From e45bf57f68cd18b2f202863c6ca35cc426ae42c2 Mon Sep 17 00:00:00 2001
From: Ynse Hoornenborg <github@ynse.nl>
Date: Sun, 21 Jul 2024 05:45:52 +0200
Subject: [PATCH] Combine Delta parameters implementation

---
 ...aLoopFilterParameters.cs => ObuDeltaParameters.cs} |  2 +-
 .../Heif/Av1/OpenBitstreamUnit/ObuDeltaQParameters.cs | 11 -----------
 .../Heif/Av1/OpenBitstreamUnit/ObuFrameHeader.cs      |  4 ++--
 .../Formats/Heif/Av1/Tiling/Av1TileDecoder.cs         |  8 +++-----
 4 files changed, 6 insertions(+), 19 deletions(-)
 rename src/ImageSharp/Formats/Heif/Av1/OpenBitstreamUnit/{ObuDeltaLoopFilterParameters.cs => ObuDeltaParameters.cs} (87%)
 delete mode 100644 src/ImageSharp/Formats/Heif/Av1/OpenBitstreamUnit/ObuDeltaQParameters.cs

diff --git a/src/ImageSharp/Formats/Heif/Av1/OpenBitstreamUnit/ObuDeltaLoopFilterParameters.cs b/src/ImageSharp/Formats/Heif/Av1/OpenBitstreamUnit/ObuDeltaParameters.cs
similarity index 87%
rename from src/ImageSharp/Formats/Heif/Av1/OpenBitstreamUnit/ObuDeltaLoopFilterParameters.cs
rename to src/ImageSharp/Formats/Heif/Av1/OpenBitstreamUnit/ObuDeltaParameters.cs
index da39e19f3..c92485eaf 100644
--- a/src/ImageSharp/Formats/Heif/Av1/OpenBitstreamUnit/ObuDeltaLoopFilterParameters.cs
+++ b/src/ImageSharp/Formats/Heif/Av1/OpenBitstreamUnit/ObuDeltaParameters.cs
@@ -3,7 +3,7 @@
 
 namespace SixLabors.ImageSharp.Formats.Heif.Av1.OpenBitstreamUnit;
 
-internal class ObuDeltaLoopFilterParameters
+internal class ObuDeltaParameters
 {
     public bool IsPresent { get; internal set; }
 
diff --git a/src/ImageSharp/Formats/Heif/Av1/OpenBitstreamUnit/ObuDeltaQParameters.cs b/src/ImageSharp/Formats/Heif/Av1/OpenBitstreamUnit/ObuDeltaQParameters.cs
deleted file mode 100644
index b82bf5cf9..000000000
--- a/src/ImageSharp/Formats/Heif/Av1/OpenBitstreamUnit/ObuDeltaQParameters.cs
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright (c) Six Labors.
-// Licensed under the Six Labors Split License.
-
-namespace SixLabors.ImageSharp.Formats.Heif.Av1.OpenBitstreamUnit;
-
-internal class ObuDeltaQParameters
-{
-    public bool IsPresent { get; set; }
-
-    public int Resolution { get; set; }
-}
diff --git a/src/ImageSharp/Formats/Heif/Av1/OpenBitstreamUnit/ObuFrameHeader.cs b/src/ImageSharp/Formats/Heif/Av1/OpenBitstreamUnit/ObuFrameHeader.cs
index 7509da20a..6540ff8af 100644
--- a/src/ImageSharp/Formats/Heif/Av1/OpenBitstreamUnit/ObuFrameHeader.cs
+++ b/src/ImageSharp/Formats/Heif/Av1/OpenBitstreamUnit/ObuFrameHeader.cs
@@ -49,9 +49,9 @@ internal class ObuFrameHeader
 
     public Av1TransformMode TransformMode { get; set; }
 
-    public ObuDeltaLoopFilterParameters DeltaLoopFilterParameters { get; set; } = new ObuDeltaLoopFilterParameters();
+    public ObuDeltaParameters DeltaLoopFilterParameters { get; set; } = new ObuDeltaParameters();
 
-    public ObuDeltaQParameters DeltaQParameters { get; set; } = new ObuDeltaQParameters();
+    public ObuDeltaParameters DeltaQParameters { get; set; } = new ObuDeltaParameters();
 
     internal ObuFrameSize FrameSize { get; set; } = new ObuFrameSize();
 
diff --git a/src/ImageSharp/Formats/Heif/Av1/Tiling/Av1TileDecoder.cs b/src/ImageSharp/Formats/Heif/Av1/Tiling/Av1TileDecoder.cs
index a05aa63a0..278eb4dbb 100644
--- a/src/ImageSharp/Formats/Heif/Av1/Tiling/Av1TileDecoder.cs
+++ b/src/ImageSharp/Formats/Heif/Av1/Tiling/Av1TileDecoder.cs
@@ -30,8 +30,6 @@ internal class Av1TileDecoder : IAv1TileDecoder
     private readonly Av1ParseLeftNeighbor4x4Context leftNeighborContext;
     private int currentQuantizerIndex;
     private readonly int[][] segmentIds = [];
-    private int deltaLoopFilterResolution = -1;
-    private readonly bool readDeltas;
     private readonly int[][] transformUnitCount;
     private readonly int[] firstTransformOffset = new int[2];
     private readonly int[] coefficientIndex = [];
@@ -40,7 +38,6 @@ internal class Av1TileDecoder : IAv1TileDecoder
     {
         this.FrameInfo = frameInfo;
         this.SequenceHeader = sequenceHeader;
-        this.readDeltas = frameInfo.DeltaQParameters.IsPresent;
 
         // init_main_frame_ctxt
         this.FrameBuffer = new(this.SequenceHeader);
@@ -1420,7 +1417,7 @@ internal class Av1TileDecoder : IAv1TileDecoder
 
         this.ReadCdef(ref reader, partitionInfo);
 
-        if (this.readDeltas)
+        if (this.FrameInfo.DeltaQParameters.IsPresent)
         {
             this.ReadDeltaQuantizerIndex(ref reader, partitionInfo);
             this.ReadDeltaLoopFilter(ref reader, partitionInfo);
@@ -1756,7 +1753,8 @@ internal class Av1TileDecoder : IAv1TileDecoder
                 {
                     bool deltaLoopFilterSign = reader.ReadLiteral(1) > 0;
                     int reducedDeltaLoopFilterLevel = deltaLoopFilterSign ? -deltaLoopFilterAbsolute : deltaLoopFilterAbsolute;
-                    currentDeltaLoopFilter[i] = Av1Math.Clip3(-Av1Constants.MaxLoopFilter, Av1Constants.MaxLoopFilter, currentDeltaLoopFilter[i] + (reducedDeltaLoopFilterLevel << this.deltaLoopFilterResolution));
+                    int deltaLoopFilterResolution = this.FrameInfo.DeltaLoopFilterParameters.Resolution;
+                    currentDeltaLoopFilter[i] = Av1Math.Clip3(-Av1Constants.MaxLoopFilter, Av1Constants.MaxLoopFilter, currentDeltaLoopFilter[i] + (reducedDeltaLoopFilterLevel << deltaLoopFilterResolution));
                 }
             }
         }