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Emmanuel_W_
New Contributor I
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H.264 quantizer rounding mode

Hi,

The function QuantizeResidual4x4Fwd has a parameter called "roundmode". The documentation state that if set to 0 an interframe is processed and if set to 1 and intra frame is processed.
Is it possible to get an actual description of what is the actual effect on the quantizer?

Thanks,
Emmanuel
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Ying_H_Intel
Employee
70 Views

Quoting - eweber
Hi,

The function QuantizeResidual4x4Fwd has a parameter called "roundmode". The documentation state that if set to 0 an interframe is processed and if set to 1 and intra frame is processed.
Is it possible to get an actual description of what is the actual effect on the quantizer?

Thanks,
Emmanuel

Hello Emmanuel,

Do you mean the description:
The functions ippiQuantizeResidual4x4Fwd_H264_16s_C1,
ippiQuantizeResidual4x4Fwd_H264_16s32s_C1, and
ippiQuantizeResidual4x4Fwd_H264_32s_C1 are declared in the ippvc.h file. These functions
perform forward quantization for a 4x4 residual block. A 4x4 residual block (pSrc) is quantized.
All values are rounded towards nearest (intra frame, roundmode=1 ) or towards zero (inter frame, roundmode=0 ). Then the number of non-zero elements and index of the last non-zero element are calculated and stored.
If pQuantTable is NULL, the default quantization table is used.

This function is used in the H.264 encoder included into Intel IPP Samples.

Regards,
Ying
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