Pitch filter for audio signals
First Claim
1. A pitch filter for filtering a preliminary audio signal generated from an audio bitstream, the pitch filter having an operating mode selected from one of either:
- (i) an active mode where the preliminary audio signal is filtered using filtering information to obtain a filtered audio signal, and(ii) an inactive mode where the pitch filter is disabled;
wherein the preliminary audio signal is generated in an audio decoder operating in a coding mode selected from at least two distinct coding modes, and the pitch filter is capable of being selectively operated in either the active mode or the inactive mode based on control information while the audio decoder is operating in the coding mode, wherein the audio bitstream is segmented into frames of audio content and the control information includes a frame type parameter with one or more first values of the frame type parameter indicating that the pitch filter should be operated in the active mode and a second value of the parameter indicating that the pitch filter should be operated in the inactive mode.
1 Assignment
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Accused Products
Abstract
In some embodiments, a pitch filter for filtering a preliminary audio signal generated from an audio bitstream is disclosed. The pitch filter has an operating mode selected from one of either: (i) an active mode where the preliminary audio signal is filtered using filtering information to obtain a filtered audio signal, and (ii) an inactive mode where the pitch filter is disabled. The preliminary audio signal is generated in an audio encoder or audio decoder having a coding mode selected from at least two distinct coding modes, and the pitch filter is capable of being selectively operated in either the active mode or the inactive mode while operating in the coding mode based on control information.
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Citations
18 Claims
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1. A pitch filter for filtering a preliminary audio signal generated from an audio bitstream, the pitch filter having an operating mode selected from one of either:
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(i) an active mode where the preliminary audio signal is filtered using filtering information to obtain a filtered audio signal, and (ii) an inactive mode where the pitch filter is disabled; wherein the preliminary audio signal is generated in an audio decoder operating in a coding mode selected from at least two distinct coding modes, and the pitch filter is capable of being selectively operated in either the active mode or the inactive mode based on control information while the audio decoder is operating in the coding mode, wherein the audio bitstream is segmented into frames of audio content and the control information includes a frame type parameter with one or more first values of the frame type parameter indicating that the pitch filter should be operated in the active mode and a second value of the parameter indicating that the pitch filter should be operated in the inactive mode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method for filtering a preliminary audio signal with a pitch filter, the pitch filter having an operating mode selected from one of either an active mode where the preliminary audio signal is filtered using filtering information or an inactive mode where the preliminary audio signal is not filtered, the method comprising:
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obtaining the preliminary audio signal, the preliminary audio signal generated from an audio bitstream in a coding mode selected from either a first coding mode or a second coding mode; obtaining control information; and selectively operating the pitch filter in either the active mode or the inactive mode while operating in the coding mode based on the control information, wherein the preliminary audio signal is derived from an audio bitstream segmented into frames of audio content and the control information includes a frame type parameter with one or more first values of the frame type parameter indicating that the pitch filter should be operated in the active mode and a second value of the parameter indicating that the pitch filter should be operated in the inactive mode. - View Dependent Claims (17, 18)
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Specification