Extract ImageResampler from X11Grabber

Former-commit-id: 63e95fa85fc0ef5a66f6eb8b396cf4b6370cf5dd

include/utils/PixelFormat.h

@@ -0,0 +1,41 @@
+#pragma once
+
+#include <string>
+#include <algorithm>
+
+/**
+ * Enumeration of the possible pixel formats the grabber can be set to
+ */
+enum PixelFormat {
+	PIXELFORMAT_YUYV,
+	PIXELFORMAT_UYVY,
+    PIXELFORMAT_RGB32,
+    PIXELFORMAT_BGR32,
+    PIXELFORMAT_NO_CHANGE
+};
+
+inline PixelFormat parsePixelFormat(std::string pixelFormat)
+{
+	// convert to lower case
+	std::transform(pixelFormat.begin(), pixelFormat.end(), pixelFormat.begin(), ::tolower);
+
+	if (pixelFormat == "yuyv")
+	{
+		return PIXELFORMAT_YUYV;
+	}
+	else if (pixelFormat == "uyvy")
+	{
+		return PIXELFORMAT_UYVY;
+	}
+    else if (pixelFormat == "rgb32")
+    {
+        return PIXELFORMAT_RGB32;
+    }
+    else if (pixelFormat == "bgr32")
+    {
+        return PIXELFORMAT_BGR32;
+    }
+
+	// return the default NO_CHANGE
+	return PIXELFORMAT_NO_CHANGE;
+}