452 lines
17 KiB
C#

//! \file ArcUnityFS.cs
//! \date Tue Apr 04 22:27:22 2017
//! \brief Unity asset archive.
//
// Copyright (C) 2017 by morkt
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//
using System;
using System.Collections.Generic;
using System.ComponentModel.Composition;
using System.IO;
using System.Linq;
using System.Text;
using GameRes.Compression;
using GameRes.Utility;
namespace GameRes.Formats.Unity
{
[Export(typeof(ArchiveFormat))]
public class UnityFSOpener : ArchiveFormat
{
public override string Tag { get { return "UNITY/FS"; } }
public override string Description { get { return "Unity game engine asset archive"; } }
public override uint Signature { get { return 0x74696E55; } } // 'UnityFS'
public override bool IsHierarchic { get { return true; } }
public override bool CanWrite { get { return false; } }
public UnityFSOpener ()
{
Extensions = new string[] { "", "unity3d", "asset" };
}
public override ArcFile TryOpen (ArcView file)
{
if (!file.View.AsciiEqual (0, "UnityFS\0"))
return null;
int arc_version = Binary.BigEndian (file.View.ReadInt32 (8));
if (arc_version != 6)
return null;
long data_offset;
byte[] index_data;
using (var input = file.CreateStream())
{
input.Position = 0xC;
input.ReadCString (Encoding.UTF8);
input.ReadCString (Encoding.UTF8);
long file_size = Binary.BigEndian (input.ReadInt64());
int packed_index_size = Binary.BigEndian (input.ReadInt32());
int index_size = Binary.BigEndian (input.ReadInt32());
int flags = Binary.BigEndian (input.ReadInt32());
long index_offset;
if (0 == (flags & 0x80))
{
index_offset = input.Position;
data_offset = index_offset + packed_index_size;
}
else
{
index_offset = file_size - packed_index_size;
data_offset = input.Position;
}
input.Position = index_offset;
var packed = input.ReadBytes (packed_index_size);
switch (flags & 0x3F)
{
case 0:
index_data = packed;
break;
case 1:
index_data = UnpackLzma (packed, index_size);
break;
case 2:
case 3:
index_data = new byte[index_size];
Lz4Compressor.DecompressBlock (packed, packed.Length, index_data, index_data.Length);
break;
default:
return null;
}
}
var index = new AssetDeserializer (file, data_offset);
using (var input = new BinMemoryStream (index_data))
index.Parse (input);
var dir = index.LoadObjects();
return new UnityBundle (file, this, dir, index.Segments, index.Bundles);
}
public override Stream OpenEntry (ArcFile arc, Entry entry)
{
var uarc = (UnityBundle)arc;
Stream input = new BundleStream (uarc.File, uarc.Segments);
input = new StreamRegion (input, entry.Offset, entry.Size);
var aent = entry as AssetEntry;
if (null == aent || !aent.IsEncrypted)
return input;
using (input)
{
var data = new byte[entry.Size];
input.Read (data, 0, data.Length);
DecryptAsset (data);
return new BinMemoryStream (data);
}
}
public override IImageDecoder OpenImage (ArcFile arc, Entry entry)
{
var aent = entry as AssetEntry;
if (null == aent || aent.AssetObject.TypeName != "Texture2D")
return base.OpenImage (arc, entry);
var uarc = (UnityBundle)arc;
var obj = aent.AssetObject;
var bundles = new BundleStream (uarc.File, uarc.Segments);
var input = new StreamRegion (bundles, obj.Offset, obj.Size);
var reader = new AssetReader (input, entry.Name);
reader.SetupReaders (obj.Asset);
Texture2D tex = null;
var type = obj.Type;
if (type != null && type.Children.Any (t => t.Type == "StreamingInfo"))
{
var fields = obj.Deserialize (reader);
tex = new Texture2D();
tex.Import (fields);
var info = fields["m_StreamData"] as StreamingInfo;
if (info != null)
{
var bundle = uarc.Bundles.FirstOrDefault (b => VFS.IsPathEqualsToFileName (info.Path, b.Name));
if (bundle != null)
{
tex.m_DataLength = (int)info.Size;
input = new StreamRegion (bundles, bundle.Offset+info.Offset, info.Size);
reader = new AssetReader (input, entry.Name);
}
}
}
if (null == tex)
{
tex = new Texture2D();
tex.Load (reader);
}
return new Texture2DDecoder (tex, reader);
}
internal static byte[] UnpackLzma (byte[] input, int unpacked_size)
{
throw new NotImplementedException();
}
internal void DecryptAsset (byte[] data)
{
uint key = 0xBF8766F5u;
for (int i = 0; i < data.Length; ++i)
{
key = ((0x343FD * key + 0x269EC3) >> 16) & 0x7FFF; // MSVC rand()
data[i] ^= (byte)key;
}
}
}
internal class BundleEntry : Entry
{
public uint Flags;
}
internal class AssetEntry : Entry
{
public BundleEntry Bundle;
public UnityObject AssetObject;
public bool IsEncrypted;
}
internal class UnityBundle : ArcFile
{
public readonly List<BundleSegment> Segments;
public readonly List<BundleEntry> Bundles;
public UnityBundle (ArcView arc, ArchiveFormat impl, ICollection<Entry> dir, List<BundleSegment> segments, List<BundleEntry> bundles)
: base (arc, impl, dir)
{
Segments = segments;
Bundles = bundles;
}
}
internal class BundleSegment
{
public long Offset;
public uint PackedSize;
public long UnpackedOffset;
public uint UnpackedSize;
public int Compression;
public bool IsCompressed { get { return (Compression & 0x3F) != 0; } }
}
internal class AssetDeserializer
{
readonly ArcView m_file;
readonly long m_data_offset;
List<BundleSegment> m_segments;
List<BundleEntry> m_bundles;
public List<BundleSegment> Segments { get { return m_segments; } }
public List<BundleEntry> Bundles { get { return m_bundles; } }
public AssetDeserializer (ArcView file, long data_offset)
{
m_file = file;
m_data_offset = data_offset;
}
public void Parse (IBinaryStream index)
{
index.Position = 16;
int segment_count = Binary.BigEndian (index.ReadInt32());
m_segments = new List<BundleSegment> (segment_count);
long packed_offset = m_data_offset;
long unpacked_offset = 0;
for (int i = 0; i < segment_count; ++i)
{
var segment = new BundleSegment();
segment.Offset = packed_offset;
segment.UnpackedOffset = unpacked_offset;
segment.UnpackedSize = Binary.BigEndian (index.ReadUInt32());
segment.PackedSize = Binary.BigEndian (index.ReadUInt32());
segment.Compression = Binary.BigEndian (index.ReadUInt16());
m_segments.Add (segment);
packed_offset += segment.PackedSize;
unpacked_offset += segment.UnpackedSize;
}
int count = Binary.BigEndian (index.ReadInt32());
m_bundles = new List<BundleEntry> (count);
for (int i = 0; i < count; ++i)
{
var entry = new BundleEntry();
entry.Offset = Binary.BigEndian (index.ReadInt64());
entry.Size = (uint)Binary.BigEndian (index.ReadInt64());
entry.Flags = Binary.BigEndian (index.ReadUInt32());
entry.Name = index.ReadCString (Encoding.UTF8);
m_bundles.Add (entry);
}
}
public List<Entry> LoadObjects ()
{
var dir = new List<Entry>();
using (var stream = new BundleStream (m_file, m_segments))
{
foreach (BundleEntry bundle in m_bundles)
{
if (bundle.Name.HasAnyOfExtensions (".resource", ".resS"))
continue;
using (var asset_stream = new StreamRegion (stream, bundle.Offset, bundle.Size, true))
using (var reader = new AssetReader (asset_stream, bundle.Name))
{
var asset = new Asset();
asset.Load (reader);
var object_dir = ParseAsset (stream, bundle, asset);
dir.AddRange (object_dir);
}
}
if (0 == dir.Count)
dir.AddRange (m_bundles);
}
return dir;
}
IEnumerable<Entry> ParseAsset (Stream file, BundleEntry bundle, Asset asset)
{
Dictionary<long, string> id_map = null;
var bundle_types = asset.Tree.TypeTrees.Where (t => t.Value.Type == "AssetBundle").Select (t => t.Key);
if (bundle_types.Any())
{
// try to read entry names from AssetBundle object
int bundle_type_id = bundle_types.First();
var asset_bundle = asset.Objects.FirstOrDefault (x => x.TypeId == bundle_type_id);
if (asset_bundle != null)
{
id_map = ReadAssetBundle (file, asset_bundle);
}
}
if (null == id_map)
id_map = new Dictionary<long, string>();
foreach (var obj in asset.Objects)
{
var entry = ReadAsset (file, obj);
if (null == entry)
continue;
if (null == entry.Bundle)
entry.Bundle = bundle;
string name;
if (!id_map.TryGetValue (obj.PathId, out name))
name = GetObjectName (file, obj);
else
name = ShortenPath (name);
entry.Name = name;
yield return entry;
}
}
AssetEntry ReadAsset (Stream file, UnityObject obj)
{
string type = obj.TypeName;
if ("AudioClip" == type)
return ReadAudioClip (file, obj);
else if ("TextAsset" == type)
return ReadTextAsset (file, obj);
else if ("Texture2D" == type)
type = "image";
else if ("AssetBundle" == type)
return null;
return new AssetEntry {
Type = type,
AssetObject = obj,
Offset = obj.Offset,
Size = obj.Size,
};
}
Dictionary<long, string> ReadAssetBundle (Stream input, UnityObject bundle)
{
using (var reader = bundle.Open (input))
{
var name = reader.ReadString(); // m_Name
reader.Align();
int count = reader.ReadInt32(); // m_PreloadTable
for (int i = 0; i < count; ++i)
{
reader.ReadInt32(); // m_FileID
reader.ReadInt64(); // m_PathID
}
count = reader.ReadInt32(); // m_Container
var id_map = new Dictionary<long, string> (count+1);
id_map[bundle.PathId] = name;
for (int i = 0; i < count; ++i)
{
name = reader.ReadString();
reader.Align();
reader.ReadInt32(); // preloadIndex
reader.ReadInt32(); // preloadSize
reader.ReadInt32(); // m_FileID
long id = reader.ReadInt64();
id_map[id] = name;
}
return id_map;
}
}
string GetObjectName (Stream input, UnityObject obj)
{
var type = obj.Type;
if (type != null && type.Children.Count > 0)
{
var first_field = type.Children[0];
if ("m_Name" == first_field.Name && "string" == first_field.Type)
{
using (var reader = obj.Open (input))
{
var name = reader.ReadString();
if (!string.IsNullOrEmpty (name))
return name;
}
}
}
return obj.PathId.ToString ("X16");
}
AssetEntry ReadTextAsset (Stream input, UnityObject obj)
{
var script = obj.Type.Children.FirstOrDefault (f => f.Name == "m_Script");
if (null == script)
return null;
using (var reader = obj.Open (input))
{
var name = reader.ReadString();
reader.Align();
uint size = reader.ReadUInt32();
var entry = new AssetEntry {
AssetObject = obj,
Offset = obj.Offset + reader.Position,
Size = size,
IsEncrypted = 0 != (script.Flags & 0x04000000),
};
if (entry.IsEncrypted)
{
uint signature = reader.ReadUInt32();
if (0x0D15F641 == signature)
entry.Type = "image";
else if (0x474E5089 == signature)
{
entry.Type = "image";
entry.IsEncrypted = false;
}
}
return entry;
}
}
AssetEntry ReadAudioClip (Stream input, UnityObject obj)
{
using (var reader = obj.Open (input))
{
var clip = new AudioClip();
clip.Load (reader);
var bundle_name = Path.GetFileName (clip.m_Source);
var bundle = m_bundles.FirstOrDefault (b => b.Name == bundle_name);
if (null == bundle)
return null;
return new AssetEntry {
Type = "audio",
Bundle = bundle,
AssetObject = obj,
Offset = bundle.Offset + clip.m_Offset,
Size = (uint)clip.m_Size,
};
}
}
/// <summary>
/// Shorten asset path to contain only the bottom directory component.
/// </summary>
static string ShortenPath (string name)
{
int slash_pos = name.LastIndexOf ('/');
if (-1 == slash_pos)
return name;
slash_pos = name.LastIndexOf ('/', slash_pos-1);
if (-1 == slash_pos)
return name;
return name.Substring (slash_pos+1);
}
}
}