Frequency and phase interpolation in sinusoidal model-based music and speech synthesis
AssigneeTexas Instruments Incorporated
InventorsXiaoshu Qian, Yinong Ding
Life of this patent
Estimating the term…
Abstract
A quadratic phase interpolation method for synthesis of musical tones incorporates both phase and frequency measurements at the boundaries of a data frame using a weighted least square algorithm approach. The approach assumes that the true frequency and phase at the two ends of a data frame conform to a quadratic phase model and that exact match between measured phase and frequency with the quadratic model is not necessary because of the noise in the measurements.
Claims7
A method for synthesizing music and/or speech sound signals using sinusoidal modeling, comprising the steps of:
- measuring frequency and phase values at frame boundries t=ti and t=ti+1 (0≦i≦N) for N data frames of interval length T of a sampled signal;
- modeling phase and frequency functions for the ith data frame using a quadratic phase model θi(τ)=ai+biτ+ciτ2, ωi(τ)=bi+2ciτ, where τ=t−tI;
- determining polynomial coefficients ai, bi, Ci assuming unwrapped phase and frequency are continuous at frame boundries, and determining unknowns by minimizing a square error function;
- and
- synthesizing said music and/or speech sound signals fron said model and coefficients.
A method for synthesizing music and speech sound signals using sinusoidal modeling, comprising the steps of:
- measuring frequency and phase values at frame boundries t=ti and t=ti+1 (0≦i<N) of N data frames of interval length T of a sampled signal;
- modeling phase and frequency functions for each ith data frame using a quadratic phase model θi(τ)=ai+biτ+ciτ2, ωi(τ)=bi+2ciτ, where τ=t−ti;
- determining polynomial coefficients ai, bi, Ci directly in terms of phase and frequency at frame boundries at frame boundries as follows:
- ai=(1/4)(θi+1+2θi+θi−1)−(T/8)(ωi+1−ωi−1),
- bi=(1/2T)(θi+1−θi−1)−(1/1/4)(ωi+1−2ωi+ωi−1),
- ci=(1/4T2)(θn+2−θi+1−θi+θi−1)−(1/8T)(−ωn+2+3ωi+1−3ωi+ωi−1);
- for n=1, . . . , N−1 (except CN−1);
- and
- a0=(1/4)(3θ0+θ1)−(T1/8)(ωi+1−ωi−1),
- b0=(1/2T)(θ1−θ0)+(1/4)(3ω0−ω1),
- c0=(1/4T2)(θ2−θ1)+(1/8T)(−ω2+3ω1−4ω0),
- cN−1=(1/4T2)(−θN−1+θN−2)+(1/8T)(4ωN−3ωN−1+ωN−2;
- and
- synthesizing said music and/or speech sound signals from said model and coefficients.
Dependencies are inferred from the claim text.