private long OneStatPass(int width, int height, int yStride, int uvStride, Vp8RdLevel rdOpt, int nbMbs, PassStats stats)
{
Span <byte> y = this.Y.GetSpan();
Span <byte> u = this.U.GetSpan();
Span <byte> v = this.V.GetSpan();
var it = new Vp8EncIterator(this.YTop, this.UvTop, this.Nz, this.MbInfo, this.Preds, this.TopDerr, this.Mbw, this.Mbh);
long size = 0;
long sizeP0 = 0;
long distortion = 0;
long pixelCount = nbMbs * 384;
it.Init();
this.SetLoopParams(stats.Q);
var info = new Vp8ModeScore();
do
{
info.Clear();
it.Import(y, u, v, yStride, uvStride, width, height, false);
if (this.Decimate(it, ref info, rdOpt))
{
// Just record the number of skips and act like skipProba is not used.
++this.Proba.NbSkip;
}
this.RecordResiduals(it, info);
size += info.R + info.H;
sizeP0 += info.H;
distortion += info.D;
it.SaveBoundary();
}while (it.Next() && --nbMbs > 0);
sizeP0 += this.SegmentHeader.Size;
if (stats.DoSizeSearch)
{
size += this.Proba.FinalizeSkipProba(this.Mbw, this.Mbh);
size += this.Proba.FinalizeTokenProbas();
size = ((size + sizeP0 + 1024) >> 11) + HeaderSizeEstimate;
stats.Value = size;
}
else
{
stats.Value = GetPsnr(distortion, pixelCount);
}
return(sizeP0);
}
private int MacroBlockAnalysis(int width, int height, Vp8EncIterator it, Span <byte> y, Span <byte> u, Span <byte> v, int yStride, int uvStride, int[] alphas, out int uvAlpha)
{
int alpha = 0;
uvAlpha = 0;
if (!it.IsDone())
{
do
{
it.Import(y, u, v, yStride, uvStride, width, height, true);
int bestAlpha = this.MbAnalyze(it, alphas, out int bestUvAlpha);
// Accumulate for later complexity analysis.
alpha += bestAlpha;
uvAlpha += bestUvAlpha;
}while (it.Next());
}
return(alpha);
}
/// <summary>
/// Encodes the image to the specified stream from the <see cref="Image{TPixel}"/>.
/// </summary>
/// <typeparam name="TPixel">The pixel format.</typeparam>
/// <param name="image">The <see cref="Image{TPixel}"/> to encode from.</param>
/// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
public void Encode <TPixel>(Image <TPixel> image, Stream stream)
where TPixel : unmanaged, IPixel <TPixel>
{
int width = image.Width;
int height = image.Height;
Span <byte> y = this.Y.GetSpan();
Span <byte> u = this.U.GetSpan();
Span <byte> v = this.V.GetSpan();
YuvConversion.ConvertRgbToYuv(image, this.configuration, this.memoryAllocator, y, u, v);
int yStride = width;
int uvStride = (yStride + 1) >> 1;
var it = new Vp8EncIterator(this.YTop, this.UvTop, this.Nz, this.MbInfo, this.Preds, this.TopDerr, this.Mbw, this.Mbh);
int[] alphas = new int[WebpConstants.MaxAlpha + 1];
this.alpha = this.MacroBlockAnalysis(width, height, it, y, u, v, yStride, uvStride, alphas, out this.uvAlpha);
int totalMb = this.Mbw * this.Mbw;
this.alpha /= totalMb;
this.uvAlpha /= totalMb;
// Analysis is done, proceed to actual encoding.
this.SegmentHeader = new Vp8EncSegmentHeader(4);
this.AssignSegments(alphas);
this.SetLoopParams(this.quality);
// Initialize the bitwriter.
int averageBytesPerMacroBlock = this.averageBytesPerMb[this.BaseQuant >> 4];
int expectedSize = this.Mbw * this.Mbh * averageBytesPerMacroBlock;
this.bitWriter = new Vp8BitWriter(expectedSize, this);
// TODO: EncodeAlpha();
bool hasAlpha = false;
// Stats-collection loop.
this.StatLoop(width, height, yStride, uvStride);
it.Init();
it.InitFilter();
var info = new Vp8ModeScore();
var residual = new Vp8Residual();
do
{
bool dontUseSkip = !this.Proba.UseSkipProba;
info.Clear();
it.Import(y, u, v, yStride, uvStride, width, height, false);
// Warning! order is important: first call VP8Decimate() and
// *then* decide how to code the skip decision if there's one.
if (!this.Decimate(it, ref info, this.rdOptLevel) || dontUseSkip)
{
this.CodeResiduals(it, info, residual);
}
else
{
it.ResetAfterSkip();
}
it.SaveBoundary();
}while (it.Next());
// Store filter stats.
this.AdjustFilterStrength();
// Write bytes from the bitwriter buffer to the stream.
image.Metadata.SyncProfiles();
this.bitWriter.WriteEncodedImageToStream(stream, image.Metadata.ExifProfile, (uint)width, (uint)height, hasAlpha);
}