alc/bformatdec.h

   1 #ifndef BFORMATDEC_H
   2 #define BFORMATDEC_H
   3
   4 #include <array>
   5 #include <cstddef>
   6 #include <memory>
   7
   8 #include "AL/al.h"
   9
  10 #include "alcmain.h"
  11 #include "almalloc.h"
  12 #include "alspan.h"
  13 #include "ambidefs.h"
  14 #include "devformat.h"
  15 #include "filters/splitter.h"
  16
  17 struct AmbDecConf;
  18 struct FrontStablizer;
  19
  20
  21 using ChannelDec = std::array<float,MAX_AMBI_CHANNELS>;
  22
  23 class BFormatDec {
  24     static constexpr size_t sHFBand{0};
  25     static constexpr size_t sLFBand{1};
  26     static constexpr size_t sNumBands{2};
  27
  28     struct ChannelDecoder {
  29         union MatrixU {
  30             float Dual[sNumBands][MAX_OUTPUT_CHANNELS];
  31             float Single[MAX_OUTPUT_CHANNELS];
  32         } mGains{};
  33
  34         /* NOTE: BandSplitter filter is unused with single-band decoding. */
  35         BandSplitter mXOver;
  36     };
  37
  38     alignas(16) std::array<FloatBufferLine,2> mSamples;
  39
  40     const std::unique_ptr<FrontStablizer> mStablizer;
  41     const bool mDualBand{false};
  42
  43     al::FlexArray<ChannelDecoder> mChannelDec;
  44
  45 public:
  46     BFormatDec(const AmbDecConf *conf, const bool allow_2band, const size_t inchans,
  47         const ALuint srate, const ALuint (&chanmap)[MAX_OUTPUT_CHANNELS],
  48         std::unique_ptr<FrontStablizer> stablizer);
  49     BFormatDec(const size_t inchans, const al::span<const ChannelDec> coeffs,
  50         const al::span<const ChannelDec> coeffslf, std::unique_ptr<FrontStablizer> stablizer);
  51
  52     bool hasStablizer() const noexcept { return mStablizer != nullptr; };
  53
  54     /* Decodes the ambisonic input to the given output channels. */
  55     void process(const al::span<FloatBufferLine> OutBuffer, const FloatBufferLine *InSamples,
  56         const size_t SamplesToDo);
  57
  58     /* Decodes the ambisonic input to the given output channels with stablization. */
  59     void processStablize(const al::span<FloatBufferLine> OutBuffer,
  60         const FloatBufferLine *InSamples, const size_t lidx, const size_t ridx, const size_t cidx,
  61         const size_t SamplesToDo);
  62
  63     /* Retrieves per-order HF scaling factors for "upsampling" ambisonic data. */
  64     static std::array<float,MAX_AMBI_ORDER+1> GetHFOrderScales(const ALuint in_order,
  65         const ALuint out_order) noexcept;
  66
  67     static std::unique_ptr<BFormatDec> Create(const AmbDecConf *conf, const bool allow_2band,
  68         const size_t inchans, const ALuint srate, const ALuint (&chanmap)[MAX_OUTPUT_CHANNELS],
  69         std::unique_ptr<FrontStablizer> stablizer);
  70     static std::unique_ptr<BFormatDec> Create(const size_t inchans,
  71         const al::span<const ChannelDec> coeffs, const al::span<const ChannelDec> coeffslf,
  72         std::unique_ptr<FrontStablizer> stablizer);
  73
  74     DEF_FAM_NEWDEL(BFormatDec, mChannelDec)
  75 };
  76
  77 #endif /* BFORMATDEC_H */