Patent ID: 7873513

Claim:
A method of transcoding an Enhance Full Rate (EFR) 12.2 Kbps encoded frame into an Adaptive Multi-Rate (AMR) 12.2 Kbps encoded frame for use by a first gateway, the method comprising: receiving the EFR 12.2 Kbps encoded frame from a first codec; determining if the EFR 12.2 Kbps encoded frame is a Silence Insertion Descriptor (SID) frame; if the EFR 12.2 Kbps encoded frame is determined to be the SID frame, the method further comprising: calculating and quantizing an average log energy for the frame; updating gain predictor values for the frame; calculating index of quantized average Line Spectral Pair (LSP) by split three VQ and index of lowest prediction residual energy; and setting frame type to indicate an AMR SID frame.