Local picture identifier and computation of co-located information

Abstract

Video decoding innovations for using local picture identifiers and computing co-located information are described. In one aspect, a decoder identifies reference pictures in a reference picture list of a temporal direct prediction mode macroblock that match reference pictures used by a co-located macroblock using local picture identifiers. In another aspect, a decoder determines whether reference pictures used by blocks are the same by comparing local picture identifiers during calculation of boundary strength. In yet another aspect, a decoder determines a picture type of a picture and based on the picture type selectively skips or simplifies computation of co-located information for use in reconstructing direct prediction mode macroblocks outside the picture.

1 - 9 . (canceled) 
     
     
         10 . A computer-implemented method for transforming encoded video information using a video decoder, the method comprising:
 receiving encoded video information in a bitstream;   performing loop filtering during decoding the encoded video information, comprising:
 calculating boundary strength values for plural blocks, wherein the calculating comprises determining whether reference pictures used by the plural blocks are the same by comparing local picture identifiers of the reference pictures, wherein the local picture identifiers are assigned to picture structures when allocated, and wherein the decoder reuses the local picture identifiers during the decoding based on availability of the local picture identifiers; and 
   outputting the filtered macroblock.   
     
     
         11 . The method of  claim 10  wherein the local picture identifiers are 8-bit local picture identifiers, and wherein the decoder sets the local picture identifiers independent of picture order count. 
     
     
         12 . The method of  claim 10  wherein the local picture identifiers are 5-bit local picture identifiers. 
     
     
         13 . The method of  claim 10  wherein the local picture identifiers are greater than or equal to 5-bits, and less than or equal to 32-bits, and wherein the decoder selectively reuses the local picture identifiers during decoding based on which of the local picture identifiers are in use, thereby controlling bit depth of the local picture identifiers and speeding up the determination of whether reference pictures used by the plural blocks are the same during the loop filtering. 
     
     
         14 . The method of  claim 10  wherein the encoded video information is H.264 encoded video information. 
     
     
         15 - 20 . (canceled) 
     
     
         21 . The method of  claim 10  wherein the local picture identifiers are 8-bit local picture identifiers, and wherein an invalid picture identifier is assigned an 8-bit value of 255. 
     
     
         22 . The method of  claim 10  wherein the local picture identifiers are 32-bit local picture identifiers. 
     
     
         23 . The method of  claim 10  wherein the loop filtering is performed as part of deblock filtering to smooth reconstructed sample data across block boundaries. 
     
     
         24 . A computing device implementing a video decoder, the computing device comprising:
 a processing unit; and   memory;   wherein the computing device is configured to perform operations for decoding video, the operations comprising:
 receiving encoded video information in a bitstream; 
 performing loop filtering during decoding the encoded video information, comprising:
 calculating boundary strength values for plural blocks, wherein the calculating comprises determining whether reference pictures used by the plural blocks are the same by comparing local picture identifiers of the reference pictures, wherein the local picture identifiers are assigned to picture structures when allocated, and wherein the decoder reuses the local picture identifiers during the decoding based on availability of the local picture identifiers; and 
 
 outputting the filtered macroblock. 
   
     
     
         25 . The computing device of  claim 24  wherein the local picture identifiers are 8-bit local picture identifiers, and wherein the decoder sets the local picture identifiers independent of picture order count. 
     
     
         26 . The computing device of  claim 24  wherein the local picture identifiers are 5-bit local picture identifiers. 
     
     
         27 . The computing device of  claim 24  wherein the local picture identifiers are greater than or equal to 5-bits, and less than or equal to 32-bits, and wherein the decoder selectively reuses the local picture identifiers during decoding based on which of the local picture identifiers are in use, thereby controlling bit depth of the local picture identifiers and speeding up the determination of whether reference pictures used by the plural blocks are the same during the loop filtering. 
     
     
         28 . The computing device of  claim 24  wherein the encoded video information is H.264 encoded video information. 
     
     
         29 . The computing device of  claim 24  wherein the local picture identifiers are 8-bit local picture identifiers, and wherein an invalid picture identifier is assigned an 8-bit value of 255. 
     
     
         30 . The computing device of  claim 24  wherein the local picture identifiers are 32-bit local picture identifiers. 
     
     
         31 . The computing device of  claim 24  wherein the loop filtering is performed as part of deblock filtering to smooth reconstructed sample data across block boundaries. 
     
     
         32 . A computer-readable storage medium storing computer-executable instructions for causing a computing device programmed thereby to perform a method for decoding encoded video information, the method comprising:
 receiving encoded video information in a bitstream;   performing loop filtering during decoding the encoded video information, comprising:
 calculating boundary strength values for plural blocks, wherein the calculating comprises determining whether reference pictures used by the plural blocks are the same by comparing local picture identifiers of the reference pictures, wherein the local picture identifiers are assigned to picture structures when allocated, and wherein the decoder reuses the local picture identifiers during the decoding based on availability of the local picture identifiers; and 
   outputting the filtered macroblock.   
     
     
         33 . The computer-readable storage medium of  claim 32  wherein the local picture identifiers are one or 5-bit and 8-bit local picture identifiers, and wherein the decoder sets the local picture identifiers independent of picture order count. 
     
     
         34 . The computer-readable storage medium of  claim 32  wherein the local picture identifiers are greater than or equal to 5-bits, and less than or equal to 32-bits, and wherein the decoder selectively reuses the local picture identifiers during decoding based on which of the local picture identifiers are in use, thereby controlling bit depth of the local picture identifiers and speeding up the determination of whether reference pictures used by the plural blocks are the same during the loop filtering. 
     
     
         35 . The computer-readable storage medium of  claim 32  wherein the encoded video information is H.264 encoded video information.