Packet Loss Concealment for Speech Coding
AssigneeHuawei Technologies Co., Ltd.
InventorYang Gao
Life of this patent
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Abstract
A speech coding method of reducing error propagation due to voice packet loss, is achieved by limiting or reducing a pitch gain only for the first subframe or the first two subframes within a speech frame. The method is used for a voiced speech class. A pitch cycle length is compared to a subframe size to decide to reduce the pitch gain for the first subframe or the first two subframes within the frame. A strongly voiced class is decided by checking if the pitch lags are stable and the pitch gains are high enough with the frame; for the strongly voiced frame, the pitch lags and the pitch gains can be encoded more efficiently than other speech classes.
Claims12
A method of obtaining an excitation for encoding a speech signal, comprising:
- determining an initial pitch gain value for each subframe within a frame of the speech signal;
- reducing or limiting only the initial pitch gain value of the first subframe of the frame to obtain a reduced or limited pitch gain value that is smaller than the initial pitch gain value of the first subframe;
- obtaining an excitation of a next frame of the speech signal according to the reduced or limited pitch gain value of the first subframe, wherein the next frame of the speech signal is successive to the frame of the speech signal;
- and
- encoding the next frame of the speech signal according to the excitation.
A non-transitory computer-readable medium having program instructions stored thereon for execution by a processor, wherein the instructions, when executed, implement a method of obtaining an excitation for encoding a speech signal, comprising:
- determining an initial pitch gain value for each subframe within a frame of the speech signal;
- reducing or limiting only the initial pitch gain value of the first subframe of the frame to obtain a reduced or limited pitch gain value that is smaller than the initial pitch gain value of the first subframe;
- obtaining an excitation of a next frame of the speech signal according to the reduced or limited pitch gain value of the first subframe, wherein the next frame of the speech signal is successive to the frame of the speech signal;
- and
- encoding the next frame of the speech signal according to the excitation.
An apparatus, comprising:
- a memory for storing computer executable program instructions;
- and
- a processor operatively coupled to the memory, the processor being configured to execute the program instructions to:
- determine an initial pitch gain value for each subframe within a frame of a speech signal;
- reduce or limit only the initial pitch gain value of the first subframe of the frame to obtain a reduced or limited pitch gain value that is smaller than the initial pitch gain value of the first subframe;
- obtain an excitation of a next frame of the speech signal according to the reduced or limited pitch gain value of the first subframe, wherein the next frame of the speech signal is successive to the frame of the speech signal;
- and
- encode the next frame of the speech signal according to the excitation.
Dependencies are inferred from the claim text.