Randomly accessible visual information recording medium and recording method, and reproducing device and reproducing method
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsTomoaki Ryu, Kazuhiko Nakane, Masaaki Shimada, Yoshihisa Yamada
Life of this patent
Estimating the term…
Abstract
Access point pictures designated as randomly accessible positions are I pictures or P pictures. Information indicating the decoding sequence (I1, P1, B1, B2, B3, B4, P2, . . . ) of pictures functioning as access points and attribute information (picture_type) indicating whether a picture functions as an access point or is necessary for decoding of the access point following a given access point are recorded on the video information recording medium. Random access is possible even if the GOP interval is lengthened.
Claims8
A video information recording method for recording on a medium 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, said method comprising steps of:
- coding an access point P-picture by motion compensation prediction using an I-picture located at the beginning of a video unit or a selected preceding P-picture;
- coding said P-picture or said B-picture by motion compensation prediction using a closest access point P-picture preceding said P-picture or said B-picture as a reference picture, wherein said P-picture or said B-picture is coded without referring to any picture located before said closest access point P-picture;
- creating an entry point map used for accessing access point P-pictures, said entry point map including a list of data for identifying a location of said video information units designated as access units on said medium;
- and
- recording on said medium said video data comprising said video units and said entry point map.
A video information recording apparatus for recording on a medium 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, said apparatus comprising:
- a first coding unit for coding an access point P-picture by motion compensation prediction using an I-picture located at the beginning of a video unit or a selected preceding P-picture;
- a second coding unit for coding said P-picture or said B-picture by motion compensation prediction using a closest access point P-picture preceding said P-picture or said B-picture as a reference picture, wherein said P-picture or said B-picture is coded without referring to any picture located before said closest access point P-picture;
- a map creating unit for creating an entry point map used for accessing access point P-pictures, said entry point map including a list of data for identifying a location of said video information units designated as access units on said medium;
- and
- a recording unit for recording on said medium said video data comprising said video units and said entry point map.
A video information encoding method for producing coded 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, said method comprising steps of:
- coding an access point P-picture by motion compensation prediction using an I-picture located at the beginning of a video unit or a selected preceding P-picture;
- coding said P-picture or said B-picture by motion compensation prediction using a closest access point P-picture preceding said P-picture or said B-picture as a reference picture, wherein said P-picture or said B-picture is coded without referring to any picture located before said closest access point P-picture;
- and
- creating an entry point map used for accessing access point P-pictures, said entry point map including a list of data for identifying a location of said video information units designated as access units.
An encoder for producing coded 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, said encoder comprising:
- a first coding unit for coding an access point P-picture by motion compensation prediction using an I-picture located at the beginning of a video unit or a selected preceding P-picture;
- a second coding unit for coding said P-picture or said B-picture by motion compensation prediction using a closest access point P-picture preceding said P-picture or said B-picture as a reference picture, wherein said P-picture or said B-picture is coded without referring to any picture located before said closest access point P picture;
- and
- a map creating unit for creating an entry point map used for accessing access point P-pictures, said entry point map including a list of data for identifying a location of said video information units designated as access units.
Dependencies are inferred from the claim text.