Patent ID: 7912232
Filing Date: 2011-03-22
Classification: G10L,H04S

Abstract:
1. A method for separation of at least two sources in an audio signal, comprising the steps of: inputting a two-channel audio signal mixture; performing an STFT decomposition of each of said channels, comprising an FFT for each overlapping time frame, to form left and right complex-valued spectrograms X estimating a panning parameter at each spectrogram point and a phase offset between channels, where the phase offset may be converted to a delay estimate; estimating mixing parameters for all sources based upon said estimated panning parameters and said phase offset; given mixing parameters for each source and frequency band activity for each source, demixing said sources by creating masks from spatial window functions in a parameter space including detected panning and detected phase offset; based on a detected panning and phase for each spectrogram point and said mixing parameters, assigning some fraction of the energy in said spectrogram point to each source; for each spectrogram, employing a phase function using either an original input phase, or a phase that results when normalized weighted and delayed subtraction is performed, to eliminate any source existing in said audio signal; producing two output spectrograms for each source, wherein 2N spectrograms result; and inverting said output spectrograms and providing a final output of N time domain stereo source signal estimates.