mlib_VideoIDCT8x8_S16_S16_B12_NA(3MLIB) mediaLib Library Functions mlib_VideoIDCT8x8_S16_S16_B12_NA(3MLIB)
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 repre-
sented 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 TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Committed |
+-----------------------------+-----------------------------+
|MT-Level |MT-Safe |
+-----------------------------+-----------------------------+
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)
SunOS 5.11 2 Mar 2007 mlib_VideoIDCT8x8_S16_S16_B12_NA(3MLIB)