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//! \file ArcBGI.cs
//! \date Tue Sep 09 09:29:12 2014
//! \brief BGI/Ethornell engine archive implementation.
//
// Copyright (C) 2014 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 GameRes.Utility;
namespace GameRes.Formats.BGI
{
[Export(typeof(ArchiveFormat))]
public class ArcOpener : ArchiveFormat
{
public override string Tag { get { return "BGI"; } }
public override string Description { get { return "BGI/Ethornell engine resource archive"; } }
public override uint Signature { get { return 0x6b636150; } } // "Pack"
public override bool IsHierarchic { get { return false; } }
public override bool CanCreate { get { return false; } }
public ArcOpener ()
{
Extensions = new string[] { "arc" };
}
public override ArcFile TryOpen (ArcView file)
{
if (!file.View.AsciiEqual (4, "File "))
return null;
uint count = file.View.ReadUInt32 (12);
if (count > 0xfffff)
return null;
uint index_size = 0x20 * count;
if (index_size > file.View.Reserve (0x10, index_size))
return null;
var dir = new List<Entry> ((int)count);
long index_offset = 0x10;
long base_offset = index_offset + index_size;
for (uint i = 0; i < count; ++i)
{
string name = file.View.ReadString (index_offset, 0x10);
var entry = FormatCatalog.Instance.CreateEntry (name);
entry.Offset = base_offset + file.View.ReadUInt32 (index_offset+0x10);
entry.Size = file.View.ReadUInt32 (index_offset+0x14);
if (!entry.CheckPlacement (file.MaxOffset))
return null;
dir.Add (entry);
index_offset += 0x20;
}
return new ArcFile (file, this, dir);
}
public override Stream OpenEntry (ArcFile arc, Entry entry)
{
var entry_offset = entry.Offset;
var input = new ArcView.Frame (arc.File, entry_offset, entry.Size);
try
{
if (entry.Size > 0x220 && input.AsciiEqual (entry_offset, "DSC FORMAT 1.00\0"))
{
using (var decoder = new DscDecoder (input))
{
decoder.Unpack();
byte[] data = decoder.Output;
if (data.Length > 0x40)
{
uint data_offset = LittleEndian.ToUInt32 (data, 0);
if (data_offset < data.Length-4 && 0x20207762 == LittleEndian.ToUInt32 (data, 4))
{
if (0x5367674f == LittleEndian.ToUInt32 (data, (int)data_offset)) // 'OggS'
{
return new MemoryStream (data, (int)data_offset, data.Length-(int)data_offset, false);
}
}
}
return new MemoryStream (data, false);
}
}
if (entry.Size > 0x40)
{
uint data_offset = input.ReadUInt32 (entry_offset);
if (data_offset < entry.Size-4 && 0x20207762 == input.ReadUInt32 (entry_offset+4))
{
if (0x5367674f == input.ReadUInt32 (entry_offset+data_offset)) // 'OggS'
{
return new ArcView.ArcStream (input, entry_offset+data_offset, entry.Size-data_offset);
}
}
}
return new ArcView.ArcStream (input);
}
catch
{
input.Dispose();
throw;
}
}
}
internal sealed class DscDecoder : IDisposable
{
private Stream m_input;
private byte[] m_output;
private uint m_key;
private uint m_dst_size;
private uint m_dec_count;
private uint m_magic;
public byte[] Output { get { return m_output; } }
public DscDecoder (ArcView.Frame input)
{
m_magic = (uint)input.ReadUInt16 (input.Offset) << 16;
m_key = input.ReadUInt32 (input.Offset+0x10);
m_dst_size = input.ReadUInt32 (input.Offset+0x14);
m_dec_count = input.ReadUInt32 (input.Offset+0x18);
m_input = new ArcView.ArcStream (input, input.Offset+0x20, input.Reserved-0x20);
m_output = new byte[m_dst_size];
}
struct HuffmanCode : IComparable<HuffmanCode>
{
public ushort Code;
public ushort Depth;
public int CompareTo (HuffmanCode other)
{
int cmp = (int)Depth - (int)other.Depth;
if (0 == cmp)
cmp = (int)Code - (int)other.Code;
return cmp;
}
}
class HuffmanNode
{
public bool IsParent;
public uint Code;
public uint LeftChildIndex;
public uint RightChildIndex;
}
public void Unpack ()
{
HuffmanCode[] hcodes = new HuffmanCode[512];
HuffmanNode[] hnodes = new HuffmanNode[1023];
int leaf_node_count = 0;
for (ushort i = 0; i < 512; i++)
{
int src = m_input.ReadByte();
if (-1 == src)
throw new EndOfStreamException ("Incomplete compressed stream");
byte depth = (byte)(src - UpdateKey());
if (0 != depth)
{
hcodes[leaf_node_count].Depth = depth;
hcodes[leaf_node_count].Code = i;
leaf_node_count++;
}
}
Array.Sort (hcodes, 0, leaf_node_count);
CreateHuffmanTree (hnodes, hcodes, leaf_node_count);
HuffmanDecompress (hnodes, m_dec_count);
}
void CreateHuffmanTree (HuffmanNode[] hnodes, HuffmanCode[] hcode, int node_count)
{
uint[,] nodes_index = new uint[2,512];
uint next_node_index = 1;
int depth_nodes = 1;
uint depth = 0;
int switch_flag = 0;
nodes_index[0,0] = 0;
for (int n = 0; n < node_count; )
{
int huffman_nodes_index = switch_flag;
switch_flag ^= 1;
int child_index = switch_flag;
int depth_existed_nodes = 0;
while (hcode[n].Depth == depth)
{
var node = new HuffmanNode { IsParent = false, Code = hcode[n++].Code };
hnodes[nodes_index[huffman_nodes_index, depth_existed_nodes]] = node;
depth_existed_nodes++;
}
int depth_nodes_to_create = depth_nodes - depth_existed_nodes;
for (int i = 0; i < depth_nodes_to_create; i++)
{
var node = new HuffmanNode { IsParent = true };
nodes_index[child_index, i * 2] = node.LeftChildIndex = next_node_index++;
nodes_index[child_index, i * 2 + 1] = node.RightChildIndex = next_node_index++;
hnodes[nodes_index[huffman_nodes_index, depth_existed_nodes+i]] = node;
}
depth++;
depth_nodes = depth_nodes_to_create * 2;
}
}
int m_bits = 0;
bool GetNextBit ()
{
bool carry = 0 != (m_bits & 0x80);
m_bits <<= 1;
if (0 == (m_bits & 0xff))
{
m_bits = m_input.ReadByte();
if (-1 == m_bits)
throw new EndOfStreamException ("Invalid compressed stream");
carry = 0 != (m_bits & 0x80);
m_bits = (m_bits << 1) | 1;
}
return carry;
}
bool GetBits (int count, out int bits)
{
bits = 0;
for (int i = 0; i < count; ++i)
{
bits <<= 1;
bits |= GetNextBit() ? 1 : 0;
}
return true;
}
uint HuffmanDecompress (HuffmanNode[] hnodes, uint dec_count)
{
uint dst_ptr = 0;
for (uint k = 0; k < dec_count; k++)
{
uint node_index = 0;
do
{
if (!GetNextBit())
node_index = hnodes[node_index].LeftChildIndex;
else
node_index = hnodes[node_index].RightChildIndex;
}
while (hnodes[node_index].IsParent);
uint code = hnodes[node_index].Code;
if (code >= 256)
{
int win_pos;
if (!GetBits (12, out win_pos))
break;
uint copy_bytes = (code & 0xff) + 2;
win_pos += 2;
for (uint i = 0; i < copy_bytes; i++)
{
m_output[dst_ptr] = m_output[dst_ptr - win_pos];
dst_ptr++;
}
} else
m_output[dst_ptr++] = (byte)code;
}
return dst_ptr;
}
byte UpdateKey ()
{
uint v0 = 20021 * (m_key & 0xffff);
uint v1 = m_magic | (m_key >> 16);
v1 = v1 * 20021 + m_key * 346;
v1 = (v1 + (v0 >> 16)) & 0xffff;
m_key = (v1 << 16) + (v0 & 0xffff) + 1;
return (byte)v1;
}
#region IDisposable Members
public void Dispose ()
{
if (null != m_input)
{
m_input.Dispose();
m_input = null;
}
GC.SuppressFinalize (this);
}
#endregion
}
}