Add the required library and flags for tuning for VMAF

Change-Id: I7cc5620d4a3d51d05fab335ef7d5e0a80c704b0d
diff --git a/aom_dsp/vmaf.h b/aom_dsp/vmaf.h
new file mode 100644
index 0000000..8a9e56c
--- /dev/null
+++ b/aom_dsp/vmaf.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2019, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#ifndef AOM_AOM_DSP_VMAF_H_
+#define AOM_AOM_DSP_VMAF_H_
+
+#include "aom_scale/yv12config.h"
+
+int aom_calc_vmaf(const char *model_path, const YV12_BUFFER_CONFIG *source,
+                  const YV12_BUFFER_CONFIG *distorted, double *vmaf);
+
+#endif  // AOM_AOM_DSP_VMAF_H_