view INSTALL @ 242:f081a6850fb5

libgsmfrp: new refined implementation The previous implementation exhibited the following defects, which are now fixed: 1) The last received valid SID was cached forever for the purpose of handling future invalid SIDs - we could have received some valid SID ages ago, then lots of speech or NO_DATA, and if we then get an invalid SID, we would resurrect the last valid SID from ancient history - a bad design. In our new design, we handle invalid SID based on the current state, much like BFI. 2) GSM 06.11 spec says clearly that after the second lost SID (received BFI=1 && TAF=1 in CN state) we need to gradually decrease the output level, rather than jump directly to emitting silence frames - we previously failed to implement such logic. 3) Per GSM 06.12 section 5.2, Xmaxc should be the same in all 4 subframes in a SID frame. What should we do if we receive an otherwise valid SID frame with different Xmaxc? Our previous approach would replicate this Xmaxc oddity in every subsequent generated CN frame, which is rather bad. In our new design, the very first CN frame (which can be seen as a transformation of the SID frame itself) retains the original 4 distinct Xmaxc, but all subsequent CN frames are based on the Xmaxc from the last subframe of the most recent SID.
author Mychaela Falconia <falcon@freecalypso.org>
date Tue, 09 May 2023 05:16:31 +0000
parents 34f8549ff0b1
children 4b6fa53a8240
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Dependency graph
================

The complete Themyscira GSM codec libraries & utilities package as presented
here consists of two principal parts:

Division 1: libgsmefr and libgsmfrp, the two C code libraries intended to be
usable by other software;

Division 2: various command line utilities that were developed under the
umbrella of this project and are being released accordingly.

Division 2 components have a compile-time dependency on Division 1 (some of
these Division 2 command line utilities link with libgsmefr or libgsmfrp), but
not the other way around: neither libgsmefr nor libgsmfrp has any dependency on
any other part of this package.

However, the original GSM 06.10 library (libgsm) from 1990s is a required
dependency for several components of the present Themyscira package: libgsmfrp
and several Division 2 command line utilities have a compile-time dependency on
<gsm.h> header file provided by libgsm, and several Division 2 utilities also
have a link dependency on libgsm itself.  Therefore, libgsm should be considered
a hard dependency for the present GSM codec libraries & utilities package as a
whole, and it needs to be installed system-wide prior to compiling the present
software.

Compiling and installing Themyscira libraries and utilities
===========================================================

Running 'make' at the top level of the present gsm-codec-lib package will
compile both Division 1 and Division 2 software components (both libraries and
utilities), with the top level Makefile codifying the dependency graph among
them.  Installation, however, is a little more complicated in that there is no
single 'make install' target at the top level - instead of a single install
target, the top Makefile provides two separate installation targets:

make install-lib	Install libgsmefr and libgsmfrp system-wide:
			gsm_efr.h and gsm_fr_preproc.h are installed in
			/usr/local/include; libgsmefr.a and libgsmfrp.a are
			installed in /usr/local/lib.  Superuser privileges
			are usually required to write to these directories.

make install-utils	Install Division 2 command line utilities into
			/opt/freecalypso/bin directory, which is non-standard
			in the muggle world but has been established in our
			Themyscira community as the location for Themyscira-
			developed command line utilities working with GSM.

The just-described separation between install-lib and install-utils targets has
been created because of the difference in install paths: libraries and their
header files that need to be easily findable and usable by other people's
unrelated software need to be installed under /usr/local, requiring su to root
before each install cycle, whereas /opt/freecalypso/bin (writable without root
privileges on the Mother's development machine) is much more convenient for
Division 2 command line utilities.

However, the present gsm-codec-lib package differs from FreeCalypso host tools
and SIM tools packages in that in the present package, you ARE allowed to freely
change these installation directories to fit your own preferences.  FC host
tools and FC SIM tools packages carry very strong admonitions in their INSTALL
documents to the effect that they MUST be installed under /opt/freecalypso and
that this path cannot be changed; this strict imposition is made because of
strong intercomponent dependencies within those software suites, with different
components invoking each other or looking for their support files using hard-
coded absolute pathnames.  But the present gsm-codec-lib package is different:
you are free to move our Division 2 command line utilities from
/opt/freecalypso/bin to /usr/local/bin or anywhere else you like, and you are
likewise free to move our Division 1 libraries from /usr/local/{include,lib} to
whatever location would be most appropriate in your environment.

To change installation directories, you will need to edit subdirectory Makefiles
as follows:

Division 1:

	libgsmefr/Makefile
	libgsmfrp/Makefile

Division 2:

	amrconv/Makefile
	efrtest/Makefile
	frtest/Makefile
	miscutil/Makefile