hi Bala, i am thinking aloud here as i am not sure. speech-> STP -> LTP-> residual (near gaussian) LTP sometimes called pitch predictor. for pitch prediction, normally 2 things are determined for the pitch filter. the pitch gain and the pitch period. when i say LTP computes gain, i mean the gain for this filter which is the pitch gain. is that right? rgds, tk On Thu, 24 Feb 2005 06:57:54 -0800 (PST), V. Balakrishnan <> wrote: > > Please note that LTP is not used to compute the gain. > The short term predictor or STP removes short term > redundancies where as the LTP removes the long term > redundancies. You can say that the LTP is intended to > and tends to capture the redundancies of pitch > frequency which are longer term or roughly the > periodicity you observe in the envelope of the signal. > Regards > Bala > > --- Ilya Druker <> wrote: > > > > > > > Your question is not quite clear. Long-term > > predictor is actually an > > adaptive codebook. In analysis-by-synthesis scheme > > the search in the > > codebooks (adaptive and stochastic) gives both the > > codevector and the > > scaling factor (gain). I guess that by LTP you mean > > something like > > Harmonic Noise Filtering (in g723), but it is not > > LTP. > > > > Ilya Druker > > > > --- In , tunkeat > > <tunkeat@g...> wrote: > > > > > > hi all, > > > > > > i am puzzled about the use of long-time predictor > > in celp. > > > i see in some implementations, there is a > > long-time predictor (ltp) > > > but in others, eg fs-1016, there isn't. if I > > understand correctly, > > > the ltp is used to compute the gain. but why is > > there a need > > > to do this computation when eventually, in the > > codebook search, > > > the gain and period of the pitch is "computed". > > thanks in advance. > > > > > > rgds, > > > tk > > > > > > > > > > > > > > > > __________________________________ > > To |