Speech Coding Functions

This chapter describes the Intel^® IPP functions that can be used for implementing speech codecs which follow ITU-T recommendations for G711 (companding functions), G.722, G.722.1, G.723.1, G726, G.728, G.729.1 and G.729 codecs, the G.167, G.168 for Echo Canceller, G.169 for Audio Level control, ETSI specifications for GSM-AMR and GSM-FR codecs, as well as 3GPP specification for AMRWB and AMRWB+ codecs, and Microsoft* Real-Time Audio codec.

When properly built, such speech codecs and other components can be compliant with the bit-exact and other specifications for published test vectors.

The chapter also includes the functions that solely or in combination with other functions can be used for speech/voice quality enhancement, for example, in acoustic or network echo control, background noise artifacts removal, automatic audio level control. In tandem with the speech codec they can increase quality and save bandwidth of voice communication.

The organization of this chapter is the following. The introductory part includes description of rounding modes, defines notational conventions, header files and data structures used by the Intel IPP speech coding functions. This is succeeded by the major functionality sections, which include:

Each section starts with the table that gives the full list of Intel IPP functions specific for that functional group, followed by detailed description of the respective API.

The use of the Intel IPP speech coding functions is demonstrated in Intel IPP Samples. See Intel IPP Speech Coding Samples downloadable from http://www.intel.com/cd/software/products/asmo-na/eng/220046.htm.