ture to be used by the decoding process for a bitstream conforming to this Recommendation | International Standard. The primary coded picture contains all Rec. ITU-T H.264 (01/2012) macroblocks of the picture. The only pictures that have a normative effect on the decoding process are primary coded pictures. See also redundant coded picture. 3.114 profile: A specified subset of the syntax of this Recommendation International Standard. 3.115 quantisation parameter: A variable used by the decoding process for scaling of transform coefficient levels. 3.116 random access: The act of starting the decoding process for a bitstream at a point other than the beginning of the stream. 3.117 raster scan: A mapping of a rectangular two-dimensional pattern to a one-dimensional pattern such that the first entries in the one-dimensional pattern are from the first top row of the two-dimensional pattern scanned from left to right, followed similarly by the second, third, etc., rows of the pattern (going down) each scanned from left to right. 3.118 raw byte sequence payload (RBSP): A syntax structure containing an integer number of bytes that is encapsulated in a NAL unit. An RBSP is either empty or has the form of a string of data bits containing syntax elements followed by an RBSP stop bit and followed by zero or more subsequent bits equal to 0. 3.119 raw byte sequence payload (RBSP) stop bit: A bit equal to 1 present within a raw byte sequence payload (RBSP) after a string of data bits. The location of the end of the string of data bits within an RBSP can be identified by searching from the end of the RBSP for the RBSP stop bit, which is the last non-zero bit in the RBSP. 3.120 recovery point: A point in the bitstream at which the recovery of an exact or an approximate representation of the decoded pictures represented by the bitstream is achieved after a random access or broken link. 3.121 redundant coded picture: A coded representation of a picture or a part of a picture. The content of a redundant coded picture shall not be us