MP3 Audio Quality for Single and Multiple Encoding

Abstract

The results of several measurements of audio quality of single and multiple MPEG-Layer 3 encodings will be presented. Subjective and objective tests have been done. A comparisons between the scores of the Objective Difference Grade (ODG) and the Subjective Difference Grade (SDG) prove a more accuracy of the PEAQ method at higher bit-rate. The recent versions of the LAME encoder and PEAQ software based on the ITU recommendation have been used, in association with the ITU standards for the execution of the Subjective test for small impairments.

Marca d´Água no Domínio do Tempo para Sinais de Áudio

“…. , 0, 01 este intervalo muda para [11.69, 13.82], [14.19, 16.32 [14]. Avaliando conjuntamente os resultados apresentados nas Tabelas II e IV,é possível notar que o método vLCA/2/m, proposto neste trabalho,é capaz de melhorar consideravelmente a robustez da marca d'água sem afetar de forma significativa a qualidade do sinal marcado.…”

Displaying Sensed Tactile Cues with a Fingertip Haptic Device

“…On the other hand, it carries out subjective experiments where humans are asked to compare and rate the quality of the compressed images with respect to the original [43], [44], [45]. Similarly, researchers objectively evaluate the performance of compression algorithms for audio signals employing sophisticated ear models [46], [47], while the subjective evaluation requires human listeners to compare and rate the quality of the compressed audio signals with respect to the original [47], [48].…”