| CPC H04N 19/91 (2014.11) [H04N 19/109 (2014.11)] | 20 Claims |
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1. An apparatus for video decoding, the apparatus comprising a coded picture buffer (CPB) and a decoded picture buffer (DPB), configured to
receive a data stream having pictures of a video encoded thereinto along a coding order as a sequence of access units (AU),
feed the sequence of access units sequentially into the CPB using a selected bitrate with halting the feeding with respect to access units for which a virtual time of availability according to a temporal frame removal raster preponed by, for a first access unit in the coding order, a selected temporal removal delay and, for subsequent access units in coding order, a sum of the selected temporal removal delay and a selected temporal offset has not yet been reached, until the virtual time of availability is reached;
remove the AUs from the CPB AU-wise using the temporal raster extract from the data stream first CPB parameters relating to a first operation point and second CPB parameters relating to a second operation point, each of the first and the second CPB parameters being indicative of a CPB size, a predetermined temporal offset, a predetermined temporal removal delay and a predetermined bitrate, wherein the first CPB parameters differ from the second CPB parameters at least with respect to the predetermined bitrate,
determine the selected temporal offset by interpolating, at the selected bitrate, between the predetermined temporal offset indicated by the first CPB parameters and the predetermined temporal offset indicated by the second CPB parameters and the selected temporal removal delay by interpolating, at the selected bitrate, between the predetermined temporal removal delay indicated by the first CPB parameters and the predetermined temporal removal delay indicated by the second CPB parameters,
decode a current AU removed from the CPB using inter-picture prediction from a referenced reference picture stored in the DPB to acquire a decoded picture, and
insert the decoded picture into the DPB,
assign to each reference picture stored in the DPB a classification as one of a short-term reference picture, a long-term reference picture and an unused-for-reference picture,
read DPB mode information from the current AU,
if the DPB mode information indicates a first mode, remove one or more reference pictures classified as a short-term picture, according to a first-in-first-out (FIFO) strategy, from the DPB,
if the DPB mode information indicates a second mode,
read memory management control information comprising at least one command in the current AU and execute the at least one command so as to change the classification assigned to at least one of the reference pictures stored in the DPB, and use the classification of the reference pictures in the DPB, for managing reference picture removal from the DPB,
read an entropy coding mode indicator from the data stream, and
decode prediction residual data from a current AU using a context adaptive variable length coding mode if the entropy coding mode indicator indicates the context adaptive variable length coding mode, and using a context adaptive binary arithmetic coding mode if the entropy coding mode indicator indicates the context adaptive binary arithmetic coding mode,
wherein the apparatus is configured to, in decoding the prediction residual data from the current AU using the context adaptive variable length coding mode, use
a first syntax element indicating a total number of non-zero transform coefficient levels in a transform block,
a second syntax element indicating a total number of zero-valued transform coefficient levels in the transform block,
third syntax elements indicting a number of consecutive transform coefficient levels in a scan order with zero value from a current scan position onwards before a non-zero transform coefficient level is encountered,
one or more fourth syntax elements for each non-zero valued transform coefficient except trailing one transform coefficients, which one or more fourth syntax elements indicate a transform coefficient level value of the respective non-zero valued transform coefficient, and
one or more fifth syntax elements indicating a sign of the trailing one transform coefficient levels.
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