mlib_VideoDeQuantizeIDCT8x8_S16_S16_B12_NA(3MLIB)

Name

mlib_VideoDeQuantizeIDCT8x8_S16_S16_B12_NA - dequantization and inverse Discrete Cosine Transform (IDCT)

Synopsis

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

mlib_status mlib_VideoDeQuantizeIDCT8x8_S16_S16_B12_NA(
     mlib_s16 block[64], const mlib_s16 coeffs[64],
     const mlib_d64 dqtable[64]);

Description

The mlib_VideoDeQuantizeIDCT8x8_S16_S16_B12_NA() function dequantizes the quantized DCT coefficients and then computes the inverse DCT. It's a combination of mlib_VideoDeQuantize_S16() and mlib_VideoIDCT8x8_S16_S16_B12_NA() for better performance. The output of this function should be within the range of [-2048, 2047] if coeffs is obtained from the corresponding mlib_VideoDCT8x8Quantize_S16_S16_B12_NA() function.

This function requires no special address alignment.

This function can be used in JPEG with 12-bit precision, or in MPEG for the inter mode.

Parameters

The function takes the following arguments:

block

Pointer to an 8x8 block.

coeffs

Pointer to the input quantized DCT coefficients.

dqtable

Pointer to the dequantization table generated by mlib_VideoDeQuantizeInit_S16().

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_VideoDeQuantizeIDCT8x8_S16_S16_B12(3MLIB), mlib_VideoDeQuantizeIDCT8x8_U8_S16(3MLIB), mlib_VideoDeQuantizeIDCT8x8_U8_S16_NA(3MLIB), mlib_VideoDeQuantizeInit_S16(3MLIB), attributes(5)