//0 xxxxxxx // val 0 - 127 // 8 bits
//10 xxxxxxxx // val 128 - 383 // 10 bits
//11 xxxxxxxx0 // val 384 - 639 // 11 bits
//11 xxxxxxxx1 xxxx0 // val 384 - 4479 // 16 bits
//11 xxxxxxxx1 xxxx1 xxxx0 // 384 - 65919 // 21 bits
//11 xxxxxxxx1 xxxx1 xxxx1 xxxx1 xxxx1 xxxx1 xxxx1 xxxx1 xxxx1 xxxx1 xxxx1 xxxx1 xxxx1 xxxx1 xxxx0 // 81 bits worst case
public static void WriteDynamicLength(BitStreamWriter aWriter, ulong aValue)
{
if (aValue < 128)
{
aWriter.WriteBit(0);
aWriter.WriteBits(aValue, 7);
}
else if (aValue < 384)
{
aWriter.WriteBit(1);
aWriter.WriteBit(0);
aWriter.WriteBits(aValue - 128UL, 8);
}
else
{
aValue -= 384UL;
aWriter.WriteBit(1);
aWriter.WriteBit(1);
aWriter.WriteBits(aValue, 8);
aValue >>= 8;
while (aValue > 0)
{
aWriter.WriteBit(1);
aWriter.WriteBits(aValue, 4);
aValue >>= 4;
}
aWriter.WriteBit(0);
}
}
public static void ChangeDemoDir(SourceDemo demo, Stream s, string newDir)
{
void Write(byte[] buf) => s.Write(buf, 0, buf.Length);
string old = demo.Header.GameDirectory;
if (old == newDir)
{
// no difference
Write(demo.Reader.Data);
return;
}
int lenDiff = newDir.Length - old.Length;
BitStreamReader bsr = demo.Reader;
byte[] dirBytes = Encoding.ASCII.GetBytes(newDir);
Write(bsr.ReadBytes(796));
Write(dirBytes); // header doesn't matter but I change it anyway
Write(new byte[260 - newDir.Length]);
bsr.SkipBytes(260);
Write(bsr.ReadBytes(12));
byte[] tmp = BitConverter.GetBytes((uint)(bsr.ReadUInt() + lenDiff));
if (!BitConverter.IsLittleEndian)
{
tmp = tmp.Reverse().ToArray();
}
Write(tmp);
foreach (SignOn signOn in demo.FilterForPacket <SignOn>().Where(signOn => signOn.FilterForMessage <SvcServerInfo>().Any()))
{
// catch up to signOn packet
int byteCount = (signOn.Reader.AbsoluteBitIndex - bsr.AbsoluteBitIndex) / 8;
Write(bsr.ReadBytes(byteCount));
bsr.SkipBits(signOn.Reader.BitLength);
BitStreamWriter bsw = new BitStreamWriter();
BitStreamReader signOnReader = signOn.Reader;
bsw.WriteBits(signOnReader.ReadRemainingBits());
signOnReader = signOnReader.FromBeginning();
int bytesToMessageStreamSize = demo.DemoInfo.MaxSplitscreenPlayers * 76 + 8;
signOnReader.SkipBytes(bytesToMessageStreamSize);
// edit the message stream length - read uint, and edit at index before the reading of said uint
bsw.EditIntAtIndex((int)(signOnReader.ReadUInt() + lenDiff), signOnReader.CurrentBitIndex - 32, 32);
// actually change the game dir
SvcServerInfo serverInfo = signOn.FilterForMessage <SvcServerInfo>().Single();
int editIndex = serverInfo.GameDirBitIndex - signOn.Reader.AbsoluteBitIndex;
bsw.RemoveBitsAtIndex(editIndex, old.Length * 8);
bsw.InsertBitsAtIndex(dirBytes, editIndex, newDir.Length * 8);
Write(bsw.AsArray);
}
Write(bsr.ReadRemainingBits().bytes);
}
// writes a edited version of the given demo to the stream
// this is all manually hacked together and it shall stay this way for now
public static void RemoveCaptions(SourceDemo demo, Stream s)
{
void Write(byte[] buf) => s.Write(buf, 0, buf.Length);
Packet[] closeCaptionPackets = demo.FilterForPacket <Packet>()
.Where(packet => packet.FilterForMessage <SvcUserMessage>()
.Any(frame => frame.MessageType == UserMessageType.CloseCaption)).ToArray();
if (closeCaptionPackets.Length == 0)
{
Write(demo.Reader.Data);
return;
}
int changedPackets = 0;
Write(demo.Header.Reader.ReadRemainingBits().bytes);
foreach (PacketFrame frame in demo.Frames)
{
if (frame.Packet != closeCaptionPackets[changedPackets])
{
Write(frame.Reader.ReadRemainingBits().bytes); // write frames that aren't changed
}
else
{
Packet p = (Packet)frame.Packet;
BitStreamWriter bsw = new BitStreamWriter(frame.Reader.BitLength / 8);
var last = p.MessageStream.Last().message;
int len = last.Reader.AbsoluteStart - frame.Reader.AbsoluteStart + last.Reader.BitLength;
bsw.WriteBits(frame.Reader.ReadBits(len), len);
int msgSizeOffset = p.MessageStream.Reader.AbsoluteStart - frame.Reader.AbsoluteStart;
int typeInfoLen = demo.DemoInfo.NetMsgTypeBits + demo.DemoInfo.UserMessageLengthBits + 8;
bsw.RemoveBitsAtIndices(p.FilterForUserMessage <CloseCaption>()
.Select(caption => (caption.Reader.AbsoluteStart - frame.Reader.AbsoluteStart - typeInfoLen,
caption.Reader.BitLength + typeInfoLen)));
bsw.WriteUntilByteBoundary();
bsw.EditIntAtIndex((bsw.BitLength - msgSizeOffset - 32) >> 3, msgSizeOffset, 32);
Write(bsw.AsArray);
// if we've edited all the packets, write the rest of the data in the demo
if (++changedPackets == closeCaptionPackets.Length)
{
BitStreamReader tmp = demo.Reader;
tmp.SkipBits(frame.Reader.AbsoluteStart + frame.Reader.BitLength);
Write(tmp.ReadRemainingBits().bytes);
break;
}
}
}
}
public void WriteBits()
{
var random = new Random(0);
for (int i = 0; i < Iterations; i++)
{
int skip = i % 16;
BitStreamWriter bsw = new BitStreamWriter();
bsw.WriteBitsFromSInt(random.Next(), skip);
int bitLen = random.Next(1, 100);
byte[] rand = new byte[(bitLen >> 3) + ((bitLen & 0x07) == 0 ? 0 : 1)];
random.NextBytes(rand);
bsw.WriteBits(rand, bitLen);
if ((bitLen & 0x07) != 0)
{
rand[^ 1] &= (byte)(0xff >> (8 - (bitLen & 0x07))); // get rid of unused bits
public static byte[] Encode(byte[] aData)
{
using (MemoryStream data = new MemoryStream())
{
BitStreamWriter writer = new BitStreamWriter(data);
var leaves = Analyze(aData);
var tree = GenerateTree(leaves);
tree.Serialize(writer);
WriteDynamicLength(writer, (ulong)aData.LongLength);
var lookup = GenerateLookup(leaves);
for (int i = 0; i < aData.Length; i++)
{
var n = lookup[aData[i]];
writer.WriteBits(n.bitPattern, n.bitCount);
}
writer.Flush();
return(data.ToArray());
}
}
public void SkipBits()
{
var random = new Random(0);
BitStreamWriter bsw = new BitStreamWriter();
List <(int skipCount, uint val)> data = new List <(int skipCount, uint val)>();
byte[] randArr = new byte[100 / 8 + 1];
random.NextBytes(randArr);
for (int _ = 0; _ < Iterations; _++)
{
(int skip, uint val)r = (random.Next(0, 100), (uint)random.Next());
data.Add(r);
bsw.WriteBits(randArr, r.skip);
bsw.WriteUInt(r.val);
}
BitStreamReader bsr = new BitStreamReader(bsw);
for (int i = 0; i < Iterations; i++)
{
bsr.SkipBits(data[i].skipCount);
Assert.AreEqual(data[i].val, bsr.ReadUInt(), $"index: {i}");
}
}
/// <summary>
/// Decodes a single pixel row.
/// </summary>
public byte[] DecodeRow(byte[] data)
{
m_Reset(CCITT4DecoderState.White);
var reader = new BitStreamReaderReverse(new MemoryStream(data));
var writer = new BitStreamWriter(new MemoryStream());
while (reader.Position < reader.Length)
{
// read a bit
m_CurrentValue = (m_CurrentValue << 1) | reader.ReadBit();
m_CurrentBitLength++;
if (m_CurrentBitLength > 13)
{
throw new FormatException();
}
// did we get a EndOfLine code ?
if ((m_CurrentBitLength == EOL[1]) && (m_CurrentValue == EOL[0]))
{
m_Reset(0);
continue;
}
if (m_State == 0)
{
// white makeup search
for (int i = 0; i < WhiteMakeUpCodes.GetLength(0); i++)
{
if ((WhiteMakeUpCodes[i, 1] == m_CurrentBitLength) &&
(WhiteMakeUpCodes[i, 0] == m_CurrentValue))
{
writer.WriteBits(WhiteMakeUpCodes[i, 2], true);
m_Reset(CCITT4DecoderState.WhiteTerminationRequired);
break;
}
}
if (m_State != 0)
{
continue;
}
}
if ((int)m_State <= 1)
{
// white termination search
for (int i = 0; i < WhiteTerminatingCodes.GetLength(0); i++)
{
if ((WhiteTerminatingCodes[i, 1] == m_CurrentBitLength) &&
(WhiteTerminatingCodes[i, 0] == m_CurrentValue))
{
writer.WriteBits(i, true);
m_Reset(CCITT4DecoderState.Black);
break;
}
}
if ((int)m_State != 1)
{
continue;
}
}
if ((int)m_State == 2)
{
// black makeup search
for (int i = 0; i < BlackMakeUpCodes.GetLength(0); i++)
{
if ((BlackMakeUpCodes[i, 1] == m_CurrentBitLength) &&
(BlackMakeUpCodes[i, 0] == m_CurrentValue))
{
writer.WriteBits(BlackMakeUpCodes[i, 2], false);
m_Reset(CCITT4DecoderState.BlackTerminationRequired);
break;
}
}
if ((int)m_State != 2)
{
continue;
}
}
if ((int)m_State >= 2)
{
// black termination search
for (int i = 0; i < BlackTerminatingCodes.GetLength(0); i++)
{
if ((BlackTerminatingCodes[i, 1] == m_CurrentBitLength) &&
(BlackTerminatingCodes[i, 0] == m_CurrentValue))
{
writer.WriteBits(i, false);
m_Reset(CCITT4DecoderState.White);
break;
}
}
if ((int)m_State != 3)
{
continue;
}
}
}
return(((MemoryStream)writer.BaseStream).ToArray());
}
/// <summary>
/// Creates a 32x32 fingerprint for the specified bitmap.
/// </summary>
/// <param name="bitmap">The bitmap.</param>
/// <returns>Returns a fingerprint with 6 bits per pixel (32 px = 6144 bit = 768 byte = 1024 base32 chars).</returns>
public static FingerPrint Create(IBitmap32 bitmap)
{
using (Bitmap32 thumb = bitmap.Resize(32, 32, ResizeMode.TouchFromInside))
{
ARGBImageData data = thumb.Data;
using (var ms = new MemoryStream())
{
// calculate fingerprint and distance matrix
var writer = new BitStreamWriter(ms);
float[] distanceMatrix = new float[16];
{
int x = 0, y = 0;
ARGB last = 0;
foreach (ARGB pixel in data.Data)
{
if (++x > 15)
{
x = 0;
++y;
}
int r = pixel.Red >> 6;
int g = pixel.Green >> 6;
int b = pixel.Blue >> 6;
writer.WriteBits(r, 2);
writer.WriteBits(g, 2);
writer.WriteBits(b, 2);
unchecked
{
int i = ((y << 1) & 0xC) + (x >> 2);
float distance = Math.Abs(pixel.GetDistance(last));
distanceMatrix[i] += distance;
last = pixel;
}
}
}
// normalize matrix
float maxDistance = distanceMatrix.Max();
for (int i = 0; i < distanceMatrix.Length; i++)
{
distanceMatrix[i] /= maxDistance;
}
// calculate blocks
uint[] blocks = new uint[4];
int[] index = new int[] { 0, 2, 8, 10 };
for (int i = 0; i < 4; i++)
{
int idx = index[i];
uint blockValue = (uint)(255 * distanceMatrix[idx]) << 24;
blockValue |= (uint)(255 * distanceMatrix[idx + 1]) << 16;
blockValue |= (uint)(255 * distanceMatrix[idx + 4]) << 8;
blockValue |= (uint)(255 * distanceMatrix[idx + 5]);
blocks[i] = blockValue;
}
/*
* uint b1 = (uint)(uint.MaxValue * (distanceMatrix[0] + distanceMatrix[1] + distanceMatrix[4] + distanceMatrix[5]) /4);
* uint b2 = (uint)(uint.MaxValue * (distanceMatrix[3] + distanceMatrix[2] + distanceMatrix[7] + distanceMatrix[6]) / 4);
* uint b3 = (uint)(uint.MaxValue * (distanceMatrix[12] + distanceMatrix[13] + distanceMatrix[8] + distanceMatrix[9]) / 4);
* uint b4 = (uint)(uint.MaxValue * (distanceMatrix[15] + distanceMatrix[14] + distanceMatrix[11] + distanceMatrix[10]) / 4);
*/
return(new FingerPrint(32, blocks, ms.ToArray()));
}
}
}
public static void WriteByte(this BitStreamWriter writer, Byte value)
{
writer.WriteBits(value, 8);
}
public static void WriteFloat32(this BitStreamWriter writer, Single value)
{
writer.WriteBits(BitConverterX.Float32ToUInt32(value), 32);
}
public static void WriteUInt32(this BitStreamWriter writer, UInt32 value)
{
writer.WriteBits(value, 32);
}
public static void WriteUInt16(this BitStreamWriter writer, UInt16 value)
{
writer.WriteBits(value, 16);
}
public static void WriteInt32(this BitStreamWriter writer, Int32 value)
{
writer.WriteBits(BitConverterX.Int32ToUInt32(value), 32);
}
public static void WriteChar(this BitStreamWriter writer, Char value)
{
writer.WriteBits(value, 16);
}
public void Serialize(BitStreamWriter aWriter)
{
aWriter.WriteBit(1);
aWriter.WriteBits(data, 8);
}