core/ambidefs.cpp

   1
   2 #include "config.h"
   3
   4 #include "ambidefs.h"
   5
   6 #include <cassert>
   7
   8
   9 namespace {
  10
  11 constexpr std::array<float,MaxAmbiOrder+1> Ambi3DDecoderHFScale{{
  12     1.00000000e+00f, 1.00000000e+00f
  13 }};
  14 constexpr std::array<float,MaxAmbiOrder+1> Ambi3DDecoderHFScale2O{{
  15     7.45355990e-01f, 1.00000000e+00f, 1.00000000e+00f
  16 }};
  17 constexpr std::array<float,MaxAmbiOrder+1> Ambi3DDecoderHFScale3O{{
  18     5.89792205e-01f, 8.79693856e-01f, 1.00000000e+00f, 1.00000000e+00f
  19 }};
  20
  21 inline auto& GetDecoderHFScales(uint order) noexcept
  22 {
  23     if(order >= 3) return Ambi3DDecoderHFScale3O;
  24     if(order == 2) return Ambi3DDecoderHFScale2O;
  25     return Ambi3DDecoderHFScale;
  26 }
  27
  28 } // namespace
  29
  30 auto AmbiScale::GetHFOrderScales(const uint in_order, const uint out_order) noexcept
  31     -> std::array<float,MaxAmbiOrder+1>
  32 {
  33     std::array<float,MaxAmbiOrder+1> ret{};
  34
  35     assert(out_order >= in_order);
  36
  37     const auto &target = GetDecoderHFScales(out_order);
  38     const auto &input = GetDecoderHFScales(in_order);
  39
  40     for(size_t i{0};i < in_order+1;++i)
  41         ret[i] = input[i] / target[i];
  42
  43     return ret;
  44 }