AssetRipper.TextureDecoder/TextureDecoder/Yuy2/Yuy2Decoder.cs

using System.Runtime.CompilerServices;

namespace TextureDecoder.Yuy2
{
	public static class Yuy2Decoder
	{
		public static byte[] DecompressYUY2(byte[] input, int width, int height)
		{
			byte[] output = new byte[width * height * sizeof(uint)];
			DecompressYUY2(input, width, height, output);
			return output;
		}

		public static void DecompressYUY2(byte[] input, int width, int height, byte[] output)
		{
			int p = 0;
			int o = 0;
			int halfWidth = width / 2;
			for (int j = 0; j < height; j++)
			{
				for (int i = 0; i < halfWidth; ++i)
				{
					int y0 = input[p++];
					int u0 = input[p++];
					int y1 = input[p++];
					int v0 = input[p++];
					int c = y0 - 16;
					int d = u0 - 128;
					int e = v0 - 128;
					output[o++] = ClampByte((298 * c + 516 * d + 128) >> 8);			// blue
					output[o++] = ClampByte((298 * c - 100 * d - 208 * e + 128) >> 8);	// green
					output[o++] = ClampByte((298 * c + 409 * e + 128) >> 8);			// red
					output[o++] = 255;
					c = y1 - 16;
					output[o++] = ClampByte((298 * c + 516 * d + 128) >> 8);			// blue
					output[o++] = ClampByte((298 * c - 100 * d - 208 * e + 128) >> 8);	// green
					output[o++] = ClampByte((298 * c + 409 * e + 128) >> 8);			// red
					output[o++] = 255;
				}
			}
		}

		[MethodImpl(MethodImplOptions.AggressiveInlining)]
		private static byte ClampByte(int x)
		{
			return (byte)(byte.MaxValue < x ? byte.MaxValue : (x > byte.MinValue ? x : byte.MinValue));
		}
	}
}