public int chromaSubsampling()
{
/* Detect Chroma Subsampling
* Set General.chr:
* 0--> 4:4:4
* 1--> 4:4:0
* 2--> 4:2:2
* 3--> 4:2:0
*/
int mcu = mcuStructure();
Console.WriteLine("MCU: " + mcu);
switch (mcu)
{
case 0:
Global.yccList = blockListWith1Y;
Global.chr = 0;
Global.rgbList = Dequantizer.ycc2rgbBlockList(Global.yccList, 0);
break;
case 1:
Global.yccList = blockListWith2Y;
Global.chr = layout();
// if chr==1 General.rgbList is already setted in layout() method
break;
default:
Global.yccList = blockListWith4Y;
Global.chr = 3;
Global.rgbList = Dequantizer.ycc2rgbBlockList(Global.yccList, 3);
break;
}
return(mcu);
}
int layout()
{
// build rgbList as 4:4:0
List <double[][]>[] verList = Dequantizer.ycc2rgbBlockList(Global.yccList, 1);
// build rgbList as 4:2:2
List <double[][]>[] horList = Dequantizer.ycc2rgbBlockList(Global.yccList, 2);
List <double[]> verDiff = new List <double[]>(); // 0->tbDiff, 1->lrDiff
List <double[]> horDiff = new List <double[]>(); // 0->tbDiff, 1->lrDiff
for (int i = 0; i < verList[0].Count; i += 2)
{
verDiff.Add(borderDiff(new double[][][] { verList[0][i], verList[1][i], verList[2][i] }, new double[][][] { verList[0][i + 1], verList[1][i + 1], verList[2][i + 1] }));
}
for (int i = 0; i < horList[0].Count; i += 2)
{
horDiff.Add(borderDiff(new double[][][] { horList[0][i], horList[1][i], horList[2][i] }, new double[][][] { horList[0][i + 1], horList[1][i + 1], horList[2][i + 1] }));
}
if ((verDiff.Average(i => i[0]) < horDiff.Average(i => i[1])) && (verDiff.Average(i => i[1]) > horDiff.Average(i => i[0])))
{
Global.rgbList = verList;
return(1);
}
Global.rgbList = horList;
return(2);
}