G722 Sub-Band ADPCM Speech Codec Functions

The Intel IPP functions described later in this section if properly combined may be used to construct the G.722 speech codec compliant to the reference implementation given by ITU-T library (Rec.192, Clause 7: The ITU-T 64, 56 and 48 kbps wide-band speech coding algorithm). The description of G.722 speech codec also known as Sub-Band ADPCM compression may be found in ITU-T G.722 Recommendation: 7KHz coding within 64 kbps.

The Intel IPP functions described below are primarily concerned with the well-defined, computationally expensive core operations that comprise the G.722 subband codec.

The list of Intel IPP Subband ADPCM functions is given in the table below.

Intel IPP Subband ADPCM Functions
Function Base Name	Operation
SBADPCMEncodeStateSize_G722	Calculates the memory size required for G.722 Sub-Band ADPCM encoder.
SBADPCMEncodeInit_G722	Initializes the memory buffer for the Sub-Band ADPCM encoder.
SBADPCMEncode_G722	Performs Sub-Band ADPCM encoding of the synthesis QMF samples.
QMFEncode_G722	Performs QMF analysis of the uniform PCM input.
SBADPCMDecodeStateSize_G722	Calculates the memory size required for Sub-Band ADPCM decoder.
SBADPCMDecodeInit_G722	Initializes the memory buffer for the Sub-Band ADPCM decoder.
SBADPCMDecode_G722	Performs decoding of the Sub-Band ADPCM compressed bit-stream.
QMFDecode_G722	Performs QMF synthesis of recovered samples.