core/mixer/defs.h

   1 #ifndef CORE_MIXER_DEFS_H
   2 #define CORE_MIXER_DEFS_H
   3
   4 #include <array>
   5 #include <stdlib.h>
   6
   7 #include "alspan.h"
   8 #include "core/bufferline.h"
   9 #include "core/resampler_limits.h"
  10
  11 struct HrtfChannelState;
  12 struct HrtfFilter;
  13 struct MixHrtfFilter;
  14
  15 using uint = unsigned int;
  16 using float2 = std::array<float,2>;
  17
  18
  19 constexpr int MixerFracBits{12};
  20 constexpr int MixerFracOne{1 << MixerFracBits};
  21 constexpr int MixerFracMask{MixerFracOne - 1};
  22
  23 constexpr float GainSilenceThreshold{0.00001f}; /* -100dB */
  24
  25
  26 enum class Resampler {
  27     Point,
  28     Linear,
  29     Cubic,
  30     FastBSinc12,
  31     BSinc12,
  32     FastBSinc24,
  33     BSinc24,
  34
  35     Max = BSinc24
  36 };
  37
  38 /* Interpolator state. Kind of a misnomer since the interpolator itself is
  39  * stateless. This just keeps it from having to recompute scale-related
  40  * mappings for every sample.
  41  */
  42 struct BsincState {
  43     float sf; /* Scale interpolation factor. */
  44     uint m; /* Coefficient count. */
  45     uint l; /* Left coefficient offset. */
  46     /* Filter coefficients, followed by the phase, scale, and scale-phase
  47      * delta coefficients. Starting at phase index 0, each subsequent phase
  48      * index follows contiguously.
  49      */
  50     const float *filter;
  51 };
  52
  53 union InterpState {
  54     BsincState bsinc;
  55 };
  56
  57 using ResamplerFunc = float*(*)(const InterpState *state, float *RESTRICT src, uint frac,
  58     uint increment, const al::span<float> dst);
  59
  60 ResamplerFunc PrepareResampler(Resampler resampler, uint increment, InterpState *state);
  61
  62
  63 template<typename TypeTag, typename InstTag>
  64 float *Resample_(const InterpState *state, float *RESTRICT src, uint frac, uint increment,
  65     const al::span<float> dst);
  66
  67 template<typename InstTag>
  68 void Mix_(const al::span<const float> InSamples, const al::span<FloatBufferLine> OutBuffer,
  69     float *CurrentGains, const float *TargetGains, const size_t Counter, const size_t OutPos);
  70
  71 template<typename InstTag>
  72 void MixHrtf_(const float *InSamples, float2 *AccumSamples, const uint IrSize,
  73     const MixHrtfFilter *hrtfparams, const size_t BufferSize);
  74 template<typename InstTag>
  75 void MixHrtfBlend_(const float *InSamples, float2 *AccumSamples, const uint IrSize,
  76     const HrtfFilter *oldparams, const MixHrtfFilter *newparams, const size_t BufferSize);
  77 template<typename InstTag>
  78 void MixDirectHrtf_(const FloatBufferSpan LeftOut, const FloatBufferSpan RightOut,
  79     const al::span<const FloatBufferLine> InSamples, float2 *AccumSamples,
  80     float *TempBuf, HrtfChannelState *ChanState, const size_t IrSize, const size_t BufferSize);
  81
  82 /* Vectorized resampler helpers */
  83 template<size_t N>
  84 inline void InitPosArrays(uint frac, uint increment, uint (&frac_arr)[N], uint (&pos_arr)[N])
  85 {
  86     pos_arr[0] = 0;
  87     frac_arr[0] = frac;
  88     for(size_t i{1};i < N;i++)
  89     {
  90         const uint frac_tmp{frac_arr[i-1] + increment};
  91         pos_arr[i] = pos_arr[i-1] + (frac_tmp>>MixerFracBits);
  92         frac_arr[i] = frac_tmp&MixerFracMask;
  93     }
  94 }
  95
  96 #endif /* CORE_MIXER_DEFS_H */