Methods and apparatuses for encoding and decoding object-based audio signals
Provided are an audio encoding method and apparatus and an audio decoding method and apparatus in which audio signals can be encoded or decoded so that sound images can be localized at any desired position for each object audio signal. The audio decoding method generating a third downmix signal by combining a first downmix signal extracted from a first audio signal and a second downmix signal extracted from a second audio signal; generating third object-based side information by combining first object-based side information extracted from the first audio signal and second object-based side information extracted from the second audio signal; converting the third object-based side information into channel-based side information; and generating a multi-channel audio signal using the third downmix signal and the channel-based side information.
1. An audio decoding method comprising:
generating, by an audio decoding apparatus, a third downmix signal by combining a first downmix signal and a second downmix signal;
generating, by an audio decoding apparatus, third object-based side information by combining first object-based side information and second object-based side information;
converting, by an audio decoding apparatus, the third object-based side information into channel-based side information; and
generating a multi-channel audio signal using the third downmix signal and the channel-based side information.
2. The audio decoding method of claim 1 , further comprising generating a multi-channel audio signal with a virtual three-dimensional (3D) effect applied thereto by applying 3D information to the multi-channel audio signal.
3. The audio decoding method of claim 2 , wherein the channel-based side information comprises the 3D information.
4. The audio decoding method of claim 2 , wherein the 3D information comprises information for synchronization with the channel-based side information.
5. The audio decoding method of claim 2 , wherein the 3D information is selected from a 3D information database based on control information, the 3D information database storing a plurality of pieces of 3D information.
6. The audio decoding method of claim 2 , wherein the 3 D information comprises a head-related transfer function (HRTF).
7. The audio decoding method of claim 1 , further comprising, if the third downmix signal is a stereo downmix signal, modifying of channel signals of the third downmix signal.
8. The audio decoding method of claim 1 , further comprising applying a predetermined effect to the multi-channel audio signal.
9. The audio decoding method of claim 1 , wherein the first downmix signal and the first object-based side information are extracted from a first audio signal, and the second downmix signal and the second object-based side information are extracted from a second audio signal.
10. An audio decoding apparatus comprising:
a multi-point control unit combiner which generates a third downmix signal by combining a first downmix signal and a second downmix signal and generates third object-based side information by combining first object-based side information and second object-based side information;
a transcoder which converts the third object-based side information into channel-based side information; and
a multi-channel decoder which generates a multi-channel audio signal using the third downmix signal and the channel-based side information.
11. The audio decoding apparatus of claim 10 , wherein the multi-channel decoder generates a multi-channel audio signal to which a virtual 3D effect is applied by applying 3D information to the multi-channel audio signal.
12. The audio decoding apparatus of claim 11 , wherein the transcoder generates channel-based side information, the channel-based side information comprising the 3D information.
13. The audio decoding apparatus of claim 11 , wherein the transcoder generates information for synchronization with the channel-based side information, the information comprising the 3D information.
14. The audio decoding apparatus of claim 13 , further comprising a renderer which selects the 3D information from a 3D information database based on control information and provides the 3 D information to the transcoder.
15. The audio decoding apparatus of claim 14 , wherein the 3D information database stores a plurality of pieces of 3D information.
16. The audio decoding apparatus of claim 15 , wherein the renderer comprises the 3D information database.
17. The audio decoding apparatus of claim 11 , wherein the 3D information comprises an HRTF.
18. The audio decoding apparatus of claim 10 , further comprising, if the third downmix signal is a streo downmix signal, a downmix processor which modifies channel signals of the third downmix signal by decorrelated signals.
19. The audio decoding apparatus of claim 10 , further comprising a channel processor which applies a predetermined effect to the multi-channel audio signal.
20. The audio decoding apparatus of claim 10 , wherein the first downmix signal and the first object-based side information are extracted from a first audio signal, and the second downmix signal and the second object-based side information are extracted from a second audio signal.
21. A computer-readable, non-transitory, recording medium having recorded thereon an audio decoding method comprising:
generating a third downmix signal by combining a first downmix signal extracted from a first audio signal and a second downmix signal extracted from a second audio signal;
generating third object-based side information by combining first object-based side information extracted from the first audio signal and second object-based side information extracted from the second audio signal;
converting the third object-based side information into channel-based side information; and
generating a multi-channel audio signal using the third downmix signal and the channel-based side information.
22. The computer-readable, non-transitory, recording medium of claim 21 , wherein the audio decoding method further comprises generating a multi-channel audio signal to which a virtual 3D effect is applied by applying 3D information to the multi-channel audio signal.