Externals: Add libLZMA.

Externals/liblzma/common/easy_preset.h

@@ -0,0 +1,32 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       easy_preset.h
+/// \brief      Preset handling for easy encoder and decoder
+//
+//  Author:     Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "common.h"
+
+
+typedef struct {
+	/// We need to keep the filters array available in case
+	/// LZMA_FULL_FLUSH is used.
+	lzma_filter filters[LZMA_FILTERS_MAX + 1];
+
+	/// Options for LZMA2
+	lzma_options_lzma opt_lzma;
+
+	// Options for more filters can be added later, so this struct
+	// is not ready to be put into the public API.
+
+} lzma_options_easy;
+
+
+/// Set *easy to the settings given by the preset. Returns true on error,
+/// false on success.
+extern bool lzma_easy_preset(lzma_options_easy *easy, uint32_t preset);