Apparatuses for encoding and decoding a sequence of integer values, methods for encoding and decoding a sequence of integer values and computer program for implementing these methods

An apparatus for encoding, into a data stream, a sequence of integer values which are ordered in a strict monotonous manner, the apparatus configured for

• encoding into the data stream a predetermined integer value located at a predetermined position of the sequence of integer values;
• and
• for each position of the sequence of integer values which precedes the predetermined position,
• calculating a first difference between an integer value residing immediately following the respective position and the integer value at the respective position, reduced by 1;
• and
• encoding the first difference into the data stream;
• and
• for each position of the sequence of integer values which is located following the predetermined position,
• calculating a second difference between the integer value at the respective position and an integer value residing immediately preceding the respective position, reduced by 1;
• and
• encoding the second difference into the data stream,
• wherein the apparatus is configured for
• encoding into the data stream the predetermined integer value by
• mapping the predetermined integer value onto an unsigned integer according to a predefined mapping rule;
• and
• encoding the unsigned integer using a variable length code, and
• wherein the apparatus is configured for encoding into the data stream the unsigned integers by use of an exponential Golomb code.

A method for decoding, from a data stream, a sequence of integer values which are ordered in a strict monotonous manner, comprising

• decoding from the data stream a predetermined integer value located at a predetermined position of the sequence of integer values;
• and
• for each position of the sequence of integer values which precedes the predetermined position,
• decoding, from the data stream, a first difference between an integer value residing immediately following the respective position and the integer value at the respective position, reduced by 1;
• and
• for each position of the sequence of integer values which is located following the predetermined position,
• decoding, from the data stream, a second difference between the integer value at the respective position and an integer value residing immediately preceding the respective position, reduced by 1,
• the method further comprising:
• decoding from the data stream the predetermined integer value by
• decoding an unsigned integer via a variable length code;
• and
• retrieving the predetermined integer value by inverse mapping from the unsigned integer according to a predefined inverse mapping rule.
• wherein the method comprises decoding from the data stream the unsigned integer by use of an exponential Golomb code.