New NVDEC and VIC implementation (#1384)

* Initial NVDEC and VIC implementation

* Update FFmpeg.AutoGen to 4.3.0

* Add nvdec dependencies for Windows

* Unify some VP9 structures

* Rename VP9 structure fields

* Improvements to Video API

* XML docs for Common.Memory

* Remove now unused or redundant overloads from MemoryAccessor

* NVDEC UV surface read/write scalar paths

* Add FIXME comments about hacky things/stuff that will need to be fixed in the future

* Cleaned up VP9 memory allocation

* Remove some debug logs

* Rename some VP9 structs

* Remove unused struct

* No need to compile Ryujinx.Graphics.Host1x with unsafe anymore

* Name AsyncWorkQueue threads to make debugging easier

* Make Vp9PictureInfo a ref struct

* LayoutConverter no longer needs the depth argument (broken by rebase)

* Pooling of VP9 buffers, plus fix a memory leak on VP9

* Really wish VS could rename projects properly...

* Address feedback

* Remove using

* Catch OperationCanceledException

* Add licensing informations

* Add THIRDPARTY.md to release too

Co-authored-by: Thog <me@thog.eu>

Ryujinx.Memory/NativeMemoryManager.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Buffers;
+
+namespace Ryujinx.Memory
+{
+    unsafe class NativeMemoryManager<T> : MemoryManager<T> where T : unmanaged
+    {
+        private readonly T* _pointer;
+        private readonly int _length;
+
+        public NativeMemoryManager(T* pointer, int length)
+        {
+            _pointer = pointer;
+            _length = length;
+        }
+
+        public override Span<T> GetSpan()
+        {
+            return new Span<T>((void*)_pointer, _length);
+        }
+
+        public override MemoryHandle Pin(int elementIndex = 0)
+        {
+            if ((uint)elementIndex >= _length)
+            {
+                throw new ArgumentOutOfRangeException(nameof(elementIndex));
+            }
+
+            return new MemoryHandle((void*)(_pointer + elementIndex));
+        }
+
+        public override void Unpin()
+        {
+            // No need to do anything as pointer already points no native memory, not GC tracked.
+        }
+
+        protected override void Dispose(bool disposing)
+        {
+            // Nothing to dispose, MemoryBlock still owns the memory.
+        }
+    }
+}