Content-type: text/html Man page of mlib_VideoIDCT8x8_S16_S16_B12_NA

mlib_VideoIDCT8x8_S16_S16_B12_NA

Section: mediaLib Library Functions (3MLIB)
Updated: 2 Mar 2007
Index Return to Main Contents
 

NAME

mlib_VideoIDCT8x8_S16_S16_B12_NA, mlib_VideoIDCT8x8_S16_S16_NA - inverse Discrete Cosine Transform  

SYNOPSIS

cc [ flag... ] file... -lmlib [ library... ]
#include <mlib.h>

mlib_status mlib_VideoIDCT8x8_S16_S16_B12_NA(
    mlib_s16 block[64], const mlib_s16 coeffs[64]);

mlib_status mlib_VideoIDCT8x8_S16_S16_NA(
    mlib_s16 block[64], const mlib_s16 coeffs[64]);

 

DESCRIPTION

The mlib_VideoIDCT8x8_S16_S16_B12_NA() function computes the inverse DCT (called IDCT) for the output IDCT block of data type mlib_s16 and input DCT coefficients of data type mlib_s16. This function is not guaranteed to be IEEE-1180-compliant. The output of the IDCT routine should be within the range of [-2048, 2047] if coeffs is obtained from the corresponding forward DCT function mlib_VideoDCT8x8_S16_S16_B12_NA().

This function requires no special address alignment.

This function can be used in JPEG with 12-bit precision.

For MPEG, the output, which is really the difference between the current block and the reference block, can occupy nine bits and is represented as a 16-bit datum. The output must be added to the motion-compensated reference block in order to reconstruct the current block.

Since mediaLib 2.5, mlib_VideoIDCT8x8_S16_S16_NA() has been renamed to mlib_VideoIDCT8x8_S16_S16_B12_NA(). Now mlib_VideoIDCT8x8_S16_S16_NA() is an alias of mlib_VideoIDCT8x8_S16_S16_B12_NA().  

PARAMETERS

The function takes the following arguments:

block

Pointer to an 8x8 block in the current frame or motion-compensated reference block. block need not be 8-byte aligned.

coeffs

Pointer to the source DCT coefficients. coeffs need not be 8-byte aligned.

 

RETURN VALUES

The function returns MLIB_SUCCESS if successful. Otherwise it returns MLIB_FAILURE.  

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPEATTRIBUTE VALUE

Interface StabilityCommitted

MT-Level

 

SEE ALSO

mlib_VideoIDCT_IEEE_S16_S16(3MLIB), mlib_VideoIDCT8x8_S16_S16_B12(3MLIB), mlib_VideoIDCT8x8_S16_S16_DC(3MLIB), mlib_VideoIDCT8x8_S16_S16_Q1(3MLIB), mlib_VideoIDCT8x8_S16_S16_Q1_Mismatch(3MLIB), mlib_VideoIDCT8x8_U8_S16(3MLIB), mlib_VideoIDCT8x8_U8_S16_DC(3MLIB), mlib_VideoIDCT8x8_U8_S16_NA(3MLIB), mlib_VideoIDCT8x8_U8_S16_Q1(3MLIB), attributes(5)


 

Index

NAME
SYNOPSIS
DESCRIPTION
PARAMETERS
RETURN VALUES
ATTRIBUTES
SEE ALSO

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Time: 02:37:58 GMT, October 02, 2010