aom_dsp/blend.h

   1 /*
   2  * Copyright (c) 2016, Alliance for Open Media. All rights reserved
   3  *
   4  * This source code is subject to the terms of the BSD 2 Clause License and
   5  * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
   6  * was not distributed with this source code in the LICENSE file, you can
   7  * obtain it at www.aomedia.org/license/software. If the Alliance for Open
   8  * Media Patent License 1.0 was not distributed with this source code in the
   9  * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
  10  */
  11
  12 #ifndef AOM_AOM_DSP_BLEND_H_
  13 #define AOM_AOM_DSP_BLEND_H_
  14
  15 #include "aom_ports/mem.h"
  16
  17 // Various blending functions and macros.
  18 // See also the aom_blend_* functions in aom_dsp_rtcd.h
  19
  20 // Alpha blending with alpha values from the range [0, 64], where 64
  21 // means use the first input and 0 means use the second input.
  22
  23 #define AOM_BLEND_A64_ROUND_BITS 6
  24 #define AOM_BLEND_A64_MAX_ALPHA (1 << AOM_BLEND_A64_ROUND_BITS)  // 64
  25
  26 #define AOM_BLEND_A64(a, v0, v1)                                          \
  27   ROUND_POWER_OF_TWO((a) * (v0) + (AOM_BLEND_A64_MAX_ALPHA - (a)) * (v1), \
  28                      AOM_BLEND_A64_ROUND_BITS)
  29
  30 // Alpha blending with alpha values from the range [0, 256], where 256
  31 // means use the first input and 0 means use the second input.
  32 #define AOM_BLEND_A256_ROUND_BITS 8
  33 #define AOM_BLEND_A256_MAX_ALPHA (1 << AOM_BLEND_A256_ROUND_BITS)  // 256
  34
  35 #define AOM_BLEND_A256(a, v0, v1)                                          \
  36   ROUND_POWER_OF_TWO((a) * (v0) + (AOM_BLEND_A256_MAX_ALPHA - (a)) * (v1), \
  37                      AOM_BLEND_A256_ROUND_BITS)
  38
  39 // Blending by averaging.
  40 #define AOM_BLEND_AVG(v0, v1) ROUND_POWER_OF_TWO((v0) + (v1), 1)
  41
  42 #define DIFF_FACTOR_LOG2 4
  43 #define DIFF_FACTOR (1 << DIFF_FACTOR_LOG2)
  44
  45 #endif  // AOM_AOM_DSP_BLEND_H_