Perancangan dan Analisis Kinerja Rendering Matrix Analysis (RMA) Module untuk MPEG Spatial Audio Object Coding (SAOC)

MPEG Spatial Audio Object Coding (SAOC) merupakan standar pengkode audio berbasis objek pertama yang keluarkan oleh International Organization for Standardization (ISO). MPEG SAOC Decoder memiliki kemampuan reproduksi audio multikanal, namun MPEG SAOC Encoder hanya mendukung masukan satu objek audio multikanal saja. Untuk mengatasi permasalahan tersebut, dirancang modul RMA untuk mendukung banyak masukan objek audio multikanal pada MPEG SAOC Encoder. Berdasarkan hasil pengujian subjektif, kualitas audio yang dihasilkan MPEG SAOC yang terintegrasi dengan MPEG SAOC memiliki skor MUSHRA 30 poin lebih tinggi dibandingkan MPEG High-Efficiency Advanced Audio Coding (HE-AAC) dan juga memiliki kemampuan kompresi 35% lebih baik dibandingkan HE-AAC. Kata Kunci : Rendering Matrix Analysis Module, Spatial Audio Object Coding, Audio berbasis Objek, dan Audio Multikanal

Analysis by synthesis spatial audio coding

This study presents a novel spatial audio coding (SAC) technique, called analysis by synthesis SAC (AbS-SAC), with a capability of minimising signal distortion introduced during the encoding processes. The reverse one-to-two (R-OTT), a module applied in the MPEG Surround to down-mix two channels as a single channel, is first configured as a closed-loop system. This closed-loop module offers a capability to reduce the quantisation errors of the spatial parameters, leading to an improved quality of the synthesised audio signals. Moreover, a sub-optimal AbS optimisation, based on the closed-loop R-OTT module, is proposed. This algorithm addresses a problem of practicality in implementing an optimal AbS optimisation while it is still capable of improving further the quality of the reconstructed audio signals. In terms of algorithm complexity, the proposed sub-optimal algorithm provides scalability. The results of objective and subjective tests are presented. It is shown that significant improvement of the objective performance, when compared to the conventional open-loop approach, is achieved. On the other hand, subjective test show that the proposed technique achieves higher subjective difference grade scores than the tested advanced audio coding multichannel

Rétroingénierie du son pour l écoute active et autres applications

Ce travail s intéresse au problème de la rétroingénierie du son pour l écoute active. Le format considéré correspond au CD audio. Le contenu musical est vu comme le résultat d un enchaînement de la composition, l enregistrement, le mixage et le mastering. L inversion des deux dernières étapes constitue le fond du problème présent. Le signal audio est traité comme un mélange post-non-linéaire. Ainsi, le mélange est décompressé avant d'être décomposé en pistes audio. Le problème est abordé dans un contexte informé : l inversion est accompagnée d'une information qui est spécifique à la production du contenu. De cette manière, la qualité de l inversion est significativement améliorée. L information est réduite de taille en se servant des méthodes de quantification, codage, et des faits sur la psychoacoustique. Les méthodes proposées s appliquent en temps réel et montrent une complexité basse. Les résultats obtenus améliorent l état de l art et contribuent aux nouvelles connaissances.This work deals with the problem of reverse audio engineering for active listening. The format under consideration corresponds to the audio CD. The musical content is viewed as the result of a concatenation of the composition, the recording, the mixing, and the mastering. The inversion of the two latter stages constitutes the core of the problem at hand. The audio signal is treated as a post-nonlinear mixture. Thus, the mixture is decompressed before being decomposed into audio tracks. The problem is tackled in an informed context: The inversion is accompanied by information which is specific to the content production. In this manner, the quality of the inversion is significantly improved. The information is reduced in size by the use of quantification and coding methods, and some facts on psychoacoustics. The proposed methods are applicable in real time and have a low complexity. The obtained results advance the state of the art and contribute new insights.BORDEAUX1-Bib.electronique (335229901) / SudocSudocFranceF