A playback system (100, 120) comprising a medium containing video data and a device for reproducing the video data recorded on said medium, said video data encoded according to MPEG4-AVC and comprising a plurality of video units each of which includes an intra coded I-picture, a predictive coded P-picture including a group of blocks each of which is predicted from one picture and a bi-directionally-predictive coded B-picture including a group of blocks each of which is predicted from two pictures, at least one of said video units including an access point P-picture (P5, AP), wherein the access point P-picture (P5, AP) includes a group of blocks each of which is coded by motion compensation prediction using an I-picture located at the beginning of said video units or a selected one of preceding P-pictures, and pictures necessary for decoding said access point P-picture (P5, AP) do not include any B-picture, wherein any P-pictures, other than access point P-pictures, and any B-pictures following said access point P-picture (P5, AP) in the same video unit are all coded without referring to any picture preceding said access point P-picture (P5, AP), said medium containing an attribute data including a picture type information having a first value associated with each access point P-picture included in said video unit, and including a picture type information having a second value different from said first value associated with each P-picture included in said video unit that is not an access point P-picture but which is necessary to decode the next access point P-picture (P5, AP), wherein said attribute data is comprised in supplemental enhancement information according to MPEG4-AVC, said system comprising: means for identifying a video unit which includes a specified picture to be reproduced; means for reading said picture type information to identify an access point P-picture (P5, AP) closest to said specified picture included in said video unit and, if any, preceding P-pictures used for coding each block of said access point P-picture (P5, AP); means for accessing said I-picture and said preceding P-pictures, if any, used for coding said access point P-picture (P5, AP), and said access point P-picture (P5, AP) preceding said specified picture; means for decoding said I-picture and, if any, said P pictures used for coding said access point P-picture (P5, AP); means for decoding said access point P-picture (P5, AP) using said decoded I-picture and, if any, P-pictures; and means for decoding said specified picture using said access point P-picture (P5, AP), wherein said specified picture is decoded without referring to any picture preceding said access point P-picture (P5, AP). means for identifying a video unit which includes a specified picture to be reproduced; means for reading said picture type information to identify an access point P-picture (P5, AP) closest to said specified picture included in said video unit and, if any, preceding P-pictures used for coding each block of said access point P-picture (P5, AP); means for accessing said I-picture and said preceding P-pictures, if any, used for coding said access point P-picture (P5, AP), and said access point P-picture (P5, AP) preceding said specified picture; means for decoding said I-picture and, if any, said P pictures used for coding said access point P-picture (P5, AP); means for decoding said access point P-picture (P5, AP) using said decoded I-picture and, if any, P-pictures; and means for decoding said specified picture using said access point P-picture (P5, AP), wherein said specified picture is decoded without referring to any picture preceding said access point P-picture (P5, AP).