Add low level support for 12 bit 420, 422 and 444 YUV video frame conversion.

include/libyuv/row.h

 /*
  *  Copyright 2011 The LibYuv Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS. All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 234 matching lines @@
 // TODO(fbarchard): Port to gcc.
 #if !defined(LIBYUV_DISABLE_X86) && defined(_M_IX86) && \
     (defined(VISUALC_HAS_AVX2) || defined(CLANG_HAS_AVX2))
 #define HAS_ARGB1555TOARGBROW_AVX2
 #define HAS_ARGB4444TOARGBROW_AVX2
 #define HAS_ARGBTOARGB1555ROW_AVX2
 #define HAS_ARGBTOARGB4444ROW_AVX2
 #define HAS_ARGBTORGB565ROW_AVX2
 #define HAS_J400TOARGBROW_AVX2
 #define HAS_RGB565TOARGBROW_AVX2
-#define HAS_SHORTTOF16ROW_AVX2
+#define HAS_HALFFLOATROW_AVX2
 #endif
 
 // The following are also available on x64 Visual C.
 #if !defined(LIBYUV_DISABLE_X86) && defined(_MSC_VER) && defined(_M_X64) && \
     (!defined(__clang__) || defined(__SSSE3__))
 #define HAS_I422ALPHATOARGBROW_SSSE3
 #define HAS_I422TOARGBROW_SSSE3
 #endif
 
 // The following are available on Neon platforms:
@@ skipping 1661 matching lines @@
                          uint8* dst_argb, const float* poly,
                          int width);
 void ARGBPolynomialRow_SSE2(const uint8* src_argb,
                             uint8* dst_argb, const float* poly,
                             int width);
 void ARGBPolynomialRow_AVX2(const uint8* src_argb,
                             uint8* dst_argb, const float* poly,
                             int width);
 
 // Scale and convert to half float.
-void ShortToF16Row_C(const uint16* src, int16* dst, float scale, int width);
-void ShortToF16Row_AVX2(const uint16* src, int16* dst, float scale, int width);
+void HalfFloatRow_C(const uint16* src, int16* dst, float scale, int width);
+void HalfFloatRow_AVX2(const uint16* src, int16* dst, float scale, int width);
 
 void ARGBLumaColorTableRow_C(const uint8* src_argb, uint8* dst_argb, int width,
                              const uint8* luma, uint32 lumacoeff);
 void ARGBLumaColorTableRow_SSSE3(const uint8* src_argb, uint8* dst_argb,
                                  int width,
                                  const uint8* luma, uint32 lumacoeff);
 
 #ifdef __cplusplus
 }  // extern "C"
 }  // namespace libyuv
 #endif
 
 #endif  // INCLUDE_LIBYUV_ROW_H_