Encode444 using YCbCrForwardConverter<TPixel>

src/ImageSharp/Formats/Jpeg/GolangPort/JpegEncoderCore.cs

@@ -232,10 +232,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort
             this.WriteDefineHuffmanTables(componentCount);
 
             // Write the image data.
-            using (PixelAccessor<TPixel> pixels = image.Lock())
+            this.WriteStartOfScan(image);
-            {
-                this.WriteStartOfScan(pixels);
-            }
 
             // Write the End Of Image marker.
             this.buffer[0] = OrigJpegConstants.Markers.XFF;
@@ -439,14 +436,11 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort
         /// </summary>
         /// <typeparam name="TPixel">The pixel format.</typeparam>
         /// <param name="pixels">The pixel accessor providing access to the image pixels.</param>
-        private void Encode444<TPixel>(PixelAccessor<TPixel> pixels)
+        private void Encode444<TPixel>(Image<TPixel> pixels)
             where TPixel : struct, IPixel<TPixel>
         {
             // TODO: Need a JpegScanEncoder<TPixel> class or struct that encapsulates the scan-encoding implementation. (Similar to JpegScanDecoder.)
-            Block8x8F b = default(Block8x8F);
+            // (Partially done with YCbCrForwardConverter<TPixel>)
-            Block8x8F cb = default(Block8x8F);
-            Block8x8F cr = default(Block8x8F);
-
             Block8x8F temp1 = default(Block8x8F);
             Block8x8F temp2 = default(Block8x8F);
 
@@ -460,20 +454,16 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort
 
             YCbCrForwardConverter<TPixel> pixelConverter = YCbCrForwardConverter<TPixel>.Create();
 
-            fixed (RgbToYCbCrTables* tables = &rgbToYCbCrTables)
-            {
-                using (PixelArea<TPixel> rgbBytes = new PixelArea<TPixel>(8, 8, ComponentOrder.Xyz))
-                {
             for (int y = 0; y < pixels.Height; y += 8)
             {
                 for (int x = 0; x < pixels.Width; x += 8)
                 {
-                            ToYCbCr(pixels, tables, x, y, ref b, ref cb, ref cr, rgbBytes);
+                    pixelConverter.Convert(pixels.Frames.RootFrame, x, y);
 
                     prevDCY = this.WriteBlock(
                         QuantIndex.Luminance,
                         prevDCY,
-                                &b,
+                        &pixelConverter.Y,
                         &temp1,
                         &temp2,
                         &onStackLuminanceQuantTable,
@@ -481,7 +471,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort
                     prevDCCb = this.WriteBlock(
                         QuantIndex.Chrominance,
                         prevDCCb,
-                                &cb,
+                        &pixelConverter.Cb,
                         &temp1,
                         &temp2,
                         &onStackChrominanceQuantTable,
@@ -489,7 +479,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort
                     prevDCCr = this.WriteBlock(
                         QuantIndex.Chrominance,
                         prevDCCr,
-                                &cr,
+                        &pixelConverter.Cr,
                         &temp1,
                         &temp2,
                         &onStackChrominanceQuantTable,
@@ -497,8 +487,6 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort
                 }
             }
         }
-            }
-        }
 
         /// <summary>
         /// Writes the application header containing the JFIF identifier plus extra data.
@@ -866,8 +854,8 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort
         /// Writes the StartOfScan marker.
         /// </summary>
         /// <typeparam name="TPixel">The pixel format.</typeparam>
-        /// <param name="pixels">The pixel accessor providing access to the image pixels.</param>
+        /// <param name="image">The pixel accessor providing access to the image pixels.</param>
-        private void WriteStartOfScan<TPixel>(PixelAccessor<TPixel> pixels)
+        private void WriteStartOfScan<TPixel>(Image<TPixel> image)
             where TPixel : struct, IPixel<TPixel>
         {
             // TODO: Need a JpegScanEncoder<TPixel> class or struct that encapsulates the scan-encoding implementation. (Similar to JpegScanDecoder.)
@@ -877,10 +865,14 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort
             switch (this.subsample)
             {
                 case JpegSubsample.Ratio444:
-                    this.Encode444(pixels);
+                    this.Encode444(image);
                     break;
                 case JpegSubsample.Ratio420:
+                    using (var pixels = image.Lock())
+                    {
                         this.Encode420(pixels);
+                    }
+                    
                     break;
             }