摘要:
A system (200) for processing a sound signal (212) that allows dynamic customization of perceived spatial positions and sound qualities of sound components associated with the sound signal (212). The system provides apparatus for processing a sound signal (212) that includes an input to receive the sound signal (212), a sound unmixer (204) coupled to the input to receive the sound signal (212) and unmix at least one sound stream (216) from the sound signal (212) based on at least one unmixing instruction (214), and an output coupled to the sound unmixer (214) to output the at least one sound stream (216).
摘要:
A method and apparatus for synchronizing audio to an asynchronous clock while preserving pitch utilizes a phase-vocoder to implement time-scaling without pitch-shifting.
摘要:
A method and apparatus for an audio scrubbing system for synchronizing audio to an asynchronous clock while preserving pitch utilizes a phase-vocoder to implement time-scaling without pitch-shifting.
摘要:
A system for pitch-shifting an audio signal wherein resampling is done in the frequency domain. The system includes a method for pitch-shifting a signal by converting the signal to a frequency domain representation and then identifying a specific region in the frequency domain representation. The region being located at a first frequency location. Next, the region is shifted to a second frequency location to form a adjusted frequency domain representation. Finally, the adjusted frequency domain representation is transformed to a time domain signal representing the input signal with shifted pitch. This eliminates the expensive time domain resampling stage and allows the computational costs to become independent of the pitch modification factor.
摘要:
A frequency band of an audio input signal is analyzed to determine if a transient is present. When transients are detected, modifications are made to the intensity levels corresponding to the frequency band for a brief time period.
摘要:
A method and apparatus for transient detection and time-scaling an audio signal detects transients and scales only intervals located between transients to avoid artifacts. In one embodiment, the transient detection process compares frequency characteristic energy between succeeding windows of the audio signal and calculates values of an energy curve where the energy increases. Transients are detected at maxima of the energy curve.
摘要:
A method and apparatus for removing or amplifying voice or other signals panned to the center of a stereo recording utilizes frequency domain techniques to calculate a frequency dependent gain factor based on the difference between the frequency domain spectra of the stereo channels.
摘要:
In accordance with the present invention, a method and apparatus are provided wherein loop discontinuities are eliminated. In the case of amplitude discontinuities, the harmonic amplitudes contained in the loop are progressively scaled over the duration of the loop, so that for each harmonic the loop end amplitude matches the loop beginning amplitude. In the case of phase discontinuities, the harmonic phases are progressively shifted over the duration of the loop, so that for each harmonic the loop end phase matches the loop beginning phase. Shifting the phase is accomplished by slightly altering the frequency of the harmonics to produce the desired amount of phase-shift at the loop end. In accordance with the present invention, the method also provides a technique to select loop begin and end points to minimize the amount of phase adjustment.
摘要:
Method and apparatus for time-scaling and/or pitch shifting by discarding and/or repeating segments of a signal. The signal is stored as a series of samples in a memory where it is readable by one or more read pointers. Periodicity of segments of the signal is determined by evaluating normalized cross-correlation over a range of possible periods. Transients are detected by monitoring changes in rms signal value. To achieve time compression or time stretching, a segment is skipped/discarded whenever a maximum time-discrepancy between the current output and an ideal output is reached or a high periodicity is detected, a jump of the optimal length would not make this time discrepancy too high, and no transient is present in the segment to be skipped/discarded.
摘要:
A digital signal is processed by splitting it into at least two frequency subbands and the two subband signals are downsampled. A filter is applied in at least one of the subband signals. At least one of the phase and magnitude of the subband filtered signals is matched in the transition frequency band between the two subbands.