Fix H.263 SAC decoder & AV1 symbol decoder

Author: winscripter

ArithmeticCoding/ArithmeticCoding.csproj

@@ -7,7 +7,7 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
 
     <AssemblyTitle>Arithmetic Coding for .NET</AssemblyTitle>
-    <AssemblyVersion>1.0.6</AssemblyVersion>
+    <AssemblyVersion>1.0.7</AssemblyVersion>
     <Company>winscripter</Company>
     <Copyright>Copyright (c) 2023-2025, winscripter</Copyright>
     <LangVersion>14</LangVersion>
@@ -22,7 +22,7 @@
     <PackageTags>h264;h.264;cabac;entropy coding;entropy;arithmetic;arithmetic coding;av1;av1 symbol;av1 decoder;av1 symbol decoder;h.264 decoder;h264 decoder;h264 entropy;h.264 entropy;h263;h.263;h263 arithmetic;h.263 arithmetic;syntax based arithmetic;arithmetic decoder;arithmetic decoding;arithmetic encoder;arithmetic encoding;h263 sac;h.263 sac;h263 sac decoder;h.263 sac decoder;h263 sac encoder; h.263 sac encoder</PackageTags>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>
     <PackageRequireLicenseAcceptance>True</PackageRequireLicenseAcceptance>
-    <Version>1.0.6</Version>
+    <Version>1.0.7</Version>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(TargetFramework)|$(Platform)'=='Debug|netstandard2.0|AnyCPU'">

ArithmeticCoding/Av1/Av1SymbolDecoder.cs

@@ -114,7 +114,7 @@ public int ReadSymbol(Span<int> cdf)
         this.symbolValue = (int)Math.Pow(paddedData, (((this.symbolValue + 1) << bits) - 1));
         this.symbolMaxBits -= bits;
 
-        int N = cdf.Length;
+        int N = cdf.Length - 1;
 
         if (!this.disableCdfUpdate)
         {

ArithmeticCoding/H263/H263SyntaxBasedArithmeticDecoder.cs

@@ -68,7 +68,7 @@ public int DecodeSymbol(ReadOnlySpan<int> cumulativeFrequencies, IH263PscFifo ps
             this.Length = this.High - this.Low + 1;
             this.Cumulative = (-1 + (this.CodeValue - this.Low + 1) *cumulativeFrequencies[0]) / this.Length;
 
-            for (int index = 1; cumulativeFrequencies[index] > this.Cumulative; index++)
+            for (this.Index = 1; cumulativeFrequencies[this.Index] > this.Cumulative; this.Index++)
             {
             }
 
@@ -115,7 +115,7 @@ public async Task<int> DecodeSymbol(int[] cumulativeFrequencies, IH263PscFifo ps
             this.Length = this.High - this.Low + 1;
             this.Cumulative = (-1 + (this.CodeValue - this.Low + 1) * cumulativeFrequencies[0]) / this.Length;
 
-            for (int index = 1; cumulativeFrequencies[index] > this.Cumulative; index++)
+            for (this.Index = 1; cumulativeFrequencies[this.Index] > this.Cumulative; this.Index++)
             {
             }