Hi Hea,
Formulae like the ones you presented are finite difference approximations to the first and second derivative, and are exact for polynomials of some order but inexact for polynomials of higher order and for general non-polynomial functions. I would say that one formula is not really more "correct" than another, and it depends on the application which one will lead to a better model.
The specific window coefficients you proposed probably won't work very well for speech synthesis, though, since in your proposed scheme the even-indexed frames and the odd-indexed frames are independent, and so you're likely to get very discontinuous speech parameter trajectories.
Matt
On 11/11/13 00:53, Hea Young Park wrote:
Dear all.I have aquestion about acceleration coefficients.
I’m trying to build HTS with my custom voice using HTS-2.2 demo script.
According to HTS book equation (5.16),
The delta coefficients in time t-1, t, t+1 are computed as below.
본문 이미지 1본문 이미지 2
Just then, the acceleration coefficients are computed as below.
However, according to /data/script/windows.pl <http://windows.pl> and본문 이미지 3
/data/win/*.win3 included in HTS-2.2 demo,
the acceleration coefficients are computed as below.
So, If it’s correct thatI’m thinking,
/data/win/*.win3 file changed as below.
Current : 3 1.0 -2.0 1.0
New : 5 0.25 0.0 -0.5 0.0 0.25
I just wonder whether or not what I think is correct.
Please comment on my calculation mentioned above.