synlpc.txt

简单lpc音码器与声激励lpc音码器比较

function synWave=synlpc(aCoeff,pitch,sr,G,fr,fs,preemp)
if(nargin<5),fr=20;end
if(nargin<6),fs=30;end
if(nargin<7),preemp=.9378;end
msfs=round(sr*fs/1000);
msfr=round(sr*fr/1000);
msoverlap=msfs-msfr;
ramp=[0:1/(msoverlap-1):1]';
[L1 nframe]=size(aCoeff);
for frameIndex=1:nframe
    A=aCoeff(:,frameIndex);
    if(pitch(frameIndex)~=0)
        t=0:1/sr:fs*10^(-3);
        d=0:1/pitch(frameIndex):1;
        residFrame=(pulstran(t,d,'tripuls',0.001))';
        residFrame=residFrame+0.001*randn(msfs+1,1);
    else
        residFrame=[];
        for m=1:msfs
            residFrame=[residFrame;randn];
        end
    end;
    synFrame=filter(G(frameIndex),A',residFrame);
    if(frameIndex==1)
        synWave=synFrame(1:msfr);
    else
        synWave=[synFrame;overlap+synFrame(1:msoverlap).*ramp;...
                synFrame(msoverlap+1:msfr)];
    end
    if(frameIndex==nframe)
        synWave=[synWave;synFrame(msfr+1:msfs)];
    else
        overlap=synFrame(msfr+1:msfs).*flipud(ramp);
    end
end;
synWave=filter(1,[1-preemp],synWave);