Patent ID: 6584438
Filing Date: 2003-06-24
Classification: G10L

Abstract:
A method of compensating for a frame erasure in a variable rate speech coder, comprising:dequantizing a pitch lag value and a first delta value for a current frame processed after an erased frame is declared, the first delta value being equal to the difference between the pitch lag value for the current frame and a pitch lag value for a frame immediately preceding the current frame, the current frame encoded according to a first encoding mode; dequantizing at least one delta value for at least one frame prior to the current frame and after the frame erasure, wherein the at least one delta value is equal to the difference between a pitch lag value for the at least one frame and a pitch lag value for a frame immediately preceding the at least one frame, the at least one frame encoded according to a second encoding mode different from the first encoding mode; and subtracting each delta value from the pitch lag value for the current frame to generate a pitch lag value for the erased frame.