1 files changed, 1190 insertions, 0 deletions
diff --git a/Ryujinx.Graphics.Nvdec.Vp9/DecodeFrame.cs b/Ryujinx.Graphics.Nvdec.Vp9/DecodeFrame.cs
new file mode 100644
index 00000000..81c187e1
--- /dev/null
+++ b/Ryujinx.Graphics.Nvdec.Vp9/DecodeFrame.cs
@@ -0,0 +1,1190 @@
+using Ryujinx.Common.Memory;
+using System;
+using System.Buffers.Binary;
+using System.Diagnostics;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using Ryujinx.Graphics.Nvdec.Vp9.Common;
+using Ryujinx.Graphics.Nvdec.Vp9.Dsp;
+using Ryujinx.Graphics.Nvdec.Vp9.Types;
+using Ryujinx.Graphics.Video;
+using Mv = Ryujinx.Graphics.Nvdec.Vp9.Types.Mv;
+
+namespace Ryujinx.Graphics.Nvdec.Vp9
+{
+    static class DecodeFrame
+    {
+        private static bool ReadIsValid(ArrayPtr<byte> start, int len)
+        {
+            return len != 0 && len <= start.Length;
+        }
+
+        private static void InverseTransformBlockInter(ref MacroBlockD xd, int plane, TxSize txSize, Span<byte> dst, int stride, int eob)
+        {
+            ref MacroBlockDPlane pd = ref xd.Plane[plane];
+            ArrayPtr<int> dqcoeff = pd.DqCoeff;
+            Debug.Assert(eob > 0);
+            if (xd.CurBuf.HighBd)
+            {
+                Span<ushort> dst16 = MemoryMarshal.Cast<byte, ushort>(dst);
+                if (xd.Lossless)
+                {
+                    Idct.HighbdIwht4x4Add(dqcoeff.ToSpan(), dst16, stride, eob, xd.Bd);
+                }
+                else
+                {
+                    switch (txSize)
+                    {
+                        case TxSize.Tx4x4:
+                            Idct.HighbdIdct4x4Add(dqcoeff.ToSpan(), dst16, stride, eob, xd.Bd);
+                            break;
+                        case TxSize.Tx8x8:
+                            Idct.HighbdIdct8x8Add(dqcoeff.ToSpan(), dst16, stride, eob, xd.Bd);
+                            break;
+                        case TxSize.Tx16x16:
+                            Idct.HighbdIdct16x16Add(dqcoeff.ToSpan(), dst16, stride, eob, xd.Bd);
+                            break;
+                        case TxSize.Tx32x32:
+                            Idct.HighbdIdct32x32Add(dqcoeff.ToSpan(), dst16, stride, eob, xd.Bd);
+                            break;
+                        default: Debug.Assert(false, "Invalid transform size"); break;
+                    }
+                }
+            }
+            else
+            {
+                if (xd.Lossless)
+                {
+                    Idct.Iwht4x4Add(dqcoeff.ToSpan(), dst, stride, eob);
+                }
+                else
+                {
+                    switch (txSize)
+                    {
+                        case TxSize.Tx4x4: Idct.Idct4x4Add(dqcoeff.ToSpan(), dst, stride, eob); break;
+                        case TxSize.Tx8x8: Idct.Idct8x8Add(dqcoeff.ToSpan(), dst, stride, eob); break;
+                        case TxSize.Tx16x16: Idct.Idct16x16Add(dqcoeff.ToSpan(), dst, stride, eob); break;
+                        case TxSize.Tx32x32: Idct.Idct32x32Add(dqcoeff.ToSpan(), dst, stride, eob); break;
+                        default: Debug.Assert(false, "Invalid transform size"); return;
+                    }
+                }
+            }
+
+            if (eob == 1)
+            {
+                dqcoeff.ToSpan()[0] = 0;
+            }
+            else
+            {
+                if (txSize <= TxSize.Tx16x16 && eob <= 10)
+                {
+                    dqcoeff.ToSpan().Slice(0, 4 * (4 << (int)txSize)).Fill(0);
+                }
+                else if (txSize == TxSize.Tx32x32 && eob <= 34)
+                {
+                    dqcoeff.ToSpan().Slice(0, 256).Fill(0);
+                }
+                else
+                {
+                    dqcoeff.ToSpan().Slice(0, 16 << ((int)txSize << 1)).Fill(0);
+                }
+            }
+        }
+
+        private static void InverseTransformBlockIntra(
+            ref MacroBlockD xd,
+            int plane,
+            TxType txType,
+            TxSize txSize,
+            Span<byte> dst,
+            int stride,
+            int eob)
+        {
+            ref MacroBlockDPlane pd = ref xd.Plane[plane];
+            ArrayPtr<int> dqcoeff = pd.DqCoeff;
+            Debug.Assert(eob > 0);
+            if (xd.CurBuf.HighBd)
+            {
+                Span<ushort> dst16 = MemoryMarshal.Cast<byte, ushort>(dst);
+                if (xd.Lossless)
+                {
+                    Idct.HighbdIwht4x4Add(dqcoeff.ToSpan(), dst16, stride, eob, xd.Bd);
+                }
+                else
+                {
+                    switch (txSize)
+                    {
+                        case TxSize.Tx4x4:
+                            Idct.HighbdIht4x4Add(txType, dqcoeff.ToSpan(), dst16, stride, eob, xd.Bd);
+                            break;
+                        case TxSize.Tx8x8:
+                            Idct.HighbdIht8x8Add(txType, dqcoeff.ToSpan(), dst16, stride, eob, xd.Bd);
+                            break;
+                        case TxSize.Tx16x16:
+                            Idct.HighbdIht16x16Add(txType, dqcoeff.ToSpan(), dst16, stride, eob, xd.Bd);
+                            break;
+                        case TxSize.Tx32x32:
+                            Idct.HighbdIdct32x32Add(dqcoeff.ToSpan(), dst16, stride, eob, xd.Bd);
+                            break;
+                        default: Debug.Assert(false, "Invalid transform size"); break;
+                    }
+                }
+            }
+            else
+            {
+                if (xd.Lossless)
+                {
+                    Idct.Iwht4x4Add(dqcoeff.ToSpan(), dst, stride, eob);
+                }
+                else
+                {
+                    switch (txSize)
+                    {
+                        case TxSize.Tx4x4: Idct.Iht4x4Add(txType, dqcoeff.ToSpan(), dst, stride, eob); break;
+                        case TxSize.Tx8x8: Idct.Iht8x8Add(txType, dqcoeff.ToSpan(), dst, stride, eob); break;
+                        case TxSize.Tx16x16: Idct.Iht16x16Add(txType, dqcoeff.ToSpan(), dst, stride, eob); break;
+                        case TxSize.Tx32x32: Idct.Idct32x32Add(dqcoeff.ToSpan(), dst, stride, eob); break;
+                        default: Debug.Assert(false, "Invalid transform size"); return;
+                    }
+                }
+            }
+
+            if (eob == 1)
+            {
+                dqcoeff.ToSpan()[0] = 0;
+            }
+            else
+            {
+                if (txType == TxType.DctDct && txSize <= TxSize.Tx16x16 && eob <= 10)
+                {
+                    dqcoeff.ToSpan().Slice(0, 4 * (4 << (int)txSize)).Fill(0);
+                }
+                else if (txSize == TxSize.Tx32x32 && eob <= 34)
+                {
+                    dqcoeff.ToSpan().Slice(0, 256).Fill(0);
+                }
+                else
+                {
+                    dqcoeff.ToSpan().Slice(0, 16 << ((int)txSize << 1)).Fill(0);
+                }
+            }
+        }
+
+        private static unsafe void PredictAndReconstructIntraBlock(
+            ref TileWorkerData twd,
+            ref ModeInfo mi,
+            int plane,
+            int row,
+            int col,
+            TxSize txSize)
+        {
+            ref MacroBlockD xd = ref twd.Xd;
+            ref MacroBlockDPlane pd = ref xd.Plane[plane];
+            PredictionMode mode = (plane == 0) ? mi.Mode : mi.UvMode;
+            int dstOffset = 4 * row * pd.Dst.Stride + 4 * col;
+            byte* dst = &pd.Dst.Buf.ToPointer()[dstOffset];
+            Span<byte> dstSpan = pd.Dst.Buf.ToSpan().Slice(dstOffset);
+
+            if (mi.SbType < BlockSize.Block8x8)
+            {
+                if (plane == 0)
+                {
+                    mode = xd.Mi[0].Value.Bmi[(row << 1) + col].Mode;
+                }
+            }
+
+            ReconIntra.PredictIntraBlock(ref xd, pd.N4Wl, txSize, mode, dst, pd.Dst.Stride, dst, pd.Dst.Stride, col, row, plane);
+
+            if (mi.Skip == 0)
+            {
+                TxType txType =
+                    (plane != 0 || xd.Lossless) ? TxType.DctDct : ReconIntra.IntraModeToTxTypeLookup[(int)mode];
+                var sc = (plane != 0 || xd.Lossless)
+                    ? Luts.Vp9DefaultScanOrders[(int)txSize]
+                    : Luts.Vp9ScanOrders[(int)txSize][(int)txType];
+                int eob = Detokenize.DecodeBlockTokens(ref twd, plane, sc, col, row, txSize, mi.SegmentId);
+                if (eob > 0)
+                {
+                    InverseTransformBlockIntra(ref xd, plane, txType, txSize, dstSpan, pd.Dst.Stride, eob);
+                }
+            }
+        }
+
+        private static int ReconstructInterBlock(
+            ref TileWorkerData twd,
+            ref ModeInfo mi,
+            int plane,
+            int row,
+            int col,
+            TxSize txSize)
+        {
+            ref MacroBlockD xd = ref twd.Xd;
+            ref MacroBlockDPlane pd = ref xd.Plane[plane];
+            var sc = Luts.Vp9DefaultScanOrders[(int)txSize];
+            int eob = Detokenize.DecodeBlockTokens(ref twd, plane, sc, col, row, txSize, mi.SegmentId);
+            Span<byte> dst = pd.Dst.Buf.ToSpan().Slice(4 * row * pd.Dst.Stride + 4 * col);
+
+            if (eob > 0)
+            {
+                InverseTransformBlockInter(ref xd, plane, txSize, dst, pd.Dst.Stride, eob);
+            }
+            return eob;
+        }
+
+        private static unsafe void BuildMcBorder(
+            byte* src,
+            int srcStride,
+            byte* dst,
+            int dstStride,
+            int x,
+            int y,
+            int bW,
+            int bH,
+            int w,
+            int h)
+        {
+            // Get a pointer to the start of the real data for this row.
+            byte* refRow = src - x - y * srcStride;
+
+            if (y >= h)
+            {
+                refRow += (h - 1) * srcStride;
+            }
+            else if (y > 0)
+            {
+                refRow += y * srcStride;
+            }
+
+            do
+            {
+                int right = 0, copy;
+                int left = x < 0 ? -x : 0;
+
+                if (left > bW)
+                {
+                    left = bW;
+                }
+
+                if (x + bW > w)
+                {
+                    right = x + bW - w;
+                }
+
+                if (right > bW)
+                {
+                    right = bW;
+                }
+
+                copy = bW - left - right;
+
+                if (left != 0)
+                {
+                    MemoryUtil.Fill(dst, refRow[0], left);
+                }
+
+                if (copy != 0)
+                {
+                    MemoryUtil.Copy(dst + left, refRow + x + left, copy);
+                }
+
+                if (right != 0)
+                {
+                    MemoryUtil.Fill(dst + left + copy, refRow[w - 1], right);
+                }
+
+                dst += dstStride;
+                ++y;
+
+                if (y > 0 && y < h)
+                {
+                    refRow += srcStride;
+                }
+            } while (--bH != 0);
+        }
+
+        private static unsafe void HighBuildMcBorder(
+            byte* src8,
+            int srcStride,
+            ushort* dst,
+            int dstStride,
+            int x,
+            int y,
+            int bW,
+            int bH,
+            int w,
+            int h)
+        {
+            // Get a pointer to the start of the real data for this row.
+            ushort* src = (ushort*)src8;
+            ushort* refRow = src - x - y * srcStride;
+
+            if (y >= h)
+            {
+                refRow += (h - 1) * srcStride;
+            }
+            else if (y > 0)
+            {
+                refRow += y * srcStride;
+            }
+
+            do
+            {
+                int right = 0, copy;
+                int left = x < 0 ? -x : 0;
+
+                if (left > bW)
+                {
+                    left = bW;
+                }
+
+                if (x + bW > w)
+                {
+                    right = x + bW - w;
+                }
+
+                if (right > bW)
+                {
+                    right = bW;
+                }
+
+                copy = bW - left - right;
+
+                if (left != 0)
+                {
+                    MemoryUtil.Fill(dst, refRow[0], left);
+                }
+
+                if (copy != 0)
+                {
+                    MemoryUtil.Copy(dst + left, refRow + x + left, copy);
+                }
+
+                if (right != 0)
+                {
+                    MemoryUtil.Fill(dst + left + copy, refRow[w - 1], right);
+                }
+
+                dst += dstStride;
+                ++y;
+
+                if (y > 0 && y < h)
+                {
+                    refRow += srcStride;
+                }
+            } while (--bH != 0);
+        }
+
+        [StructLayout(LayoutKind.Sequential, Size = 80 * 2 * 80 * 2)]
+        struct McBufHigh
+        {
+        }
+
+        private static unsafe void ExtendAndPredict(
+            byte* bufPtr1,
+            int preBufStride,
+            int x0,
+            int y0,
+            int bW,
+            int bH,
+            int frameWidth,
+            int frameHeight,
+            int borderOffset,
+            byte* dst,
+            int dstBufStride,
+            int subpelX,
+            int subpelY,
+            Array8<short>[] kernel,
+            ref ScaleFactors sf,
+            ref MacroBlockD xd,
+            int w,
+            int h,
+            int refr,
+            int xs,
+            int ys)
+        {
+            McBufHigh mcBufHighStruct;
+            ushort* mcBufHigh = (ushort*)Unsafe.AsPointer(ref mcBufHighStruct); // Avoid zero initialization.
+            if (xd.CurBuf.HighBd)
+            {
+                HighBuildMcBorder(bufPtr1, preBufStride, mcBufHigh, bW, x0, y0, bW, bH, frameWidth, frameHeight);
+                ReconInter.HighbdInterPredictor(
+                    mcBufHigh + borderOffset,
+                    bW,
+                    (ushort*)dst,
+                    dstBufStride,
+                    subpelX,
+                    subpelY,
+                    ref sf,
+                    w,
+                    h,
+                    refr,
+                    kernel,
+                    xs,
+                    ys,
+                    xd.Bd);
+            }
+            else
+            {
+                BuildMcBorder(bufPtr1, preBufStride, (byte*)mcBufHigh, bW, x0, y0, bW, bH, frameWidth, frameHeight);
+                ReconInter.InterPredictor(
+                    (byte*)mcBufHigh + borderOffset,
+                    bW,
+                    dst,
+                    dstBufStride,
+                    subpelX,
+                    subpelY,
+                    ref sf,
+                    w,
+                    h,
+                    refr,
+                    kernel,
+                    xs,
+                    ys);
+            }
+        }
+
+        private static unsafe void DecBuildInterPredictors(
+            ref MacroBlockD xd,
+            int plane,
+            int bw,
+            int bh,
+            int x,
+            int y,
+            int w,
+            int h,
+            int miX,
+            int miY,
+            Array8<short>[] kernel,
+            ref ScaleFactors sf,
+            ref Buf2D preBuf,
+            ref Buf2D dstBuf,
+            ref Mv mv,
+            ref Surface refFrameBuf,
+            bool isScaled,
+            int refr)
+        {
+            ref MacroBlockDPlane pd = ref xd.Plane[plane];
+            byte* dst = dstBuf.Buf.ToPointer() + dstBuf.Stride * y + x;
+            Mv32 scaledMv;
+            int xs, ys, x0, y0, x0_16, y0_16, frameWidth, frameHeight, bufStride, subpelX, subpelY;
+            byte* refFrame;
+            byte* bufPtr;
+
+            // Get reference frame pointer, width and height.
+            if (plane == 0)
+            {
+                frameWidth = refFrameBuf.Width;
+                frameHeight = refFrameBuf.Height;
+                refFrame = refFrameBuf.YBuffer.ToPointer();
+            }
+            else
+            {
+                frameWidth = refFrameBuf.UvWidth;
+                frameHeight = refFrameBuf.UvHeight;
+                refFrame = plane == 1 ? refFrameBuf.UBuffer.ToPointer() : refFrameBuf.VBuffer.ToPointer();
+            }
+
+            if (isScaled)
+            {
+                Mv mvQ4 = ReconInter.ClampMvToUmvBorderSb(ref xd, ref mv, bw, bh, pd.SubsamplingX, pd.SubsamplingY);
+                // Co-ordinate of containing block to pixel precision.
+                int xStart = (-xd.MbToLeftEdge >> (3 + pd.SubsamplingX));
+                int yStart = (-xd.MbToTopEdge >> (3 + pd.SubsamplingY));
+                // Co-ordinate of the block to 1/16th pixel precision.
+                x0_16 = (xStart + x) << Filter.SubpelBits;
+                y0_16 = (yStart + y) << Filter.SubpelBits;
+
+                // Co-ordinate of current block in reference frame
+                // to 1/16th pixel precision.
+                x0_16 = sf.ScaleValueX(x0_16);
+                y0_16 = sf.ScaleValueY(y0_16);
+
+                // Map the top left corner of the block into the reference frame.
+                x0 = sf.ScaleValueX(xStart + x);
+                y0 = sf.ScaleValueY(yStart + y);
+
+                // Scale the MV and incorporate the sub-pixel offset of the block
+                // in the reference frame.
+                scaledMv = sf.ScaleMv(ref mvQ4, miX + x, miY + y);
+                xs = sf.XStepQ4;
+                ys = sf.YStepQ4;
+            }
+            else
+            {
+                // Co-ordinate of containing block to pixel precision.
+                x0 = (-xd.MbToLeftEdge >> (3 + pd.SubsamplingX)) + x;
+                y0 = (-xd.MbToTopEdge >> (3 + pd.SubsamplingY)) + y;
+
+                // Co-ordinate of the block to 1/16th pixel precision.
+                x0_16 = x0 << Filter.SubpelBits;
+                y0_16 = y0 << Filter.SubpelBits;
+
+                scaledMv.Row = mv.Row * (1 << (1 - pd.SubsamplingY));
+                scaledMv.Col = mv.Col * (1 << (1 - pd.SubsamplingX));
+                xs = ys = 16;
+            }
+            subpelX = scaledMv.Col & Filter.SubpelMask;
+            subpelY = scaledMv.Row & Filter.SubpelMask;
+
+            // Calculate the top left corner of the best matching block in the
+            // reference frame.
+            x0 += scaledMv.Col >> Filter.SubpelBits;
+            y0 += scaledMv.Row >> Filter.SubpelBits;
+            x0_16 += scaledMv.Col;
+            y0_16 += scaledMv.Row;
+
+            // Get reference block pointer.
+            bufPtr = refFrame + y0 * preBuf.Stride + x0;
+            bufStride = preBuf.Stride;
+
+            // Do border extension if there is motion or the
+            // width/height is not a multiple of 8 pixels.
+            if (isScaled || scaledMv.Col != 0 || scaledMv.Row != 0 || (frameWidth & 0x7) != 0 || (frameHeight & 0x7) != 0)
+            {
+                int y1 = ((y0_16 + (h - 1) * ys) >> Filter.SubpelBits) + 1;
+
+                // Get reference block bottom right horizontal coordinate.
+                int x1 = ((x0_16 + (w - 1) * xs) >> Filter.SubpelBits) + 1;
+                int xPad = 0, yPad = 0;
+
+                if (subpelX != 0 || (sf.XStepQ4 != Filter.SubpelShifts))
+                {
+                    x0 -= Constants.Vp9InterpExtend - 1;
+                    x1 += Constants.Vp9InterpExtend;
+                    xPad = 1;
+                }
+
+                if (subpelY != 0 || (sf.YStepQ4 != Filter.SubpelShifts))
+                {
+                    y0 -= Constants.Vp9InterpExtend - 1;
+                    y1 += Constants.Vp9InterpExtend;
+                    yPad = 1;
+                }
+
+                // Skip border extension if block is inside the frame.
+                if (x0 < 0 || x0 > frameWidth - 1 || x1 < 0 || x1 > frameWidth - 1 ||
+                    y0 < 0 || y0 > frameHeight - 1 || y1 < 0 || y1 > frameHeight - 1)
+                {
+                    // Extend the border.
+                    byte* bufPtr1 = refFrame + y0 * bufStride + x0;
+                    int bW = x1 - x0 + 1;
+                    int bH = y1 - y0 + 1;
+                    int borderOffset = yPad * 3 * bW + xPad * 3;
+
+                    ExtendAndPredict(
+                        bufPtr1,
+                        bufStride,
+                        x0,
+                        y0,
+                        bW,
+                        bH,
+                        frameWidth,
+                        frameHeight,
+                        borderOffset,
+                        dst,
+                        dstBuf.Stride,
+                        subpelX,
+                        subpelY,
+                        kernel,
+                        ref sf,
+                        ref xd,
+                        w,
+                        h,
+                        refr,
+                        xs,
+                        ys);
+                    return;
+                }
+            }
+            if (xd.CurBuf.HighBd)
+            {
+                ReconInter.HighbdInterPredictor(
+                    (ushort*)bufPtr,
+                    bufStride,
+                    (ushort*)dst,
+                    dstBuf.Stride,
+                    subpelX,
+                    subpelY,
+                    ref sf,
+                    w,
+                    h,
+                    refr,
+                    kernel,
+                    xs,
+                    ys,
+                    xd.Bd);
+            }
+            else
+            {
+                ReconInter.InterPredictor(
+                    bufPtr,
+                    bufStride,
+                    dst,
+                    dstBuf.Stride,
+                    subpelX,
+                    subpelY,
+                    ref sf,
+                    w,
+                    h,
+                    refr,
+                    kernel,
+                    xs,
+                    ys);
+            }
+        }
+
+        private static void DecBuildInterPredictorsSb(ref Vp9Common cm, ref MacroBlockD xd, int miRow, int miCol)
+        {
+            int plane;
+            int miX = miCol * Constants.MiSize;
+            int miY = miRow * Constants.MiSize;
+            ref ModeInfo mi = ref xd.Mi[0].Value;
+            Array8<short>[] kernel = Luts.Vp9FilterKernels[mi.InterpFilter];
+            BlockSize sbType = mi.SbType;
+            int isCompound = mi.HasSecondRef() ? 1 : 0;
+            int refr;
+            bool isScaled;
+
+            for (refr = 0; refr < 1 + isCompound; ++refr)
+            {
+                int frame = mi.RefFrame[refr];
+                ref RefBuffer refBuf = ref cm.FrameRefs[frame - Constants.LastFrame];
+                ref ScaleFactors sf = ref refBuf.Sf;
+                ref Surface refFrameBuf = ref refBuf.Buf;
+
+                if (!sf.IsValidScale())
+                {
+                    xd.ErrorInfo.Value.InternalError(CodecErr.CodecUnsupBitstream, "Reference frame has invalid dimensions");
+                }
+
+                isScaled = sf.IsScaled();
+                ReconInter.SetupPrePlanes(ref xd, refr, ref refFrameBuf, miRow, miCol, isScaled ? new Ptr<ScaleFactors>(ref sf) : Ptr<ScaleFactors>.Null);
+                xd.BlockRefs[refr] = new Ptr<RefBuffer>(ref refBuf);
+
+                if (sbType < BlockSize.Block8x8)
+                {
+                    for (plane = 0; plane < Constants.MaxMbPlane; ++plane)
+                    {
+                        ref MacroBlockDPlane pd = ref xd.Plane[plane];
+                        ref Buf2D dstBuf = ref pd.Dst;
+                        int num4x4W = pd.N4W;
+                        int num4x4H = pd.N4H;
+                        int n4Wx4 = 4 * num4x4W;
+                        int n4Hx4 = 4 * num4x4H;
+                        ref Buf2D preBuf = ref pd.Pre[refr];
+                        int i = 0, x, y;
+                        for (y = 0; y < num4x4H; ++y)
+                        {
+                            for (x = 0; x < num4x4W; ++x)
+                            {
+                                Mv mv = ReconInter.AverageSplitMvs(ref pd, ref mi, refr, i++);
+                                DecBuildInterPredictors(
+                                    ref xd,
+                                    plane,
+                                    n4Wx4,
+                                    n4Hx4,
+                                    4 * x,
+                                    4 * y,
+                                    4,
+                                    4,
+                                    miX,
+                                    miY,
+                                    kernel,
+                                    ref sf,
+                                    ref preBuf,
+                                    ref dstBuf,
+                                    ref mv,
+                                    ref refFrameBuf,
+                                    isScaled,
+                                    refr);
+                            }
+                        }
+                    }
+                }
+                else
+                {
+                    Mv mv = mi.Mv[refr];
+                    for (plane = 0; plane < Constants.MaxMbPlane; ++plane)
+                    {
+                        ref MacroBlockDPlane pd = ref xd.Plane[plane];
+                        ref Buf2D dstBuf = ref pd.Dst;
+                        int num4x4W = pd.N4W;
+                        int num4x4H = pd.N4H;
+                        int n4Wx4 = 4 * num4x4W;
+                        int n4Hx4 = 4 * num4x4H;
+                        ref Buf2D preBuf = ref pd.Pre[refr];
+                        DecBuildInterPredictors(
+                            ref xd,
+                            plane,
+                            n4Wx4,
+                            n4Hx4,
+                            0,
+                            0,
+                            n4Wx4,
+                            n4Hx4,
+                            miX,
+                            miY,
+                            kernel,
+                            ref sf,
+                            ref preBuf,
+                            ref dstBuf,
+                            ref mv,
+                            ref refFrameBuf,
+                            isScaled,
+                            refr);
+                    }
+                }
+            }
+        }
+
+        private static unsafe void DecResetSkipContext(ref MacroBlockD xd)
+        {
+            int i;
+            for (i = 0; i < Constants.MaxMbPlane; i++)
+            {
+                ref MacroBlockDPlane pd = ref xd.Plane[i];
+                MemoryUtil.Fill(pd.AboveContext.ToPointer(), (sbyte)0, pd.N4W);
+                MemoryUtil.Fill(pd.LeftContext.ToPointer(), (sbyte)0, pd.N4H);
+            }
+        }
+
+        private static void SetPlaneN4(ref MacroBlockD xd, int bw, int bh, int bwl, int bhl)
+        {
+            int i;
+            for (i = 0; i < Constants.MaxMbPlane; i++)
+            {
+                xd.Plane[i].N4W = (ushort)((bw << 1) >> xd.Plane[i].SubsamplingX);
+                xd.Plane[i].N4H = (ushort)((bh << 1) >> xd.Plane[i].SubsamplingY);
+                xd.Plane[i].N4Wl = (byte)(bwl - xd.Plane[i].SubsamplingX);
+                xd.Plane[i].N4Hl = (byte)(bhl - xd.Plane[i].SubsamplingY);
+            }
+        }
+
+        private static ref ModeInfo SetOffsets(
+            ref Vp9Common cm,
+            ref MacroBlockD xd,
+            BlockSize bsize,
+            int miRow,
+            int miCol,
+            int bw,
+            int bh,
+            int xMis,
+            int yMis,
+            int bwl,
+            int bhl)
+        {
+            int offset = miRow * cm.MiStride + miCol;
+            int x, y;
+            ref TileInfo tile = ref xd.Tile;
+
+            xd.Mi = cm.MiGridVisible.Slice(offset);
+            xd.Mi[0] = new Ptr<ModeInfo>(ref cm.Mi[offset]);
+            xd.Mi[0].Value.SbType = bsize;
+            for (y = 0; y < yMis; ++y)
+            {
+                for (x = y == 0 ? 1 : 0; x < xMis; ++x)
+                {
+                    xd.Mi[y * cm.MiStride + x] = xd.Mi[0];
+                }
+            }
+
+            SetPlaneN4(ref xd, bw, bh, bwl, bhl);
+
+            xd.SetSkipContext(miRow, miCol);
+
+            // Distance of Mb to the various image edges. These are specified to 8th pel
+            // as they are always compared to values that are in 1/8th pel units
+            xd.SetMiRowCol(ref tile, miRow, bh, miCol, bw, cm.MiRows, cm.MiCols);
+
+            ReconInter.SetupDstPlanes(ref xd.Plane, ref xd.CurBuf, miRow, miCol);
+            return ref xd.Mi[0].Value;
+        }
+
+        private static void DecodeBlock(
+            ref TileWorkerData twd,
+            ref Vp9Common cm,
+            int miRow,
+            int miCol,
+            BlockSize bsize,
+            int bwl,
+            int bhl)
+        {
+            bool less8x8 = bsize < BlockSize.Block8x8;
+            int bw = 1 << (bwl - 1);
+            int bh = 1 << (bhl - 1);
+            int xMis = Math.Min(bw, cm.MiCols - miCol);
+            int yMis = Math.Min(bh, cm.MiRows - miRow);
+            ref Reader r = ref twd.BitReader;
+            ref MacroBlockD xd = ref twd.Xd;
+
+            ref ModeInfo mi = ref SetOffsets(ref cm, ref xd, bsize, miRow, miCol, bw, bh, xMis, yMis, bwl, bhl);
+
+            if (bsize >= BlockSize.Block8x8 && (cm.SubsamplingX != 0 || cm.SubsamplingY != 0))
+            {
+                BlockSize uvSubsize = Luts.SsSizeLookup[(int)bsize][cm.SubsamplingX][cm.SubsamplingY];
+                if (uvSubsize == BlockSize.BlockInvalid)
+                {
+                    xd.ErrorInfo.Value.InternalError(CodecErr.CodecCorruptFrame, "Invalid block size.");
+                }
+            }
+
+            DecodeMv.ReadModeInfo(ref twd, ref cm, miRow, miCol, xMis, yMis);
+
+            if (mi.Skip != 0)
+            {
+                DecResetSkipContext(ref xd);
+            }
+
+            if (!mi.IsInterBlock())
+            {
+                int plane;
+                for (plane = 0; plane < Constants.MaxMbPlane; ++plane)
+                {
+                    ref MacroBlockDPlane pd = ref xd.Plane[plane];
+                    TxSize txSize = plane != 0 ? mi.GetUvTxSize(ref pd) : mi.TxSize;
+                    int num4x4W = pd.N4W;
+                    int num4x4H = pd.N4H;
+                    int step = 1 << (int)txSize;
+                    int row, col;
+                    int maxBlocksWide = num4x4W + (xd.MbToRightEdge >= 0 ? 0 : xd.MbToRightEdge >> (5 + pd.SubsamplingX));
+                    int maxBlocksHigh = num4x4H + (xd.MbToBottomEdge >= 0 ? 0 : xd.MbToBottomEdge >> (5 + pd.SubsamplingY));
+
+                    xd.MaxBlocksWide = (uint)(xd.MbToRightEdge >= 0 ? 0 : maxBlocksWide);
+                    xd.MaxBlocksHigh = (uint)(xd.MbToBottomEdge >= 0 ? 0 : maxBlocksHigh);
+
+                    for (row = 0; row < maxBlocksHigh; row += step)
+                    {
+                        for (col = 0; col < maxBlocksWide; col += step)
+                        {
+                            PredictAndReconstructIntraBlock(ref twd, ref mi, plane, row, col, txSize);
+                        }
+                    }
+                }
+            }
+            else
+            {
+                // Prediction
+                DecBuildInterPredictorsSb(ref cm, ref xd, miRow, miCol);
+
+                // Reconstruction
+                if (mi.Skip == 0)
+                {
+                    int eobtotal = 0;
+                    int plane;
+
+                    for (plane = 0; plane < Constants.MaxMbPlane; ++plane)
+                    {
+                        ref MacroBlockDPlane pd = ref xd.Plane[plane];
+                        TxSize txSize = plane != 0 ? mi.GetUvTxSize(ref pd) : mi.TxSize;
+                        int num4x4W = pd.N4W;
+                        int num4x4H = pd.N4H;
+                        int step = 1 << (int)txSize;
+                        int row, col;
+                        int maxBlocksWide = num4x4W + (xd.MbToRightEdge >= 0 ? 0 : xd.MbToRightEdge >> (5 + pd.SubsamplingX));
+                        int maxBlocksHigh = num4x4H + (xd.MbToBottomEdge >= 0 ? 0 : xd.MbToBottomEdge >> (5 + pd.SubsamplingY));
+
+                        xd.MaxBlocksWide = (uint)(xd.MbToRightEdge >= 0 ? 0 : maxBlocksWide);
+                        xd.MaxBlocksHigh = (uint)(xd.MbToBottomEdge >= 0 ? 0 : maxBlocksHigh);
+
+                        for (row = 0; row < maxBlocksHigh; row += step)
+                        {
+                            for (col = 0; col < maxBlocksWide; col += step)
+                            {
+                                eobtotal += ReconstructInterBlock(ref twd, ref mi, plane, row, col, txSize);
+                            }
+                        }
+                    }
+
+                    if (!less8x8 && eobtotal == 0)
+                    {
+                        mi.Skip = 1;  // Skip loopfilter
+                    }
+                }
+            }
+
+            xd.Corrupted |= r.HasError();
+
+            if (cm.Lf.FilterLevel != 0)
+            {
+                LoopFilter.BuildMask(ref cm, ref mi, miRow, miCol, bw, bh);
+            }
+        }
+
+        private static int DecPartitionPlaneContext(ref TileWorkerData twd, int miRow, int miCol, int bsl)
+        {
+            ref sbyte aboveCtx = ref twd.Xd.AboveSegContext[miCol];
+            ref sbyte leftCtx = ref twd.Xd.LeftSegContext[miRow & Constants.MiMask];
+            int above = (aboveCtx >> bsl) & 1, left = (leftCtx >> bsl) & 1;
+
+            return (left * 2 + above) + bsl * Constants.PartitionPloffset;
+        }
+
+        private static void DecUpdatePartitionContext(
+            ref TileWorkerData twd,
+            int miRow,
+            int miCol,
+            BlockSize subsize,
+            int bw)
+        {
+            Span<sbyte> aboveCtx = twd.Xd.AboveSegContext.Slice(miCol).ToSpan();
+            Span<sbyte> leftCtx = MemoryMarshal.CreateSpan(ref twd.Xd.LeftSegContext[miRow & Constants.MiMask], 8 - (miRow & Constants.MiMask));
+
+            // Update the partition context at the end notes. Set partition bits
+            // of block sizes larger than the current one to be one, and partition
+            // bits of smaller block sizes to be zero.
+            aboveCtx.Slice(0, bw).Fill(Luts.PartitionContextLookup[(int)subsize].Above);
+            leftCtx.Slice(0, bw).Fill(Luts.PartitionContextLookup[(int)subsize].Left);
+        }
+
+        private static PartitionType ReadPartition(
+            ref TileWorkerData twd,
+            int miRow,
+            int miCol,
+            int hasRows,
+            int hasCols,
+            int bsl)
+        {
+            int ctx = DecPartitionPlaneContext(ref twd, miRow, miCol, bsl);
+            ReadOnlySpan<byte> probs = MemoryMarshal.CreateReadOnlySpan(ref twd.Xd.PartitionProbs[ctx][0], 3);
+            PartitionType p;
+            ref Reader r = ref twd.BitReader;
+
+            if (hasRows != 0 && hasCols != 0)
+            {
+                p = (PartitionType)r.ReadTree(Luts.Vp9PartitionTree, probs);
+            }
+            else if (hasRows == 0 && hasCols != 0)
+            {
+                p = r.Read(probs[1]) != 0 ? PartitionType.PartitionSplit : PartitionType.PartitionHorz;
+            }
+            else if (hasRows != 0 && hasCols == 0)
+            {
+                p = r.Read(probs[2]) != 0 ? PartitionType.PartitionSplit : PartitionType.PartitionVert;
+            }
+            else
+            {
+                p = PartitionType.PartitionSplit;
+            }
+
+            if (!twd.Xd.Counts.IsNull)
+            {
+                ++twd.Xd.Counts.Value.Partition[ctx][(int)p];
+            }
+
+            return p;
+        }
+
+        private static void DecodePartition(
+            ref TileWorkerData twd,
+            ref Vp9Common cm,
+            int miRow,
+            int miCol,
+            BlockSize bsize,
+            int n4x4L2)
+        {
+            int n8x8L2 = n4x4L2 - 1;
+            int num8x8Wh = 1 << n8x8L2;
+            int hbs = num8x8Wh >> 1;
+            PartitionType partition;
+            BlockSize subsize;
+            bool hasRows = (miRow + hbs) < cm.MiRows;
+            bool hasCols = (miCol + hbs) < cm.MiCols;
+            ref MacroBlockD xd = ref twd.Xd;
+
+            if (miRow >= cm.MiRows || miCol >= cm.MiCols)
+            {
+                return;
+            }
+
+            partition = ReadPartition(ref twd, miRow, miCol, hasRows ? 1 : 0, hasCols ? 1 : 0, n8x8L2);
+            subsize = Luts.SubsizeLookup[(int)partition][(int)bsize];
+            if (hbs == 0)
+            {
+                // Calculate bmode block dimensions (log 2)
+                xd.BmodeBlocksWl = (byte)(1 >> ((partition & PartitionType.PartitionVert) != 0 ? 1 : 0));
+                xd.BmodeBlocksHl = (byte)(1 >> ((partition & PartitionType.PartitionHorz) != 0 ? 1 : 0));
+                DecodeBlock(ref twd, ref cm, miRow, miCol, subsize, 1, 1);
+            }
+            else
+            {
+                switch (partition)
+                {
+                    case PartitionType.PartitionNone:
+                        DecodeBlock(ref twd, ref cm, miRow, miCol, subsize, n4x4L2, n4x4L2);
+                        break;
+                    case PartitionType.PartitionHorz:
+                        DecodeBlock(ref twd, ref cm, miRow, miCol, subsize, n4x4L2, n8x8L2);
+                        if (hasRows)
+                        {
+                            DecodeBlock(ref twd, ref cm, miRow + hbs, miCol, subsize, n4x4L2, n8x8L2);
+                        }
+
+                        break;
+                    case PartitionType.PartitionVert:
+                        DecodeBlock(ref twd, ref cm, miRow, miCol, subsize, n8x8L2, n4x4L2);
+                        if (hasCols)
+                        {
+                            DecodeBlock(ref twd, ref cm, miRow, miCol + hbs, subsize, n8x8L2, n4x4L2);
+                        }
+
+                        break;
+                    case PartitionType.PartitionSplit:
+                        DecodePartition(ref twd, ref cm, miRow, miCol, subsize, n8x8L2);
+                        DecodePartition(ref twd, ref cm, miRow, miCol + hbs, subsize, n8x8L2);
+                        DecodePartition(ref twd, ref cm, miRow + hbs, miCol, subsize, n8x8L2);
+                        DecodePartition(ref twd, ref cm, miRow + hbs, miCol + hbs, subsize, n8x8L2);
+                        break;
+                    default: Debug.Assert(false, "Invalid partition type"); break;
+                }
+            }
+
+            // Update partition context
+            if (bsize >= BlockSize.Block8x8 && (bsize == BlockSize.Block8x8 || partition != PartitionType.PartitionSplit))
+            {
+                DecUpdatePartitionContext(ref twd, miRow, miCol, subsize, num8x8Wh);
+            }
+        }
+
+        private static void SetupTokenDecoder(
+            ArrayPtr<byte> data,
+            int readSize,
+            ref InternalErrorInfo errorInfo,
+            ref Reader r)
+        {
+            // Validate the calculated partition length. If the buffer described by the
+            // partition can't be fully read then throw an error.
+            if (!ReadIsValid(data, readSize))
+            {
+                errorInfo.InternalError(CodecErr.CodecCorruptFrame, "Truncated packet or corrupt tile length");
+            }
+
+            if (r.Init(data, readSize))
+            {
+                errorInfo.InternalError(CodecErr.CodecMemError, "Failed to allocate bool decoder 1");
+            }
+        }
+
+        // Reads the next tile returning its size and adjusting '*data' accordingly
+        // based on 'isLast'.
+        private static void GetTileBuffer(
+            bool isLast,
+            ref InternalErrorInfo errorInfo,
+            ref ArrayPtr<byte> data,
+            ref TileBuffer buf)
+        {
+            int size;
+
+            if (!isLast)
+            {
+                if (!ReadIsValid(data, 4))
+                {
+                    errorInfo.InternalError(CodecErr.CodecCorruptFrame, "Truncated packet or corrupt tile length");
+                }
+
+                size = BinaryPrimitives.ReadInt32BigEndian(data.ToSpan());
+                data = data.Slice(4);
+
+                if (size > data.Length)
+                {
+                    errorInfo.InternalError(CodecErr.CodecCorruptFrame, "Truncated packet or corrupt tile size");
+                }
+            }
+            else
+            {
+                size = data.Length;
+            }
+
+            buf.Data = data;
+            buf.Size = size;
+
+            data = data.Slice(size);
+        }
+
+        private static void GetTileBuffers(
+            ref Vp9Common cm,
+            ArrayPtr<byte> data,
+            int tileCols,
+            int tileRows,
+            ref Array4<Array64<TileBuffer>> tileBuffers)
+        {
+            int r, c;
+
+            for (r = 0; r < tileRows; ++r)
+            {
+                for (c = 0; c < tileCols; ++c)
+                {
+                    bool isLast = (r == tileRows - 1) && (c == tileCols - 1);
+                    ref TileBuffer buf = ref tileBuffers[r][c];
+                    GetTileBuffer(isLast, ref cm.Error, ref data, ref buf);
+                }
+            }
+        }
+
+        public static unsafe ArrayPtr<byte> DecodeTiles(ref Vp9Common cm, ArrayPtr<byte> data)
+        {
+            int alignedCols = TileInfo.MiColsAlignedToSb(cm.MiCols);
+            int tileCols = 1 << cm.Log2TileCols;
+            int tileRows = 1 << cm.Log2TileRows;
+            Array4<Array64<TileBuffer>> tileBuffers = new Array4<Array64<TileBuffer>>();
+            int tileRow, tileCol;
+            int miRow, miCol;
+
+            Debug.Assert(tileRows <= 4);
+            Debug.Assert(tileCols <= (1 << 6));
+
+            // Note: this memset assumes above_context[0], [1] and [2]
+            // are allocated as part of the same buffer.
+            MemoryUtil.Fill(cm.AboveContext.ToPointer(), (sbyte)0, Constants.MaxMbPlane * 2 * alignedCols);
+            MemoryUtil.Fill(cm.AboveSegContext.ToPointer(), (sbyte)0, alignedCols);
+
+            LoopFilter.ResetLfm(ref cm);
+
+            GetTileBuffers(ref cm, data, tileCols, tileRows, ref tileBuffers);
+            // Load all tile information into tile_data.
+            for (tileRow = 0; tileRow < tileRows; ++tileRow)
+            {
+                for (tileCol = 0; tileCol < tileCols; ++tileCol)
+                {
+                    ref TileBuffer buf = ref tileBuffers[tileRow][tileCol];
+                    ref TileWorkerData tileData = ref cm.TileWorkerData[tileCols * tileRow + tileCol];
+                    tileData.Xd = cm.Mb;
+                    tileData.Xd.Corrupted = false;
+                    tileData.Xd.Counts = cm.FrameParallelDecodingMode ? Ptr<Vp9BackwardUpdates>.Null : cm.Counts;
+                    tileData.Dqcoeff = new Array32<Array32<int>>();
+                    tileData.Xd.Tile.Init(ref cm, tileRow, tileCol);
+                    SetupTokenDecoder(buf.Data, buf.Size, ref cm.Error, ref tileData.BitReader);
+                    cm.InitMacroBlockD(ref tileData.Xd, new ArrayPtr<int>(ref tileData.Dqcoeff[0][0], 32 * 32));
+                }
+            }
+
+            for (tileRow = 0; tileRow < tileRows; ++tileRow)
+            {
+                TileInfo tile = new TileInfo();
+                tile.SetRow(ref cm, tileRow);
+                for (miRow = tile.MiRowStart; miRow < tile.MiRowEnd; miRow += Constants.MiBlockSize)
+                {
+                    for (tileCol = 0; tileCol < tileCols; ++tileCol)
+                    {
+                        int col = tileCol;
+                        ref TileWorkerData tileData = ref cm.TileWorkerData[tileCols * tileRow + col];
+                        tile.SetCol(ref cm, col);
+                        tileData.Xd.LeftContext = new Array3<Array16<sbyte>>();
+                        tileData.Xd.LeftSegContext = new Array8<sbyte>();
+                        for (miCol = tile.MiColStart; miCol < tile.MiColEnd; miCol += Constants.MiBlockSize)
+                        {
+                            DecodePartition(ref tileData, ref cm, miRow, miCol, BlockSize.Block64x64, 4);
+                        }
+                        cm.Mb.Corrupted |= tileData.Xd.Corrupted;
+                        if (cm.Mb.Corrupted)
+                        {
+                            cm.Error.InternalError(CodecErr.CodecCorruptFrame, "Failed to decode tile data");
+                        };
+                    }
+                }
+            }
+
+            // Get last tile data.
+            return cm.TileWorkerData[tileCols * tileRows - 1].BitReader.FindEnd();
+        }
+    }
+}