Current File : //usr/man/man3mlib/mlib_VideoDeQuantizeIDCT8x8_S16_S16_B12.3mlib

'\" te
.\" Copyright (c) 2007, Sun Microsystems, Inc.  All Rights Reserved 
.TH mlib_VideoDeQuantizeIDCT8x8_S16_S16_B12 3MLIB "2 Mar 2007" "SunOS 5.11" "mediaLib Library Functions"
.SH NAME
mlib_VideoDeQuantizeIDCT8x8_S16_S16_B12 \- dequantization and inverse Discrete Cosine Transform (IDCT)
.SH SYNOPSIS
.LP
.nf
cc [ \fIflag\fR... ] \fIfile\fR... \fB-lmlib\fR [ \fIlibrary\fR... ]
#include <mlib.h>

\fBmlib_status\fR \fBmlib_VideoDeQuantizeIDCT8x8_S16_S16_B12\fR(
     \fBmlib_s16\fR \fIblock[64]\fR, \fBconst mlib_s16\fR \fIcoeffs[64]\fR,
     \fBconst mlib_d64\fR \fIdqtable[64]\fR);
.fi

.SH DESCRIPTION
.sp
.LP
The \fBmlib_VideoDeQuantizeIDCT8x8_S16_S16_B12()\fR function dequantizes the quantized DCT coefficients and then computes the inverse DCT. It's a combination of \fBmlib_VideoDeQuantize_S16()\fR and \fBmlib_VideoIDCT8x8_S16_S16_B12()\fR for better performance. The output of this function should be within the range of [-2048, 2047] if \fBcoeffs\fR is obtained from the corresponding \fBmlib_VideoDCT8x8Quantize_S16_S16_B12()\fR function.
.sp
.LP
The source and destination buffer addresses must be 8-byte aligned.
.sp
.LP
This function can be used in JPEG with 12-bit precision, or in MPEG for the inter mode.
.SH PARAMETERS
.sp
.LP
The function takes the following arguments:
.sp
.ne 2
.mk
.na
\fB\fIblock\fR\fR
.ad
.RS 11n
.rt  
Pointer to an 8x8 block. Note that \fBblock\fR must be 8-byte aligned.
.RE

.sp
.ne 2
.mk
.na
\fB\fIcoeffs\fR\fR
.ad
.RS 11n
.rt  
Pointer to the input quantized DCT coefficients. Note that \fBcoeffs\fR must be 8-byte aligned.
.RE

.sp
.ne 2
.mk
.na
\fB\fIdqtable\fR\fR
.ad
.RS 11n
.rt  
Pointer to the dequantization table generated by \fBmlib_VideoDeQuantizeInit_S16()\fR.
.RE

.SH RETURN VALUES
.sp
.LP
The function returns \fBMLIB_SUCCESS\fR if successful. Otherwise it returns \fBMLIB_FAILURE\fR.
.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp

.sp
.TS
tab() box;
cw(2.75i) |cw(2.75i) 
lw(2.75i) |lw(2.75i) 
.
ATTRIBUTE TYPEATTRIBUTE VALUE
_
Interface StabilityCommitted
_
MT-LevelMT-Safe
.TE

.SH SEE ALSO
.sp
.LP
\fBmlib_VideoDeQuantizeIDCT8x8_S16_S16_B12_NA\fR(3MLIB), \fBmlib_VideoDeQuantizeIDCT8x8_U8_S16\fR(3MLIB), \fBmlib_VideoDeQuantizeIDCT8x8_U8_S16_NA\fR(3MLIB), \fBmlib_VideoDeQuantizeInit_S16\fR(3MLIB), \fBattributes\fR(5)