diff --git a/ArcFormats/ArcFormats.csproj b/ArcFormats/ArcFormats.csproj
index 61a8ff7d..c065772f 100644
--- a/ArcFormats/ArcFormats.csproj
+++ b/ArcFormats/ArcFormats.csproj
@@ -14,6 +14,8 @@
     <TargetFrameworkProfile />
     <SolutionDir Condition="$(SolutionDir) == '' Or $(SolutionDir) == '*Undefined*'">..\</SolutionDir>
     <RestorePackages>true</RestorePackages>
+    <NuGetPackageImportStamp>
+    </NuGetPackageImportStamp>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -102,6 +104,9 @@
     <Reference Include="System.Data" />
     <Reference Include="System.Xml" />
     <Reference Include="WindowsBase" />
+    <Reference Include="ZstdNet, Version=1.4.5.0, Culture=neutral, processorArchitecture=MSIL">
+      <HintPath>..\packages\ZstdNet.1.4.5\lib\net45\ZstdNet.dll</HintPath>
+    </Reference>
   </ItemGroup>
   <ItemGroup>
     <Compile Include="Abel\ArcARC.cs" />
@@ -1322,6 +1327,13 @@ exit 0</PreBuildEvent>
     <PostBuildEvent>if not exist "$(TargetDir)\GameData" mkdir "$(TargetDir)\GameData"
 xcopy "$(ProjectDir)\Resources\Formats.dat" "$(TargetDir)\GameData\" /D /Y &gt;NUL</PostBuildEvent>
   </PropertyGroup>
+  <Import Project="..\packages\ZstdNet.1.4.5\build\ZstdNet.targets" Condition="Exists('..\packages\ZstdNet.1.4.5\build\ZstdNet.targets')" />
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>这台计算机上缺少此项目引用的 NuGet 程序包。使用“NuGet 程序包还原”可下载这些程序包。有关更多信息，请参见 http://go.microsoft.com/fwlink/?LinkID=322105。缺少的文件是 {0}。</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('..\packages\ZstdNet.1.4.5\build\ZstdNet.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\ZstdNet.1.4.5\build\ZstdNet.targets'))" />
+  </Target>
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.
   <Target Name="BeforeBuild">
diff --git a/ArcFormats/Nexas/ArcPAC.cs b/ArcFormats/Nexas/ArcPAC.cs
index e391cba0..fc520cc3 100644
--- a/ArcFormats/Nexas/ArcPAC.cs
+++ b/ArcFormats/Nexas/ArcPAC.cs
@@ -32,6 +32,7 @@ using System.ComponentModel.Composition;
 using GameRes.Compression;
 using GameRes.Formats.Strings;
 using GameRes.Utility;
+using ZstdNet;
 
 namespace GameRes.Formats.NeXAS
 {
@@ -42,6 +43,10 @@ namespace GameRes.Formats.NeXAS
         Huffman,
         Deflate,
         DeflateOrNone,
+
+        None2,
+        Zstd,
+        ZstdOrNone,
     }
 
     public class PacArchive : ArcFile
@@ -67,13 +72,16 @@ namespace GameRes.Formats.NeXAS
         public PacOpener ()
         {
             Signatures = new uint[] { 0x00434150, 0 };
+            Settings = new[] { PacEncoding };
         }
 
+        EncodingSetting PacEncoding = new EncodingSetting("NexasEncodingCP", "DefaultEncoding");
+
         public override ArcFile TryOpen (ArcView file)
         {
             if (!file.View.AsciiEqual (0, "PAC") || 'K' == file.View.ReadByte (3))
                 return null;
-            var reader = new IndexReader (file);
+            var reader = new IndexReader(file, PacEncoding.Get<Encoding>());
             var dir = reader.Read();
             if (null == dir)
                 return null;
@@ -88,16 +96,18 @@ namespace GameRes.Formats.NeXAS
             ArcView     m_file;
             int         m_count;
             int         m_pack_type;
+            Encoding    m_encoding;
 
             const int MaxNameLength = 0x40;
 
             public Compression PackType { get { return (Compression)m_pack_type; } }
 
-            public IndexReader (ArcView file)
+            public IndexReader (ArcView file, Encoding enc)
             {
                 m_file = file;
                 m_count = file.View.ReadInt32 (4);
                 m_pack_type = file.View.ReadInt32 (8);
+                m_encoding = enc;
             }
 
             List<Entry> m_dir;
@@ -151,7 +161,7 @@ namespace GameRes.Formats.NeXAS
                 m_dir.Clear();
                 for (int i = 0; i < m_count; ++i)
                 {
-                    var name = index.ReadCString (name_length);
+                    var name = index.ReadCString(name_length, m_encoding);
                     if (string.IsNullOrWhiteSpace (name))
                         return false;
                     var entry = FormatCatalog.Instance.Create<PackedEntry> (name);
@@ -160,7 +170,27 @@ namespace GameRes.Formats.NeXAS
                     entry.Size          = index.ReadUInt32();
                     if (!entry.CheckPlacement (m_file.MaxOffset))
                         return false;
-                    entry.IsPacked = m_pack_type != 0 && (m_pack_type != 4 || entry.Size != entry.UnpackedSize);
+
+                    bool isPacked = false;
+                    switch (m_pack_type)
+                    {
+                        case 1:
+                        case 2:
+                        case 3:
+                        case 6:
+                        {
+                            isPacked = true;
+                            break;
+                        }
+                        case 4:
+                        case 7:
+                        {
+                            isPacked = entry.Size != entry.UnpackedSize;
+                            break;
+                        }
+                    }
+                    entry.IsPacked = isPacked;
+
                     m_dir.Add (entry);
                 }
                 return true;
@@ -188,8 +218,18 @@ namespace GameRes.Formats.NeXAS
                     return new BinMemoryStream (unpacked, 0, (int)pent.UnpackedSize, entry.Name);
                 }
             case Compression.Deflate:
+            case Compression.DeflateOrNone:
+                {
+                    return new ZLibStream(input, CompressionMode.Decompress);
+                }
+            case Compression.Zstd:
+            case Compression.ZstdOrNone:
+                {
+                    byte[] unpacked = ZstdDecompress(input, pent.UnpackedSize);
+                    return new BinMemoryStream(unpacked, entry.Name);
+                }
             default:
-                return new ZLibStream (input, CompressionMode.Decompress);
+                    throw new NotImplementedException();
             }
         }
 
@@ -199,5 +239,15 @@ namespace GameRes.Formats.NeXAS
             var decoder = new HuffmanDecoder (packed, dst);
             return decoder.Unpack();
         }
+
+        static private byte[] ZstdDecompress(Stream s, uint unpackedSize)
+        {
+            using(DecompressionStream zstdDecStream = new DecompressionStream(s))
+            {
+                byte[] dest = new byte[unpackedSize];
+                zstdDecStream.Read(dest, 0, dest.Length);
+                return dest;
+            }
+        }
     }
 }
diff --git a/ArcFormats/Properties/Settings.Designer.cs b/ArcFormats/Properties/Settings.Designer.cs
index 7844d50b..814e8e4e 100644
--- a/ArcFormats/Properties/Settings.Designer.cs
+++ b/ArcFormats/Properties/Settings.Designer.cs
@@ -1,10 +1,10 @@
 //------------------------------------------------------------------------------
 // <auto-generated>
-//     This code was generated by a tool.
-//     Runtime Version:4.0.30319.42000
+//     此代码由工具生成。
+//     运行时版本:4.0.30319.42000
 //
-//     Changes to this file may cause incorrect behavior and will be lost if
-//     the code is regenerated.
+//     对此文件的更改可能会导致不正确的行为，并且如果
+//     重新生成代码，这些更改将会丢失。
 // </auto-generated>
 //------------------------------------------------------------------------------
 
@@ -12,7 +12,7 @@ namespace GameRes.Formats.Properties {
     
     
     [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]
-    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.VisualStudio.Editors.SettingsDesigner.SettingsSingleFileGenerator", "17.10.0.0")]
+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.VisualStudio.Editors.SettingsDesigner.SettingsSingleFileGenerator", "17.6.0.0")]
     public sealed partial class Settings : global::System.Configuration.ApplicationSettingsBase {
         
         private static Settings defaultInstance = ((Settings)(global::System.Configuration.ApplicationSettingsBase.Synchronized(new Settings())));
@@ -825,5 +825,17 @@ namespace GameRes.Formats.Properties {
                 this["DXAPassword"] = value;
             }
         }
+        
+        [global::System.Configuration.UserScopedSettingAttribute()]
+        [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
+        [global::System.Configuration.DefaultSettingValueAttribute("932")]
+        public int NexasEncodingCP {
+            get {
+                return ((int)(this["NexasEncodingCP"]));
+            }
+            set {
+                this["NexasEncodingCP"] = value;
+            }
+        }
     }
 }
diff --git a/ArcFormats/Properties/Settings.settings b/ArcFormats/Properties/Settings.settings
index ebd367cb..a6aa5543 100644
--- a/ArcFormats/Properties/Settings.settings
+++ b/ArcFormats/Properties/Settings.settings
@@ -203,5 +203,8 @@
     <Setting Name="DXAPassword" Type="System.String" Scope="User">
       <Value Profile="(Default)">DXARC</Value>
     </Setting>
+    <Setting Name="NexasEncodingCP" Type="System.Int32" Scope="User">
+      <Value Profile="(Default)">932</Value>
+    </Setting>
   </Settings>
 </SettingsFile>
\ No newline at end of file
diff --git a/ArcFormats/app.config b/ArcFormats/app.config
index e78ee4ea..eb7f9ea8 100644
--- a/ArcFormats/app.config
+++ b/ArcFormats/app.config
@@ -205,6 +205,9 @@
             <setting name="DXAPassword" serializeAs="String">
                 <value>DXARC</value>
             </setting>
+            <setting name="NexasEncodingCP" serializeAs="String">
+                <value>932</value>
+            </setting>
         </GameRes.Formats.Properties.Settings>
     </userSettings>
 <startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" /></startup>
diff --git a/ArcFormats/packages.config b/ArcFormats/packages.config
index c9e8b0fb..79d8b3f2 100644
--- a/ArcFormats/packages.config
+++ b/ArcFormats/packages.config
@@ -6,8 +6,10 @@
   <package id="System.IO.FileSystem" version="4.3.0" targetFramework="net46" />
   <package id="System.IO.FileSystem.Primitives" version="4.3.0" targetFramework="net46" />
   <package id="System.Memory" version="4.5.4" targetFramework="net46" />
+  <package id="System.Numerics.Vectors" version="4.5.0" targetFramework="net461" />
   <package id="System.Runtime.CompilerServices.Unsafe" version="4.6.0" targetFramework="net46" />
   <package id="System.Security.Cryptography.Algorithms" version="4.3.1" targetFramework="net46" />
   <package id="System.Security.Cryptography.Primitives" version="4.3.0" targetFramework="net46" />
   <package id="System.ValueTuple" version="4.5.0" targetFramework="net46" />
+  <package id="ZstdNet" version="1.4.5" targetFramework="net461" />
 </packages>
\ No newline at end of file