To reduce delay in change-over of coded data which is stored in an interleaved structure by changing the size of a buffer in accordance with a detected operation state.

An coded data output device 2 reads coded data 11 from an coded data storing part 1 in accordance with an address 10 outputted from a reproduction control part 5. The buffer 3 changes the buffer size for storing coded data in accordance with the operation state 12 which is outputted from the control part 5. That is, the size of the buffer 3 is reduced when the reproduction control part 5 confirms that reproduction is of coded data in the interleaved structure. The succeeding read address is analyzed by the control part 5 concerning coded data 15 which is stored in the buffer 3 and designated to an coded data output device 2. A decoding device 4 takes out coded data from the buffer 3, decodes them and outputs a video signal.