Study of the subjective performance of a range of MPEG-2 encoders

This contribution represents the results of subjective tests organized in November '94 by the HAMLET subgroup WP2. These tests, carried out in accordance with Rec. ITU-R 500-5, compare the performances of different types of MPEG-2 encoders: (1) the software encoder of the MPEG-2 technical documentation (reference); (2) an exact simulation of the hardware encoder that is being built in the same RACE project, (3) an optimized software encoder and (4) an SNR scalable encoder. The results reveal that the MPEG-2 standard leaves much room for optimization in the encoder. They also illustrate that optimizations carried out for the HAMLET hardware encoder lead to important improvements. Finally, they show the almost comparable quality of the MPEG-2 reference software encoder at 7 Mbit/s and the SNR scalable encoder at 3+4 Mbit/s for the base + enhancement layer.