METHOD AND DEVICE FOR CODING TRANSITION FRAMES IN SPEECH SIGNALS

摘要

There is provided a transition mode device and method for use in a predic tive-type sound signal codec for producing a transition mode excitation repl acing an adaptive codebook excitation in a transition frame and/or a frame f ollowing the transition in the sound signal, comprising an input for receivi ng a codebook index and a transition mode codebook for generating a set of c odevectors independent from past excitation. The transition mode codebook is responsive to the index for generating, in the transition frame and/or fram e following the transition, one of the codevectors of the set corresponding to the transition mode excitation. There is also provided an encoding device and method and a decoding device and method using the above described trans ition mode device and method.