[Stk] Pitch Shifting and Sample Rate Conversion

[Ravi Kiran]

Dear All,
       I am working on MIDI software synthesizer based on wavetable
synthesis. Right now, I am studying the techniques for pitch shifting
to simulate vibrato effects. But I am unable to find the appropriate
material for that. Specifically I would like to know whether there are
any specialised algorithms for the case when the pitch changes
continuously from sample to sample. I would also like to implement the
sample rate conversion (if the wavetable sampling frequency and my
output frequency do not match) together with pitch shifting. I am
considering algorithms which do not preserve the time duration of the
playback (i.e., if the pitch is increased by an octave the play back
time reduces by half). Is it practically possible to do pitch shifting
while conserving the playback time?
       STK implements pitch shifting based on delay lines. Is this
method applicable to my problem? If not, how does STK implement
vibrato effects? Thanks a lot!!!

Regards
Ravi Kiran