private int[] GetHistogram(IEnumerable <VideoFrame> frames, VideoFrame maskFrame, int pixelSize, int channel, YUVPlanes plane, ColorSpaces pixelType, int bits, bool limitedRange)
{
var hist = new int[1 << bits];
var chroma = plane == YUVPlanes.PLANAR_U || plane == YUVPlanes.PLANAR_V;
var widthMult = chroma ? pixelType.GetWidthSubsample() : 1;
var heightMult = chroma ? pixelType.GetHeightSubsample() : 1;
var maskPitch = maskFrame?.GetPitch() * heightMult ?? 0;
var maskPtr = maskFrame?.GetReadPtr() + channel ?? IntPtr.Zero;
foreach (var frame in frames)
{
NativeUtils.FillHistogram(hist,
frame.GetRowSize(plane), frame.GetHeight(plane), channel,
frame.GetReadPtr(plane), frame.GetPitch(plane), pixelSize,
maskPtr, maskPitch, widthMult);
}
if (limitedRange)
{
var min = GetLowColor(bits);
for (var color = 0; color < min; color++)
{
hist[min] += hist[color];
hist[color] = 0;
}
var max = GetHighColor(bits, plane);
for (var color = max + 1; color < 1 << bits; color++)
{
hist[max] += hist[color];
hist[color] = 0;
}
}
return(GetUniHistogram(hist));
}