Updated SDL's YUV support, many thanks to Adrien Descamps

New functions get and set the YUV colorspace conversion mode:
	SDL_SetYUVConversionMode()
	SDL_GetYUVConversionMode()
	SDL_GetYUVConversionModeForResolution()

SDL_ConvertPixels() converts between all supported RGB and YUV formats, with SSE acceleration for converting from planar YUV formats (YV12, NV12, etc) to common RGB/RGBA formats.

Added a new test program, testyuv, to verify correctness and speed of YUV conversion functionality.

src/render/direct3d11/SDL_shaders_d3d11.h

@@ -0,0 +1,43 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "../../SDL_internal.h"
+
+/* D3D11 shader implementation */
+
+typedef enum {
+    SHADER_SOLID,
+    SHADER_RGB,
+    SHADER_YUV_JPEG,
+    SHADER_YUV_BT601,
+    SHADER_YUV_BT709,
+    SHADER_NV12_JPEG,
+    SHADER_NV12_BT601,
+    SHADER_NV12_BT709,
+    SHADER_NV21_JPEG,
+    SHADER_NV21_BT601,
+    SHADER_NV21_BT709,
+    NUM_SHADERS
+} D3D11_Shader;
+
+extern int D3D11_CreateVertexShader(ID3D11Device1 *d3dDevice, ID3D11VertexShader **vertexShader, ID3D11InputLayout **inputLayout);
+extern int D3D11_CreatePixelShader(ID3D11Device1 *d3dDevice, D3D11_Shader shader, ID3D11PixelShader **pixelShader);
+
+/* vi: set ts=4 sw=4 expandtab: */