Wavelet-based spatial audio framework : from ambisonics to wavelets: a novel approach to spatial audio
Ambisonics is a complete theory for spatial audio whose building blocks are the spherical harmonics. Some of the drawbacks of low order Ambisonics, like poor source directivity and small sweet-spot, are directly related to the properties of spherical harmonics. In this thesis we illustrate a novel s...
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| Formato: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2019 |
| País: | España |
| Recursos: | CBUC, CESCA |
| Repositorio: | TDR. Tesis Doctorales en Red |
| OAI Identifier: | oai:www.tdx.cat:10803/668214 |
| Acesso em linha: | http://hdl.handle.net/10803/668214 |
| Access Level: | acceso abierto |
| Palavra-chave: | Wavelets Ambisonics Lifting scheme Wavelet optimization Ambisonics decoding Spatial audio Spherical audio format Spatial downsampling Decoding to speakers Ondetes Optimització de ondetes Decodificació d'ambisonics Àudio espacial Format d'àudio esfèric Mostreig espacial Descodificació a altaveus 62 |
| Resumo: | Ambisonics is a complete theory for spatial audio whose building blocks are the spherical harmonics. Some of the drawbacks of low order Ambisonics, like poor source directivity and small sweet-spot, are directly related to the properties of spherical harmonics. In this thesis we illustrate a novel spatial audio framework similar in spirit to Ambisonics that replaces the spherical harmonics by an alternative set of functions with compact support: the spherical wavelets. We develop a complete audio chain from encoding to decoding, using discrete spherical wavelets built on a multiresolution mesh. We show how the wavelet family and the decoding matrices to loudspeakers can be generated via numerical optimization. In particular, we present a decoding algorithm optimizing acoustic and psychoacoustic parameters that can generate decoding matrices to irregular layouts for both Ambisonics and the new wavelet format. This audio workflow is directly compared with Ambisonics. |
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