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.Graphics.Vic/Image/BufferPool.cs

@@ -0,0 +1,103 @@
+using System;
+
+namespace Ryujinx.Graphics.Vic.Image
+{
+    class BufferPool<T>
+    {
+        /// <summary>
+        /// Maximum number of buffers on the pool.
+        /// </summary>
+        private const int MaxBuffers = 4;
+
+        /// <summary>
+        /// Maximum size of a buffer that can be added on the pool.
+        /// If the required buffer is larger than this, it won't be
+        /// added to the pool to avoid long term high memory usage.
+        /// </summary>
+        private const int MaxBufferSize = 2048 * 1280;
+
+        private struct PoolItem
+        {
+            public bool InUse;
+            public T[] Buffer;
+        }
+
+        private readonly PoolItem[] _pool = new PoolItem[MaxBuffers];
+
+        /// <summary>
+        /// Rents a buffer with the exact size requested.
+        /// </summary>
+        /// <param name="length">Size of the buffer</param>
+        /// <param name="buffer">Span of the requested size</param>
+        /// <returns>The index of the buffer on the pool</returns>
+        public int Rent(int length, out Span<T> buffer)
+        {
+            int index = RentMinimum(length, out T[] bufferArray);
+
+            buffer = new Span<T>(bufferArray).Slice(0, length);
+
+            return index;
+        }
+
+        /// <summary>
+        /// Rents a buffer with a size greater than or equal to the requested size.
+        /// </summary>
+        /// <param name="length">Size of the buffer</param>
+        /// <param name="buffer">Array with a length greater than or equal to the requested length</param>
+        /// <returns>The index of the buffer on the pool</returns>
+        public int RentMinimum(int length, out T[] buffer)
+        {
+            if ((uint)length > MaxBufferSize)
+            {
+                buffer = new T[length];
+                return -1;
+            }
+
+            // Try to find a buffer that is larger or the same size of the requested one.
+            // This will avoid an allocation.
+            for (int i = 0; i < MaxBuffers; i++)
+            {
+                ref PoolItem item = ref _pool[i];
+
+                if (!item.InUse && item.Buffer != null && item.Buffer.Length >= length)
+                {
+                    buffer = item.Buffer;
+                    item.InUse = true;
+                    return i;
+                }
+            }
+
+            buffer = new T[length];
+
+            // Try to add the new buffer to the pool.
+            // We try to find a slot that is not in use, and replace the buffer in it.
+            for (int i = 0; i < MaxBuffers; i++)
+            {
+                ref PoolItem item = ref _pool[i];
+
+                if (!item.InUse)
+                {
+                    item.Buffer = buffer;
+                    item.InUse = true;
+                    return i;
+                }
+            }
+
+            return -1;
+        }
+
+        /// <summary>
+        /// Returns a buffer returned from <see cref="Rent(int)"/> to the pool.
+        /// </summary>
+        /// <param name="index">Index of the buffer on the pool</param>
+        public void Return(int index)
+        {
+            if (index < 0)
+            {
+                return;
+            }
+
+            _pool[index].InUse = false;
+        }
+    }
+}