ISO/IEC TR 14496-24:2025

This document describes the desired joint behaviour of MPEG-4 Systems (MPEG-4 File Format) and MPEG-4 Audio codecs. It is desired that MPEG-4 Audio encoders and decoders permit finite length signals to be encoded to a file (particularly MPEG-4 files) and decoded again to obtain the identical signal, subject to codec distortions. This enables the use of audio in systems implementations (particularly MPEG-4 Systems), perhaps with other media such as video, in a deterministic fashion. Most importantly, the decoded signal has nothing “extra” at the beginning or “missing” at the end.

This permits:

Examples are given that show how a finite length signals can be encoded to an MPEG-4 file and decoded again to obtain the identical signal, excepting codec distortions. Most importantly, the decoded signal has nothing “extra” at the beginning or “missing” at the end.