Audio object extraction with sub-band object probability estimation

1. A method for audio object extraction from audio content, comprising:

determining a sub-band object probability value for a sub-band of an audio signal in a frame of the audio content, the sub-band object probability value indicating a probability of the sub-band of the audio signal containing an audio object; and

splitting the sub-band of the audio signal into an audio object portion and a residual audio portion using the determined sub-band object probability value,

wherein the determination of the sub-band object probability value for the sub-band of the audio signal is based on at least one of the following:

a) a first probability determined based on a spatial position of the sub-band of the audio signal;

b) a second probability determined based on correlation between multiple channels of the sub-band of the audio signal when the audio content is of a format based on multiple-channels;

c) a third probability determined based on at least one panning rule in audio mixing; or

d) a fourth probability determined based on a frequency range of the sub-band of the audio signal; and

rendering the audio object portion to estimate a spatial location of the audio object; and

rendering the residual audio portion to estimate one or more bed channels of the audio content.

2. The method according to claim 1 , further comprising:

dividing the frame of the audio content into a plurality of sub-bands of the audio signal in a frequency domain,

wherein, for the plurality of sub-bands of audio signal, respective sub-band object probabilities are determined, and wherein each of the plurality of sub-bands of the audio signal is split into an audio object portion and a residual audio portion based on a respective sub-band object probability.

3. The method according to claim 1 , wherein splitting the sub-band of the audio signal into the audio object portion and the residual audio portion based on the determined sub-band object probability comprises:

determining an object gain of the sub-band of the audio signal based on the sub-band object probability; and

splitting the sub-band of the audio signal into the audio object portion and the residual audio portion based on the determined object gain.

4. The method according to claim 3 , wherein determining the object gain of the sub-band of the audio signal based on the sub-band object probability comprises determining the sub-band object probability as the object gain of the sub-band of the audio signal;

wherein the method further comprises at least one of:

smoothing the object gain of the sub-band of the audio signal with a time related smoothing factor; and

smoothing the object gain of the sub-band of the audio signal in a frequency window.

5. The method according to claim 4 , wherein the time related smoothing factor is associated with appearance and disappearance of an audio object in the sub-band of the audio signal over time; and

wherein a length of the frequency window is predetermined or is associated with a low boundary and a high boundary of a spectral segment of the sub-band of the audio signal.

6. The method according to claim 2 , further comprising:

clustering the audio object portions of the plurality of sub-bands of audio signal.

7. The method according to claim 6 , wherein the clustering of the audio object portions of the plurality of sub-bands of audio signal is based on at least one of: critical bands, spatial positions of the audio object portions of the plurality of sub-bands of the audio signal, or perceptual criteria.

8. A system for audio object extraction from audio content, comprising:

a probability determining unit configured to determine a sub-band object probability value for a sub-band of an audio signal in a frame of the audio content, the sub-band object probability value indicating a probability of the sub-band of the audio signal containing an audio object; and

an audio splitting unit configured to split the sub-band of the audio signal into an audio object portion and a residual audio portion using the determined sub-band object probability value,

wherein the determination of the sub-band object probability value for the sub-band of the audio signal is based on at least one of the following:

a) a first probability determined based on a spatial position of the sub-band of the audio signal;

b) a second probability determined based on correlation between multiple channels of the sub-band of the audio signal when the audio content is of a format based on multiple-channels;

c) a third probability determined based on at least one panning rule in audio mixing; or

d) a fourth probability determined based on a frequency range of the sub-band of the audio signal; and

a rendering unit configured to render the audio object portion to estimate a spatial location of the audio object; and render the residual audio portion to estimate one or more bed channels of the audio content.

9. The system according to claim 8 , further comprising:

a frequency band dividing unit configured to divide the frame of the audio content into a plurality of sub-bands of the audio signal in a frequency domain,

wherein, for the plurality of sub-bands of the audio signal, respective sub-band object probabilities are determined, and wherein each of the plurality of sub-bands of the audio signal is split into an audio object portion and a residual audio portion based on a respective sub-band object probability.

10. The system according to claim 8 , wherein the audio splitting unit comprises:

an object gain determining unit configured to determine an object gain of the sub-band of the audio signal based on the sub-band object probability,

wherein the audio splitting unit is further configured to split the sub-band of the audio signal into the audio object portion and the residual audio portion based on the determined object gain.

11. The system according to claim 10 , wherein the object gain determining unit is further configured to determine the sub-band object probability as the object gain of the sub-band of the audio signal;

wherein the system further comprises at least one of:

a temporal smoothing unit configured to smooth the object gain of the sub-band of the audio signal with a time related smoothing factor, wherein the time related smoothing factor is associated with appearance and disappearance of an audio object in the sub-band of the audio signal over time; and

a spectral smoothing unit configured to smooth the object gain of the sub-band of the audio signal in a frequency window, wherein a length of the frequency window is predetermined or is associated with a low boundary and a high boundary of a spectral segment of the sub-band of the audio signal.

12. The system according to claim 9 , further comprising:

a clustering unit configured to cluster the audio object portions of the plurality of sub-bands of audio signal, wherein the clustering of the audio object portions of the plurality of sub-bands of the audio signal is based on at least one of: critical bands, spatial positions of the audio object portions of the plurality of sub-bands of the audio signal, and perceptual criteria.

13. A computer program product, comprising a computer program tangibly embodied on a non-transitory machine readable medium, the computer program containing program code for performing the method of claim 1 .