to the video device according to the voltage deference, and outputting a controlling signal to the signal generating circuit; an auxiliary detecting circuit connected to the output port of the controlling circuit, and configured for generating an auxiliary detecting signal transmitted to the internal resistor.