qccvectorintsubsample.3

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

.TH QCCVECTORINTSUBSAMPLE 3 "QCCPACK" ""
.SH NAME
QccVectorIntSubsample, QccVectorIntUpsample \- integer-vector down/up sampling
.SH SYNOPSIS
.B #include "libQccPack.h"
.sp
.BI "int QccVectorIntSubsample(const QccVectorInt " input_signal ", int " input_length ", QccVectorInt " output_signal ", int " output_length ", int " sampling_flag );
.br
.BI "int QccVectorIntUpsample(const QccVectorInt " input_signal ", int " input_length ", QccVectorInt " output_signal ", int " output_length ", int " sampling_flag );
.SH DESCRIPTION
.B QccVectorIntSubsample()
removes every other vector component from
.IR input_signal ,
returning the result in
.IR output_signal .
That is
.I input_signal
is downsampled, or subsampled, by a factor of 2.
If
.I sampling_flag
is
.BR QCCVECTORINT_EVEN ,
every odd-indexed vector component is discarded;
if
.I sampling_flag
is
.BR QCCVECTORINT_ODD ,
every even-indexed vector component is discarded.
The vector components are assumed to be
indexed such that the first component in the
vector is index 0 (and even index).
The subsampling operation is performed until either
.IR output_signal
is full, as determined from
.IR output_length ,
or until the end of 
.IR input_signal
is reached.
Note that it is not necessary for
.IR output_length
to be exactly half of
.IR input_length ;
for example, it is permissible for 
.IR input_length
to be odd.
.IR output_signal
is assumed to be allocated with length at least
.IR output_length .
.LP
.B QccVectorIntUpsample()
inserts zeros between every other vector component of
.IR input_signal ,
returning the result as
.IR output_signal ,
which is assumed to be allocated to length
.IR output_length
before the function call.
If 
.I sampling_flag 
is 
.BR QCCVECTORINT_EVEN ,
the odd-indexed vector components of
.I output_signal
are zeros; if
.I sampling_flag
is
.BR QCCVECTORINT_ODD ,
the even-indexed vector components of
.I output_signal
are zeros.
The upsampling operation is performed until either
.IR output_signal
is completely filled with samples or zeros,
or the end of
.IR input_signal
is reached.
Note that it is not necessary for
.IR output_length
to be exactly twice
.IR input_length .
.SH "SEE ALSO"
.BR QccVectorInt (3),
.BR QccPack (3)
.SH AUTHOR
Copyright (C) 1997-2009  James E. Fowler
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