The present invention relates to a method of playing back a bitstream for transferring a group of pictures, the method comprising the steps of: parsing, when a random access occurs in a first picture, a network abstraction layer (NAL) unit header of at least one second picture following the first picture and determining a NAL unit type of the at least one second picture; removing the at least one second picture from the bitstream on the basis of the determined NAL unit type; and decoding and displaying the bitstream from which the at least one second picture has been removed.