发明名称 Complex exponential modulated filter bank for high frequency reconstruction
摘要 An apparatus and method are disclosed for filtering and performing high frequency reconstruction of an audio signal. The apparatus includes an analysis filter bank, a high frequency reconstructor, and a synthesis filter bank. The analysis filterbank receives real-valued time domain input audio samples and generates complex valued subband samples. The high frequency reconstructor modifies at least some of the complex valued subband samples. The synthesis filter bank receives the modified complex valued subband samples and generates time domain output audio samples. The analysis filter bank comprises analysis filters that are complex exponential modulated versions of a prototype filter with an arbitrary phase shift.
申请公布号 US9583118(B1) 申请公布日期 2017.02.28
申请号 US201615353860 申请日期 2016.11.17
申请人 Dolby International AB 发明人 Ekstrand Per
分类号 G10L19/26;G10L19/02;H03H17/02 主分类号 G10L19/26
代理机构 代理人
主权项 1. A signal processing device for filtering and performing high frequency reconstruction of an audio signal, the signal processing device comprising: an analysis filter bank that receives real valued time domain input audio samples and generates complex valued subband samples; a high frequency reconstructor that generates modified complex valued subband samples through a high frequency reconstruction process; and a synthesis filter bank that receives the modified complex valued subband samples and generates time domain output audio samples, wherein the analysis filter bank comprises analysis filters (hk(n)) that are complex exponential modulated versions of a prototype filter (p0(n)) according to: hk⁡(n)=p0⁡(n)⁢exp⁢{i⁢πM⁢(k+12)⁢(n-D2-A)},0≦n<N,0≦k<M where A is an arbitrary phase shift constant, the analysis filter bank has M channels, the prototype filter (p0(n)) has a length N, and the analysis filter bank and synthesis filter bank have a system delay of D samples, wherein one or more of the analysis filter bank, the high frequency reconstructor, and the synthesis filter bank is implemented, at least in part, by one or more hardware elements of the signal processing device.
地址 Amsterdam NL