view README @ 348:3da7ab45910d

libgsmefr: inline L_Comp() and L_Extract()
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 22 Apr 2024 00:05:01 +0000
parents 1b8cb3490d48
children 614ae8dc6807
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Themyscira Wireless GSM codec libraries & utilities package
===========================================================

Themyscira Wireless, a technical initiative of the Women's Republic of
Themyscira, is proud to present this package of GSM codec libraries and
associated command line test and development utilities.  The present package
provides two linkable C libraries, intended to be usable by any application
that needs GSM codec functionality:

libgsmefr	An implementation of EFR codec in the same spirit as classic
		libgsm, i.e., like libgsm, but for EFR instead of 06.10.  It is
		based on the reference code from ETSI.

libgsmfrp	An Rx DTX handler preprocessor to be invoked prior to
		gsm_decode() from classic libgsm, implementing GSM 06.11, 06.12
		and 06.31 functionality in the Rx direction.

These two libraries are intended primarily for use as part of GSM network
deployment, i.e., as part of the necessary speech transcoder implementation in
whichever network-side server process acts as the voice gateway to PSTN or
other networks.  However, they can also be used as part of development and
testing on the mobile side of GSM: for example, to decode TCH downlink bits and
voice memo recordings read out of FreeCalypso GSM MS devices, or to implement
your own lab-oriented GSM MS on top of some other PHY.

Each of these two Themyscira libraries (libgsmefr and libgsmfrp) is free-
standing and independent of the other.  libgsmfrp makes use of <gsm.h> header
file from libgsm (for gsm_byte and gsm_frame defined types) and requires this
header file in order to compile; libgsmefr has zero dependencies nominally but
will often be used together with libgsm and libgsmfrp.

Included command line utilities
===============================

In addition to the two main libraries, the present package includes a number of
command line utilities, falling into the following groups:

* Some utilities specifically exercise and test the two core libraries;

* Some utilities are not specifically for library testing but make use of
  our libraries;

* Some utilities are included because they implement some closely related and
  relevant debug and development functionality, even though they don't link
  with either libgsmefr or libgsmfrp.

Please see the included documentation in the doc subdirectory.