Image data reproducing method, image data reproducing apparatus, image data recording method and image data recording apparatus

An apparatus for reproducing at least first images and second images simultaneously, synchronizing the first images with the second images, the apparatus comprising:

• a reading device for reading first image data which is compressed data representing the first images and second image data which is compressed data representing the second images from a recording medium;
• a first memory device for storing the first image data read from the recording medium;
• a second memory device for storing the second image data read from the recording medium;
• a first decoding device for decoding the first image data stored in the first memory device;
• and
• a second decoding device for decoding the second image data stored in the second memory device,
• wherein, on the recording medium, each of the first image data and the second image data is divided into a plurality of data units each having an equal time length, each of the data units of the first image data and each of the data units of the second image data are alternately arranged on the recording medium, the reading device sequentially reads the data units from the recording medium in an order of an arrangement of the data units recorded on the recording medium, an operation of storing the first image data into the first memory device and an operation of storing the second image data into the second memory device are alternately carried out for each of the data units, and the first decoding device and the second decoding device separately and simultaneously decode the first image data and the second image data at a same decoding rate.