发明名称 |
Method and apparatus for encoding and decoding an audio signal using adaptively switched temporal resolution in the spectral domain |
摘要 |
Perceptual audio codecs make use of filter banks and MDCT in order to achieve a compact representation of the audio signal, by removing redundancy and irrelevancy from the original audio signal. During quasi-stationary parts of the audio signal a high frequency resolution of the filter bank is advantageous in order to achieve a high coding gain, but this high frequency resolution is coupled to a coarse temporal resolution that becomes a problem during transient signal parts by producing audible pre-echo effects. The invention achieves improved coding/decoding quality by applying on top of the output of a first filter bank a second non-uniform filter bank, i.e. a cascaded MDCT. The inventive codec uses switching to an additional extension filter bank (or multi-resolution filter bank) in order to re-group the time-frequency representation during transient or fast changing audio signal sections. By applying a corresponding switching control, pre-echo effects are avoided and a high coding gain and a low coding delay are achieved. |
申请公布号 |
EP2003643(A1) |
申请公布日期 |
2008.12.17 |
申请号 |
EP20080157415 |
申请日期 |
2008.06.02 |
申请人 |
THOMSON LICENSING |
发明人 |
BOEHM, JOHANNES;KORDON, SVEN |
分类号 |
G10L19/022;G10L19/02;G10L19/093 |
主分类号 |
G10L19/022 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|