BitMiracle.LibTiff.Classic.TiffRgbaImage.putcontig8bitYCbCr44tile C# (CSharp) Method

        private static void putcontig8bitYCbCr44tile(
            TiffRgbaImage img, int[] raster, int rasterOffset, int rasterShift,
            int x, int y, int width, int height, byte[] buffer, int offset, int bufferShift)
        {
            int rasterOffset1 = rasterOffset + width + rasterShift;
            int rasterOffset2 = rasterOffset1 + width + rasterShift;
            int rasterOffset3 = rasterOffset2 + width + rasterShift;
            int incr = 3 * width + 4 * rasterShift;

            // adjust bufferShift
            bufferShift = (bufferShift * 18) / 4;
            if ((height & 3) == 0 && (width & 3) == 0)
            {
                for (; height >= 4; height -= 4)
                {
                    x = width >> 2;
                    do
                    {
                        int Cb = buffer[offset + 16];
                        int Cr = buffer[offset + 17];

                        img.YCbCrtoRGB(out raster[rasterOffset], buffer[offset + 0], Cb, Cr);
                        img.YCbCrtoRGB(out raster[rasterOffset + 1], buffer[offset + 1], Cb, Cr);
                        img.YCbCrtoRGB(out raster[rasterOffset + 2], buffer[offset + 2], Cb, Cr);
                        img.YCbCrtoRGB(out raster[rasterOffset + 3], buffer[offset + 3], Cb, Cr);
                        img.YCbCrtoRGB(out raster[rasterOffset1 + 0], buffer[offset + 4], Cb, Cr);
                        img.YCbCrtoRGB(out raster[rasterOffset1 + 1], buffer[offset + 5], Cb, Cr);
                        img.YCbCrtoRGB(out raster[rasterOffset1 + 2], buffer[offset + 6], Cb, Cr);
                        img.YCbCrtoRGB(out raster[rasterOffset1 + 3], buffer[offset + 7], Cb, Cr);
                        img.YCbCrtoRGB(out raster[rasterOffset2 + 0], buffer[offset + 8], Cb, Cr);
                        img.YCbCrtoRGB(out raster[rasterOffset2 + 1], buffer[offset + 9], Cb, Cr);
                        img.YCbCrtoRGB(out raster[rasterOffset2 + 2], buffer[offset + 10], Cb, Cr);
                        img.YCbCrtoRGB(out raster[rasterOffset2 + 3], buffer[offset + 11], Cb, Cr);
                        img.YCbCrtoRGB(out raster[rasterOffset3 + 0], buffer[offset + 12], Cb, Cr);
                        img.YCbCrtoRGB(out raster[rasterOffset3 + 1], buffer[offset + 13], Cb, Cr);
                        img.YCbCrtoRGB(out raster[rasterOffset3 + 2], buffer[offset + 14], Cb, Cr);
                        img.YCbCrtoRGB(out raster[rasterOffset3 + 3], buffer[offset + 15], Cb, Cr);

                        rasterOffset += 4;
                        rasterOffset1 += 4;
                        rasterOffset2 += 4;
                        rasterOffset3 += 4;
                        offset += 18;
                    }
                    while (--x != 0);

                    rasterOffset += incr;
                    rasterOffset1 += incr;
                    rasterOffset2 += incr;
                    rasterOffset3 += incr;
                    offset += bufferShift;
                }
            }
            else
            {
                while (height > 0)
                {
                    for (x = width; x > 0; )
                    {
                        int Cb = buffer[offset + 16];
                        int Cr = buffer[offset + 17];

                        bool h_goOn = false;
                        bool x_goOn = false;

                        // order of if's is important
                        if (x < 1 || x > 3)
                        {
                            // order of if's is important
                            h_goOn = false;
                            if (height < 1 || height > 3)
                            {
                                img.YCbCrtoRGB(out raster[rasterOffset3 + 3], buffer[offset + 15], Cb, Cr);
                                h_goOn = true;
                            }

                            if (height == 3 || h_goOn)
                            {
                                img.YCbCrtoRGB(out raster[rasterOffset2 + 3], buffer[offset + 11], Cb, Cr);
                                h_goOn = true;
                            }

                            if (height == 2 || h_goOn)
                            {
                                img.YCbCrtoRGB(out raster[rasterOffset1 + 3], buffer[offset + 7], Cb, Cr);
                                h_goOn = true;
                            }

                            if (height == 1 || h_goOn)
                                img.YCbCrtoRGB(out raster[rasterOffset + 3], buffer[offset + 3], Cb, Cr);

                            x_goOn = true;
                        }

                        if (x == 3 || x_goOn)
                        {
                            // order of if's is important
                            h_goOn = false;
                            if (height < 1 || height > 3)
                            {
                                img.YCbCrtoRGB(out raster[rasterOffset3 + 2], buffer[offset + 14], Cb, Cr);
                                h_goOn = true;
                            }

                            if (height == 3 || h_goOn)
                            {
                                img.YCbCrtoRGB(out raster[rasterOffset2 + 2], buffer[offset + 10], Cb, Cr);
                                h_goOn = true;
                            }

                            if (height == 2 || h_goOn)
                            {
                                img.YCbCrtoRGB(out raster[rasterOffset1 + 2], buffer[offset + 6], Cb, Cr);
                                h_goOn = true;
                            }

                            if (height == 1 || h_goOn)
                                img.YCbCrtoRGB(out raster[rasterOffset + 2], buffer[offset + 2], Cb, Cr);

                            x_goOn = true;
                        }

                        if (x == 2 || x_goOn)
                        {
                            // order of if's is important
                            h_goOn = false;
                            if (height < 1 || height > 3)
                            {
                                img.YCbCrtoRGB(out raster[rasterOffset3 + 1], buffer[offset + 13], Cb, Cr);
                                h_goOn = true;
                            }

                            if (height == 3 || h_goOn)
                            {
                                img.YCbCrtoRGB(out raster[rasterOffset2 + 1], buffer[offset + 9], Cb, Cr);
                                h_goOn = true;
                            }

                            if (height == 2 || h_goOn)
                            {
                                img.YCbCrtoRGB(out raster[rasterOffset1 + 1], buffer[offset + 5], Cb, Cr);
                                h_goOn = true;
                            }

                            if (height == 1 || h_goOn)
                                img.YCbCrtoRGB(out raster[rasterOffset + 1], buffer[offset + 1], Cb, Cr);
                        }

                        if (x == 1 || x_goOn)
                        {
                            // order of if's is important
                            h_goOn = false;
                            if (height < 1 || height > 3)
                            {
                                img.YCbCrtoRGB(out raster[rasterOffset3 + 0], buffer[offset + 12], Cb, Cr);
                                h_goOn = true;
                            }

                            if (height == 3 || h_goOn)
                            {
                                img.YCbCrtoRGB(out raster[rasterOffset2 + 0], buffer[offset + 8], Cb, Cr);
                                h_goOn = true;
                            }

                            if (height == 2 || h_goOn)
                            {
                                img.YCbCrtoRGB(out raster[rasterOffset1 + 0], buffer[offset + 4], Cb, Cr);
                                h_goOn = true;
                            }

                            if (height == 1 || h_goOn)
                                img.YCbCrtoRGB(out raster[rasterOffset + 0], buffer[offset + 0], Cb, Cr);
                        }

                        if (x < 4)
                        {
                            rasterOffset += x;
                            rasterOffset1 += x;
                            rasterOffset2 += x;
                            rasterOffset3 += x;
                            x = 0;
                        }
                        else
                        {
                            rasterOffset += 4;
                            rasterOffset1 += 4;
                            rasterOffset2 += 4;
                            rasterOffset3 += 4;
                            x -= 4;
                        }

                        offset += 18;
                    }

                    if (height <= 4)
                        break;

                    height -= 4;
                    rasterOffset += incr;
                    rasterOffset1 += incr;
                    rasterOffset2 += incr;
                    rasterOffset3 += incr;
                    offset += bufferShift;
                }
            }
        }