Discontinuous Transmission (DTX)

This section describes primitives that are concerned with discontinuous transmission (DTX), including primitives that perform the following functions:

• Signal pre-emphasis prior to VAD option 2
• VAD Decision Function for Option 1
• VAD Decision Function for Option 2
• Parameter Extraction for the SID frame
• DTX Handler
• DTX Buffering

Each of these primitives is described next.

• Preemphasize_GSMAMR
  Computes pre-emphasis of an input signal in VAD option 2.
• VAD1_GSMAMR
  Implements the VAD functionality corresponding to VAD option 1.
• VAD2_GSMAMR
  Implements the VAD functionality corresponding to VAD option 2.
• EncDTXSID_GSMAMR
  Extracts parameters for the SID frame.
• EncDTXHandler_GSMAMR
  Determines the SID flag of current frame.
• EncDTXBuffer_GSMAMR, DecDTXBuffer_GSMAMR
  Buffer the LSP (or LSF) coefficients and previous log energy coefficients.

Copyright © 2000 - 2011, Intel Corporation. All rights reserved.