chnarithmeticencode.1

spiht for linux this is used to decod and encode vedio i wich all enjoy

.TH CHNARITHMETICENCODE 1 "QCCPACK" ""
.SH NAME
chnarithmeticencode \- adaptive arithmetic encoding of a channel
.SH SYNOPSIS
.B chnarithmeticencode
.RB "[\|" \-s "\|]"
.RB "[\|" \-vo "\|]"
.RB "[\|" \-d 
.IR vector\_dimension "\|]"
.RB "[\|" \-o
.IR  order "\|]"
.I channelfile
.I outfile
.SH OPTIONS
.TP
.B \-s
Silent mode (no printed output).
.TP
.B \-vo
Print only the value of the rate to stdout (terse output).
.TP
.BI \-d " vector\_dimension"
Print rate in terms of bits per vector component rather than
bits per channel symbol.
.TP
.BI \-o " order"
Integer. Order of adaptive model. Possible value = 1 or 2; default = 1.
.SH DESCRIPTION
.LP
.B chnarithmeticencode
implements adaptive arithmetic coding of the channel sequence,
.IR channelfile 
(CHN format).
.B chnarithmeticencode
is based on the well known and frequently used
implementation of arithmetic coding popularized by Witten 
.IR "et al" .
.B chnarithmeticencode
includes their first-order adaptive model; additionally, it can use
a second-order model for more complex modeling of data sources.
.LP
The
.B \-o
option specifies the order of the adaptive model.
If
.I order
is 1, 
.B chnarithmeticencode
simply replicates the operation of
the coder and adaptive model described by Witten 
.IR "et al" .
If 
.I order
is 2,
the previous symbol in the channel
serves as a context for the coding of the current symbol.
This higher order model should provide greater coding efficiency
(i.e., more compression) if the data source 
.RI ( channelfile )
possesses some degree of memory rather than being the memoryless
source assumed by the first-order model.
.LP
.B chnarithmeticencode
initially outputs a few bytes of header information
(original number of symbols in 
.IR channelfile ,
symbol alphabet size, and
arithmetic-coding order) to
.IR outfile .
The byte-packed bitstream produced by the arithmetic coding follows.
As in the implementation by Witten
.IR "et al" .,
a special EOF symbol is output at the end of the bitstream to allow
the decode,
.BR chnarithmeticdecode (1),
to detect the stopping point.
.LP
Normally,
.B chnarithemticencode
prints to 
.B stdout 
the rate achieved by the arithmetic coding, expressed in terms
of bits per channel symbol.  This output may be suppressed by the
.B \-s
option (silent mode).
The
.B \-vo
option indicates that only the value of the rate is to be
printed (terse output).  The
.B \-s
option overrides the
.B \-vo
option.
If option 
.B \-d 
is given, the rate is printed as bits per vector component (i.e.,
it is the bit rate of the arithmetic coding
divided by 
.IR vector\_dimension ).  
For example, the
.B \-d 
option gives a convenient way to calculate the bit rate, in bits per
original source symbol, when the channel corresponds to indices output
from a vector quantizer (see 
.BR vqencode (1)).
Note: the specification of the
.B \-d
option in no way affects the operation of the arithmetic encoder; it affects
only the printed output of the rate.
.SH "NOTES"
.B chnarithmeticencode
removes all null channel symbols from the channel with a call to
.BR QccChannelRemoveNullSymbols (3)
prior to arithmetic coding.
.SH "SEE ALSO"
.BR chnarithmeticdecode (1),
.BR chnentropy (1),
.BR vqencode (1),
.BR QccPackENT (3),
.BR QccPack (3)

I. A. Witten, R. M. Neal, and J. G. Cleary,
"Arithmetic Coding For Data Compression,"
.IR "Communications of the ACM" ,
vol. 30, no. 6, pp. 520-540, June 1987.

T. M. Cover and J. T. Thomas, 
.IR "Elements of Information Theory" .
New York: John Wiley & Sons, Inc., 1991.

.SH AUTHOR
Copyright (C) 1997-2009  James E. Fowler
.\"  The programs herein are free software; you can redistribute them and/or
.\"  modify them under the terms of the GNU General Public License
.\"  as published by the Free Software Foundation; either version 2
.\"  of the License, or (at your option) any later version.
.\"  
.\"  These programs are distributed in the hope that they will be useful,
.\"  but WITHOUT ANY WARRANTY; without even the implied warranty of
.\"  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
.\"  GNU General Public License for more details.
.\"  
.\"  You should have received a copy of the GNU General Public License
.\"  along with these programs; if not, write to the Free Software
.\"  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.