public HuffTreeNode(HUFF_STREAM stream, bool isData, long relOffset, long maxStreamPos) { if (stream.p >= maxStreamPos) { return; } int readData = stream.ReadByte(); this.data = (byte)readData; this.isData = isData; if (!this.isData) { int offset = this.data & 0x3F; bool zeroIsData = (this.data & 0x80) > 0; bool oneIsData = (this.data & 0x40) > 0; long zeroRelOffset = (relOffset ^ (relOffset & 1)) + (offset * 2) + 2; int currStreamPos = stream.p; stream.p += (int)(zeroRelOffset - relOffset) - 1; this.child0 = new HuffTreeNode(stream, zeroIsData, zeroRelOffset, maxStreamPos); this.child1 = new HuffTreeNode(stream, oneIsData, zeroRelOffset + 1, maxStreamPos); stream.p = currStreamPos; } }
/// <summary> /// Creates a new node in the Huffman tree. /// </summary> /// <param name="stream">The stream to read from. It is assumed that there is (at least) /// one more byte available to read.</param> /// <param name="isData">If this node is a data-node.</param> /// <param name="relOffset">The offset of this node in the source data, relative to the start /// of the compressed file.</param> /// <param name="maxStreamPos">The indicated end of the huffman tree. If the stream is past /// this position, the tree is invalid.</param> public HuffTreeNode(Stream stream, bool isData, long relOffset, long maxStreamPos) { /* * Tree Table (list of 8bit nodes, starting with the root node) * Root Node and Non-Data-Child Nodes are: * Bit0-5 Offset to next child node, * Next child node0 is at (CurrentAddr AND NOT 1)+Offset*2+2 * Next child node1 is at (CurrentAddr AND NOT 1)+Offset*2+2+1 * Bit6 Node1 End Flag (1=Next child node is data) * Bit7 Node0 End Flag (1=Next child node is data) * Data nodes are (when End Flag was set in parent node): * Bit0-7 Data (upper bits should be zero if Data Size is less than 8) */ if (stream.Position >= maxStreamPos) { // this happens when part of the tree is unused. this.isFilled = false; return; } this.isFilled = true; int readData = stream.ReadByte(); if (readData < 0) { throw new StreamTooShortException(); } this.data = (byte)readData; this.isData = isData; if (!this.isData) { int offset = this.data & 0x3F; bool zeroIsData = (this.data & 0x80) > 0; bool oneIsData = (this.data & 0x40) > 0; // off AND NOT 1 == off XOR (off AND 1) long zeroRelOffset = (relOffset ^ (relOffset & 1)) + offset * 2 + 2; long currStreamPos = stream.Position; // position the stream right before the 0-node stream.Position += (zeroRelOffset - relOffset) - 1; // read the 0-node this.child0 = new HuffTreeNode(stream, zeroIsData, zeroRelOffset, maxStreamPos); this.child0.Parent = this; // the 1-node is directly behind the 0-node this.child1 = new HuffTreeNode(stream, oneIsData, zeroRelOffset + 1, maxStreamPos); this.child1.Parent = this; // reset the stream position to right behind this node's data stream.Position = currStreamPos; } }
/// <summary> /// Manually creates a new node for a huffman tree. /// </summary> /// <param name="data">The data for this node.</param> /// <param name="isData">If this node represents data.</param> /// <param name="child0">The child of this node on the 0 side.</param> /// <param name="child1">The child of this node on the 1 side.</param> public HuffTreeNode(byte data, bool isData, HuffTreeNode child0, HuffTreeNode child1) { this.data = data; this.isData = isData; this.child0 = child0; this.child1 = child1; this.isFilled = true; if (!isData) { this.child0.Parent = this; this.child1.Parent = this; } }
/// <summary> /// Shifts the node at the given index one to the right. /// If the distance between parent and child becomes too large due to this shift, the parent is shifted as well. /// </summary> /// <param name="array">The array to shift the node in.</param> /// <param name="idx">The index of the node to shift.</param> /// <param name="maxOffset">The maximum distance between parent and children.</param> private void ShiftRight(HuffTreeNode[] array, int idx, int maxOffset) { HuffTreeNode node = array[idx]; if (array[idx + 1] != null) { ShiftRight(array, idx + 1, maxOffset); } if (node.Parent.index > 0 && node.index - maxOffset + 1 > node.Parent.index) { ShiftRight(array, node.Parent.index, maxOffset); } if (node != array[idx]) { return; // already done indirectly. } array[idx + 1] = array[idx]; array[idx] = null; node.index++; }
internal bool getValue(LinkedListNode <byte> code, out int value) { value = data; if (code == null) { return(node0 == null && node1 == null && data >= 0); } if (code.Value > 1) { throw new Exception(String.Format("the list should be a list of bytes < 2. got:{0:g}", code.Value)); } byte c = code.Value; bool retVal; HuffTreeNode n = c == 0 ? node0 : node1; retVal = n != null && n.getValue(code.Previous, out value); return(retVal); }
internal void parseData(BinaryReader br) { node0 = new HuffTreeNode(); node1 = new HuffTreeNode(); long currPos = br.BaseStream.Position; byte b = br.ReadByte(); long offset = b & 0x3F; bool end0 = (b & 0x80) > 0, end1 = (b & 0x40) > 0; br.BaseStream.Position = (currPos - (currPos & 1)) + offset * 2 + 2; if (br.BaseStream.Position < maxInpos) { if (end0) { node0.data = br.ReadByte(); } else { node0.parseData(br); } } br.BaseStream.Position = (currPos - (currPos & 1)) + offset * 2 + 2 + 1; if (br.BaseStream.Position < maxInpos) { if (end1) { node1.data = br.ReadByte(); } else { node1.parseData(br); } } br.BaseStream.Position = currPos; }
/// <summary> /// Applies Huffman compression with a datablock size of 8 bits. /// </summary> /// <param name="instream">The stream to compress.</param> /// <param name="inLength">The length of the input stream.</param> /// <param name="outstream">The stream to write the decompressed data to.</param> /// <returns>The size of the decompressed data.</returns> public override int Compress(Stream instream, long inLength, Stream outstream) { if (inLength > 0xFFFFFF) { throw new InputTooLargeException(); } // cache the input, as we need to build a frequency table byte[] inputData = new byte[inLength]; instream.Read(inputData, 0, (int)inLength); // build that frequency table. int[] frequencies = new int[0x100]; for (int i = 0; i < inLength; i++) { frequencies[inputData[i]]++; } #region Build the Huffman tree SimpleReversedPrioQueue <int, HuffTreeNode> leafQueue = new SimpleReversedPrioQueue <int, HuffTreeNode>(); SimpleReversedPrioQueue <int, HuffTreeNode> nodeQueue = new SimpleReversedPrioQueue <int, HuffTreeNode>(); int nodeCount = 0; // make all leaf nodes, and put them in the leaf queue. Also save them for later use. HuffTreeNode[] leaves = new HuffTreeNode[0x100]; for (int i = 0; i < 0x100; i++) { // there is no need to store leaves that are not used if (frequencies[i] == 0) { continue; } HuffTreeNode node = new HuffTreeNode((byte)i, true, null, null); leaves[i] = node; leafQueue.Enqueue(frequencies[i], node); nodeCount++; } while (leafQueue.Count + nodeQueue.Count > 1) { // get the two nodes with the lowest priority. HuffTreeNode one = null, two = null; int onePrio, twoPrio; one = GetLowest(leafQueue, nodeQueue, out onePrio); two = GetLowest(leafQueue, nodeQueue, out twoPrio); // give those two a common parent, and put that node in the node queue HuffTreeNode newNode = new HuffTreeNode(0, false, one, two); nodeQueue.Enqueue(onePrio + twoPrio, newNode); nodeCount++; } int rootPrio; HuffTreeNode root = nodeQueue.Dequeue(out rootPrio); // set the depth of all nodes in the tree, such that we know for each leaf how long // its codeword is. root.Depth = 0; #endregion // now that we have a tree, we can write that tree and follow with the data. // write the compression header first outstream.WriteByte((byte)BlockSize.EIGHTBIT); // this is block size 8 only outstream.WriteByte((byte)(inLength & 0xFF)); outstream.WriteByte((byte)((inLength >> 8) & 0xFF)); outstream.WriteByte((byte)((inLength >> 16) & 0xFF)); int compressedLength = 4; #region write the tree outstream.WriteByte((byte)((nodeCount - 1) / 2)); compressedLength++; // use a breadth-first traversal to store the tree, such that we do not need to store/calculate the size of each sub-tree. // NO! BF results in an ordering that may overflow the offset field. // find the BF order of all nodes that have two leaves as children. We're going to insert them in an array in reverse BF order, // inserting the parent whenever both children have been inserted. LinkedList <HuffTreeNode> leafStemQueue = new LinkedList <HuffTreeNode>(); #region fill the leaf queue; first->last will be reverse BF LinkedList <HuffTreeNode> nodeCodeStack = new LinkedList <HuffTreeNode>(); nodeCodeStack.AddLast(root); while (nodeCodeStack.Count > 0) { HuffTreeNode node = nodeCodeStack.First.Value; nodeCodeStack.RemoveFirst(); if (node.IsData) { continue; } if (node.Child0.IsData && node.Child1.IsData) { leafStemQueue.AddFirst(node); } else { nodeCodeStack.AddLast(node.Child0); nodeCodeStack.AddLast(node.Child1); } } #endregion HuffTreeNode[] nodeArray = new HuffTreeNode[0x1FF]; // this array does not contain the leaves themselves! while (leafStemQueue.Count > 0) { Insert(leafStemQueue.First.Value, nodeArray, 0x3F + 1); leafStemQueue.RemoveFirst(); } // update the indices to ignore all gaps int nodeIndex = 0; for (int i = 0; i < nodeArray.Length; i++) { if (nodeArray[i] != null) { nodeArray[i].index = nodeIndex++; } } // write the nodes in their given order. However when 'writing' a node, write the data of its children instead. // the root node is always the first node. byte rootData = 0; if (root.Child0.IsData) { rootData |= 0x80; } if (root.Child1.IsData) { rootData |= 0x40; } outstream.WriteByte(rootData); compressedLength++; for (int i = 0; i < nodeArray.Length; i++) { if (nodeArray[i] != null) { // nodes in this array are never data! HuffTreeNode node0 = nodeArray[i].Child0; if (node0.IsData) { outstream.WriteByte(node0.Data); } else { int offset = node0.index - nodeArray[i].index - 1; if (offset > 0x3F) { throw new Exception("Offset overflow!"); } byte data = (byte)offset; if (node0.Child0.IsData) { data |= 0x80; } if (node0.Child1.IsData) { data |= 0x40; } outstream.WriteByte(data); } HuffTreeNode node1 = nodeArray[i].Child1; if (node1.IsData) { outstream.WriteByte(node1.Data); } else { int offset = node1.index - nodeArray[i].index - 1; if (offset > 0x3F) { throw new Exception("Offset overflow!"); } byte data = (byte)offset; if (node0.Child0.IsData) { data |= 0x80; } if (node0.Child1.IsData) { data |= 0x40; } outstream.WriteByte(data); } compressedLength += 2; } } #endregion #region write the data // the codewords are stored in blocks of 32 bits uint datablock = 0; byte bitsLeftToWrite = 32; for (int i = 0; i < inLength; i++) { byte data = inputData[i]; HuffTreeNode node = leaves[data]; // the depth of the node is the length of the codeword required to encode the byte int depth = node.Depth; bool[] path = new bool[depth]; for (int d = 0; d < depth; d++) { path[depth - d - 1] = node.IsChild1; node = node.Parent; } for (int d = 0; d < depth; d++) { if (bitsLeftToWrite == 0) { outstream.Write(IOUtils.FromNDSu32(datablock), 0, 4); compressedLength += 4; datablock = 0; bitsLeftToWrite = 32; } bitsLeftToWrite--; if (path[d]) { datablock |= (uint)(1 << bitsLeftToWrite); } // no need to OR the buffer with 0 if it is child0 } } // write the partly filled data block as well if (bitsLeftToWrite != 32) { outstream.Write(IOUtils.FromNDSu32(datablock), 0, 4); compressedLength += 4; } #endregion return(compressedLength); }
/// <summary> /// Inserts the given node into the given array, in such a location that /// the offset to both of its children is at most the given maximum, and as large as possible. /// In order to do this, the contents of the array may be shifted to the right. /// </summary> /// <param name="node">The node to insert.</param> /// <param name="array">The array to insert the node in.</param> /// <param name="maxOffset">The maximum offset between parent and children.</param> private void Insert(HuffTreeNode node, HuffTreeNode[] array, int maxOffset) { // if the node has two data-children, insert it as far to the end as possible. if (node.Child0.IsData && node.Child1.IsData) { for (int i = array.Length - 1; i >= 0; i--) { if (array[i] == null) { array[i] = node; node.index = i; break; } } } else { // if the node is not data, insert it as far left as possible. // we know that both children are already present. int offset = Math.Max(node.Child0.index - maxOffset, node.Child1.index - maxOffset); offset = Math.Max(0, offset); if (offset >= node.Child0.index || offset >= node.Child1.index) { // it may be that the childen are too far apart, with lots of empty entries in-between. // shift the bottom child right until the node fits in its left-most place for the top child. // (there should be more than enough room in the array) while (offset >= Math.Min(node.Child0.index, node.Child1.index)) { ShiftRight(array, Math.Min(node.Child0.index, node.Child1.index), maxOffset); } while (array[offset] != null) { ShiftRight(array, offset, maxOffset); } array[offset] = node; node.index = offset; } else { for (int i = offset; i < node.Child0.index && i < node.Child1.index; i++) { if (array[i] == null) { array[i] = node; node.index = i; break; } } } } if (node.index < 0) { throw new Exception("Node could not be inserted!"); } // if the insertion of this node means that the parent has both children inserted, insert the parent. if (node.Parent != null) { if ((node.Parent.Child0.index >= 0 || node.Parent.Child0.IsData) && (node.Parent.Child1.index >= 0 || node.Parent.Child1.IsData)) { Insert(node.Parent, array, maxOffset); } } }
public override long Decompress(Stream instream, long inLength, Stream outstream) { #region GBATEK format specification /* Data Header (32bit) Bit0-3 Data size in bit units (normally 4 or 8) Bit4-7 Compressed type (must be 2 for Huffman) Bit8-31 24bit size of decompressed data in bytes Tree Size (8bit) Bit0-7 Size of Tree Table/2-1 (ie. Offset to Compressed Bitstream) Tree Table (list of 8bit nodes, starting with the root node) Root Node and Non-Data-Child Nodes are: Bit0-5 Offset to next child node, Next child node0 is at (CurrentAddr AND NOT 1)+Offset*2+2 Next child node1 is at (CurrentAddr AND NOT 1)+Offset*2+2+1 Bit6 Node1 End Flag (1=Next child node is data) Bit7 Node0 End Flag (1=Next child node is data) Data nodes are (when End Flag was set in parent node): Bit0-7 Data (upper bits should be zero if Data Size is less than 8) Compressed Bitstream (stored in units of 32bits) Bit0-31 Node Bits (Bit31=First Bit) (0=Node0, 1=Node1) */ #endregion long readBytes = 0; byte type = (byte)instream.ReadByte(); BlockSize blockSize = BlockSize.FOURBIT; if (type != (byte)blockSize) blockSize = BlockSize.EIGHTBIT; if (type != (byte)blockSize) throw new InvalidDataException(String.Format(Main.Get_Traduction("S05"), type.ToString("X"))); byte[] sizeBytes = new byte[3]; instream.Read(sizeBytes, 0, 3); int decompressedSize = IOUtils.ToNDSu24(sizeBytes, 0); readBytes += 4; if (decompressedSize == 0) { sizeBytes = new byte[4]; instream.Read(sizeBytes, 0, 4); decompressedSize = IOUtils.ToNDSs32(sizeBytes, 0); readBytes += 4; } #region Read the Huff-tree if (readBytes >= inLength) throw new NotEnoughDataException(0, decompressedSize); int treeSize = instream.ReadByte(); readBytes++; if (treeSize < 0) throw new InvalidDataException(Main.Get_Traduction("S06")); treeSize = (treeSize + 1) * 2; if (readBytes + treeSize >= inLength) throw new InvalidDataException(Main.Get_Traduction("S07")); long treeEnd = (instream.Position - 1) + treeSize; // the relative offset may be 4 more (when the initial decompressed size is 0), but // since it's relative that doesn't matter, especially when it only matters if // the given value is odd or even. HuffTreeNode rootNode = new HuffTreeNode(instream, false, 5, treeEnd); readBytes += treeSize; // re-position the stream after the tree (the stream is currently positioned after the root // node, which is located at the start of the tree definition) instream.Position = treeEnd; #endregion // the current u32 we are reading bits from. uint data = 0; // the amount of bits left to read from <data> byte bitsLeft = 0; // a cache used for writing when the block size is four bits int cachedByte = -1; // the current output size int currentSize = 0; HuffTreeNode currentNode = rootNode; byte[] buffer = new byte[4]; while (currentSize < decompressedSize) { #region find the next reference to a data node while (!currentNode.IsData) { // if there are no bits left to read in the data, get a new byte from the input if (bitsLeft == 0) { if (readBytes >= inLength) throw new NotEnoughDataException(currentSize, decompressedSize); int nRead = instream.Read(buffer, 0, 4); if (nRead < 4) throw new StreamTooShortException(); readBytes += nRead; data = IOUtils.ToNDSu32(buffer, 0); bitsLeft = 32; } // get the next bit bitsLeft--; bool nextIsOne = (data & (1 << bitsLeft)) != 0; // go to the next node, the direction of the child depending on the value of the current/next bit currentNode = nextIsOne ? currentNode.Child1 : currentNode.Child0; } #endregion #region write the data in the current node (when possible) switch (blockSize) { case BlockSize.EIGHTBIT: { // just copy the data if the block size is a full byte outstream.WriteByte(currentNode.Data); currentSize++; break; } case BlockSize.FOURBIT: { // cache the first half of the data if the block size is a half byte if (cachedByte < 0) { cachedByte = currentNode.Data << 4; } else { // if we already cached a half-byte, combine the two halves and write the full byte. cachedByte |= currentNode.Data; outstream.WriteByte((byte)cachedByte); currentSize++; // be sure to forget the two written half-bytes cachedByte = -1; } break; } default: throw new Exception(String.Format(Main.Get_Traduction("S08"), blockSize.ToString())); } #endregion outstream.Flush(); // make sure to start over next round currentNode = rootNode; } // the data is 4-byte aligned. Although very unlikely in this case (compressed bit blocks // are always 4 bytes long, and the tree size is generally 4-byte aligned as well), // skip any padding due to alignment. if (readBytes % 4 != 0) readBytes += 4 - (readBytes % 4); if (readBytes < inLength) { throw new TooMuchInputException(readBytes, inLength); } return decompressedSize; }
/// <summary> /// Creates a new node in the Huffman tree. /// </summary> /// <param name="stream">The stream to read from. It is assumed that there is (at least) /// one more byte available to read.</param> /// <param name="isData">If this node is a data-node.</param> /// <param name="relOffset">The offset of this node in the source data, relative to the start /// of the compressed file.</param> /// <param name="maxStreamPos">The indicated end of the huffman tree. If the stream is past /// this position, the tree is invalid.</param> public HuffTreeNode(Stream stream, bool isData, long relOffset, long maxStreamPos) { /* Tree Table (list of 8bit nodes, starting with the root node) Root Node and Non-Data-Child Nodes are: Bit0-5 Offset to next child node, Next child node0 is at (CurrentAddr AND NOT 1)+Offset*2+2 Next child node1 is at (CurrentAddr AND NOT 1)+Offset*2+2+1 Bit6 Node1 End Flag (1=Next child node is data) Bit7 Node0 End Flag (1=Next child node is data) Data nodes are (when End Flag was set in parent node): Bit0-7 Data (upper bits should be zero if Data Size is less than 8) */ if (stream.Position >= maxStreamPos) { // this happens when part of the tree is unused. this.isFilled = false; return; } this.isFilled = true; int readData = stream.ReadByte(); if (readData < 0) throw new StreamTooShortException(); this.data = (byte)readData; this.isData = isData; if (!this.isData) { int offset = this.data & 0x3F; bool zeroIsData = (this.data & 0x80) > 0; bool oneIsData = (this.data & 0x40) > 0; // off AND NOT 1 == off XOR (off AND 1) long zeroRelOffset = (relOffset ^ (relOffset & 1)) + offset * 2 + 2; long currStreamPos = stream.Position; // position the stream right before the 0-node stream.Position += (zeroRelOffset - relOffset) - 1; // read the 0-node this.child0 = new HuffTreeNode(stream, zeroIsData, zeroRelOffset, maxStreamPos); this.child0.Parent = this; // the 1-node is directly behind the 0-node this.child1 = new HuffTreeNode(stream, oneIsData, zeroRelOffset + 1, maxStreamPos); this.child1.Parent = this; // reset the stream position to right behind this node's data stream.Position = currStreamPos; } }
/// <summary> /// Applies Huffman compression with a datablock size of 8 bits. /// </summary> /// <param name="instream">The stream to compress.</param> /// <param name="inLength">The length of the input stream.</param> /// <param name="outstream">The stream to write the decompressed data to.</param> /// <returns>The size of the decompressed data.</returns> public override int Compress(Stream instream, long inLength, Stream outstream) { if (inLength > 0xFFFFFF) throw new InputTooLargeException(); // cache the input, as we need to build a frequency table byte[] inputData = new byte[inLength]; instream.Read(inputData, 0, (int)inLength); // build that frequency table. int[] frequencies = new int[0x100]; for (int i = 0; i < inLength; i++) frequencies[inputData[i]]++; #region Build the Huffman tree SimpleReversedPrioQueue<int, HuffTreeNode> leafQueue = new SimpleReversedPrioQueue<int, HuffTreeNode>(); SimpleReversedPrioQueue<int, HuffTreeNode> nodeQueue = new SimpleReversedPrioQueue<int, HuffTreeNode>(); int nodeCount = 0; // make all leaf nodes, and put them in the leaf queue. Also save them for later use. HuffTreeNode[] leaves = new HuffTreeNode[0x100]; for (int i = 0; i < 0x100; i++) { // there is no need to store leaves that are not used if (frequencies[i] == 0) continue; HuffTreeNode node = new HuffTreeNode((byte)i, true, null, null); leaves[i] = node; leafQueue.Enqueue(frequencies[i], node); nodeCount++; } while (leafQueue.Count + nodeQueue.Count > 1) { // get the two nodes with the lowest priority. HuffTreeNode one = null, two = null; int onePrio, twoPrio; one = GetLowest(leafQueue, nodeQueue, out onePrio); two = GetLowest(leafQueue, nodeQueue, out twoPrio); // give those two a common parent, and put that node in the node queue HuffTreeNode newNode = new HuffTreeNode(0, false, one, two); nodeQueue.Enqueue(onePrio + twoPrio, newNode); nodeCount++; } int rootPrio; HuffTreeNode root = nodeQueue.Dequeue(out rootPrio); // set the depth of all nodes in the tree, such that we know for each leaf how long // its codeword is. root.Depth = 0; #endregion // now that we have a tree, we can write that tree and follow with the data. // write the compression header first outstream.WriteByte((byte)BlockSize.EIGHTBIT); // this is block size 8 only outstream.WriteByte((byte)(inLength & 0xFF)); outstream.WriteByte((byte)((inLength >> 8) & 0xFF)); outstream.WriteByte((byte)((inLength >> 16) & 0xFF)); int compressedLength = 4; #region write the tree outstream.WriteByte((byte)((nodeCount - 1) / 2)); compressedLength++; // use a breadth-first traversal to store the tree, such that we do not need to store/calculate the size of each sub-tree. // NO! BF results in an ordering that may overflow the offset field. // find the BF order of all nodes that have two leaves as children. We're going to insert them in an array in reverse BF order, // inserting the parent whenever both children have been inserted. LinkedList<HuffTreeNode> leafStemQueue = new LinkedList<HuffTreeNode>(); #region fill the leaf queue; first->last will be reverse BF LinkedList<HuffTreeNode> nodeCodeStack = new LinkedList<HuffTreeNode>(); nodeCodeStack.AddLast(root); while (nodeCodeStack.Count > 0) { HuffTreeNode node = nodeCodeStack.First.Value; nodeCodeStack.RemoveFirst(); if (node.IsData) continue; if (node.Child0.IsData && node.Child1.IsData) { leafStemQueue.AddFirst(node); } else { nodeCodeStack.AddLast(node.Child0); nodeCodeStack.AddLast(node.Child1); } } #endregion HuffTreeNode[] nodeArray = new HuffTreeNode[0x1FF]; // this array does not contain the leaves themselves! while (leafStemQueue.Count > 0) { Insert(leafStemQueue.First.Value, nodeArray, 0x3F + 1); leafStemQueue.RemoveFirst(); } // update the indices to ignore all gaps int nodeIndex = 0; for (int i = 0; i < nodeArray.Length; i++) { if (nodeArray[i] != null) nodeArray[i].index = nodeIndex++; } // write the nodes in their given order. However when 'writing' a node, write the data of its children instead. // the root node is always the first node. byte rootData = 0; if (root.Child0.IsData) rootData |= 0x80; if (root.Child1.IsData) rootData |= 0x40; outstream.WriteByte(rootData); compressedLength++; for (int i = 0; i < nodeArray.Length; i++) { if (nodeArray[i] != null) { // nodes in this array are never data! HuffTreeNode node0 = nodeArray[i].Child0; if (node0.IsData) outstream.WriteByte(node0.Data); else { int offset = node0.index - nodeArray[i].index - 1; if (offset > 0x3F) throw new Exception("Offset overflow!"); byte data = (byte)offset; if (node0.Child0.IsData) data |= 0x80; if (node0.Child1.IsData) data |= 0x40; outstream.WriteByte(data); } HuffTreeNode node1 = nodeArray[i].Child1; if (node1.IsData) outstream.WriteByte(node1.Data); else { int offset = node1.index - nodeArray[i].index - 1; if (offset > 0x3F) throw new Exception("Offset overflow!"); byte data = (byte)offset; if (node0.Child0.IsData) data |= 0x80; if (node0.Child1.IsData) data |= 0x40; outstream.WriteByte(data); } compressedLength += 2; } } #endregion #region write the data // the codewords are stored in blocks of 32 bits uint datablock = 0; byte bitsLeftToWrite = 32; for (int i = 0; i < inLength; i++) { byte data = inputData[i]; HuffTreeNode node = leaves[data]; // the depth of the node is the length of the codeword required to encode the byte int depth = node.Depth; bool[] path = new bool[depth]; for (int d = 0; d < depth; d++) { path[depth - d - 1] = node.IsChild1; node = node.Parent; } for (int d = 0; d < depth; d++) { if (bitsLeftToWrite == 0) { outstream.Write(IOUtils.FromNDSu32(datablock), 0, 4); compressedLength += 4; datablock = 0; bitsLeftToWrite = 32; } bitsLeftToWrite--; if (path[d]) datablock |= (uint)(1 << bitsLeftToWrite); // no need to OR the buffer with 0 if it is child0 } } // write the partly filled data block as well if (bitsLeftToWrite != 32) { outstream.Write(IOUtils.FromNDSu32(datablock), 0, 4); compressedLength += 4; } #endregion return compressedLength; }
public static byte[] Huffman_Decompress(byte[] b, byte atype) { HUFF_STREAM instream = new HUFF_STREAM(b); long ReadBytes = 0; byte type = (byte)instream.ReadByte(); type = atype; if (type != 0x28 && type != 0x24) { return(b); } int decompressedSize = instream.readThree(); ReadBytes += 4; if (decompressedSize == 0) { instream.p -= 3; decompressedSize = instream.ReadInt32(); ReadBytes += 4; } List <byte> o = new List <byte>(); int treeSize = instream.ReadByte(); ReadBytes++; treeSize = (treeSize + 1) * 2; long treeEnd = (instream.p - 1) + treeSize; // the relative offset may be 4 more (when the initial decompressed size is 0), but // since it's relative that doesn't matter, especially when it only matters if // the given value is odd or even. HuffTreeNode rootNode = new HuffTreeNode(instream, false, 5, treeEnd); ReadBytes += treeSize; // re-position the stream after the tree (the stream is currently positioned after the root // node, which is located at the start of the tree definition) instream.p = (int)treeEnd; // the current u32 we are reading bits from. int data = 0; // the amount of bits left to read from <data> byte bitsLeft = 0; // a cache used for writing when the block size is four bits int cachedByte = -1; // the current output size HuffTreeNode currentNode = rootNode; while (instream.hasBytes()) { while (!currentNode.isData) { // if there are no bits left to read in the data, get a new byte from the input if (bitsLeft == 0) { ReadBytes += 4; data = instream.ReadInt32(); bitsLeft = 32; } // get the next bit bitsLeft--; bool nextIsOne = (data & (1 << bitsLeft)) != 0; // go to the next node, the direction of the child depending on the value of the current/next bit currentNode = nextIsOne ? currentNode.child1 : currentNode.child0; } switch (type) { case 0x28: { // just copy the data if the block size is a full byte // outstream.WriteByte(currentNode.Data); o.Add(currentNode.data); break; } case 0x24: { // cache the first half of the data if the block size is a half byte if (cachedByte < 0) { cachedByte = currentNode.data; } else { cachedByte |= currentNode.data << 4; o.Add((byte)cachedByte); cachedByte = -1; } break; } } currentNode = rootNode; } if (ReadBytes % 4 != 0) { ReadBytes += 4 - (ReadBytes % 4); } return(o.ToArray()); }
public override byte[] Decompress(byte[] buffer, int offset) { BinaryReader br = new BinaryReader(new MemoryStream(buffer, offset, buffer.Length - offset)); byte firstByte = br.ReadByte(); int dataSize = firstByte & 0x0F; if (dataSize != 8 && dataSize != 4) { throw new Exception(string.Format("Unhandled Huffman dataSize {0:x}", dataSize)); } int decomp_size = 0; for (int i = 0; i < 3; i++) { decomp_size |= br.ReadByte() << (i * 8); } byte treeSize = br.ReadByte(); HuffTreeNode.maxInpos = 4 + (treeSize + 1) * 2; HuffTreeNode rootNode = new HuffTreeNode(); rootNode.parseData(br); br.BaseStream.Position = 4 + (treeSize + 1) * 2; uint[] indata = new uint[(br.BaseStream.Length - br.BaseStream.Position) / 4]; for (int i = 0; i < indata.Length; i++) { indata[i] = br.ReadUInt32(); } long curr_size = 0; decomp_size *= dataSize == 8 ? 1 : 2; byte[] outdata = new byte[decomp_size]; int idx = -1; string codestr = ""; LinkedList <byte> code = new LinkedList <byte>(); int value; while (curr_size < decomp_size) { try { string newstr = uint_to_bits(indata[++idx]); codestr += newstr; } catch (IndexOutOfRangeException e) { throw new IndexOutOfRangeException("not enough data.", e); } while (codestr.Length > 0) { code.AddFirst(byte.Parse(codestr[0] + "")); codestr = codestr.Remove(0, 1); if (rootNode.getValue(code.Last, out value)) { try { outdata[curr_size++] = (byte)value; } catch (IndexOutOfRangeException ex) { if (code.First.Value != 0) { throw ex; } } code.Clear(); } } } br.Close(); byte[] realout; if (dataSize == 4) { realout = new byte[decomp_size / 2]; for (int i = 0; i < decomp_size / 2; i++) { if ((outdata[i * 2] & 0xF0) > 0 || (outdata[i * 2 + 1] & 0xF0) > 0) { throw new Exception("first 4 bits of data should be 0 if dataSize = 4"); } realout[i] = (byte)((outdata[i * 2] << 4) | outdata[i * 2 + 1]); } } else { realout = outdata; } return(realout); }
/// <summary> /// Inserts the given node into the given array, in such a location that /// the offset to both of its children is at most the given maximum, and as large as possible. /// In order to do this, the contents of the array may be shifted to the right. /// </summary> /// <param name="node">The node to insert.</param> /// <param name="array">The array to insert the node in.</param> /// <param name="maxOffset">The maximum offset between parent and children.</param> private void Insert(HuffTreeNode node, HuffTreeNode[] array, int maxOffset) { // if the node has two data-children, insert it as far to the end as possible. if (node.Child0.IsData && node.Child1.IsData) { for (int i = array.Length - 1; i >= 0; i--) { if (array[i] == null) { array[i] = node; node.index = i; break; } } } else { // if the node is not data, insert it as far left as possible. // we know that both children are already present. int offset = Math.Max(node.Child0.index - maxOffset, node.Child1.index - maxOffset); offset = Math.Max(0, offset); if (offset >= node.Child0.index || offset >= node.Child1.index) { // it may be that the childen are too far apart, with lots of empty entries in-between. // shift the bottom child right until the node fits in its left-most place for the top child. // (there should be more than enough room in the array) while (offset >= Math.Min(node.Child0.index, node.Child1.index)) ShiftRight(array, Math.Min(node.Child0.index, node.Child1.index), maxOffset); while (array[offset] != null) ShiftRight(array, offset, maxOffset); array[offset] = node; node.index = offset; } else { for (int i = offset; i < node.Child0.index && i < node.Child1.index; i++) { if (array[i] == null) { array[i] = node; node.index = i; break; } } } } if (node.index < 0) throw new Exception("Node could not be inserted!"); // if the insertion of this node means that the parent has both children inserted, insert the parent. if (node.Parent != null) { if ((node.Parent.Child0.index >= 0 || node.Parent.Child0.IsData) && (node.Parent.Child1.index >= 0 || node.Parent.Child1.IsData)) Insert(node.Parent, array, maxOffset); } }
/// <summary> /// Applies Huffman compression with a datablock size of 8 bits. /// </summary> /// <param name="instream">The stream to compress.</param> /// <param name="inLength">The length of the input stream.</param> /// <param name="outstream">The stream to write the decompressed data to.</param> /// <returns>The size of the decompressed data.</returns> private int Compress8(Stream instream, long inLength, Stream outstream) { if (inLength > 0xFFFFFF) { throw new InputTooLargeException(); } // cache the input, as we need to build a frequency table byte[] inputData = new byte[inLength]; instream.Read(inputData, 0, (int)inLength); // build that frequency table. int[] frequencies = new int[0x100]; for (int i = 0; i < inLength; i++) { frequencies[inputData[i]]++; } #region Build the Huffman tree SimpleReversedPrioQueue <int, HuffTreeNode> leafQueue = new SimpleReversedPrioQueue <int, HuffTreeNode>(); SimpleReversedPrioQueue <int, HuffTreeNode> nodeQueue = new SimpleReversedPrioQueue <int, HuffTreeNode>(); int nodeCount = 0; // make all leaf nodes, and put them in the leaf queue. Also save them for later use. HuffTreeNode[] leaves = new HuffTreeNode[0x100]; for (int i = 0; i < 0x100; i++) { // there is no need to store leaves that are not used if (frequencies[i] == 0) { continue; } HuffTreeNode node = new HuffTreeNode((byte)i, true, null, null); leaves[i] = node; leafQueue.Enqueue(frequencies[i], node); nodeCount++; } while (leafQueue.Count + nodeQueue.Count > 1) { // get the two nodes with the lowest priority. HuffTreeNode one = null, two = null; int onePrio, twoPrio; one = GetLowest(leafQueue, nodeQueue, out onePrio); two = GetLowest(leafQueue, nodeQueue, out twoPrio); // give those two a common parent, and put that node in the node queue HuffTreeNode newNode = new HuffTreeNode(0, false, one, two); nodeQueue.Enqueue(onePrio + twoPrio, newNode); nodeCount++; } int rootPrio; HuffTreeNode root = nodeQueue.Dequeue(out rootPrio); // set the depth of all nodes in the tree, such that we know for each leaf how long // its codeword is. root.Depth = 0; #endregion // now that we have a tree, we can write that tree and follow with the data. // write the compression header first outstream.WriteByte((byte)BlockSize.EIGHTBIT); // this is block size 8 only outstream.WriteByte((byte)(inLength & 0xFF)); outstream.WriteByte((byte)((inLength >> 8) & 0xFF)); outstream.WriteByte((byte)((inLength >> 16) & 0xFF)); int compressedLength = 4; #region write the tree outstream.WriteByte((byte)((nodeCount - 1) / 2)); compressedLength++; // use a breadth-first traversal to store the tree, such that we do not need to store/calculate the side of each sub-tree. LinkedList <HuffTreeNode> printQueue = new LinkedList <HuffTreeNode>(); printQueue.AddLast(root); while (printQueue.Count > 0) { HuffTreeNode node = printQueue.First.Value; printQueue.RemoveFirst(); if (node.IsData) { outstream.WriteByte(node.Data); } else { // bits 0-5: 'offset' = # nodes in queue left // bit 6: node1 end flag // bit 7: node0 end flag byte data = (byte)(printQueue.Count / 2); data = (byte)(data & 0x3F); if (node.Child0.IsData) { data |= 0x80; } if (node.Child1.IsData) { data |= 0x40; } outstream.WriteByte(data); printQueue.AddLast(node.Child0); printQueue.AddLast(node.Child1); } compressedLength++; } #endregion #region write the data // the codewords are stored in blocks of 32 bits uint datablock = 0; byte bitsLeftToWrite = 32; for (int i = 0; i < inLength; i++) { byte data = inputData[i]; HuffTreeNode node = leaves[data]; // the depth of the node is the length of the codeword required to encode the byte int depth = node.Depth; bool[] path = new bool[depth]; for (int d = 0; d < depth; d++) { path[depth - d - 1] = node.IsChild1; node = node.Parent; } for (int d = 0; d < depth; d++) { if (bitsLeftToWrite == 0) { outstream.Write(IOUtils.FromNDSu32(datablock), 0, 4); compressedLength += 4; datablock = 0; bitsLeftToWrite = 32; } bitsLeftToWrite--; if (path[d]) { datablock |= (uint)(1 << bitsLeftToWrite); } // no need to OR the buffer with 0 if it is child0 } } // write the partly filled data block as well if (bitsLeftToWrite != 32) { outstream.Write(IOUtils.FromNDSu32(datablock), 0, 4); compressedLength += 4; } #endregion return(compressedLength); }
public override long Decompress(Stream instream, long inLength, Stream outstream) { #region GBATEK format specification /* * Data Header (32bit) * Bit0-3 Data size in bit units (normally 4 or 8) * Bit4-7 Compressed type (must be 2 for Huffman) * Bit8-31 24bit size of decompressed data in bytes * Tree Size (8bit) * Bit0-7 Size of Tree Table/2-1 (ie. Offset to Compressed Bitstream) * Tree Table (list of 8bit nodes, starting with the root node) * Root Node and Non-Data-Child Nodes are: * Bit0-5 Offset to next child node, * Next child node0 is at (CurrentAddr AND NOT 1)+Offset*2+2 * Next child node1 is at (CurrentAddr AND NOT 1)+Offset*2+2+1 * Bit6 Node1 End Flag (1=Next child node is data) * Bit7 Node0 End Flag (1=Next child node is data) * Data nodes are (when End Flag was set in parent node): * Bit0-7 Data (upper bits should be zero if Data Size is less than 8) * Compressed Bitstream (stored in units of 32bits) * Bit0-31 Node Bits (Bit31=First Bit) (0=Node0, 1=Node1) */ #endregion long readBytes = 0; byte type = (byte)instream.ReadByte(); BlockSize blockSize = BlockSize.FOURBIT; if (type != (byte)blockSize) { blockSize = BlockSize.EIGHTBIT; } if (type != (byte)blockSize) { throw new InvalidDataException(String.Format(Main.Get_Traduction("S05"), type.ToString("X"))); } byte[] sizeBytes = new byte[3]; instream.Read(sizeBytes, 0, 3); int decompressedSize = IOUtils.ToNDSu24(sizeBytes, 0); readBytes += 4; if (decompressedSize == 0) { sizeBytes = new byte[4]; instream.Read(sizeBytes, 0, 4); decompressedSize = IOUtils.ToNDSs32(sizeBytes, 0); readBytes += 4; } #region Read the Huff-tree if (readBytes >= inLength) { throw new NotEnoughDataException(0, decompressedSize); } int treeSize = instream.ReadByte(); readBytes++; if (treeSize < 0) { throw new InvalidDataException(Main.Get_Traduction("S06")); } treeSize = (treeSize + 1) * 2; if (readBytes + treeSize >= inLength) { throw new InvalidDataException(Main.Get_Traduction("S07")); } long treeEnd = (instream.Position - 1) + treeSize; // the relative offset may be 4 more (when the initial decompressed size is 0), but // since it's relative that doesn't matter, especially when it only matters if // the given value is odd or even. HuffTreeNode rootNode = new HuffTreeNode(instream, false, 5, treeEnd); readBytes += treeSize; // re-position the stream after the tree (the stream is currently positioned after the root // node, which is located at the start of the tree definition) instream.Position = treeEnd; #endregion // the current u32 we are reading bits from. uint data = 0; // the amount of bits left to read from <data> byte bitsLeft = 0; // a cache used for writing when the block size is four bits int cachedByte = -1; // the current output size int currentSize = 0; HuffTreeNode currentNode = rootNode; byte[] buffer = new byte[4]; while (currentSize < decompressedSize) { #region find the next reference to a data node while (!currentNode.IsData) { // if there are no bits left to read in the data, get a new byte from the input if (bitsLeft == 0) { if (readBytes >= inLength) { throw new NotEnoughDataException(currentSize, decompressedSize); } int nRead = instream.Read(buffer, 0, 4); if (nRead < 4) { throw new StreamTooShortException(); } readBytes += nRead; data = IOUtils.ToNDSu32(buffer, 0); bitsLeft = 32; } // get the next bit bitsLeft--; bool nextIsOne = (data & (1 << bitsLeft)) != 0; // go to the next node, the direction of the child depending on the value of the current/next bit currentNode = nextIsOne ? currentNode.Child1 : currentNode.Child0; } #endregion #region write the data in the current node (when possible) switch (blockSize) { case BlockSize.EIGHTBIT: { // just copy the data if the block size is a full byte outstream.WriteByte(currentNode.Data); currentSize++; break; } case BlockSize.FOURBIT: { // cache the first half of the data if the block size is a half byte if (cachedByte < 0) { cachedByte = currentNode.Data << 4; } else { // if we already cached a half-byte, combine the two halves and write the full byte. cachedByte |= currentNode.Data; outstream.WriteByte((byte)cachedByte); currentSize++; // be sure to forget the two written half-bytes cachedByte = -1; } break; } default: throw new Exception(String.Format(Main.Get_Traduction("S08"), blockSize.ToString())); } #endregion outstream.Flush(); // make sure to start over next round currentNode = rootNode; } // the data is 4-byte aligned. Although very unlikely in this case (compressed bit blocks // are always 4 bytes long, and the tree size is generally 4-byte aligned as well), // skip any padding due to alignment. if (readBytes % 4 != 0) { readBytes += 4 - (readBytes % 4); } if (readBytes < inLength) { throw new TooMuchInputException(readBytes, inLength); } return(decompressedSize); }
/// <summary> /// Applies Huffman compression with a datablock size of 8 bits. /// </summary> /// <param name="instream">The stream to compress.</param> /// <param name="inLength">The length of the input stream.</param> /// <param name="outstream">The stream to write the decompressed data to.</param> /// <returns>The size of the decompressed data.</returns> private int Compress8(Stream instream, long inLength, Stream outstream) { if (inLength > 0xFFFFFF) throw new InputTooLargeException(); // cache the input, as we need to build a frequency table byte[] inputData = new byte[inLength]; instream.Read(inputData, 0, (int)inLength); // build that frequency table. int[] frequencies = new int[0x100]; for (int i = 0; i < inLength; i++) frequencies[inputData[i]]++; #region Build the Huffman tree SimpleReversedPrioQueue<int, HuffTreeNode> leafQueue = new SimpleReversedPrioQueue<int, HuffTreeNode>(); SimpleReversedPrioQueue<int, HuffTreeNode> nodeQueue = new SimpleReversedPrioQueue<int, HuffTreeNode>(); int nodeCount = 0; // make all leaf nodes, and put them in the leaf queue. Also save them for later use. HuffTreeNode[] leaves = new HuffTreeNode[0x100]; for (int i = 0; i < 0x100; i++) { // there is no need to store leaves that are not used if (frequencies[i] == 0) continue; HuffTreeNode node = new HuffTreeNode((byte)i, true, null, null); leaves[i] = node; leafQueue.Enqueue(frequencies[i], node); nodeCount++; } while (leafQueue.Count + nodeQueue.Count > 1) { // get the two nodes with the lowest priority. HuffTreeNode one = null, two = null; int onePrio, twoPrio; one = GetLowest(leafQueue, nodeQueue, out onePrio); two = GetLowest(leafQueue, nodeQueue, out twoPrio); // give those two a common parent, and put that node in the node queue HuffTreeNode newNode = new HuffTreeNode(0, false, one, two); nodeQueue.Enqueue(onePrio + twoPrio, newNode); nodeCount++; } int rootPrio; HuffTreeNode root = nodeQueue.Dequeue(out rootPrio); // set the depth of all nodes in the tree, such that we know for each leaf how long // its codeword is. root.Depth = 0; #endregion // now that we have a tree, we can write that tree and follow with the data. // write the compression header first outstream.WriteByte((byte)BlockSize.EIGHTBIT); // this is block size 8 only outstream.WriteByte((byte)(inLength & 0xFF)); outstream.WriteByte((byte)((inLength >> 8) & 0xFF)); outstream.WriteByte((byte)((inLength >> 16) & 0xFF)); int compressedLength = 4; #region write the tree outstream.WriteByte((byte)((nodeCount - 1) / 2)); compressedLength++; // use a breadth-first traversal to store the tree, such that we do not need to store/calculate the side of each sub-tree. LinkedList<HuffTreeNode> printQueue = new LinkedList<HuffTreeNode>(); printQueue.AddLast(root); while (printQueue.Count > 0) { HuffTreeNode node = printQueue.First.Value; printQueue.RemoveFirst(); if (node.IsData) { outstream.WriteByte(node.Data); } else { // bits 0-5: 'offset' = # nodes in queue left // bit 6: node1 end flag // bit 7: node0 end flag byte data = (byte)(printQueue.Count / 2); data = (byte)(data & 0x3F); if (node.Child0.IsData) data |= 0x80; if (node.Child1.IsData) data |= 0x40; outstream.WriteByte(data); printQueue.AddLast(node.Child0); printQueue.AddLast(node.Child1); } compressedLength++; } #endregion #region write the data // the codewords are stored in blocks of 32 bits uint datablock = 0; byte bitsLeftToWrite = 32; for (int i = 0; i < inLength; i++) { byte data = inputData[i]; HuffTreeNode node = leaves[data]; // the depth of the node is the length of the codeword required to encode the byte int depth = node.Depth; bool[] path = new bool[depth]; for (int d = 0; d < depth; d++) { path[depth - d - 1] = node.IsChild1; node = node.Parent; } for (int d = 0; d < depth; d++) { if (bitsLeftToWrite == 0) { outstream.Write(IOUtils.FromNDSu32(datablock), 0, 4); compressedLength += 4; datablock = 0; bitsLeftToWrite = 32; } bitsLeftToWrite--; if (path[d]) datablock |= (uint)(1 << bitsLeftToWrite); // no need to OR the buffer with 0 if it is child0 } } // write the partly filled data block as well if (bitsLeftToWrite != 32) { outstream.Write(IOUtils.FromNDSu32(datablock), 0, 4); compressedLength += 4; } #endregion return compressedLength; }
/// <summary> /// Shifts the node at the given index one to the right. /// If the distance between parent and child becomes too large due to this shift, the parent is shifted as well. /// </summary> /// <param name="array">The array to shift the node in.</param> /// <param name="idx">The index of the node to shift.</param> /// <param name="maxOffset">The maximum distance between parent and children.</param> private void ShiftRight(HuffTreeNode[] array, int idx, int maxOffset) { HuffTreeNode node = array[idx]; if (array[idx + 1] != null) ShiftRight(array, idx + 1, maxOffset); if (node.Parent.index > 0 && node.index - maxOffset + 1 > node.Parent.index) ShiftRight(array, node.Parent.index, maxOffset); if (node != array[idx]) return; // already done indirectly. array[idx + 1] = array[idx]; array[idx] = null; node.index++; }