An electronic apparatus for receiving encoded content data from a first external electronic apparatus or reading the encoded content data from a memory, wherein the electronic apparatus comprises: a unit configured to extract a control stream from the encoded content data, the encoded content data comprising an audio/video stream with first time information and the control stream with second time information, wherein the control stream is used for controlling the audio/video stream; a decoder configured to decode the extracted control stream; an encoder configured to encode the decoded control stream; a transmitter configured to transmit the encoded content data and the said control stream o a second external electronic apparatus, wherein the extracted control stream is transcoded by the decoder and the encoder into a codec supported by the second external electronic apparatus; a receiver configured to receive operation data indicative of a user operation from the second external electronic apparatus during receiving the encoded content data by the second external electronic apparatus and displaying a video of the encoded content data on a screen of the second external electronic apparatus, wherein the user operation is performed on the second external electronic apparatus and relates to the video; and an operation processor configured to execute, in response to the operation data a process specified by the user operation by using the decoded control stream; wherein the transmitter is further configured to transmit a result of the process to the second external electronic apparatus, and the result of the process is reflected on the screen of the second external electronic apparatus. a unit configured to extract a control stream from the encoded content data, the encoded content data comprising an audio/video stream with first time information and the control stream with second time information, wherein the control stream is used for controlling the audio/video stream; a decoder configured to decode the extracted control stream; an encoder configured to encode the decoded control stream; a transmitter configured to transmit the encoded content data and the said control stream o a second external electronic apparatus, wherein the extracted control stream is transcoded by the decoder and the encoder into a codec supported by the second external electronic apparatus; a receiver configured to receive operation data indicative of a user operation from the second external electronic apparatus during receiving the encoded content data by the second external electronic apparatus and displaying a video of the encoded content data on a screen of the second external electronic apparatus, wherein the user operation is performed on the second external electronic apparatus and relates to the video; and an operation processor configured to execute, in response to the operation data a process specified by the user operation by using the decoded control stream; wherein the transmitter is further configured to transmit a result of the process to the second external electronic apparatus, and the result of the process is reflected on the screen of the second external electronic apparatus.