An image data recording apparatus that sets a video image aspect ratio for a recording medium according to a predetermined recording format includes a determining unit for determining whether the aspect ratio has been set for the recording medium, a selecting unit for allowing a user to select the aspect ratio to be set for the recording medium, a writing unit for writing the selected aspect ratio information in a predetermined area of the recording medium, a reading unit for reading out the aspect ratio information set for the recording medium, a setting unit for setting each unit of the image data recording apparatus according to the aspect ratio information written in the predetermined area of the recording medium or the read out aspect ratio information, and a forbidding unit for forbidding changing of the set aspect ratio.