APPARATUS AND METHOD FOR AUDIO FRAME LOSS RECOVERY
First Claim
1. A method for generating a decoded frame in response to a loss of a frame in an audio codec, comprising:
- identifying that a frame is lost;
generating a set of estimated linear predictive coefficients corresponding to a previous transform frame based on a decoded set of audio samples from the previous transform frame;
generating an estimated residual of the previous transform frame based on the set of estimated linear predicative coefficients and the decoded set of audio samples;
determining a pitch delay from a set of frame error recovery parameters received with the previous transform frame;
generating an extended residual based on the pitch delay and the estimated residual;
generating a first synthesized signal based on the extended residual and the set of linear predicative coefficients; and
generating a decoded audio output corresponding to at least the lost frame based on the first synthesized signal.
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Accused Products
Abstract
A method and apparatus provides for frame loss recovery following a loss of a frame in an audio codec. The lost frame is identified. Estimated linear predictive coefficients of a previous transform frame are generated based on a decoded audio of the previous transform frame. An estimated residual of the previous transform frame is generated based on the estimated linear predicative coefficients and the decoded audio. A pitch delay is determined from frame error recovery parameters received with the previous transform frame. An extended residual is generated based on the pitch delay and the estimated residual. A first synthesized signal is generated based on the extended residual and the linear predicative coefficients. A decoded audio output of at least the lost frame is generated based on the first synthesized signal. The frame error recovery parameters are generated by an encoder.
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Citations
19 Claims
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1. A method for generating a decoded frame in response to a loss of a frame in an audio codec, comprising:
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identifying that a frame is lost; generating a set of estimated linear predictive coefficients corresponding to a previous transform frame based on a decoded set of audio samples from the previous transform frame; generating an estimated residual of the previous transform frame based on the set of estimated linear predicative coefficients and the decoded set of audio samples; determining a pitch delay from a set of frame error recovery parameters received with the previous transform frame; generating an extended residual based on the pitch delay and the estimated residual; generating a first synthesized signal based on the extended residual and the set of linear predicative coefficients; and generating a decoded audio output corresponding to at least the lost frame based on the first synthesized signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of encoding a frame, comprising:
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receiving the frame and other audio information associated with the frame from a frame encoder; determining from the other audio information at least one of a classification as to whether the frame is a speech or music frame, a high frequency energy, and a low frequency energy; setting a frame error recovery (FER) indicator to one of a pitch FER state and a MDCT FER state based on the at least one of a classification as to whether the frame is a speech or music frame, a high frequency energy, and a low frequency energy; determining at least a pitch delay from the other audio information, wherein the pitch delay is a best estimate of a pitch delay of a next frame; and transmitting the frame, the FER indicator, and the pitch delay. - View Dependent Claims (12)
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13. An apparatus for generating a decoded frame following a loss of a frame, wherein the frames are a sequence of encoded audio frames, comprising:
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a receiver that receives the sequence of audio frames; and at least one processor that executes program instructions stored in memory, wherein the executed program instructions identify that a frame is lost, generate a set of estimated linear predictive coefficients corresponding to a previous transform frame based on a decoded set of audio samples from the previous transform frame, generate an estimated residual of the previous transform frame based on the set of estimated linear predicative coefficients and the decoded set of audio samples, determine a pitch delay from frame error recovery parameters received with the previous transform frame, generate an extended residual based on the pitch delay and estimated residual, generate a first synthesized signal based on the extended residual and the linear predicative coefficients, and generate a decoded audio output of at least the lost frame based on the first synthesized signal. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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Specification