Adaptive voice playout in VOP

Abstract

Packetized CELP-encoded speech playout with frame truncation only during silence and frame expansion method dependent upon voicing classification with voiced frame expansion maintaining phase alignment.

What is claimed is  
     
         1 . A method for playout of packetized speech, comprising: 
 (a) deferring truncation of an active frame; and    (b) truncating a silence frame.    
     
     
         2 . The method of  claim 1 , wherein: 
 (a) said packetized speech includes CELP-encoded frames; and    (b) said truncating a silence frame includes truncating an excitation for said silence frame.    
     
     
         3 . The method of  claim 1 , further comprising: 
 (a) expanding an active frame according to a voicing classification for said active frame.    
     
     
         4 . A method of frame playout expansion, comprising: 
 (a) classifying a frame as voiced or not; and    (b) expanding a voiced frame by a multiple of the pitch of said voiced frame.    
     
     
         5 . The method of  claim 4 , wherein: 
 (a) said frames are CELP-encoded frames; and    (b) said expanding a voiced frame includes expanding an excitation for said voiced frame by a multiple of the pitch of said voiced frame.    
     
     
         6 . The method of  claim 4 , wherein: 
 (a) said classifying a frame of step (a) classifies an active frame as one of (i) voiced, (ii) unvoiced, or (iii) transition; and    (b) expanding an unvoiced frame includes expanding an excitation for said unvoiced frame with a random fixed-codebook vector.    
     
     
         7 . A receiver, comprising: 
 (a) an input for receiving CELP-encoded frames;    (b) a decoder coupled to said input; and    (c) a playout scheduler coupled to said input;    (d) said decoder operable to provide expansion of a voiced frame in response to said playout scheduler, wherein said expansion is a multiple of the pitch for said voiced frame.    
     
     
         8 . The receiver of  claim 7 , wherein: 
 (a) said decoder operable to provide truncation of a frame in response to said playout scheduler only when said frame is a silence frame.