Echo Canceller Functions

The functions described in this section implement building blocks that can be used to create an acoustic and network echo cancellers compliant to the appropriate ITU-T Recommendations: G.168-2000, and G.167 (superseded by G.161, P.340).

• SubbandProcessGetSize
  Calculates size of the subband process state structure.
• SubbandProcessInit
  Initializes the subband process state structure.
• SubbandAnalysis
  Decomposes a frame into a complex subband representation.
• SubbandSynthesis
  Reconstructs frame from a complex subband representation.
• SubbandControllerGetSize_EC
  Calculates size of the subband controller state structure.
• SubbandControllerInit_EC
  Initializes the subband controller state structure.
• SubbandControllerUpdate_EC
  Updates controller state and returns the step sizes.
• SubbandController_EC
  Updates filter coefficients and returns output gain coefficients.
• SubbandControllerReset_EC
  Resets the subband controller state.
• SubbandControllerDTGetSize_EC
  Calculates the size of the subband DT controller state structure.
• SubbandControllerDTInit_EC
  Initializes the subband DT controller state structure.
• SubbandControllerDTReset_EC
  Resets the subband DT controller state.
• SubbandControllerDT_EC
  Updates filter coefficients and returns output gain coefficients.
• SubbandControllerDTUpdate_EC
  Updates the state of the DT controller and returns the step sizes.
• ToneDetectGetStateSize_EC
  Calculates size of the tone detector state structure.
• ToneDetectInit_EC
  Initializes the tone detector state structure.
• ToneDetect_EC
  Detects the signal of 2100 Hz frequency with every 450 ms phase reversal.
• FullbandControllerGetSize_EC
  Calculates size of the fullband controller state structure.
• FullbandControllerInit_EC
  Initializes the fullband controller state structure.
• FullbandControllerUpdate_EC
  Updates the fullband controller state and returns the step sizes.
• FullbandController_EC
  The main fullband controller function which updates filter coefficients and returns output gain coefficients.
• FullbandControllerReset_EC
  Resets fullband controller state.
• FIR_EC
  Computes FIR filter results.
• FIRSubband_EC, FIRSubbandLow_EC
  Computes the frequency-domain adaptive filter output
• FIRSubbandCoeffUpdate_EC, FIRSubbandLowCoeffUpdate_EC
  Updates the adaptive filter coefficients
• NLMS_EC
  Performs FIR filtering with coefficients update.

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