erence of the recording medium to an outermost circumference thereof, and A is an average bit rate of a digital video image to be recorded, data recorded on the recording area is reproduced and written into the buffer memory, at a reproducing speed defined by (T1+T2+2S)B/T2 or more, where B is an average bit rate of a digital video image to be reproduced, and data to be reproduced, stored in the b