According to a playback device, a reading unit reads extent blocks from a recording medium. A switching unit extracts a main-view stream and a sub-view stream from the extent blocks. Each stream is stored in a different read buffer. A decoding unit reads and decodes each stream from a corresponding read buffer. A time (t) required for the decoding unit to decode all data blocks in one extent block is greater than or equal to the sum (t1+t2+t3) of a time (t1) required for the reading unit to read the data blocks except for the top data block in the extent block, a time (t2) required for the reading unit to start to read the top of a next extent block from the time of finishing reading the tail of the extent block, and a time (t3) required for the reading unit to read the top data block in the next extent block.