Encoder, decoder, encoding method and decoding method, and recording medium

A decoder comprising:

• a receiving unit including a plurality of code blocks having variable length codes and receiving a generated bit stream such that a boundary between the code blocks is recognized;
• a specifying unit specifying a start end and a termination end of the code blocks based on the boundary between the code blocks;
• and
• a parallel decoding unit variable-length-decoding the bit stream received by the receiving unit in parallel from the start end and the termination end of the code blocks specified by the specifying unit.

An encoding method comprising the steps of:

• separating image data into a plurality of data blocks;
• variable-length-encoding the data blocks so as to generate variable length code sequences;
• generating code blocks variable-length-decoded in parallel from a start end and a termination end by combining two variable length code sequences generated in the variable-length-encoding step;
• and
• generating a bit stream such that a boundary between the code blocks is recognized.

A decoding method comprising the steps of:

• receiving a generated bit stream such that a boundary between code blocks is recognized, with a plurality of code blocks having variable length codes;
• specifying a start end and a termination end of the code blocks based on the boundary between the code blocks;
• and
• variable-length-decoding the bit stream received in the receiving step in parallel from the start end and the termination end specified by the specifying unit.

A recording medium having an encoding program recorded thereon, which executes a method with respect to a computer, the method comprising the steps of:

• separating image data into a plurality of data blocks;
• variable-length-encoding the data blocks so as to generate variable length code sequences;
• generating code blocks variable-length-decoded in parallel from a start end and a termination end by combining two variable length code sequences generated in the variable-length-encoding step;
• and
• generating a bit stream such that a boundary between the code blocks is recognized.

A recording medium having a decoding program recorded thereon, which executes a method with respect to a computer, the method comprising the steps of:

• receiving a generated bit stream such that a boundary between code blocks is recognized, with a plurality of code blocks having variable length codes;
• specifying a start end and a termination end of the code blocks based on the boundary between the code blocks;
• and
• variable-length-decoding the bit stream received in the receiving step in parallel from the start end and the termination end specified by the specifying unit.