core/bformatdec.h

   1 #ifndef CORE_BFORMATDEC_H
   2 #define CORE_BFORMATDEC_H
   3
   4 #include <array>
   5 #include <cstddef>
   6 #include <memory>
   7
   8 #include "almalloc.h"
   9 #include "alspan.h"
  10 #include "ambidefs.h"
  11 #include "bufferline.h"
  12 #include "devformat.h"
  13 #include "filters/splitter.h"
  14 #include "vector.h"
  15
  16 struct FrontStablizer;
  17
  18
  19 using ChannelDec = std::array<float,MaxAmbiChannels>;
  20
  21 class BFormatDec {
  22     static constexpr size_t sHFBand{0};
  23     static constexpr size_t sLFBand{1};
  24     static constexpr size_t sNumBands{2};
  25
  26     struct ChannelDecoder {
  27         union MatrixU {
  28             float Dual[sNumBands][MAX_OUTPUT_CHANNELS];
  29             float Single[MAX_OUTPUT_CHANNELS];
  30         } mGains{};
  31
  32         /* NOTE: BandSplitter filter is unused with single-band decoding. */
  33         BandSplitter mXOver;
  34     };
  35
  36     alignas(16) std::array<FloatBufferLine,2> mSamples;
  37
  38     const std::unique_ptr<FrontStablizer> mStablizer;
  39     const bool mDualBand{false};
  40
  41     /* TODO: This should ideally be a FlexArray, since ChannelDecoder is rather
  42      * small and only a few are needed (3, 4, 5, 7, typically). But that can
  43      * only be used in a standard layout struct, and a std::unique_ptr member
  44      * (mStablizer) causes GCC and Clang to warn it's not.
  45      */
  46     al::vector<ChannelDecoder> mChannelDec;
  47
  48 public:
  49     BFormatDec(const size_t inchans, const al::span<const ChannelDec> coeffs,
  50         const al::span<const ChannelDec> coeffslf, const float xover_f0norm,
  51         std::unique_ptr<FrontStablizer> stablizer);
  52
  53     bool hasStablizer() const noexcept { return mStablizer != nullptr; }
  54
  55     /* Decodes the ambisonic input to the given output channels. */
  56     void process(const al::span<FloatBufferLine> OutBuffer, const FloatBufferLine *InSamples,
  57         const size_t SamplesToDo);
  58
  59     /* Decodes the ambisonic input to the given output channels with stablization. */
  60     void processStablize(const al::span<FloatBufferLine> OutBuffer,
  61         const FloatBufferLine *InSamples, const size_t lidx, const size_t ridx, const size_t cidx,
  62         const size_t SamplesToDo);
  63
  64     static std::unique_ptr<BFormatDec> Create(const size_t inchans,
  65         const al::span<const ChannelDec> coeffs, const al::span<const ChannelDec> coeffslf,
  66         const float xover_f0norm, std::unique_ptr<FrontStablizer> stablizer);
  67
  68     DEF_NEWDEL(BFormatDec)
  69 };
  70
  71 #endif /* CORE_BFORMATDEC_H */