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.Cpu/MemoryManager.cs

@@ -193,6 +193,38 @@ namespace Ryujinx.Cpu
             }
         }
 
+        /// <summary>
+        /// Gets a region of memory that can be written to.
+        /// </summary>
+        /// <remarks>
+        /// If the requested region is not contiguous in physical memory,
+        /// this will perform an allocation, and flush the data (writing it
+        /// back to guest memory) on disposal.
+        /// </remarks>
+        /// <param name="va">Virtual address of the data</param>
+        /// <param name="size">Size of the data</param>
+        /// <returns>A writable region of memory containing the data</returns>
+        public WritableRegion GetWritableRegion(ulong va, int size)
+        {
+            if (size == 0)
+            {
+                return new WritableRegion(null, va, Memory<byte>.Empty);
+            }
+
+            if (IsContiguous(va, size))
+            {
+                return new WritableRegion(null, va, _backingMemory.GetMemory(GetPhysicalAddressInternal(va), size));
+            }
+            else
+            {
+                Memory<byte> memory = new byte[size];
+
+                GetSpan(va, size).CopyTo(memory.Span);
+
+                return new WritableRegion(this, va, memory);
+            }
+        }
+
         /// <summary>
         /// Gets a reference for the given type at the specified virtual memory address.
         /// </summary>