Time/Frequency Two Dimension Post-processing
AssigneeHuawei Technologies Co., Ltd.
InventorYang Gao
Life of this patent
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Abstract
In accordance with an embodiment, a time-frequency post-processing method of improving perceptual quality of a decoded audio signal, the method includes determining a time-frequency representation (such as filter bank analysis and synthesis) of an audio signal, estimating a time-frequency energy distribution of an audio signal from a time-frequency filter bank, computing a modification gain for each time-frequency representation point to have a modified time-frequency representation, and outputting audio signal from a modified time-frequency representation.
Claims22
A post-processing method of generating a decoded audio signal, the method comprising:
- estimating a time-frequency energy array of a decoded audio signal from a time-frequency filter bank;
- estimating a time direction energy distribution by averaging frequency direction energies;
- estimating a frequency direction energy distribution by averaging time direction energies;
- estimating time direction energy modification gains based on the time direction energy distribution;
- estimating frequency direction energy modification gains based on the frequency direction energy distribution;
- estimating final two dimension energy modification gains for each T/F point of the time-frequency filter bank;
- applying the final T/F gains to each corresponding T/F point of the time-frequency filter bank to obtain the modified filter bank coefficients before sent to filter bank synthesis;
- and
- outputting final audio signal from the filter bank synthesis.
A post-processing method of generating a decoded audio signal, the method comprising:
- receiving a frame comprising a time-frequency (T/F) representation of an input audio signal, the T/F representation having time slots, each time slot having frequency subbands;
- estimating energy distribution in the time slots and the frequency subbands;
- estimating post-processing modification gain for each T/F point of time slot and frequency subband according to the T/F energy distribution;
- making the modification gain smaller at T/F point of lower energy;
- making the over all energy of after the T/F post-processing equivalent to the one of before the T/F post-processing;
- applying the final T/F gains to each corresponding T/F point to obtain the modified T/F representation;
- and
- outputting final audio signal from the modified T/F representation.
Dependencies are inferred from the claim text.