Reference Software

MPEG-4 Reference Software

MPEG doc#: N7650
Date: Oct. 2005
Author:

This part of ISO/IEC 14496 contains simulation software for tools defined in parts 1, 2, 3 and 6 of ISO/IEC 14496. This software has been derived from verification models used in the process of developing the standard. Due to the delay between acceptance of a tool and its availability in source code form, the source for some tools described in other parts of ISO/IEC 14496 may not be present.

Where bitstream encoding software is provided, attention is called to the fact that these encoders are provided for the purpose of creating bitstreams with normative syntax. The performance of these encoders should not be taken as indicative of that which can be obtained from implementations where quality and computational optimization are given priority. The techniques used for encoding are not specified by this specification.

Reference software is normative in the sense that any conforming implementation of the software, taking the same conformant bitstreams, using the same output file format, will output the same file. Complying ISO/IEC 14496 implementations are not expected to follow the algorithms or the programming techniques used by the reference software. Although the decoding software is considered normative, it cannot add anything to the textual technical description included in parts 1, 2, 3 and 6 of ISO/IEC 14496.

The software contained in this part of ISO/IEC 14496 is divided into three categories:

• Elementary stream decoding software is catalogued in clauses 3, 4 and 5. This software accepts elementary streams encoded according to the normative specification in parts 1, 2, 3 and 6 of ISO/IEC 14496 and decodes the streams into the media types associated with each elementary stream. While this software appears in the normative part of this specification, attention is drawn to the fact that the implementation techniques used in this software are not considered normative – several different implementations could produce the same result – but the software is considered normative in that it correctly implements the decoding processes described in parts 1, 2, 3 and 6 of ISO/IEC 14496.
• Elementary stream encoding software is catalogued in Annex A (informative). This software creates elementary streams from associated media types. The encoders are provided as a means to obtain elementary streams with the normative syntax described in parts 1, 2 and 3 of ISO/IEC 14496. The techniques used for encoding are not specified by this specification, and the quality and complexity of these encoders has not been optimized.
• Utility software is catalogued in Annex B (informative). This software was found useful by the developers of the standard, but may not conform to the normative specifications given in parts 1, 2, 3 and 6 of ISO/IEC 14496.

File locations given in this part of ISO/IEC 14496 are expressed relative to its location in the source tree.