Move HalfFloatMaker to media

media/video/half_float_maker.h

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef MEDIA_VIDEO_HALF_FLOAT_MAKER_H_
+#define MEDIA_VIDEO_HALF_FLOAT_MAKER_H_
+
+#include <stddef.h>
+#include <stdint.h>
+#include <memory>
+
+#include "media/base/media_export.h"
+
+namespace media {
+
+class MEDIA_EXPORT HalfFloatMaker {
+ public:
+  // Convert an array of short integers into an array of half-floats.
+  // |src| is an array of integers in range 0 .. 2^{bits_per_channel} - 1
+  // |num| is number of entries in input and output array.
+  // The numbers stored in |dst| will be half floats in range 0.0..1.0
+  virtual void MakeHalfFloats(const uint16_t* src,
+                              size_t num,
+                              uint16_t* dst) = 0;
+  // The half-floats made needs by this class will be in the range
+  // [Offset() .. Offset() + 1.0/Multiplier]. So if you want results
+  // in the 0-1 range, you need to do:
+  //   (half_float - Offset()) * Multiplier()
+  // to each returned value.
+  virtual float Offset() const = 0;
+  virtual float Multiplier() const = 0;
+  // Below is a factory method which can be used to create halffloatmaker.
+  static std::unique_ptr<HalfFloatMaker> NewHalfFloatMaker(
+      int bits_per_channel);
+};
+
+}  // namespace media
+#endif  // MEDIA_VIDEO_HALF_FLOAT_MAKER_H_