Patent ID: 7769273
Filing Date: 2010-08-03
Classification: G11B,H04N

Abstract:
1. A playback method for reproducing video data recorded on a medium, said video data comprising a plurality of video units which each include an intra coded I-picture, a predictive coded P-picture including a group of blocks predicted from one picture and a bidirectionally-predictive coded B-picture including a group of blocks predicted from two pictures, at least one of said video units including an access point P-picture coded by motion compensation prediction using an I-picture located at the beginning of a video unit or a selected preceding P-picture, wherein said P-picture or said B-picture following said access point P-picture is coded without referring to any picture preceding said access point P picture, said method comprising steps of: identifying a closest access point P-picture preceding a start picture to display, in the case of starting playback from said start picture; accessing an I-picture or a selected preceding P-picture used for coding said access point P-picture; decoding said I-picture or said P-picture used for coding said access point P-picture; decoding said access point P-picture using decoded I-picture or P-picture as a reference picture; and decoding said start picture using said closest access point P-picture as a reference picture, wherein said start picture is decoded without referring to any picture preceding said closest access point P-picture.