public override void Encode(IntField image, Stream output)
{
// Predictive transform
image.ArgbTo4c();
image.PredictionEnTransformXor(Seer);
// Convert to three fields' runlengths
var fields = CodecUtil.FieldcodeRunlengthsEn(image, new RunLength01MaxSmartCodec(FieldcodeSymbols), this);
// Write size
DeltaTracker pos = new DeltaTracker();
output.WriteUInt32Optim((uint)image.Width);
output.WriteUInt32Optim((uint)image.Height);
SetCounter("bytes|size", pos.Next(output.Position));
// Write probs
ulong[] probs = CodecUtil.GetFreqsForAllSections(fields, FieldcodeSymbols + 1);
probs[0] = 6;
CodecUtil.SaveFreqsCrappy(output, probs);
SetCounter("bytes|probs", pos.Next(output.Position));
// Write fields
ArithmeticSectionsCodec ac = new ArithmeticSectionsCodec(probs, 6, output);
for (int i = 0; i < fields.Count; i++)
{
ac.WriteSection(fields[i]);
SetCounter("bytes|fields|" + (i + 1), pos.Next(output.Position));
}
ac.Encode();
SetCounter("bytes|arith-err", pos.Next(output.Position));
}
public override IntField Decode(Stream input)
{
// Read size
int w = (int)input.ReadUInt32Optim();
int h = (int)input.ReadUInt32Optim();
// Read probabilities
ulong[] probs = CodecUtil.LoadFreqsCrappy(input, FieldcodeSymbols + 1);
// Read fields
ArithmeticSectionsCodec ac = new ArithmeticSectionsCodec(probs, 6);
ac.Decode(input);
var fields = new List <int[]>();
for (int i = 1; i <= 3; i++)
{
fields.Add(ac.ReadSection());
}
// Undo fieldcode
IntField transformed = CodecUtil.FieldcodeRunlengthsDe(fields, w, h, new RunLength01MaxSmartCodec(FieldcodeSymbols), this);
// Undo predictive transform
transformed.PredictionDeTransformXor(Seer);
transformed.ArgbFromField(0, 3);
return(transformed);
}
