METHOD AND APPARATUS FOR DOWN-MIXING MULTI-CHANNEL AUDIO

摘要

PURPOSE: A device for downmixing multi-channel audio signals and a method thereof are provided to quickly and simply downmix multi-channel audio signals by executing only frequency-time inverse transformation optimized for the number of output channels. CONSTITUTION: Encoded multi-channel audio signals are inputted by using a sub-band coding method(S201). An inverse quantization part decodes sub-band PCM(Pulse Coded Modulation) samples for each channel of the inputted multi-channel audio signals. A scaling part performs a scaling function according to a downmix related to scaling setting for the decoded sub-band PCM samples for each channel(S202). A pre-downmixing part pre-downmixes the scaled sub-band samples for each channel to predetermined channels(S203). An inverse sub-band filter part outputs frequency-domain audio signals as time-domain audio signals by inverse sub-band filtering each pre-downmixed channel(S204). [Reference numerals] (AA) Start; (BB) End; (S201) Restoring a sub-band PCM sample for each channel by dequantizing an inputted multi-channel audio signal; (S202) Scaling according to setting; (S203) Pre-downmixing to predetermined channels; (S204) Inverse sub-band filtering for each channel