G.729 Functions

The Intel IPP functions described in this section implement building blocks that can be used to create speech codecs compliant with the ITU-T Recommendation G.729 (see [ITU729], [ITU729A], [ITU729B]).

These functions are used in the Intel^® IPP G.729 Speech Encoder-Decoder sample downloadable from http://www.intel.com/cd/software/products/asmo-na/eng/220046.htm.

The list of these functions is given in the table below.

Intel IPP G.729 Functions
Function Base Name	Operation
Basic Functions
DotProd_G729	Computes the dot product of two vectors.
Interpolate_G729	Computes the weighted sum of two vectors.
Linear Prediction Analysis Functions
AutoCorr_G729	Estimates the autocorrelation of a vector.
LevinsonDurbin_G729	Calculates LP coefficients from the autocorrelation coefficients.
LPCToLSP_G729	Converts LP coefficients to LSP coefficients.
LSFToLSP_G729	Converts Line Spectral Frequencies to LSP coefficients.
LSFQuant_G729	Performs quantization of LSF coefficients.
LSFDecode_G729	Decodes quantized LSFs.
LSFDecodeErased_G729	Reconstructs quantized LSFs in case when a frame is erased.
LSPToLPC_G729	Converts LSP coefficients to LP coefficients.
LSPQuant_G729	Quantizes the LSP coefficients.
LSPToLSF_G729	Converts LSP coefficients to LSF coefficients.
LagWindow_G729	Applies 60Hz bandwidth expansion.
Codebook Search Functions
OpenLoopPitchSearch_G729	Searches for an optimal pitch value.
AdaptiveCodebookSearch_G729	Searches for the integer delay and the fraction delay, and computes the adaptive vector.
DecodeAdaptiveVector_G729	Restores the adaptive codebook vector by interpolating the past excitation.
FixedCodebookSearch_G729	Searches for the fixed codebook vector.
GainCodebookSearch_G729	Finds pitch and fixed gains.
ToeplizMatrix_G729	Calculates 616 elements of the Toepliz matrix for the fixed codebook search.
Codebook Gain Functions
DecodeGain_G729	Decodes the adaptive and fixed-codebook gains.
GainControl_G729	Calculates adaptive gain control.
GainQuant_G729	Quantizes the codebook gain using a two-stage conjugate-structured codebook.
AdaptiveCodebookContribution_G729	Updates target vector for codebook search by subtracting adaptive codebook contribution.
AdaptiveCodebookGain_G729	Calculates the gain of the adaptive-codeblock vector and the filtered codebook vector.
Filter Functions
ResidualFilter_G729	Implements an inverse LP filter and obtains the residual signal.
SynthesisFilter_G729	Reconstructs the speech signal from LP coefficients and residuals.
LongTermPostFilter_G729	Restores the long-term information from the old speech signal.
ShortTermPostFilter_G729	Restores speech signal from the residuals.
TiltCompensation_G729	Compensates for the tilt in the short-term filter.
HarmonicFilter	Calculates the harmonic filter.
HighPassFilterSize_G729	calculates the G729 high-pass filter size.
HighPassFilterInit_G729	Initializes the high-pass filter.
HighPassFilter_G729	Performs G729 high-pass filtering.
IIR16s_G729	Performs IIR filtering.
PhaseDispersionGetStateSize_G729D	Queries the memory length of the phase dispersion filter.
PhaseDispersionInit_G729D	Initializes the phase dispersion filter memory.
PhaseDispersionUpdate_G729D	Updates the phase dispersion filter state.
PhaseDispersion_G729D	Performs the phase dispersion filtering.
Preemphasize_G729A	Computes pre-emphasis of a post filter.
WinHybridGetStateSize_G729E	Queries the length of the hybrid windowing module memory.
WinHybridInit_G729E	Initializes the hybrid windowing module memory.
WinHybrid_G729E	Applies the hybrid window and computes autocorrelation coefficients.
RandomNoiseExcitation_G729B	Initializes a random vector with a Gaussian distribution.
FilteredExcitation_G729	Computes filtered exitation.