public static void PickBestUv(Vp8EncIterator it, ref Vp8ModeScore rd, Vp8SegmentInfo[] segmentInfos, Vp8EncProba proba) { const int numBlocks = 8; Vp8SegmentInfo dqm = segmentInfos[it.CurrentMacroBlockInfo.Segment]; int lambda = dqm.LambdaUv; Span <byte> src = it.YuvIn.AsSpan(Vp8EncIterator.UOffEnc); Span <byte> tmpDst = it.YuvOut2.AsSpan(Vp8EncIterator.UOffEnc); Span <byte> dst0 = it.YuvOut.AsSpan(Vp8EncIterator.UOffEnc); Span <byte> dst = dst0; var rdBest = new Vp8ModeScore(); var rdUv = new Vp8ModeScore(); var res = new Vp8Residual(); int mode; rd.ModeUv = -1; rdBest.InitScore(); for (mode = 0; mode < WebpConstants.NumPredModes; ++mode) { rdUv.Clear(); // Reconstruct rdUv.Nz = (uint)ReconstructUv(it, dqm, rdUv, tmpDst, mode); // Compute RD-score rdUv.D = LossyUtils.Vp8_Sse16X8(src, tmpDst); rdUv.SD = 0; // not calling TDisto here: it tends to flatten areas. rdUv.H = WebpConstants.Vp8FixedCostsUv[mode]; rdUv.R = it.GetCostUv(rdUv, proba, res); if (mode > 0 && IsFlat(rdUv.UvLevels, numBlocks, WebpConstants.FlatnessLimitIUv)) { rdUv.R += WebpConstants.FlatnessPenality * numBlocks; } rdUv.SetRdScore(lambda); if (mode == 0 || rdUv.Score < rdBest.Score) { rdBest.CopyScore(rdUv); rd.ModeUv = mode; rdUv.UvLevels.CopyTo(rd.UvLevels.AsSpan()); for (int i = 0; i < 2; i++) { rd.Derr[i, 0] = rdUv.Derr[i, 0]; rd.Derr[i, 1] = rdUv.Derr[i, 1]; rd.Derr[i, 2] = rdUv.Derr[i, 2]; } Span <byte> tmp = dst; dst = tmpDst; tmpDst = tmp; } } it.SetIntraUvMode(rd.ModeUv); rd.AddScore(rdBest); if (dst != dst0) { // copy 16x8 block if needed. LossyUtils.Vp8Copy16X8(dst, dst0); } // Store diffusion errors for next block. it.StoreDiffusionErrors(rd); }