3 files changed, 70 insertions, 4 deletions
diff --git a/Ryujinx.Graphics.Nvdec/H264Decoder.cs b/Ryujinx.Graphics.Nvdec/H264Decoder.cs
index 69eeb494..6efeb899 100644
--- a/Ryujinx.Graphics.Nvdec/H264Decoder.cs
+++ b/Ryujinx.Graphics.Nvdec/H264Decoder.cs
@@ -31,7 +31,24 @@ namespace Ryujinx.Graphics.Nvdec
 
             if (decoder.Decode(ref info, outputSurface, bitstream))
             {
-                SurfaceWriter.Write(rm.Gmm, outputSurface, lumaOffset, chromaOffset);
+                if (outputSurface.Field == FrameField.Progressive)
+                {
+                    SurfaceWriter.Write(
+                        rm.Gmm,
+                        outputSurface,
+                        lumaOffset   + pictureInfo.LumaFrameOffset,
+                        chromaOffset + pictureInfo.ChromaFrameOffset);
+                }
+                else
+                {
+                    SurfaceWriter.WriteInterlaced(
+                        rm.Gmm,
+                        outputSurface,
+                        lumaOffset   + pictureInfo.LumaTopFieldOffset,
+                        chromaOffset + pictureInfo.ChromaTopFieldOffset,
+                        lumaOffset   + pictureInfo.LumaBottomFieldOffset,
+                        chromaOffset + pictureInfo.ChromaBottomFieldOffset);
+                }
             }
 
             rm.Cache.Put(outputSurface);
diff --git a/Ryujinx.Graphics.Nvdec/Image/SurfaceWriter.cs b/Ryujinx.Graphics.Nvdec/Image/SurfaceWriter.cs
index 5c294621..cc5c251b 100644
--- a/Ryujinx.Graphics.Nvdec/Image/SurfaceWriter.cs
+++ b/Ryujinx.Graphics.Nvdec/Image/SurfaceWriter.cs
@@ -38,6 +38,55 @@ namespace Ryujinx.Graphics.Nvdec.Image
                 surface.UvHeight);
         }
 
+        public static void WriteInterlaced(
+            MemoryManager gmm,
+            ISurface surface,
+            uint lumaTopOffset,
+            uint chromaTopOffset,
+            uint lumaBottomOffset,
+            uint chromaBottomOffset)
+        {
+            int lumaSize = GetBlockLinearSize(surface.Width, surface.Height / 2, 1);
+
+            using var lumaTop = gmm.GetWritableRegion(ExtendOffset(lumaTopOffset), lumaSize);
+            using var lumaBottom = gmm.GetWritableRegion(ExtendOffset(lumaBottomOffset), lumaSize);
+
+            WriteLuma(
+                lumaTop.Memory.Span,
+                surface.YPlane.AsSpan(),
+                surface.Stride * 2,
+                surface.Width,
+                surface.Height / 2);
+
+            WriteLuma(
+                lumaBottom.Memory.Span,
+                surface.YPlane.AsSpan().Slice(surface.Stride),
+                surface.Stride * 2,
+                surface.Width,
+                surface.Height / 2);
+
+            int chromaSize = GetBlockLinearSize(surface.UvWidth, surface.UvHeight / 2, 2);
+
+            using var chromaTop = gmm.GetWritableRegion(ExtendOffset(chromaTopOffset), chromaSize);
+            using var chromaBottom = gmm.GetWritableRegion(ExtendOffset(chromaBottomOffset), chromaSize);
+
+            WriteChroma(
+                chromaTop.Memory.Span,
+                surface.UPlane.AsSpan(),
+                surface.VPlane.AsSpan(),
+                surface.UvStride * 2,
+                surface.UvWidth,
+                surface.UvHeight / 2);
+
+            WriteChroma(
+                chromaBottom.Memory.Span,
+                surface.UPlane.AsSpan().Slice(surface.UvStride),
+                surface.VPlane.AsSpan().Slice(surface.UvStride),
+                surface.UvStride * 2,
+                surface.UvWidth,
+                surface.UvHeight / 2);
+        }
+
         private static void WriteLuma(Span<byte> dst, ReadOnlySpan<byte> src, int srcStride, int width, int height)
         {
             LayoutConverter.ConvertLinearToBlockLinear(dst, width, height, srcStride, 1, 2, src);
diff --git a/Ryujinx.Graphics.Nvdec/Types/H264/PictureInfo.cs b/Ryujinx.Graphics.Nvdec/Types/H264/PictureInfo.cs
index 326c40ae..7c779dff 100644
--- a/Ryujinx.Graphics.Nvdec/Types/H264/PictureInfo.cs
+++ b/Ryujinx.Graphics.Nvdec/Types/H264/PictureInfo.cs
@@ -26,10 +26,10 @@ namespace Ryujinx.Graphics.Nvdec.Types.H264
         public uint Transform8x8ModeFlag;
         public uint LumaPitch;
         public uint ChromaPitch;
-        public uint LumaTopOffset;
-        public uint LumaBottomOffset;
+        public uint LumaTopFieldOffset;
+        public uint LumaBottomFieldOffset;
         public uint LumaFrameOffset;
-        public uint ChromaTopOffset;
+        public uint ChromaTopFieldOffset;
         public uint ChromaBottomFieldOffset;
         public uint ChromaFrameOffset;
         public uint HistBufferSize;