Time-varying audio-signal level using a time-varying estimated probability density of the level
First Claim
1. A method for smoothing a time-varying level of a signal, the method comprising:
- estimating a time-varying probability density of the time-varying level of the signal;
computing a probability of a prior smoothed time-varying level using the time-varying probability density estimate;
adapting a smoothing filter in response to the probability; and
applying the adapted smoothing filter to the time-varying level to generate the smoothed time-varying level.
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Abstract
Methods, media and apparatus for smoothing a time-varying level of a signal. A method includes estimating a time-varying probability density of a short-term level of the signal and smoothing a level of the signal by using the probability density. The signal may be an audio signal. The short-term level and the smoothed level may be time series, each having current and previous time indices. Here, before the smoothing, computing a probability of the smoothed level at the previous time index may occur. Before the smoothing, calculating smoothing parameters using the probability density may occur. Calculating the smoothing parameters may include calculating the smoothing parameters using the smoothed level at the previous time index, the short-term level at the current time index and the probability of the smoothed level at the previous time index. Calculating the smoothing parameters may include calculating the smoothing parameters using breadth of the estimated probability density.
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Citations
17 Claims
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1. A method for smoothing a time-varying level of a signal, the method comprising:
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estimating a time-varying probability density of the time-varying level of the signal; computing a probability of a prior smoothed time-varying level using the time-varying probability density estimate; adapting a smoothing filter in response to the probability; and applying the adapted smoothing filter to the time-varying level to generate the smoothed time-varying level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An apparatus for smoothing a time-varying level of an audio signal, wherein the apparatus comprises:
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an input terminal for receiving the audio signal; a short-term-level computer coupled to the input terminal for computing a short-term level of the audio signal; a level smoother coupled to an output of the short-term level computer for smoothing the short-term level of the audio signal using smoothing parameters; a probability-density estimator coupled to the output of the short-term-level computer for estimating a probability density of the short-term level; a delay coupled to an output of the level smoother for delaying the smoothed short-term-level of the audio signal; a probability computer coupled to an output of the probability-density estimator and to an output of the delay for computing a probability of the delayed smoothed short-term level; and a smoothing-parameters calculator coupled to the output of the short-term level computer, coupled to an output of the probability computer, and coupled to the output of the delay for calculating the smoothing parameters, wherein the level smoother is also coupled to an output of the smoothing-parameters calculator. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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Specification