APPARATUS, METHOD, IMAGE SIGNAL, AND COMPUTER PROGRAM IMPLEMENTING A DISPLAY CYCLE IDENTIFIER OPERABLE TO INDICATE IF INTERVALS BETWEEN IMAGE DISPLAY TIMES OF SUCCESSIVE FRAMES ARE EITHER CONSTANT OR VARIABLE

摘要

A data structure of an image signal includes a reproduction cycle identifier indicating whether the cycle of image display for each frame is variable or not. When the display cycle identifier indicates that the display cycle is fixed, display cycle data is inserted in a header of the coded image data, and data relating to the frame number is inserted in each frame. On the other hand, when the display cycle identifier indicates that the display cycle is variable, display time data is inserted for each frame. Therefore, when decoding and displaying the coded image data having a fixed display cycle, the decoded image data can be displayed by a simple circuit structure, i.e., based on the display cycle data and the frame number data having a relatively small data quantity (bit number), without referring to the display time data having a relatively large data quantity for each frame. Furthermore, this data structure can be applied to a coded image signal having a variable display cycle.