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- TOAST(1) User Commands TOAST(1)
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- NAME
- toast - GSM 06.10 lossy sound compression
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- SYNOPSIS
- toast [ -cdfpvhualsFC ] [ filename... ]
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- untoast [ -cfpvhuaslF ] [ filename... ]
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- tcat [ -vhuaslF ] [ filename... ]
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- DESCRIPTION
- Toast compresses the sound files given on its command line.
- Each file is replaced by a file with the extension .gsm . If
- no files are specified, the compression is applied to the
- standard input, and its result is written to standard out-
- put.
-
- Toasted files can be restored to something not quite unlike
- their original form by running toast -d , or untoast , on
- the .gsm-files or standard input.
-
- The program tcat (the same as running untoast - c )
- uncompresses its input on standard output, but leaves the
- compressed .gsm-files alone.
-
- 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.
-
- OPTIONS
- -c (cat) Write to the standard output; no files are
- changed.
-
- -d (decode) Decode, rather than encode, the files.
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- -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.
-
- -p (precious) Do not delete the source files. Source
- files are implicitly left alone whenever -c is speci-
- fied or tcat is run.
-
- -C (LTP cut-off) Ignore most sample values when calculat-
- ing 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.
- The -C option applies only to the encoder and is
- silently ignored by the decoder.
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- SunOS 5.4 Last change: local 1
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- TOAST(1) User Commands TOAST(1)
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-
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- -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.
- 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.
- The default is standard-conforming operation.
-
- -v (version) outputs the version of toast (or untoast or
- tcat) to stdout and exits.
-
- -h (help) prints a short overview of the options.
-
- 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.
- The following formats are supported:
-
- -u (,U-law) 8 kHz, 8 bit ,U-law encoding (file suffix .u)
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- -a (A-law) 8 kHz, 8 bit A-law encoding (file suffix .A)
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- -s (Sun audio) 8 kHz, 8 bit ,U-law encoding with audio
- header (file suffix .au)
-
- -l (linear) 8 kHz, 16 bit signed linear encoding in host
- byte order with 13 significant bits (file suffix .l)
-
- In absence of options or suffixes to specify a format, ,
- U-law encoding as forced by -u is assumed.
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- 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 han-
- dle.
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- WARNING
- The compression algorithm used is a lossy compression algo-
- rithm devised especially for speech; on no account should it
- be used for text, pictures or any other non-speech-data you
- consider valuable.
-
- BUGS
- Please direct bug reports to jutta@cs.tu-berlin.de.
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- SEE ALSO
- gsm(3)
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- SunOS 5.4 Last change: local 2
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