根据编码质量修改原始量化表,NPP实现与普通实现对比 #C++ #NPP

setQTByQuality.cpp

#include <iostream>
#include <npp.h>
using namespace std;

unsigned char _STD_Y_QT[64] =
{
	16, 11, 10, 16, 24, 40, 51, 61,
	12, 12, 14, 19, 26, 58, 60, 55,
	14, 13, 16, 24, 40, 57, 69, 56,
	14, 17, 22, 29, 51, 87, 80, 62,
	18, 22, 37, 56, 68, 109, 103, 77,
	24, 35, 55, 64, 81, 104, 113, 92,
	49, 64, 78, 87, 103, 121, 120, 101,
	72, 92, 95, 98, 112, 100, 103, 99
};
unsigned char _STD_UV_QT[64] =
{
	17, 18, 24, 47, 99, 99, 99, 99,
	18, 21, 26, 66, 99, 99, 99, 99,
	24, 26, 56, 99, 99, 99, 99, 99,
	47, 66, 99, 99, 99, 99, 99, 99,
	99, 99, 99, 99, 99, 99, 99, 99,
	99, 99, 99, 99, 99, 99, 99, 99,
	99, 99, 99, 99, 99, 99, 99, 99,
	99, 99, 99, 99, 99, 99, 99, 99
};

unsigned char _STD_Y_QT_npp[64] =
{
	16, 11, 10, 16, 24, 40, 51, 61,
	12, 12, 14, 19, 26, 58, 60, 55,
	14, 13, 16, 24, 40, 57, 69, 56,
	14, 17, 22, 29, 51, 87, 80, 62,
	18, 22, 37, 56, 68, 109, 103, 77,
	24, 35, 55, 64, 81, 104, 113, 92,
	49, 64, 78, 87, 103, 121, 120, 101,
	72, 92, 95, 98, 112, 100, 103, 99
};
unsigned char _STD_UV_QT_npp[64] =
{
	17, 18, 24, 47, 99, 99, 99, 99,
	18, 21, 26, 66, 99, 99, 99, 99,
	24, 26, 56, 99, 99, 99, 99, 99,
	47, 66, 99, 99, 99, 99, 99, 99,
	99, 99, 99, 99, 99, 99, 99, 99,
	99, 99, 99, 99, 99, 99, 99, 99,
	99, 99, 99, 99, 99, 99, 99, 99,
	99, 99, 99, 99, 99, 99, 99, 99
};
void nppsetQTByQuality(int nQualityFactor) {
	nppiQuantFwdRawTableInit_JPEG_8u(_STD_Y_QT_npp, nQualityFactor);
	nppiQuantFwdRawTableInit_JPEG_8u(_STD_UV_QT_npp, nQualityFactor);
}

void setQTByQuality(int quality)
{
	float s;
	if (quality < 50)
		s = 5000.0f / quality;
	else s = 200.0f - 2 * quality;

	for (size_t i = 0; i < 64; i++) {
		// 亮度
		float luminVal = (float)_STD_Y_QT[i];
		luminVal = floor((s * luminVal + 50.0f) / 100.0f);
		if (luminVal < 1)
			luminVal = 1;
		else if (luminVal > 255)
			luminVal = 255;
		_STD_Y_QT[i] = (unsigned char)luminVal;
		// 色度
		float chromaVal = (float)_STD_UV_QT[i];
		chromaVal = floor((s * chromaVal + 50.0f) / 100.0f);
		if (chromaVal < 1)
			chromaVal = 1;
		else if (chromaVal > 255)
			chromaVal = 255;
		_STD_UV_QT[i] = (unsigned char)chromaVal;
	}
}

void printResult() {
	for (size_t i = 0; i < 64; i++)
	{
		if (i % 8 == 0)
		{
			cout << endl;
		}
		cout << (int)_STD_Y_QT[i] << ",";
	}
	cout << endl;
	for (size_t i = 0; i < 64; i++)
	{
		if (i % 8 == 0)
		{
			cout << endl;
		}
		cout << (int)_STD_UV_QT[i] << ",";
	}
	cout << endl;
}


int main()
{
	cout << "setQTByQuality:" << endl;
	setQTByQuality(90);
	printResult();

	cout << endl;

	cout << "nppsetQTByQuality:" << endl;
	nppsetQTByQuality(90);
	printResult();
}
/*
结果完全相同.
setQTByQuality:

3,2,2,3,5,8,10,12,
2,2,3,4,5,12,12,11,
3,3,3,5,8,11,14,11,
3,3,4,6,10,17,16,12,
4,4,7,11,14,22,21,15,
5,7,11,13,16,21,23,18,
10,13,16,17,21,24,24,20,
14,18,19,20,22,20,21,20,

3,4,5,9,20,20,20,20,
4,4,5,13,20,20,20,20,
5,5,11,20,20,20,20,20,
9,13,20,20,20,20,20,20,
20,20,20,20,20,20,20,20,
20,20,20,20,20,20,20,20,
20,20,20,20,20,20,20,20,
20,20,20,20,20,20,20,20,

nppsetQTByQuality:

3,2,2,3,5,8,10,12,
2,2,3,4,5,12,12,11,
3,3,3,5,8,11,14,11,
3,3,4,6,10,17,16,12,
4,4,7,11,14,22,21,15,
5,7,11,13,16,21,23,18,
10,13,16,17,21,24,24,20,
14,18,19,20,22,20,21,20,

3,4,5,9,20,20,20,20,
4,4,5,13,20,20,20,20,
5,5,11,20,20,20,20,20,
9,13,20,20,20,20,20,20,
20,20,20,20,20,20,20,20,
20,20,20,20,20,20,20,20,
20,20,20,20,20,20,20,20,
20,20,20,20,20,20,20,20,
*/