A data processing apparatus supporting simultaneous playback includes a processor, two tuners, a receiving element and a transmitting element. The first tuner generates first television data transmitted via a first frequency range, and provides the first television data to an internal playback device. The second tuner generates second television data transmitted via a second frequency range. The receiving element receives a data request for a selected television channel from an external electronic device. In response to the data request, the processor controls the second tuner to generate the second television data including video/audio data of the selected television channel. When the internal playback device performs playback according to the first television data, the transmitting element transmits the video/audio data of the selected television channel to the external electronic device for playback.