mlib_VideoIDCT8x8_S16_S16_mediaLibBLibrarymlib_VideoIDCT8x8_S16_S16_B12(3MLIB)NAME
mlib_VideoIDCT8x8_S16_S16_B12, mlib_VideoIDCT8x8_S16_S16 - inverse Dis‐
crete Cosine Transform
SYNOPSIS
cc [ flag... ] file... -lmlib [ library... ]
#include <mlib.h>
mlib_status mlib_VideoIDCT8x8_S16_S16_B12(
mlib_s16 block[64], const mlib_s16 coeffs[64]);
mlib_status mlib_VideoIDCT8x8_S16_S16(
mlib_s16 block[64], const mlib_s16 coeffs[64]);
DESCRIPTION
The mlib_VideoIDCT8x8_S16_S16_B12() 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 corre‐
sponding forward DCT function mlib_VideoDCT8x8_S16_S16_B12().
The source and destination buffer addresses must be 8-byte aligned.
This function can be used in JPEG with 12-bit precision.
For MPEG, the output, which is really the difference between the cur‐
rent block and the reference block, can occupy nine bits and is repre‐
sented as a 16-bit datum. The output must be added to the motion-com‐
pensated reference block in order to reconstruct the current block.
Since mediaLib 2.5, mlib_VideoIDCT8x8_S16_S16() has been renamed to
mlib_VideoIDCT8x8_S16_S16_B12(). Now mlib_VideoIDCT8x8_S16_S16() is an
alias of mlib_VideoIDCT8x8_S16_S16_B12().
PARAMETERS
The function takes the following arguments:
block Pointer to an 8x8 block in the current frame or motion-com‐
pensated reference block. block must be 8-byte aligned.
coeffs Pointer to the source DCT coefficients. coeffs must 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 TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │Committed │
├─────────────────────────────┼─────────────────────────────┤
│MT-Level │MT-Safe │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOmlib_VideoIDCT_IEEE_S16_S16(3MLIB),
mlib_VideoIDCT8x8_S16_S16_B12_NA(3MLIB),
mlib_VideoIDCT8x8_S16_S16_DC(3MLIB),
mlib_VideoIDCT8x8_S16_S16_Q1(3MLIB), mlib_VideoIDCT8x8_S16_S16_Q1_Mis‐
match(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)SunOS 5.10 2 Mar 20mlib_VideoIDCT8x8_S16_S16_B12(3MLIB)
