public HdrColor Pow(HdrColor exponent)
{
return(new HdrColor
{
R = Math.Pow(R, exponent.R),
G = Math.Pow(G, exponent.G),
B = Math.Pow(B, exponent.B)
});
}
private static PaletteEntry GetClosestPaletteEntry(PaletteEntry[] palette, HdrColor color)
{
PaletteEntry closestEntry = null;
var closestDistance = double.PositiveInfinity;
for (var palleteIndex = 0; palleteIndex < palette.Length; palleteIndex++)
{
var currentEntry = palette[palleteIndex];
var currentDistance = (currentEntry.Color - color).Length;
if (currentDistance < closestDistance)
{
closestEntry = currentEntry;
closestDistance = currentDistance;
}
}
return(closestEntry);
}
private static PaletteEntry[] GeneratePalette(HdrColor[] subPixelColors)
{
var palette = new PaletteEntry[1 << subPixelColors.Length];
for (var paletteIndex = 0; paletteIndex < palette.Length; paletteIndex++)
{
var currentColor = new HdrColor();
var outputColor = new bool[subPixelColors.Length];
for (var subPixelIndex = 0; subPixelIndex < subPixelColors.Length; subPixelIndex++)
{
if (((paletteIndex >> subPixelIndex) & 1) == 1)
{
currentColor += subPixelColors[subPixelIndex];
outputColor[subPixelIndex] = true;
}
}
palette[paletteIndex] = new PaletteEntry(currentColor, outputColor);
}
return(palette);
}
private record PaletteEntry(HdrColor Color, bool[] OutputColor);
public static void Run(VideoConfiguration configuration)
{
var videoFile = configuration.VideoFile;
var outputBlueprintFile = configuration.OutputBlueprint;
var outputJsonFile = configuration.OutputJson;
var frameWidth = configuration.FrameWidth ?? 32;
var frameHeight = configuration.FrameHeight ?? 32;
var colorMode = configuration.ColorMode ?? ColorMode.Monochrome;
var ditheringMode = configuration.DitheringMode ?? DitheringMode.None;
var romHeight = configuration.RomHeight ?? 2;
var maxFrames = romHeight * 32;
var videoBuffer = new MemoryStream();
using (var videoStream = File.OpenRead(videoFile))
{
videoStream.CopyTo(videoBuffer);
}
var pixelSize = colorMode switch
{
ColorMode.Monochrome => 1,
ColorMode.RedGreenBlue => 2,
ColorMode.RedGreenBlueWhite => 2,
_ => throw new Exception($"Unexpected color mode: {colorMode}")
};
var palette = colorMode switch
{
ColorMode.Monochrome => GeneratePalette(new HdrColor[]
{
HdrColor.FromRgb(1, 1, 1)
}),
ColorMode.RedGreenBlue => GeneratePalette(new HdrColor[]
{
HdrColor.FromRgb(1, 0, 0),
HdrColor.FromRgb(0, 1, 0),
HdrColor.FromRgb(0, 0, 1)
}),
ColorMode.RedGreenBlueWhite => GeneratePalette(new HdrColor[]
{
HdrColor.FromRgb(0.8, 0, 0),
HdrColor.FromRgb(0, 0.8, 0),
HdrColor.FromRgb(0, 0, 0.8),
HdrColor.FromRgb(0.8, 0.8, 0.8)
}),
_ => throw new Exception($"Unexpected color mode: {colorMode}")
};
// Information on dithering: https://cmitja.files.wordpress.com/2015/01/hellandtanner_imagedithering11algorithms.pdf
var ditheringWeights = ditheringMode switch
{
DitheringMode.None => Array.Empty <DitheringWeight>(),
DitheringMode.Sierra => new DitheringWeight[]
{
new DitheringWeight(5 / 32d, 1, 0),
new DitheringWeight(3 / 32d, 2, 0),
new DitheringWeight(2 / 32d, -2, 1),
new DitheringWeight(4 / 32d, -1, 1),
new DitheringWeight(5 / 32d, 0, 1),
new DitheringWeight(4 / 32d, 1, 1),
new DitheringWeight(2 / 32d, 2, 1),
new DitheringWeight(2 / 32d, -1, 2),
new DitheringWeight(3 / 32d, 0, 2),
new DitheringWeight(2 / 32d, 1, 2),
},
DitheringMode.SierraLite => new DitheringWeight[]
{
new DitheringWeight(2 / 4d, 1, 0),
new DitheringWeight(1 / 4d, -1, 1),
new DitheringWeight(1 / 4d, 0, 1)
},
DitheringMode.Temporal => new DitheringWeight[]
{
new DitheringWeight(2 / 6d, 1, 0, 0),
new DitheringWeight(1 / 6d, -1, 1, 0),
new DitheringWeight(1 / 6d, 0, 1, 0),
new DitheringWeight(2 / 6d, 0, 0, 1)
},
_ => throw new Exception($"Unexpected dithering mode: {ditheringMode}")
};
var rawFrameWidth = frameWidth / pixelSize;
var rawFrameHeight = frameHeight / pixelSize;
var video = new Video(videoBuffer, rawFrameWidth, rawFrameHeight);
var rawFrame = new int[rawFrameWidth * rawFrameHeight];
var frames = new List <bool[, ]>();
var ditheringFrames = ditheringWeights.Max(ditheringWeight => ditheringWeight.Frame) + 1;
var colorErrors = new HdrColor[ditheringFrames][, ];
for (var index = 0; index < ditheringFrames; index++)
{
colorErrors[index] = new HdrColor[frameHeight, frameWidth];
}
while (video.AdvanceFrame(rawFrame) && frames.Count < maxFrames)
{
var frame = new bool[frameHeight, frameWidth];
frames.Add(frame);
var totalBrightness = 0d;
for (var rawY = 0; rawY < rawFrameHeight; rawY++)
{
for (var rawX = 0; rawX < rawFrameWidth; rawX++)
{
var color = System.Drawing.Color.FromArgb(rawFrame[rawX + rawY * rawFrameWidth]);
totalBrightness += color.GetBrightness();
}
}
var averageBrightness = totalBrightness / (rawFrameWidth * rawFrameHeight);
const double gammaMultiplier = 2;
var gamma = gammaMultiplier * (averageBrightness is > 0.1 and < 0.9 ? Math.Log(0.5, averageBrightness) : 1);
for (var rawY = 0; rawY < rawFrameHeight; rawY++)
{
for (var rawX = 0; rawX < rawFrameWidth; rawX++)
{
var x = rawX * pixelSize;
var y = rawY * pixelSize;
var rawColor = HdrColor.FromArgb(rawFrame[rawX + rawY * rawFrameWidth]);
var gammaCorrectedColor = rawColor.Pow(gamma);
var ditheredColor = gammaCorrectedColor + colorErrors[0][rawY, rawX];
var closestPaletteEntry = GetClosestPaletteEntry(palette, ditheredColor);
var newColorError = ditheredColor - closestPaletteEntry.Color;
var outputColor = closestPaletteEntry.OutputColor;
for (var subPixelY = 0; subPixelY < pixelSize; subPixelY++)
{
for (var subPixelX = 0; subPixelX < pixelSize; subPixelX++)
{
var subPixelIndex = subPixelX + subPixelY * pixelSize;
if (subPixelIndex < outputColor.Length)
{
frame[y + subPixelY, x + subPixelX] = outputColor[subPixelIndex];
}
}
}
for (var index = 0; index < ditheringWeights.Length; index++)
{
var ditheringWeight = ditheringWeights[index];
var errorX = rawX + ditheringWeight.X;
var errorY = rawY + ditheringWeight.Y;
if (errorX >= 0 && errorX < frameWidth && errorY < frameHeight)
{
colorErrors[ditheringWeight.Frame][errorY, errorX] += newColorError * ditheringWeight.Weight;
}
}
}
}
for (var index = 0; index < ditheringFrames - 1; index++)
{
colorErrors[index] = colorErrors[index + 1];
}
colorErrors[ditheringFrames - 1] = new HdrColor[frameHeight, frameWidth];
Console.Write('.');
}
Console.WriteLine($"Frames: {frames.Count}");
var blueprint = VideoRomGenerator.Generate(new VideoMemoryConfiguration
{
SnapToGrid = configuration.SnapToGrid,
X = configuration.X,
Y = configuration.Y,
Width = frameWidth,
Height = romHeight,
BaseAddress = configuration.BaseAddress
}, frames);
BlueprintUtil.PopulateIndices(blueprint);
var blueprintWrapper = new BlueprintWrapper {
Blueprint = blueprint
};
BlueprintUtil.WriteOutBlueprint(outputBlueprintFile, blueprintWrapper);
BlueprintUtil.WriteOutJson(outputJsonFile, blueprintWrapper);
}