QuantInterUniform_VC1, QuantInterNonuniform

Perform uniform/nonuniform quantization of inter blocks.

Syntax

IppStatus ippiQuantInterUniform_VC1_16s_C1IR( Ipp16s* pSrcDst, Ipp32s srcDstStep, Ipp32s doubleQuant, IppiSize roiSize );

IppStatus ippiQuantInterNonuniform_VC1_16s_C1IR( Ipp16s* pSrcDst, Ipp32s srcDstStep, Ipp32s doubleQuant, IppiSize roiSize );

Parameters

pSrcDst	Pointer to the source and destination block.
srcDstStep	Distance in bytes between starts of the consecutive lines in the source and destination blocks.
doubleQuant	Quant coefficient; should be an even number within the range [2, 62].
roiSize	Inter block size; should be 8x8, 8x4, 4x8 or 4x4.

Description

The functions ippiQuantInterUniform_VC1_16s_C1IR and ippiQuantInterNonuniform_VC1_16s_C1IR are declared in the ippvc.h file. The functions perform quantization of inter blocks according to 8.1.2.8 of [SMPTE421M] .

In the case of uniform quantization:

a[i]=a[i]/quant_coef;

In the case of nonuniform quantization:

a[i]=(a[i]-sign(a[i])*(quant_coef >> 1))/quant_coef;

where a[i] is the coefficient of the inter block, and quant_coef is the quant coefficient.

The doubleQuant parameter should be equal to 2*MQUANT+HALFQP, where MQUANT and HALFQP are defined in the VC-1 standard. MQUANT should be within the range [1;31], HALFQP should be within the range [0,1] if MQUANT ≤ 8 and should be equal to 0, if MQUANT > 8.

ippiQuantInterUniform_VC1_16s_C1IR Usage

{
Ipp16s*  pSrcDstData = pointer_on_source_and_destination_block;
Ipp32s doubleQuant = quant_coefficient; /* It should be an even number in the
range [2,62]; */
Ipp32s srcDstStep = source_and_destination_step; /* Step of the pointer
pSrcDstData (source and destination array) in bytes */
IppSize roiSize = inter_block_size;
/* It should be: 
8x8 (roiSize.width=8, roiSize.height=8)
4x8 (roiSize.width=4, roiSize.height=8)
8x4 (roiSize.width=8, roiSize.height=4)
4x4 (roiSize.width=4, roiSize.height=4)
*/
IppStatus result;

/*
ippStsNoErr         Indicates no error
ippStsNullPtrErr    Indicates an error when pSrcDstData is NULL
ippStsOutOfRangeErr Indicates an error when quantizer doubleQuant is less than 2
or higher than 62 
ippStsSizeErr       Indicates an error when roiSize.height is not equal 4 or 8
or roiSize.width is not equal 4 or 8
*/

result = ippiQuantInterUniform_VC1_16s_C1IR( pSrcDstData, srcDstStep,
doubleQuant );

/*  Performs uniform quantization process for inter block according to 8.1.2.8
"Inverse AC Coefficient Quantization" specification of SMPTE 421M
*/
}

ippiQuantInterNonuniform_VC1_16s_C1IR Usage

{
Ipp16s*  pSrcDstData = pointer_on_source_and_destination_block;
Ipp32s doubleQuant = quant_coefficient;  /* It should be an even number in the
range [2,62]; */
Ipp32s srcDstStep = source_and_destination_step; /* Step of the pointer
pSrcDstData (source and destination array) in bytes */
IppSize roiSize = inter_block_size;
/* It should be:
8x8 (roiSize.width=8, roiSize.height=8)
4x8 (roiSize.width=4, roiSize.height=8)
8x4 (roiSize.width=8, roiSize.height=4)
4x4 (roiSize.width=4, roiSize.height=4)
*/
IppStatus result;
/*
ippStsNoErr         Indicates no error
ippStsNullPtrErr    Indicates an error when pSrcDstData is NULL
ippStsOutOfRangeErr Indicates an error when quantizer doubleQuant is less than 2
or higher than 62
ippStsSizeErr       Indicates an error when roiSize.height is not equal 4 or 8
or roiSize.width is not equal 4 or 8
*/

result = ippiQuantInterNonuniform_VC1_16s_C1IR( pSrcDstData, srcDstStep,
doubleQuant );

/*  Performs nonuniform quantization process for inter block according to
8.1.2.8 "Inverse AC Coefficient Quantization" specification of SMPTE 421M
*/
}

Return Values