public void CalculateLevelCosts()
{
if (!this.Dirty)
{
return; // Nothing to do.
}
for (int ctype = 0; ctype < WebpConstants.NumTypes; ++ctype)
{
for (int band = 0; band < WebpConstants.NumBands; ++band)
{
for (int ctx = 0; ctx < WebpConstants.NumCtx; ++ctx)
{
Vp8ProbaArray p = this.Coeffs[ctype][band].Probabilities[ctx];
Vp8CostArray table = this.LevelCost[ctype][band].Costs[ctx];
int cost0 = ctx > 0 ? LossyUtils.Vp8BitCost(1, p.Probabilities[0]) : 0;
int costBase = LossyUtils.Vp8BitCost(1, p.Probabilities[1]) + cost0;
int v;
table.Costs[0] = (ushort)(LossyUtils.Vp8BitCost(0, p.Probabilities[1]) + cost0);
for (v = 1; v <= MaxVariableLevel; ++v)
{
table.Costs[v] = (ushort)(costBase + VariableLevelCost(v, p.Probabilities));
}
// Starting at level 67 and up, the variable part of the cost is actually constant
}
}
for (int n = 0; n < 16; ++n)
{
for (int ctx = 0; ctx < WebpConstants.NumCtx; ++ctx)
{
Vp8CostArray dst = this.RemappedCosts[ctype][n].Costs[ctx];
Vp8CostArray src = this.LevelCost[ctype][WebpConstants.Vp8EncBands[n]].Costs[ctx];
src.Costs.CopyTo(dst.Costs.AsSpan());
}
}
}
this.Dirty = false;
}
/// <summary>
/// Initializes a new instance of the <see cref="Vp8EncProba"/> class.
/// </summary>
public Vp8EncProba()
{
this.Dirty = true;
this.UseSkipProba = false;
this.Segments = new byte[3];
this.Coeffs = new Vp8BandProbas[WebpConstants.NumTypes][];
for (int i = 0; i < this.Coeffs.Length; i++)
{
this.Coeffs[i] = new Vp8BandProbas[WebpConstants.NumBands];
for (int j = 0; j < this.Coeffs[i].Length; j++)
{
this.Coeffs[i][j] = new Vp8BandProbas();
}
}
this.Stats = new Vp8Stats[WebpConstants.NumTypes][];
for (int i = 0; i < this.Coeffs.Length; i++)
{
this.Stats[i] = new Vp8Stats[WebpConstants.NumBands];
for (int j = 0; j < this.Stats[i].Length; j++)
{
this.Stats[i][j] = new Vp8Stats();
}
}
this.LevelCost = new Vp8Costs[WebpConstants.NumTypes][];
for (int i = 0; i < this.LevelCost.Length; i++)
{
this.LevelCost[i] = new Vp8Costs[WebpConstants.NumBands];
for (int j = 0; j < this.LevelCost[i].Length; j++)
{
this.LevelCost[i][j] = new Vp8Costs();
}
}
this.RemappedCosts = new Vp8Costs[WebpConstants.NumTypes][];
for (int i = 0; i < this.RemappedCosts.Length; i++)
{
this.RemappedCosts[i] = new Vp8Costs[16];
for (int j = 0; j < this.RemappedCosts[i].Length; j++)
{
this.RemappedCosts[i][j] = new Vp8Costs();
}
}
// Initialize with default probabilities.
this.Segments.AsSpan().Fill(255);
for (int t = 0; t < WebpConstants.NumTypes; ++t)
{
for (int b = 0; b < WebpConstants.NumBands; ++b)
{
for (int c = 0; c < WebpConstants.NumCtx; ++c)
{
Vp8ProbaArray dst = this.Coeffs[t][b].Probabilities[c];
for (int p = 0; p < WebpConstants.NumProbas; ++p)
{
dst.Probabilities[p] = WebpLookupTables.DefaultCoeffsProba[t, b, c, p];
}
}
}
}
}
