man pages section 3: Multimedia Library Functions

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Updated: July 2014
 
 

mlib_VideoDCT8x8Quantize_S16_S16_B12_NA(3MLIB)

Name

mlib_VideoDCT8x8Quantize_S16_S16_B12_NA - forward Discrete Cosine Transform (DCT) and quantization

Synopsis

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

mlib_status mlib_VideoDCT8x8Quantize_S16_S16_B12_NA(
     mlib_s16 coeffs[64], const mlib_s16 block[64],
     const mlib_d64 dqtable[64]);

Description

The mlib_VideoDCT8x8Quantize_S16_S16_B12_NA() function computes the forward DCT and then quantizes the DCT coefficients. It's a combination of mlib_VideoDCT8x8_S16_S16_B12_NA() and mlib_VideoQuantize_S16() for better performance. The source to the DCT routine can occupy up to 12 bits for each of its elements, i.e., should be within the range of [-2048, 2047].

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:

coeffs

Pointer to the quantized DCT coefficients.

block

Pointer to an 8x8 block.

dqtable

Pointer to the quantization table generated by mlib_VideoQuantizeInit_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_VideoDCT8x8Quantize_S16_S16_B12(3MLIB), mlib_VideoDCT8x8Quantize_S16_U8(3MLIB), mlib_VideoDCT8x8Quantize_S16_U8_NA(3MLIB), mlib_VideoQuantizeInit_S16(3MLIB), attributes(5)