A signal processor includes a picture input section for receiving a video bit stream, a video decoding section for decoding the video bit stream, a picture display section for outputting decoded data from the video decoding section, a digital image input section for receiving digital image data, a digital image display section for outputting the digital image data, a blending section for generating a picture signal from the digital image display section and the picture display section, an audio input section for receiving the digital audio data and the audio bit stream, an audio decoding section for decoding audio data and the audio bit stream, an audio output section for adding an audio signal to data from the audio decoding section to generate a signal and outputting the generated signal, and a synchronizing section for synchronizing respective outputs of the blending section and the audio output section.