public override void WriteHeader(Bitstream bitstream, Datastream data, Header.HeaderFlags headerFlags)
{
Header.WriteUniversalHeader(bitstream, data, headerFlags);
if (data.Count == 0)
{
return;
}
// make code tree
var tree = MakeTree(data);
// walk tree assigning codewords
AssignBitStrings(tree);
// get leaf nodes, which are the symbols
// after this the rest of the tree is not needed
leaves.Clear();
GetLeaves(tree);
MakeCanonical(leaves); // relabel codewords into canonical ordering
// write symbol table
// must have canonical labeled leaves
bitstream.WriteStream(MakeTable(leaves));
// prepare to add rest of data
if (Options.HasFlag(OptionFlags.DumpEncoding))
{
WriteLine("Huff encode: [");
}
}
public override uint ReadHeader(Bitstream bitstream, Header.HeaderFlags headerFlags)
{
var header = Header.ReadUniversalHeader(bitstream, headerFlags);
Parameter = UniversalCodec.Lomont.DecodeLomont1(bitstream, Lomont1Parameter, 0);
return(header.Item1); // total items
}
// end encoding notes http://www3.sympatico.ca/mt0000/biacode/biacode.html
// and http://bijective.dogma.net/compres10.htm
/// <summary>
/// Write the header for the compression algorithm
/// </summary>
/// <param name="bitstream"></param>
/// <param name="data"></param>
/// <param name="headerFlags">Flags telling what to put in the header. Useful when embedding in other streams.</param>
/// <returns></returns>
public override void WriteHeader(Bitstream bitstream, Datastream data, Header.HeaderFlags headerFlags)
{
// count occurrences to get probabilities
counts = new uint[data.Max() + 1];
foreach (var b in data)
{
counts[b]++;
}
total = (uint)data.Count; // total frequency
MakeSums();
ResetCoder();
// arithmetic gets total probability from the header, so ensure it gets saved
headerFlags |= Header.HeaderFlags.SymbolCount;
Header.WriteUniversalHeader(bitstream, data, headerFlags);
// we'll insert the bitlength of what follows at this spot during the footer
whereToInsertBitlength = bitstream.Position;
// write freq tables
var tables = MakeFrequencyTable();
bitstream.WriteStream(tables);
if (Options.HasFlag(OptionFlags.DumpState))
{
Write("Enc: ");
}
}
/// <summary>
/// Read the header for the compression algorithm
/// Return number of symbols in stream if known, else 0 if not present
/// </summary>
/// <param name="bitstream"></param>
/// <param name="headerFlags">Flags telling what to put in the header. Useful when embedding in other streams.</param>
/// <returns></returns>
public override uint ReadHeader(Bitstream bitstream, Header.HeaderFlags headerFlags)
{
ResetCoder();
// arithmetic gets total probability from the header, so...
headerFlags |= Header.HeaderFlags.SymbolCount;
var header = Header.ReadUniversalHeader(bitstream, headerFlags);
total = header.Item1;
bitLength = UniversalCodec.Lomont.DecodeLomont1(bitstream, 8, -1);
bitsRead = 0;
//Console.WriteLine($"Arith decode bitsize {bitLength}");
var tempPos = bitstream.Position;
DecodeTable(bitstream);
bitsRead = bitstream.Position - tempPos;
// start buffer with 31 bits
buffer = 0;
for (var i = 0; i < 31; ++i)
{
buffer = (buffer << 1) | ReadBit(bitstream);
}
if (Options.HasFlag(OptionFlags.DumpState))
{
Write("Dec: ");
}
return(total);
}
/// <summary>
/// Read the header for the compression algorithm
/// Return number of symbols in stream if known, else 0 if not present
/// </summary>
/// <param name="bitstream"></param>
/// <param name="headerFlags">Flags telling what to put in the header. Useful when embedding in other streams.</param>
/// <returns></returns>
public override uint ReadHeader(Bitstream bitstream, Header.HeaderFlags headerFlags)
{
var header = Header.ReadUniversalHeader(bitstream, headerFlags | Header.HeaderFlags.BitsPerSymbol);
uint symbolCount = header.Item1;
BitsPerSymbol = header.Item2;
return(symbolCount);
}
/// <summary>
/// Write the header for the compression algorithm
/// </summary>
/// <param name="bitstream"></param>
/// <param name="data"></param>
/// <param name="headerFlags">Flags telling what to put in the header. Useful when embedding in other streams.</param>
/// <returns></returns>
public override void WriteHeader(Bitstream bitstream, Datastream data, Header.HeaderFlags headerFlags)
{
// always store bps also
Header.WriteUniversalHeader(bitstream, data, headerFlags | Header.HeaderFlags.BitsPerSymbol);
var max = data.Any() ? data.Max() : 0;
BitsPerSymbol = BitsRequired(max);
}
/// <summary>
/// Stream version to keep from 0 padding last byte
/// </summary>
/// <param name="data"></param>
/// <param name="headerFlags">Flags telling what to put in the header. Useful when embedding in other streams.</param>
/// <returns></returns>
public Bitstream CompressToStream(Datastream data, Header.HeaderFlags headerFlags)
{
var bitstream = new Bitstream();
WriteHeader(bitstream, data, headerFlags);
foreach (var symbol in data)
{
CompressSymbol(bitstream, symbol);
}
WriteFooter(bitstream);
return(bitstream);
}
/// <summary>
/// Stream version
/// </summary>
/// <param name="bitstream"></param>
/// <param name="headerFlags"></param>
/// <returns></returns>
public Datastream DecompressFromStream(Bitstream bitstream, Header.HeaderFlags headerFlags)
{
uint symbolCount = ReadHeader(bitstream, headerFlags);
var datastream = new Datastream();
for (var i = 0U; i < symbolCount; ++i)
{
datastream.Add(DecompressSymbol(bitstream));
}
ReadFooter(bitstream);
return(datastream);
}
/// <summary>
/// Compress the data in the streams.
/// </summary>
/// <returns></returns>
private void PackHeader(Bitstream bitstream, Datastream data, Header.HeaderFlags headerFlags)
{
// actual value extremes occurring in data streams
encoderState.ActualMaxDistance = distances.Any() ? distances.Max() : 0;
encoderState.ActualMinLength = lengths.Any() ? lengths.Min() : 0;
// token (distance,length) is encoded as
// (length - actualMinLength) * (actualMaxDistance+1) + distance
// compute largest occurring token value
uint actualMaxToken = 0;
for (var i = 0; i < distances.Count; ++i)
{
uint length = lengths[i];
uint distance = distances[i];
uint token = (length - encoderState.ActualMinLength) * (encoderState.ActualMaxDistance + 1) + distance;
actualMaxToken = Math.Max(actualMaxToken, token);
}
// bit sizes
encoderState.ActualBitsPerSymbol = BitsRequired(literals.Max());
encoderState.ActualBitsPerToken = BitsRequired(actualMaxToken);
//some info to help analyze
if (Options.HasFlag(OptionFlags.DumpHeader))
{
//WriteLine("LZ77 compress:");
//WriteLine($" Data length {data.Count} ");
//WriteLine($" Bits per symbol {encoderState.actualBitsPerSymbol} ");
//WriteLine($" Bits per token {encoderState.actualBitsPerToken}");
//WriteLine($" Max token {actualMaxToken}, {lengths.Count} tokens ");
//WriteLine($" Max distance {encoderState.actualMaxDistance} ");
}
// checks
Trace.Assert(0 < encoderState.ActualBitsPerSymbol);
// header values
Header.WriteUniversalHeader(bitstream, data, headerFlags);
UniversalCodec.Lomont.EncodeLomont1(bitstream, encoderState.ActualBitsPerSymbol - 1, 3, 0); // usually 8, -1 => 7, fits in 3 bits
UniversalCodec.Lomont.EncodeLomont1(bitstream, encoderState.ActualBitsPerToken - 1, 5, 0); // around 20 or so, depends on parameters
UniversalCodec.Lomont.EncodeLomont1(bitstream, encoderState.ActualMinLength, 2, 0); // usually 2
UniversalCodec.Lomont.EncodeLomont1(bitstream, actualMaxToken, 25, -10); //
UniversalCodec.Lomont.EncodeLomont1(bitstream, encoderState.ActualMaxDistance, 14, -7); //
if (Options.HasFlag(OptionFlags.DumpHeader))
{
WriteLine("LZ77 header:");
WriteLine($" datalen {data.Count} bits/symbol {encoderState.ActualBitsPerSymbol}, bits/token {encoderState.ActualBitsPerToken}, minLen {encoderState.ActualMinLength}, max token {actualMaxToken}, max dist {encoderState.ActualMaxDistance}");
}
}
public override void WriteHeader(Bitstream bitstream, Datastream data, Header.HeaderFlags headerFlags)
{
Header.WriteUniversalHeader(bitstream, data, headerFlags);
if (Options.HasFlag(OptionFlags.Optimize))
{
Parameter = Optimize(data, headerFlags);
}
if (Options.HasFlag(OptionFlags.DumpDebug))
{
WriteLine($"Golomb encode parameter {Parameter}");
}
//Console.WriteLine("Parameter " + Parameter);
UniversalCodec.Lomont.EncodeLomont1(bitstream, Parameter, Lomont1Parameter, 0);
}
/// <summary>
/// Read the header for the compression algorithm
/// Return number of symbols in stream if known, else 0 if not present
/// </summary>
/// <param name="bitstream"></param>
/// <param name="headerFlags">Flags telling what to put in the header. Useful when embedding in other streams.</param>
/// <returns></returns>
public override uint ReadHeader(Bitstream bitstream, Header.HeaderFlags headerFlags)
{
decoderState = new DecoderState();
// read header values
var header = Header.ReadUniversalHeader(bitstream, headerFlags);
decoderState.SymbolCount = header.Item1;
// get max distance occurring, used to encode tokens, very useful to users to know window needed size
decoderState.ActualMaxDistance = UniversalCodec.Lomont.DecodeLomont1(bitstream, 10, 0);
decoderState.ActualMinLength = UniversalCodec.Lomont.DecodeLomont1(bitstream, 2, 0);
// see if decisions or decision runs
if (bitstream.Read(1) == 0)
{
decoderState.DecisionDecoder = ReadItem(bitstream);
}
else
{
// read initial value
decoderState.InitialValue = bitstream.Read(1);
// read item
decoderState.DecisionRunDecoder = ReadItem(bitstream);
}
// literals
decoderState.LiteralDecoder = ReadItem(bitstream);
// tokens or separate distance, length pairs
if (bitstream.Read(1) == 0)
{
decoderState.TokenDecoder = ReadItem(bitstream);
}
else
{
decoderState.DistanceDecoder = ReadItem(bitstream);
decoderState.LengthDecoder = ReadItem(bitstream);
}
return(decoderState.SymbolCount);
}
public override uint ReadHeader(Bitstream bitstream, Header.HeaderFlags headerFlags)
{
state = new DecompresorState();
bool useLowMemoryDecoding = Options.HasFlag(OptionFlags.UseLowMemoryDecoding);
// save stream for internal use
state.Bitstream = bitstream;
var header = Header.ReadUniversalHeader(bitstream, headerFlags);
state.SymbolLength = header.Item1;
ParseTable(state, useLowMemoryDecoding);
if (!useLowMemoryDecoding)
{
// dump table for debugging
WriteLine("Decode tree: ");
var entry = 0;
foreach (var row in state.Table)
{
++entry;
Write($" {entry,3}: {row.Item1,3} -> ");
foreach (var s in row.Item2)
{
Write($"{s,3}, ");
}
WriteLine();
}
}
if (Options.HasFlag(OptionFlags.DumpDecoding))
{
WriteLine("Huff decode [");
}
return(state.SymbolLength);
}
/// <summary>
/// Read the header for the compression algorithm
/// Return number of symbols in stream if known, else 0 if not present
/// </summary>
/// <param name="bitstream"></param>
/// <param name="headerFlags">Flags telling what to put in the header. Useful when embedding in other streams.</param>
/// <returns></returns>
public override uint ReadHeader(Bitstream bitstream, Header.HeaderFlags headerFlags)
{
var bsd = bitstream; // alias
// header values
var header = Header.ReadUniversalHeader(bitstream, headerFlags);
decoderState.ByteLength = header.Item1;
decoderState.ActualBitsPerSymbol = UniversalCodec.Lomont.DecodeLomont1(bsd, 3, 0) + 1; // usually 8, -1 => 7, fits in 3 bits
decoderState.ActualBitsPerToken = UniversalCodec.Lomont.DecodeLomont1(bsd, 5, 0) + 1; // around 20 or so, depends on parameters
decoderState.ActualMinLength = UniversalCodec.Lomont.DecodeLomont1(bsd, 2, 0); // usually 2
uint actualMaxToken = UniversalCodec.Lomont.DecodeLomont1(bsd, 25, -10); //
decoderState.ActualMaxDistance = UniversalCodec.Lomont.DecodeLomont1(bsd, 14, -7); //
if (Options.HasFlag(OptionFlags.DumpDebug))
{
//some info to help analyze
WriteLine("LZ77 decompress:");
WriteLine($" Data length {decoderState.ByteLength} ");
WriteLine($" Bits per symbol {decoderState.ActualBitsPerSymbol}");
WriteLine($" Bits per token {decoderState.ActualBitsPerToken}");
WriteLine($" Max token {actualMaxToken}");
WriteLine($" Max distance {decoderState.ActualMaxDistance}");
WriteLine($" Min length {decoderState.ActualMinLength}");
}
if (Options.HasFlag(OptionFlags.DumpDebug))
{
Write("LZ77 decode stream: ");
}
decoderState.Reset();
return(decoderState.ByteLength);
}
/// <summary>
/// Write the header for the compression algorithm
/// </summary>
/// <param name="bitstream"></param>
/// <param name="data"></param>
/// <param name="headerFlags">Flags telling what to put in the header. Useful when embedding in other streams.</param>
/// <returns></returns>
public override void WriteHeader(Bitstream bitstream, Datastream data, Header.HeaderFlags headerFlags)
{
// erase data streams
decisions.Clear();
literals.Clear();
distances.Clear();
lengths.Clear();
// fill in various data streams
ScanData(data);
// put header into stream
PackHeader(bitstream, data, headerFlags);
// start indices here
encoderState.Reset();
if (Options.HasFlag(OptionFlags.DumpEncode))
{
Write("LZ77 stream: ");
}
}
/// <summary>
/// Read the header for the compression algorithm
/// Return number of symbols in stream if known, else 0 if not present
/// </summary>
/// <param name="bitstream"></param>
/// <param name="headerFlags">Flags telling what to put in the header. Useful when embedding in other streams.</param>
/// <returns></returns>
public virtual uint ReadHeader(Bitstream bitstream, Header.HeaderFlags headerFlags)
{
return(0);
}
/// <summary>
/// try various compression on the data,
/// return list of compression results (bitLength, type, optional parameters)
/// </summary>
/// <param name="statPrefix"></param>
/// <param name="data"></param>
/// <param name="headerFlags"></param>
/// <returns></returns>
public List <Result> TestAll(string statPrefix, Datastream data, Header.HeaderFlags headerFlags)
{
var results = new List <Result>();
// perform compression algorithm
Action <string, CodecBase, Type> tryCodec = (label, codec, codecType) =>
{
var bitstream = codec.CompressToStream(data, headerFlags);
var result = new Result(label, bitstream.Length, codecType);
if (codec.GetType() == typeof(GolombCodec))
{
var g = codec as GolombCodec;
if (g != null)
{
result.Parameters.Add(g.Parameter);
result.CompressorName += $"({g.Parameter})";
}
}
results.Add(result);
};
// try compression algorithms
if (Options.HasFlag(OptionFlags.UseFixed))
{
tryCodec("Fixed size", new FixedSizeCodec(), typeof(FixedSizeCodec));
}
if (Options.HasFlag(OptionFlags.UseArithmetic))
{
tryCodec("Arithmetic", new ArithmeticCodec(), typeof(ArithmeticCodec));
}
if (Options.HasFlag(OptionFlags.UseHuffman))
{
tryCodec("Huffman", new HuffmanCodec(), typeof(HuffmanCodec));
}
if (Options.HasFlag(OptionFlags.UseGolomb) && data.Max() < GolombCodec.GolombThreshold)
{
tryCodec("Golomb", new GolombCodec(), typeof(GolombCodec));
}
/* // try Golomb encoding
* if (Options.HasFlag(OptionFlags.UseGolomb))
* {
* var bestg = UniversalCodec.Optimize(UniversalCodec.Golomb.Encode, data, 1, Math.Min(data.Max(), 256));
* var bitstream = bestg.Item1;
* var gname = $"Golomb({bestg.Item2,2})";
* results.Add(new Result(gname, bitstream.Length, typeof(GolombCodec), bestg.Item2));
* //results.Add(new Result(gname,bitstream.Length, typeof(UniversalCodec.Golomb), bestg.Item2));
* } */
Action <string, UniversalCodec.UniversalCodeDelegate, Type> tryEncoder = (label, codec, codecType) =>
{
var bitstream = UniversalCodec.CompressStream(codec, data.Select(v => v + 1).ToList());
results.Add(new Result(label, bitstream.Length, codecType));
};
// try Elias codes - all perform poorly - todo - need way to pass this back as type?
if (Options.HasFlag(OptionFlags.UseEliasDelta))
{
tryEncoder("EliasDelta", UniversalCodec.Elias.EncodeDelta, typeof(UniversalCodec.Elias));
}
if (Options.HasFlag(OptionFlags.UseEliasGamma))
{
tryEncoder("EliasGamma", UniversalCodec.Elias.EncodeGamma, typeof(UniversalCodec.Elias));
}
if (Options.HasFlag(OptionFlags.UseEliasOmega))
{
tryEncoder("EliasOmega", UniversalCodec.Elias.EncodeOmega, typeof(UniversalCodec.Elias));
}
// Stout
if (Options.HasFlag(OptionFlags.UseStout))
{
tryEncoder("Stout", (b, v) => UniversalCodec.Stout.Encode(b, v, 3), typeof(UniversalCodec.Stout));
}
// BinaryAdaptiveSequentialEncode
if (Options.HasFlag(OptionFlags.UseBasc))
{
var bitstream = new Bitstream();
UniversalCodec.BinaryAdaptiveSequentialEncode(bitstream, data, UniversalCodec.Elias.EncodeDelta);
var label = "BASC";
results.Add(new Result(label, bitstream.Length, typeof(UniversalCodec)));
}
// save stats
foreach (var result in results)
{
StatRecorder.AddStat(statPrefix + "_" + result.CompressorName, result.CompressedBitLength);
}
return(results);
}
/// <summary>
/// Write the header for the compression algorithm
/// </summary>
/// <param name="bitstream"></param>
/// <param name="data"></param>
/// <param name="headerFlags"></param>
/// <returns></returns>
public virtual void WriteHeader(Bitstream bitstream, Datastream data, Header.HeaderFlags headerFlags)
{
}
uint Optimize(Datastream data, Header.HeaderFlags headerFlags)
{
// Golomb bitlength seems to be a convex down function of the parameter:
// Let non-negative integers a1,a2,a3,..aN, parameter M. b=#bits to encode M, = Floor[log_2 M]+1
// golomb code then qi=Floor[ai/M],ri=ai-Mqi, unary encode qi in qi+1 bits, encode ri in b or b-1 bits using
// adaptive code. Then each of these is convex (true?) in M, so sum is convex, so length is convex.
// Want best parameter between M=1 (total unary) and M=max{ai} = total fixed encoding
// for large ai, unary uses lots of bits, so start at high end, 2^k=M >= max{ai}, divide by 2 until stops decreasing,
// then binary search on final range.
// todo - writeup optimal selection as blog post
var g = new GolombCodec();
g.Options &= ~OptionFlags.Optimize; // disable auto optimizer
// function to compute length given the parameter
Func <uint, uint> f = m1 =>
{
g.Parameter = m1;
var bs = g.CompressToStream(data, headerFlags);
var len1 = bs.Length;
return(len1);
};
Trace.Assert(data.Max() < 0x80000000); // needs to be true to work
// start parameters
var m = 1U << (int)BitsRequired(data.Max());
var length = f(m);
uint oldLength;
do
{
oldLength = length;
m /= 2;
length = f(m);
} while (length < oldLength && m > 1);
// now best between length and oldLength, binary search
// todo - search
Trace.Assert(m > 0);
var left = m;
var right = 2 * m;
var mid = 0U;
var a = f(left);
while (left <= right)
{
mid = (left + right) / 2;
var c = f(mid);
if (c < a)
{
left = mid + 1;
}
else
{
right = mid - 1;
}
}
if (mid == 1)
{
mid = 2;
}
// check mid, mid+1, mid-1
uint best;
if (f(mid) < f(mid + 1))
{
if (f(mid - 1) < f(mid))
{
best = mid - 1;
}
else
{
best = mid;
}
}
else
{
best = mid + 1;
}
if (Options.HasFlag(OptionFlags.DumpDebug))
{
WriteLine($"Golomb opt {mid} {f(mid-2)} {f(mid-1)} {f(mid)} {f(mid+1)} {f(mid+2)} {f(mid+3)}");
}
return(best);
}
/// <summary>
/// Write the header for the compression algorithm
/// </summary>
/// <param name="bitstream"></param>
/// <param name="data"></param>
/// <param name="headerFlags">Flags telling what to put in the header. Useful when embedding in other streams.</param>
/// <returns></returns>
public override void WriteHeader(Bitstream bitstream, Datastream data, Header.HeaderFlags headerFlags)
{
// erase data streams
decisions.Clear();
decisionRuns.Clear();
literals.Clear();
distances.Clear();
lengths.Clear();
tokens.Clear();
// fill in all the data streams
uint actualMinLength, actualMaxDistance;
ComputeStreams(data, out actualMinLength, out actualMaxDistance);
// due to the vagaries of this format, we write the entire file in the header call,
// and unfortunately ignore the encode symbol and footer sections
// dump info to help analyze
if (Options.HasFlag(OptionFlags.DumpDebug))
{
WriteLine("LZCL compress:");
WriteLine($" Data length {data.Count} ");
}
if (Options.HasFlag(OptionFlags.ShowTallies))
{
// some info to help make analyze and make decisions
Write("Length tally: ");
Tally(lengths);
WriteLine();
Write("Distance tally: ");
Tally(distances);
WriteLine();
}
// get compressed streams so we can decide what to output
var decisionChoice = GetBestCompressor("decisions", decisions);
var decisionRunsChoice = GetBestCompressor("decision runs", decisionRuns);
var literalsChoice = GetBestCompressor("literals", literals);
var tokensChoice = GetBestCompressor("tokens", tokens);
var distancesChoice = GetBestCompressor("distances", distances);
var lengthsChoice = GetBestCompressor("lengths", lengths);
// write header values
Header.WriteUniversalHeader(bitstream, data, headerFlags);
// save max distance occurring, used to encode tokens, very useful to users to know window needed size
UniversalCodec.Lomont.EncodeLomont1(bitstream, actualMaxDistance, 10, 0);
UniversalCodec.Lomont.EncodeLomont1(bitstream, actualMinLength, 2, 0);
if (Options.HasFlag(OptionFlags.DumpDebug))
{
WriteLine($"actual min length {actualMinLength}");
}
if (Options.HasFlag(OptionFlags.DumpDebug))
{
WriteLine($"Max distance {actualMaxDistance}");
}
if (decisionChoice.Item2.Length < decisionRunsChoice.Item2.Length)
{
// denote choice
bitstream.Write(0);
// save item
WriteItem(bitstream, decisionChoice);
if (Options.HasFlag(OptionFlags.DumpDebug))
{
WriteLine("Decisions smaller than decision runs");
}
StatRecorder.AddStat($"codec used: decisions {decisionChoice.Item1.Name}", 1);
}
else
{
// denote choice
bitstream.Write(1);
// save initial value
bitstream.Write(decisions[0]);
// save item
WriteItem(bitstream, decisionRunsChoice);
if (Options.HasFlag(OptionFlags.DumpDebug))
{
WriteLine("Decisions runs smaller than decisions");
}
StatRecorder.AddStat($"codec used: decision runs {decisionRunsChoice.Item1.Name}", 1);
}
// literals
WriteItem(bitstream, literalsChoice);
StatRecorder.AddStat($"codec used: literals {literalsChoice.Item1.Name}", 1);
// tokens or separate distance, length pairs
if (tokensChoice.Item2.Length < distancesChoice.Item2.Length + lengthsChoice.Item2.Length)
{
// denote choice
bitstream.Write(0);
// save item
WriteItem(bitstream, tokensChoice);
if (Options.HasFlag(OptionFlags.DumpDebug))
{
WriteLine("Tokens smaller than distance,length pairs");
}
StatRecorder.AddStat($"codec used: tokens {tokensChoice.Item1.Name}", 1);
}
else
{
// denote choice
bitstream.Write(1);
// save items
WriteItem(bitstream, distancesChoice);
WriteItem(bitstream, lengthsChoice);
if (Options.HasFlag(OptionFlags.DumpDebug))
{
WriteLine("Distance,length pairs smaller than tokens");
}
StatRecorder.AddStat($"codec used: distances {distancesChoice.Item1.Name}", 1);
StatRecorder.AddStat($"codec used: lengths {lengthsChoice.Item1.Name}", 1);
}
}