tures at and subsequent to the specified recovery point in output order derived by starting the decoding process at the access unit associated with the recovery point SEI message shall be an exact match to the pictures that would be produced by starting the decoding process at the location of a previous IDR access unit in the NAL unit stream. The value 0 indicates that the match need not be exact and the value 1 indicates that the match shall be exact. When decoding starts from the location of the recovery point SEI message, all references to not available reference pictures shall be inferred as references to pictures containing only macroblocks coded using Intra macroblock prediction modes and having sample values given by Y samples equal to BitDepthy - Cb samples equal to << BitDepthc and Cr samples equal to 1 BitDepthc (mid-level grey) for purposes of determining the conformance of the value of exact_match_flag. NOTE 3 - When performing random access, decoders should infer all references to not available reference pictures as references to pictures containing only intra macroblocks and having sample values given by Y equal to ( 1 BitDepthy - 1)), Cb equal to ( 1 (BitDepthc-1)) and Cr equal to ( 1 << (BitDepthc-1)) (mid-level grey), regardless of the value of exact_match_flag. Rec. ITU-T H.264 (01/2012) When exact_match_flag is equal to 0, the quality of the approximation at the recovery point is chosen by the encoding process and is not specified by this Recommendation | International Standard. NOTE 4 - Under some circumstances, the decoding process of pictures depends on the difference DiffPicOrderCnt( picA, picB) between the PicOrderCnt() values for two pictures picA and picB. However, no particular values of TopFieldOrderCnt and BottomFieldOrderCnt (as applicable) are specified to be assigned to the reference pictures that are not available due to the initiation of random access at the location of a picture associated with a recovery point SEI message. Also, no particular value has been specified for initia