From d3090a98b45afd0eb61cf91b80c87dd7f4d0f027 Mon Sep 17 00:00:00 2001
From: GeorgH93 <git@georgh93.eu>
Date: Wed, 26 May 2021 17:17:17 +0200
Subject: [PATCH] Add YuvUtils to assist with nv12 to planar yuv conversions

---
 openVulkanoCpp/Image/YuvUtils.hpp | 72 +++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 openVulkanoCpp/Image/YuvUtils.hpp

diff --git a/openVulkanoCpp/Image/YuvUtils.hpp b/openVulkanoCpp/Image/YuvUtils.hpp
new file mode 100644
index 0000000..672b690
--- /dev/null
+++ b/openVulkanoCpp/Image/YuvUtils.hpp
@@ -0,0 +1,72 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+#pragma once
+
+#include <memory>
+#include <cstring>
+
+namespace openVulkanoCpp
+{
+	namespace YuvUtils
+	{
+		void NV12FromChromaPlanes(unsigned char* __restrict src, unsigned char* __restrict dest, int chromaChannelPixelCount)
+		{
+			for(int i = 0; i < chromaChannelPixelCount; i++)
+			{
+				dest[i * 2] = src[i];
+			}
+			for(int i=0; i < chromaChannelPixelCount; i++)
+			{
+				dest[i * 2 + 1] = src[i + chromaChannelPixelCount];
+			}
+		}
+
+		void ChromaPlanesFromNV12(unsigned char* __restrict src, unsigned char* __restrict dest, int chromaChannelPixelCount)
+		{
+			for (int i = 0; i < chromaChannelPixelCount; i++)
+			{
+				dest[i] = src[i * 2];
+				dest[i + chromaChannelPixelCount] = src[i * 2 + 1];
+			}
+		}
+
+		std::unique_ptr<uint8_t[]> PlansFromNV12(
+				unsigned char* __restrict srcLum, unsigned char* __restrict srcChroma, uint32_t sizeLumX, uint32_t sizeLumY,
+				uint32_t sizeChromaComponentX, uint32_t sizeChromaComponentY, uint32_t strideX = 1, uint32_t strideY = 1)
+		{
+			std::unique_ptr<uint8_t[]> buffer(new uint8_t[(sizeLumX / strideX) * (sizeLumY / strideY) + 2 * (sizeChromaComponentX / strideX) * (sizeChromaComponentY / strideY)]);
+			if (strideX == 1 && strideY == 1)
+			{
+				memcpy(buffer.get(), srcLum, sizeLumX * sizeLumY);
+				ChromaPlanesFromNV12(srcChroma, buffer.get() + sizeLumX * sizeLumY, sizeChromaComponentX * sizeChromaComponentY);
+			}
+			else
+			{
+				uint8_t* dest = buffer.get();
+				size_t rowStride = strideY * sizeLumX;
+				for(int y = 0; y < sizeLumY; y += strideY, srcLum += rowStride)
+				{
+					for(int x = 0; x < sizeLumX; x += strideX, dest++)
+					{
+						*dest = srcLum[x];
+					}
+				}
+				uint32_t chromaCount = (sizeChromaComponentX / strideX) * (sizeChromaComponentY / strideY);
+				rowStride = strideY * sizeChromaComponentX * 2;
+				for(int y = 0; y < sizeChromaComponentY; y += strideY, srcChroma += rowStride)
+				{
+					for (int x = 0; x < sizeChromaComponentX * 2; x += 2 * strideX, dest++)
+					{
+						dest[0] = srcChroma[x];
+						dest[chromaCount] = srcChroma[x + 1];
+					}
+				}
+			}
+			return buffer;
+		}
+	}
+}