Rename inverse quantization lookup class

src/ImageSharp/Formats/Heif/Av1/Pipeline/Quantification/Av1QuantizationConstants.cs → src/ImageSharp/Formats/Heif/Av1/Pipeline/Quantification/Av1InverseQuantizationLookup.cs

@@ -6,7 +6,7 @@ using SixLabors.ImageSharp.Formats.Heif.Av1.Transform;
 
 namespace SixLabors.ImageSharp.Formats.Heif.Av1.Pipeline.Quantification;
 
-internal class Av1QuantizationConstants
+internal class Av1InverseQuantizationLookup
 {
     /// <summary>
     /// Gets 16 sets of quantization matrices for chroma and luma and each TX size.
@@ -6796,6 +6796,8 @@ internal class Av1QuantizationConstants
       ]
     ];
 
-    public static int[] GetQuantizationMatrix(int level, Av1Plane plane, Av1TransformSize transformSize)
+    public static ReadOnlySpan<int> GetQuantizationMatrix(int level, Av1Plane plane, Av1TransformSize transformSize)
+
+        // Transform size must be adjusted.
         => InverseWeightTable[level][Math.Min(1, (int)plane)][(int)transformSize];
 }

src/ImageSharp/Formats/Heif/Av1/Pipeline/Quantification/Av1InverseQuantizer.cs

@@ -60,8 +60,8 @@ internal class Av1InverseQuantizer
         short dequantAc = this.deQuantsDeltaQ.GetAc(mode.SegmentId, plane);
         int qmLevel = lossless || !usingQuantizationMatrix ? Av1ScanOrderConstants.QuantizationMatrixLevelCount - 1 : this.frameHeader.QuantizationParameters.QMatrix[(int)plane];
         ReadOnlySpan<int> iqMatrix = (transformType.ToClass() == Av1TransformClass.Class2D) ?
-            Av1QuantizationConstants.GetQuantizationMatrix(qmLevel, plane, qmTransformSize)
-            : Av1QuantizationConstants.GetQuantizationMatrix(Av1Constants.QuantificationMatrixLevelCount - 1, Av1Plane.Y, qmTransformSize);
+            Av1InverseQuantizationLookup.GetQuantizationMatrix(qmLevel, plane, qmTransformSize)
+            : Av1InverseQuantizationLookup.GetQuantizationMatrix(Av1Constants.QuantificationMatrixLevelCount - 1, Av1Plane.Y, qmTransformSize);
         int shift = transformSize.GetScale();
 
         int coefficientCount = level[0];