| 摘要 |
C /NRPonbl/DCC/FS/V37X191 .DOC-2812011 A method of reconstructing a time-domain output signal from an encoded bit stream and a decoder for reconstructing a time-domain output signal from an encoded bit stream are 5 disclosed. In one aspect, the method includes: receiving a scaled bit stream having a predetermined data rate within a given range as a sequence of frames, each frame containing at least one of the following (a) a plurality of quantized tonal components representing frequency domain content at different frequency resolutions of the input signal, b) quantized residual time-sample components 10 representing the time-domain residual formed from the difference between the reconstructed tonal components and the input signal, and c) scale factor grids representing signal energies of the residual signal, which at least partially span a frequency range of the input signal; receiving information for each frame about the position of the quantized 15 components and/or grids within the frequency range; parsing the frames of the scaled bit stream into the components and grids; decoding any tonal components to form transform coefficients; decoding any time-sample components and any grids; multiplying the time-sample components by grid elements to form time-domain 20 samples; and applying an inverse hierarchical filterbank to the transform coefficients and time domain samples to reconstruct a time-domain output signal. |
