1 files changed, 57 insertions, 0 deletions
diff --git a/src/Ryujinx.Graphics.Nvdec/H264Decoder.cs b/src/Ryujinx.Graphics.Nvdec/H264Decoder.cs
new file mode 100644
index 00000000..ecc7dbc7
--- /dev/null
+++ b/src/Ryujinx.Graphics.Nvdec/H264Decoder.cs
@@ -0,0 +1,57 @@
+using Ryujinx.Graphics.Nvdec.FFmpeg.H264;
+using Ryujinx.Graphics.Nvdec.Image;
+using Ryujinx.Graphics.Nvdec.Types.H264;
+using Ryujinx.Graphics.Video;
+using System;
+
+namespace Ryujinx.Graphics.Nvdec
+{
+    static class H264Decoder
+    {
+        private const int MbSizeInPixels = 16;
+
+        public static void Decode(NvdecDecoderContext context, ResourceManager rm, ref NvdecRegisters state)
+        {
+            PictureInfo pictureInfo = rm.Gmm.DeviceRead<PictureInfo>(state.SetDrvPicSetupOffset);
+            H264PictureInfo info = pictureInfo.Convert();
+
+            ReadOnlySpan<byte> bitstream = rm.Gmm.DeviceGetSpan(state.SetInBufBaseOffset, (int)pictureInfo.BitstreamSize);
+
+            int width  = (int)pictureInfo.PicWidthInMbs * MbSizeInPixels;
+            int height = (int)pictureInfo.PicHeightInMbs * MbSizeInPixels;
+
+            int surfaceIndex = (int)pictureInfo.OutputSurfaceIndex;
+
+            uint lumaOffset   = state.SetPictureLumaOffset[surfaceIndex];
+            uint chromaOffset = state.SetPictureChromaOffset[surfaceIndex];
+
+            Decoder decoder = context.GetH264Decoder();
+
+            ISurface outputSurface = rm.Cache.Get(decoder, 0, 0, width, height);
+
+            if (decoder.Decode(ref info, outputSurface, bitstream))
+            {
+                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);
+        }
+    }
+}