NVDEC (H264): Use separate contexts per channel and decode frames in DTS order (#2671)

* Use separate NVDEC contexts per channel (for FFMPEG)

* Remove NVDEC -> VIC frame override hack

* Add missing bottom_field_pic_order_in_frame_present_flag

* Make FFMPEG logging static

* nit: Remove empty lines

* New FFMPEG decoding approach -- call h264_decode_frame directly, trim surface cache to reduce memory usage

* Fix case

* Silence warnings

* PR feedback

* Per-decoder rather than per-codec ownership of surfaces on the cache

1 files changed, 35 insertions, 10 deletions

diff --git a/Ryujinx.Graphics.Nvdec/NvdecDevice.cs b/Ryujinx.Graphics.Nvdec/NvdecDevice.cs
index 08f802a1..5319429b 100644
--- a/Ryujinx.Graphics.Nvdec/NvdecDevice.cs
+++ b/Ryujinx.Graphics.Nvdec/NvdecDevice.cs
@@ -2,17 +2,20 @@
 using Ryujinx.Graphics.Device;
 using Ryujinx.Graphics.Gpu.Memory;
 using Ryujinx.Graphics.Nvdec.Image;
-using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
+using System.Threading;
 
 namespace Ryujinx.Graphics.Nvdec
 {
-    public class NvdecDevice : IDeviceState
+    public class NvdecDevice : IDeviceStateWithContext
     {
         private readonly ResourceManager _rm;
         private readonly DeviceState<NvdecRegisters> _state;
 
-        public event Action<FrameDecodedEventArgs> FrameDecoded;
+        private long _currentId;
+        private ConcurrentDictionary<long, NvdecDecoderContext> _contexts;
+        private NvdecDecoderContext _currentContext;
 
         public NvdecDevice(MemoryManager gmm)
         {
@@ -21,6 +24,33 @@ namespace Ryujinx.Graphics.Nvdec
             {
                 { nameof(NvdecRegisters.Execute), new RwCallback(Execute, null) }
             });
+            _contexts = new ConcurrentDictionary<long, NvdecDecoderContext>();
+        }
+
+        public long CreateContext()
+        {
+            long id = Interlocked.Increment(ref _currentId);
+            _contexts.TryAdd(id, new NvdecDecoderContext());
+
+            return id;
+        }
+
+        public void DestroyContext(long id)
+        {
+            if (_contexts.TryRemove(id, out var context))
+            {
+                context.Dispose();
+            }
+
+            _rm.Cache.Trim();
+        }
+
+        public void BindContext(long id)
+        {
+            if (_contexts.TryGetValue(id, out var context))
+            {
+                _currentContext = context;
+            }
         }
 
         public int Read(int offset) => _state.Read(offset);
@@ -36,20 +66,15 @@ namespace Ryujinx.Graphics.Nvdec
             switch (codecId)
             {
                 case CodecId.H264:
-                    H264Decoder.Decode(this, _rm, ref _state.State);
+                    H264Decoder.Decode(_currentContext, _rm, ref _state.State);
                     break;
                 case CodecId.Vp9:
-                    Vp9Decoder.Decode(this, _rm, ref _state.State);
+                    Vp9Decoder.Decode(_rm, ref _state.State);
                     break;
                 default:
                     Logger.Error?.Print(LogClass.Nvdec, $"Unsupported codec \"{codecId}\".");
                     break;
             }
         }
-
-        internal void OnFrameDecoded(CodecId codecId, uint lumaOffset, uint chromaOffset)
-        {
-            FrameDecoded?.Invoke(new FrameDecodedEventArgs(codecId, lumaOffset, chromaOffset));
-        }
     }
 }