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Tests on MPEG-4 audio codec proposals

1997; Elsevier BV; Volume: 9; Issue: 4 Linguagem: Inglês

10.1016/s0923-5965(97)00005-2

1879-2677

L. Contin, Bernd Edler, D. J. Meares, Peter R. Schreiner,

Digital Rights Management and Security

Abstract During December 1995, subjective tests were carried out by members of the Moving Picture Experts Group (MPEG, ISO/JTC1/SC29/WG11) to select the proposed technology for inclusion in the audio part of the new MPEG-4 standard. The new standard addresses coding for more than just the functionality of data rate compression. Material coded at very low bit-rates is also included. Thus, different testing methodologies were applied, according to ITU-R Rec. BS 1116 for a bit-rate of 64 kbit/s per channel and according to ITU-T Rec. P.80 for lower bit-rates or functionalities other than data rate compression. Proposals were subjectively tested for coding efficiency, error resilience, scalability and speed change: a subset of the MPEG-4 ‘functionalities’. This paper describes how two different evaluation methods were used and adjusted to fit the different testing requirements. This first major effort to test coding schemes at low bit-rates proved successful. Based on the test results, decisions for MPEG-4 technology were made. This was the first opportunity for MPEG members to carry out tests on the submitted functionalities. In the process, much was learnt. As a result, some suggestions are made to improve the way new functionalities can be subjectively evaluated.