Apparatus and method for processing multi-channel audio signal

1. A multichannel audio signal processing method processed by a decoder, comprising:

generating an N-channel audio signal of N channels by down-mixing an M-channel audio signal of M channels in a format converter using playback environment or virtual layout, the number of M channels being greater than the number of N channels;

generating a stereo audio signal by performing binaural rendering of the N-channel audio signal in a binaural renderer; and

outputting the stereo audio signal,

wherein a plurality of channels corresponding to the M channel audio signal of M channels are inputted to the format converter through a first dynamic range control (DRC1).

2. The method of claim 1 , wherein the decoder extracts a plurality of channel/prerendered objects and a plurality of objects from a bitstream.

3. The method of claim 1 , wherein a plurality of objects are inputted to an object renderer through the first dynamic range control (DRC1).

4. The method of claim 1 , wherein the N-channel audio signal of N channels are outputted from a mixer.

5. The method of claim 1 , wherein the N-channel audio signal of N channels is inputted into a binaural renderer connected with a second dynamic range control (DRC2) or is inputted into a third dynamic range control (DRC3) connected with the second dynamic range control (DRC2) for a loudspeaker feed.

6. The method of claim 1 , wherein the generating of the stereo audio signal comprises:

applying a N binaural filter for binaural rendering into each channel audio signal of N-channel audio signal, for each left channel audio signal and each right channel audio signal of the stereo audio signal.

7. The method of claim 6 , wherein the generating of the stereo audio signal comprises:

summing a filtering result of the N binaural filter related to to a head related transfer function (HRTF) or a binaural room impulse response (BRIR) for binaural rendering.

8. A multichannel audio signal processing method processed by a decoder, comprising:

downmixing a M-channel audio signal of M channels for generating N-channel audio signal of N channels in a format converter using playback environment or virtual layout; and

generating a stereo audio signal by performing binaural rendering the downmixed N-channel audio signal in a binaural renderer; and

outputting the stereo audio signal,

wherein a plurality of channels corresponding to the M channel audio signal of M channels are inputted to the format converter through a first dynamic range control (DRC1).

9. The method of claim 8 , wherein a plurality of channel/prerendered objects and a plurality of objects are extracted from a bitstream.

10. The method of claim 8 , wherein a plurality of objects are inputted to an object renderer through the first dynamic range control (DRC1).

11. The method of claim 8 , wherein the N-channel audio signal of N channels are outputted from a mixer.

12. The method of claim 8 , wherein the N-channel audio signal of N channels is inputted into the binaural renderer connected with a second dynamic range control (DRC2) or is inputted into a third dynamic range control (DRC3) connected with the second dynamic range control (DRC2) for a loudspeaker feed.

13. The method of claim 8 , wherein the generating of the stereo audio signal comprises performing binaural rendering of the downmixed multichannel audio signal in a frequency domain.

14. The method of claim 8 , wherein the generating of the stereo audio signal comprises generating the stereo audio signal using a plurality of binaural filters respectively corresponding to the N channels of the N-channel audio signal.

15. A multichannel audio signal processing apparatus processed by a Unified Speech Audio Coding (USAC) 3D decoder, comprising:

one or more processor configured to:

downmix a M-channel audio signal of M channels in a format converter for generating N-channel audio signal of N channels based on a three-dimensional (3D) loudspeaker layout; and

generate a stereo audio signal by performing binaural rendering of the downmixed N-channel audio signal in a binaural renderer; and

output the stereo audio signal,

wherein a plurality of channels corresponding to the M channel audio signal of M channels are inputted to the format converter through a first dynamic range control (DRC1).

16. The apparatus of claim 15 , wherein the USAC 3D decoder extracts a plurality of channel/prerendered objects and a plurality of objects from a bitstream.

17. The apparatus of claim 15 , wherein a plurality of objects are inputted to an object renderer through the first dynamic range control (DRC1).

18. The apparatus of claim 15 , wherein the N-channel audio signal of N channels are outputted from a mixer,

wherein the N-channel audio signal of N channels is inputted into the binaural renderer connected with a second dynamic range control (DRC2) or is inputted into a third dynamic range control (DRC3) connected with the second dynamic range control (DRC2) for a loudspeaker feed.