% Juergen Kosel <Juergen.Kosel@gmx.de>
% $Id: compression_settings,v 1.2 2005/03/13 17:27:40 gert Exp $
%
% This file should become part of vgetty.info someday ...
% Otherwise SUSE/Red-Hat binary users wouldn't have any vgetty manual
%
rec_compression

For the V253modem (ITU V 253 compatible modems) the followings voice-
compressions are defined for vgetty/vm:

0,1,8:	8 bit unsigned PCM / 8 bit linear
	This format means no compression. Therefore it doesn't matter
	with what DSP the voice-file was recorded. It can be played
	with every other. This format is also the default one of the
	soundblaster.

	This compression is mapped to: "AT+VSM=1,<rec_speed>"
	% Many modems have the voice-format mapped to "AT+VSM=128"
	% Can mvm benefit of this common format ?

	% VSM settings above 127 are manufacturer specific!

2:	2 bit adpcm with rec_speed 7200 for some ELSA-modems
	Mapped to: "AT+VSM=129,7200" and/or to: "AT+VSM=140,7200"

4:	4 bit adpcm with rec_speed 7200 for some ELSA-modems
	Mapped to: "AT+VSM=131,7200" and/or "AT+VSM=141,7200"

5:	4 bit IMA ADPCM with rec_speed 8000 for some other ELSA
	modems (ML 56k FUN, ML 56k Internet II).
	Mapped to: "AT+VSM=129,8000"

6:	8 bit \mu Law with rec_speed 8000 for the "ML 56k Fun"
	Mapped to: "AT+VSM=131,8000"

7:	8 bit ALaw with rec_speed 8000 for the "ML 56k Fun" and the
	"ML 56k Internet II"
	Mapped to: "AT+VSM=132,8000"

9:	8 bit signed PCM
	Mapped to "AT+VSM=0,<rec_speed>"

10:	\mu Law.
	Mapped to "AT+VSM=4,<rec_speed>"

11:	ALaw
	Mapped to "AT+VSM=5,<rec_speed>"

12:	16 bit signed PCM
	Mapped to "AT+VSM=0,<rec_speed>"

13:	16 bit unsigned PCM
	Mapped to "AT+VSM=1,<rec_speed>"
