When a switching target device receives a media output indication from a sender device, a switch connects with contact B, which causes all image data stored in an extended media buffer to be inputted in a decoder, starting from the first frame (which is an I-frame) of the image data. The decoder decodes the image data, starting from the I-frame, and stores a reconstructed image in a reconstructed-image buffer. A reconstructed image required for decoding video picture data outputted from a media buffer is held in the reconstructed-image buffer. Thus, when device switching occurs, the decoder can immediately start decoding regardless of whether video picture data inputted from the media buffer is an intraframe.