public int GetPreviewBitrateInKbps(CurveFittingSettings curveSettings, int imgWidth, int imgHeight)
{
// Get the Curve Fitting Function
ICurveFittingService service = _curveFittingFactory.GetCurveFittingService(curveSettings.CurveFittingType);
var func = service.GetCurveFittingFunction(
curveSettings.Data.
ToDictionary(
k => (double)k.Width * k.Height,
v => (double)v.Bitrate / (double)(v.Width * v.Height)
)
);
var targetRatio = func(imgWidth * imgHeight);
var targetBitrate = Convert.ToInt32(imgWidth * imgHeight * targetRatio / 1000.0);
return(targetBitrate);
}
public Image GetPreviewImage(CurveFittingSettings curveSettings, int imgWidth, int imgHeight)
{
// Get the Curve Fitting Function
ICurveFittingService service = _curveFittingFactory.GetCurveFittingService(curveSettings.CurveFittingType);
var func = service.GetCurveFittingFunction(
curveSettings.Data.
ToDictionary(
k => (double)k.Width * k.Height,
v => (double)v.Bitrate / (double)(v.Width * v.Height)
)
);
// Prepare the image for the graph
Bitmap bmp = new Bitmap(imgWidth, imgHeight);
using (var g = Graphics.FromImage(bmp))
{
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
// Background
g.FillRectangle(Brushes.White, 0, 0, imgWidth, imgHeight);
// X Axis
g.DrawLine(Pens.Black, 0, imgHeight - _xAxisPadding, imgWidth, imgHeight - _xAxisPadding);
// Y Axis
g.DrawLine(Pens.Black, _yAxisPadding, 0, _yAxisPadding, imgHeight);
// Get points data
var pointsData = curveSettings.Data
.ToDictionary(x => (double)x.Width * x.Height, y => (double)y.Bitrate / (y.Width * y.Height));
// Find minX, maxX with 10% off in order to have better visual graph
double minX = pointsData.Min(x => x.Key) * 0.9;
double maxX = pointsData.Max(x => x.Key) * 1.1;
// Find minY, maxY with 10% off in order to have better visual graph
double minY = pointsData.Min(y => y.Value) * 0.9;
double maxY = pointsData.Max(y => y.Value) * 1.1;
// Get X step for 100 steps
double xStep = Convert.ToInt32((maxX - minX) / (double)_numberOfSteps);
// Get Data Values
Dictionary <double, double> data = new Dictionary <double, double>();
for (double x = minX; x < maxX; x += xStep)
{
data.Add(x, func(x));
}
// Normalize values to pixels to range [a - b]
int aX = _xAxisPadding;
int bX = imgWidth - _xAxisPadding;
int aY = _yAxisPadding;
int bY = imgHeight - _yAxisPadding;
// Normalize the data
pointsData = pointsData.ScaleValues(minX, maxX, minY, maxY, aX, bX, aY, bY)
// Inverse Y values for drawing
.InverseYValues(imgHeight);
// Draw the data points
foreach (var point in pointsData)
{
g.FillEllipse(Brushes.Red, (float)point.Key, (float)point.Value, _pointRadius, _pointRadius);
}
// Normalize the data based on previous scale
data = data.ScaleValues(minX, maxX, minY, maxY, aX, bX, aY, bY)
// Inverse Y values for drawing
.InverseYValues(imgHeight);
// Draw the line
g.DrawCurve(Pens.Blue,
data
// Filter out of scope values
.Where(x => x.Key >= _xAxisPadding)
// Convert to PointF structure
.Select(x => new PointF((float)x.Key, (float)x.Value))
.ToArray()
);
}
return(bmp);
}
