man pages section 3: Multimedia Library Functions

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Updated: July 2014
 
 

mlib_VideoIDCT8x8_U8_S16_DC(3MLIB)

Name

mlib_VideoIDCT8x8_U8_S16_DC - inverse Discrete Cosine Transform

Synopsis

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

mlib_status mlib_VideoIDCT8x8_U8_S16_DC(mlib_u8 *block,
     const mlib_s16 *coeffs, mlib_s32 stride);

Description

The mlib_VideoIDCT8x8_U8_S16_DC() function can be used only when F(0,0) is nonzero. It computes the inverse DCT (called IDCT) for the destination IDCT block of data type mlib_u8 and source DCT coefficients of data type mlib_s16. This function is not guaranteed to be IEEE-1180-compliant. The output of the IDCT routine is the difference between the current block and the reference block. The difference pixel 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.

Parameters

The function takes the following arguments:

block

Pointer to the current block. block must be 8-byte aligned.

coeffs

Pointer to the source DCT coefficients. coeffs must be 8-byte aligned.

stride

Stride, in bytes, between adjacent rows in a block. stride must be a multiple of eight..

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(3MLIB), mlib_VideoIDCT8x8_S16_S16_DC(3MLIB), mlib_VideoIDCT8x8_S16_S16_NA(3MLIB), mlib_VideoIDCT8x8_S16_S16_Q1(3MLIB), mlib_VideoIDCT8x8_U8_S16(3MLIB), mlib_VideoIDCT8x8_U8_S16_NA(3MLIB), mlib_VideoIDCT8x8_U8_S16_Q1(3MLIB), attributes(5)