Personal Video Recorder

Abstract

A sequence of picture slices is encoded as reference slices and non-reference slices, wherein the reference slices include B slices, by forming, for each B slice, at least one data packet containing data values derived from brightness and color information pertaining to the slice. The data packet for each B slice includes a header element indicating whether the B slice is a reference slice. The header element of each reference B slice has a value that depends on depth of the reference B slice in a hierarchy of discardability.

1 - 19  (canceled) 
     
     
         20 . A method of decoding a plurality of coded pictures provided in a bitstream, the method comprising:
 identifying each of the plurality of coded pictures as being one of a reference picture or nonreference picture;   determining a hierarchy of data dependency where each of the coded pictures is located, wherein a first level in the hierarchy of data dependency identifies discardable pictures, and a second level in the hierarchy of data dependency identifies discardable pictures;   determining whether to decode or discard each of the coded pictures based on where the coded picture is located within the plurality of levels in the hierarchy of data dependency; and   not decoding the coded pictures in the bitstream that are determined for discarding.   
     
     
         21 . The method of  claim 20 , the hierarchy of data dependency including at least one level of discardability for reference pictures. 
     
     
         22 . The method of  claim 20 , wherein the at least one bitstream header element is a two-bit syntax element. 
     
     
         23 . The method of  claim 20 , further comprising interpreting one or more of the values of the bitstream header element to determine a coded picture type or slice types of the at least one coded picture. 
     
     
         24 . The method of  claim 23 , further comprising interpreting one or more of the values of the bitstream header element to determine whether one or more slices of the coded picture is a reference slice. 
     
     
         25 . The method of  claim 20 , further comprising interpreting one or more of the values of the bitstream header element to determine whether any part of the coded picture is identified as a reference in a decoding process for decoding one or more other coded pictures in the bitstream.