The data recording and reproducing apparatus comprises a transcoding module and a recording and reproducing module. The transcoding module transcodes a video or audio signal based on one compression method to a signal based on another compression method, the video or audio signal being inputted through a tuner. The recording and reproducing module records, to a recording medium, the transcoded video or audio signal together with the inputted video or audio signal, the transcoded video or audio signal having been transcoded by the transcoding module. The recording and reproducing module records one of the video or audio signals, which are identical but based on different compression methods, with the other video or audio signal being written to the recording medium as a hidden file.