Coding generic audio signals at low bitrates and low delay
First Claim
1. A mixed time-domain/frequency-domain coding device for coding an input sound signal, comprising:
- a calculator of a time-domain excitation contribution in response to the input sound signal;
a calculator of a cut-off frequency for the time-domain excitation contribution in response to the input sound signal;
a filter responsive to the cut-off frequency for adjusting a frequency extent of the time-domain excitation contribution;
a calculator of a frequency-domain excitation contribution in response to the input sound signal; and
an adder of the filtered time-domain excitation contribution and the frequency-domain excitation contribution to form a mixed time-domain/frequency-domain excitation constituting a coded version of the input sound signal.
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Abstract
A mixed time-domain/frequency-domain coding device and method for coding an input sound signal, wherein a time-domain excitation contribution is calculated in response to the input sound signal. A cut-off frequency for the time-domain excitation contribution is also calculated in response to the input sound signal, and a frequency extent of the time-domain excitation contribution is adjusted in relation to this cut-off frequency. Following calculation of a frequency-domain excitation contribution in response to the input sound signal, the adjusted time-domain excitation contribution and the frequency-domain excitation contribution are added to form a mixed time-domain/frequency-domain excitation constituting a coded version of the input sound signal. In the calculation of the time-domain excitation contribution, the input sound signal may be processed in successive frames of the input sound signal and a number of sub-frames to be used in a current frame may be calculated.
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Citations
58 Claims
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1. A mixed time-domain/frequency-domain coding device for coding an input sound signal, comprising:
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a calculator of a time-domain excitation contribution in response to the input sound signal; a calculator of a cut-off frequency for the time-domain excitation contribution in response to the input sound signal; a filter responsive to the cut-off frequency for adjusting a frequency extent of the time-domain excitation contribution; a calculator of a frequency-domain excitation contribution in response to the input sound signal; and an adder of the filtered time-domain excitation contribution and the frequency-domain excitation contribution to form a mixed time-domain/frequency-domain excitation constituting a coded version of the input sound signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A mixed time-domain/frequency-domain coding device for coding an input sound signal, comprising:
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a calculator of a time-domain excitation contribution in response to the input sound signal, wherein the calculator of time-domain excitation contribution processes the input sound signal in successive frames of said input sound signal and comprises a calculator of a number of sub-frames to be used in a current frame of the input sound signal, wherein the sub-frame number calculator is responsive to at least one of an available bit budget and a high frequency spectral dynamic of the input sound signal and wherein the calculator of time-domain excitation contribution uses in the current frame the number of sub-frames determined by the sub-frame number calculator for said current frame; a calculator of a frequency-domain excitation contribution in response to the input sound signal; and an adder of the time-domain excitation contribution and the frequency-domain excitation contribution to form a mixed time-domain/frequency-domain excitation constituting a coded version of the input sound signal. - View Dependent Claims (29)
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30. A mixed time-domain/frequency-domain coding method for coding an input sound signal, comprising:
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calculating a time-domain excitation contribution in response to the input sound signal; calculating a cut-off frequency for the time-domain excitation contribution in response to the input sound signal; in response to the cut-off frequency, adjusting a frequency extent of the time-domain excitation contribution; calculating a frequency-domain excitation contribution in response to the input sound signal; and adding the adjusted time-domain excitation contribution and the frequency-domain excitation contribution to form a mixed time-domain/frequency-domain excitation constituting a coded version of the input sound signal. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56)
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57. A mixed time-domain/frequency-domain coding method for coding an input sound signal, comprising:
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calculating a time-domain excitation contribution in response to the input sound signal, wherein calculating the time-domain excitation contribution comprises processing the input sound signal in successive frames of said input sound signal and calculating a number of sub-frames to be used in a current frame of the input sound signal, wherein calculating the number of sub-frames in the current frame is responsive to at least one of an available bit budget and a high frequency spectral dynamic of the input sound signal and wherein calculating the time-domain excitation contribution also comprises using in the current frame the number of sub-frames calculated for said current frame; calculating a frequency-domain excitation contribution in response to the input sound signal; and adding the time-domain excitation contribution and the frequency-domain excitation contribution to form a mixed time-domain/frequency-domain excitation constituting a coded version of the input sound signal. - View Dependent Claims (58)
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Specification