From 47be2ba79a35ac217f2934559fe8e09ebaf4ae21 Mon Sep 17 00:00:00 2001
From: James Jackson-South <james_south@hotmail.com>
Date: Thu, 26 Aug 2021 21:38:46 +1000
Subject: [PATCH 1/2] Revert "Update JpegEncoderCore.cs"

This reverts commit f25ce22ed85b4c7a7d481af5d92e6101632eac5d.
---
 .../Formats/Jpeg/JpegEncoderCore.cs           | 28 +++++++++++--------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs b/src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs
index 14e7cc677..3fd1a3c48 100644
--- a/src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs
+++ b/src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs
@@ -167,10 +167,14 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
         /// <param name="colorType">The color type.</param>
         /// <returns>true, if color type is supported.</returns>
         private static bool IsSupportedColorType(JpegColorType? colorType)
-            => colorType == JpegColorType.YCbCrRatio444
-            || colorType == JpegColorType.YCbCrRatio420
-            || colorType == JpegColorType.Luminance
-            || colorType == JpegColorType.Rgb;
+        {
+            if (colorType == JpegColorType.YCbCrRatio444 || colorType == JpegColorType.YCbCrRatio420 || colorType == JpegColorType.Luminance || colorType == JpegColorType.Rgb)
+            {
+                return true;
+            }
+
+            return false;
+        }
 
         /// <summary>
         /// Gets the component ids.
@@ -567,14 +571,14 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
             // This uses a C#'s compiler optimization that refers to the static data segment of the assembly,
             // and doesn't incur any allocation at all.
             // "default" to 4:2:0
-            ReadOnlySpan<byte> subsamples = stackalloc byte[]
+            ReadOnlySpan<byte> subsamples = new byte[]
             {
                 0x22,
                 0x11,
                 0x11
             };
 
-            ReadOnlySpan<byte> chroma = stackalloc byte[]
+            ReadOnlySpan<byte> chroma = new byte[]
             {
                 0x00,
                 0x01,
@@ -583,7 +587,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
 
             if (this.colorType == JpegColorType.Luminance)
             {
-                subsamples = stackalloc byte[]
+                subsamples = new byte[]
                 {
                     0x11,
                     0x00,
@@ -596,7 +600,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
                 {
                     case JpegColorType.YCbCrRatio444:
                     case JpegColorType.Rgb:
-                        subsamples = stackalloc byte[]
+                        subsamples = new byte[]
                         {
                             0x11,
                             0x11,
@@ -605,7 +609,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
 
                         if (this.colorType == JpegColorType.Rgb)
                         {
-                            chroma = stackalloc byte[]
+                            chroma = new byte[]
                             {
                                 0x00,
                                 0x00,
@@ -615,7 +619,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
 
                         break;
                     case JpegColorType.YCbCrRatio420:
-                        subsamples = stackalloc byte[]
+                        subsamples = new byte[]
                         {
                             0x22,
                             0x11,
@@ -658,7 +662,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
         {
             // This uses a C#'s compiler optimization that refers to the static data segment of the assembly,
             // and doesn't incur any allocation at all.
-            ReadOnlySpan<byte> huffmanId = stackalloc byte[]
+            ReadOnlySpan<byte> huffmanId = new byte[]
             {
                 0x00,
                 0x11,
@@ -668,7 +672,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
             // Use the same DC/AC tables for all channels for RGB.
             if (this.colorType == JpegColorType.Rgb)
             {
-                huffmanId = stackalloc byte[]
+                huffmanId = new byte[]
                 {
                     0x00,
                     0x00,

From b4a5335a388fc26a0e9cc61f0fa2ddb097dfe787 Mon Sep 17 00:00:00 2001
From: James Jackson-South <james_south@hotmail.com>
Date: Thu, 26 Aug 2021 21:42:46 +1000
Subject: [PATCH 2/2] Add nint optimization

---
 src/ImageSharp/Formats/Jpeg/Components/Block8x8F.cs  |  4 ++--
 .../Encoder/RgbForwardConverter{TPixel}.cs           |  2 +-
 src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs       | 12 ++++--------
 3 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/src/ImageSharp/Formats/Jpeg/Components/Block8x8F.cs b/src/ImageSharp/Formats/Jpeg/Components/Block8x8F.cs
index d55dfced7..f669a7ad9 100644
--- a/src/ImageSharp/Formats/Jpeg/Components/Block8x8F.cs
+++ b/src/ImageSharp/Formats/Jpeg/Components/Block8x8F.cs
@@ -104,7 +104,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components
             {
                 GuardBlockIndex(idx);
                 ref float selfRef = ref Unsafe.As<Block8x8F, float>(ref this);
-                return Unsafe.Add(ref selfRef, idx);
+                return Unsafe.Add(ref selfRef, (nint)(uint)idx);
             }
 
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -112,7 +112,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components
             {
                 GuardBlockIndex(idx);
                 ref float selfRef = ref Unsafe.As<Block8x8F, float>(ref this);
-                Unsafe.Add(ref selfRef, idx) = value;
+                Unsafe.Add(ref selfRef, (nint)(uint)idx) = value;
             }
         }
 
diff --git a/src/ImageSharp/Formats/Jpeg/Components/Encoder/RgbForwardConverter{TPixel}.cs b/src/ImageSharp/Formats/Jpeg/Components/Encoder/RgbForwardConverter{TPixel}.cs
index 7fad63e11..0be1076e2 100644
--- a/src/ImageSharp/Formats/Jpeg/Components/Encoder/RgbForwardConverter{TPixel}.cs
+++ b/src/ImageSharp/Formats/Jpeg/Components/Encoder/RgbForwardConverter{TPixel}.cs
@@ -103,7 +103,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Encoder
 
             for (int i = 0; i < Block8x8F.Size; i++)
             {
-                Rgb24 c = Unsafe.Add(ref rgbStart, i);
+                Rgb24 c = Unsafe.Add(ref rgbStart, (nint)(uint)i);
 
                 redBlock[i] = c.R;
                 greenBlock[i] = c.G;
diff --git a/src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs b/src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs
index 3fd1a3c48..270a11ed6 100644
--- a/src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs
+++ b/src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs
@@ -167,14 +167,10 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
         /// <param name="colorType">The color type.</param>
         /// <returns>true, if color type is supported.</returns>
         private static bool IsSupportedColorType(JpegColorType? colorType)
-        {
-            if (colorType == JpegColorType.YCbCrRatio444 || colorType == JpegColorType.YCbCrRatio420 || colorType == JpegColorType.Luminance || colorType == JpegColorType.Rgb)
-            {
-                return true;
-            }
-
-            return false;
-        }
+            => colorType == JpegColorType.YCbCrRatio444
+            || colorType == JpegColorType.YCbCrRatio420
+            || colorType == JpegColorType.Luminance
+            || colorType == JpegColorType.Rgb;
 
         /// <summary>
         /// Gets the component ids.