You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
157 lines
3.8 KiB
157 lines
3.8 KiB
.\"
|
|
.\" Copyright 1992 by Jutta Degener and Carsten Bormann, Technische
|
|
.\" Universitaet Berlin. See the accompanying file "COPYRIGHT" for
|
|
.\" details. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE.
|
|
.\"
|
|
.if n .ds mU u
|
|
.if t .ds mU \(*m
|
|
.\"
|
|
.TH TOAST 1 local
|
|
.SH NAME
|
|
toast \(em GSM\ 06.10 lossy sound compression
|
|
.SH SYNOPSIS
|
|
.ll +8
|
|
.B toast
|
|
[
|
|
.B \-cdfpvhualsFC
|
|
] [
|
|
.I "filename...\&"
|
|
]
|
|
.LP
|
|
.B untoast
|
|
[
|
|
.B \-cfpvhuaslF
|
|
] [
|
|
.I "filename...\&"
|
|
]
|
|
.LP
|
|
.B tcat
|
|
[
|
|
.B \-vhuaslF
|
|
] [
|
|
.I "filename...\&"
|
|
]
|
|
.ll -8
|
|
.SH DESCRIPTION
|
|
Toast compresses the sound files given on its command line.
|
|
Each file is replaced by a file with the extension
|
|
.I \&.gsm .
|
|
If no files are specified, the compression is applied to the
|
|
standard input, and its result is written to standard output.
|
|
.PP
|
|
Toasted files can be restored to something not quite unlike
|
|
their original form by running toast
|
|
.I "\-d"
|
|
, or
|
|
.I untoast
|
|
, on the \&.gsm-files or standard input.
|
|
.PP
|
|
The program
|
|
.I tcat
|
|
(the same as running
|
|
.I "untoast \-c"
|
|
) uncompresses its input on standard output,
|
|
but leaves the compressed .gsm\-files alone.
|
|
.PP
|
|
When files are compressed or uncompressed into other files,
|
|
the ownership (if run by root), modes, accessed and modified times
|
|
are maintained between both versions.
|
|
.SH OPTIONS
|
|
.TP
|
|
.B \-c
|
|
(cat)
|
|
Write to the standard output; no files are changed.
|
|
.TP
|
|
.B \-d
|
|
(decode)
|
|
Decode, rather than encode, the files.
|
|
.TP
|
|
.B \-f
|
|
(force)
|
|
Force replacement of output files if they exist.
|
|
If \-f is omitted and toast (or untoast) is run interactively from
|
|
a terminal, the user is prompted as to whether the file should be replaced.
|
|
.TP
|
|
.B \-p
|
|
(precious)
|
|
Do not delete the source files.
|
|
Source files are implicitly left alone whenever \-c is
|
|
specified or tcat is run.
|
|
.TP
|
|
.B \-C
|
|
(LTP cut-off)
|
|
Ignore most sample values when calculating the GSM long-term
|
|
correlation lag during encoding.
|
|
(The multiplications that do this are a bottleneck
|
|
of the algorithm.)
|
|
The resulting encoding process will not produce
|
|
exactly the same results as GSM 06.10 would,
|
|
but remains close enough to be compatible.
|
|
.br
|
|
The
|
|
.B \-C
|
|
option applies only to the encoder and is silently
|
|
ignored by the decoder.
|
|
.TP
|
|
.B \-F
|
|
(fast)
|
|
On systems with a floating point processor, but without
|
|
a multiplication instruction, \-F sacrifices standard conformance to
|
|
performance and nearly doubles the speed of the algorithm.
|
|
.br
|
|
The resulting encoding and decoding process will not produce
|
|
exactly the same results as GSM 06.10 would, but remains close
|
|
enough to be compatible.
|
|
.br
|
|
The default is standard-conforming operation.
|
|
.TP
|
|
.B \-v
|
|
(version)\
|
|
outputs the version of toast (or untoast or tcat) to stdout and exits.
|
|
.TP
|
|
.B \-h
|
|
(help)\
|
|
prints a short overview of the options.
|
|
.PP
|
|
Toast, untoast and tcat try to guess the appropriate audio data
|
|
format from the file suffix.
|
|
Command line options can also specify a format to be used for
|
|
all files.
|
|
.br
|
|
The following formats are supported:
|
|
.TP
|
|
.B "\-u"
|
|
(\(*mU-law)
|
|
8 kHz, 8 bit \(*mU-law encoding (file suffix .u)
|
|
.TP
|
|
.B "\-a"
|
|
(A-law)
|
|
8 kHz, 8 bit A-law encoding (file suffix .A)
|
|
.TP
|
|
.B "\-s"
|
|
(Sun audio)
|
|
8 kHz, 8 bit \(*mU-law encoding with audio header (file suffix .au)
|
|
.TP
|
|
.B "-l"
|
|
(linear)
|
|
8 kHz, 16 bit signed linear encoding in host byte order
|
|
with 13 significant bits (file suffix .l)
|
|
.PP
|
|
In absence of options or suffixes to specify a format,
|
|
\(*mU-law encoding as forced by \-u is assumed.
|
|
.PP
|
|
.SH PECULIARITIES
|
|
A four bit magic number is prefixed to each 32 1/2-byte GSM frame,
|
|
mainly because 32 1/2-bytes are rather clumsy to handle.
|
|
.SH WARNING
|
|
The compression algorithm used is a lossy compression algorithm
|
|
devised especially for speech; on no account should it be used
|
|
for text, pictures or any other non-speech-data you consider
|
|
valuable.
|
|
.SH BUGS
|
|
Please direct bug reports to jutta@pobox.com and cabo@tzi.org.
|
|
.SH "SEE ALSO"
|
|
gsm(3)
|
|
.\"
|
|
.\" Toast is dedicated to Bill Sienkiewicz, author of "Stray Toasters".
|