Alc/bformatdec.h

   1 #ifndef BFORMATDEC_H
   2 #define BFORMATDEC_H
   3
   4 #include "alMain.h"
   5 #include "filters/splitter.h"
   6 #include "almalloc.h"
   7
   8
   9 struct AmbDecConf;
  10
  11
  12 /* These are the necessary scales for first-order HF responses to play over
  13  * higher-order 2D (non-periphonic) decoders.
  14  */
  15 #define W_SCALE_2H0P   1.224744871f /* sqrt(1.5) */
  16 #define XYZ_SCALE_2H0P 1.0f
  17 #define W_SCALE_3H0P   1.414213562f /* sqrt(2) */
  18 #define XYZ_SCALE_3H0P 1.082392196f
  19
  20 /* These are the necessary scales for first-order HF responses to play over
  21  * higher-order 3D (periphonic) decoders.
  22  */
  23 #define W_SCALE_2H2P   1.341640787f /* sqrt(1.8) */
  24 #define XYZ_SCALE_2H2P 1.0f
  25 #define W_SCALE_3H3P   1.695486018f
  26 #define XYZ_SCALE_3H3P 1.136697713f
  27
  28
  29 /* NOTE: These are scale factors as applied to Ambisonics content. Decoder
  30  * coefficients should be divided by these values to get proper N3D scalings.
  31  */
  32 extern const ALfloat N3D2N3DScale[MAX_AMBI_COEFFS];
  33 extern const ALfloat SN3D2N3DScale[MAX_AMBI_COEFFS];
  34 extern const ALfloat FuMa2N3DScale[MAX_AMBI_COEFFS];
  35
  36
  37 class BFormatDec {
  38 public:
  39     static constexpr size_t sNumBands{2};
  40
  41 private:
  42     ALuint mEnabled; /* Bitfield of enabled channels. */
  43
  44     union {
  45         alignas(16) ALfloat Dual[MAX_OUTPUT_CHANNELS][sNumBands][MAX_AMBI_COEFFS];
  46         alignas(16) ALfloat Single[MAX_OUTPUT_CHANNELS][MAX_AMBI_COEFFS];
  47     } mMatrix;
  48
  49     /* NOTE: BandSplitter filters are unused with single-band decoding */
  50     BandSplitter mXOver[MAX_AMBI_COEFFS];
  51
  52     al::vector<std::array<ALfloat,BUFFERSIZE>, 16> mSamples;
  53     /* These two alias into Samples */
  54     std::array<ALfloat,BUFFERSIZE> *mSamplesHF;
  55     std::array<ALfloat,BUFFERSIZE> *mSamplesLF;
  56
  57     alignas(16) ALfloat mChannelMix[BUFFERSIZE];
  58
  59     struct {
  60         BandSplitter XOver;
  61         ALfloat Gains[sNumBands];
  62     } mUpSampler[4];
  63
  64     ALsizei mNumChannels;
  65     ALboolean mDualBand;
  66
  67 public:
  68     void reset(const AmbDecConf *conf, ALsizei chancount, ALuint srate, const ALsizei (&chanmap)[MAX_OUTPUT_CHANNELS]);
  69
  70     /* Decodes the ambisonic input to the given output channels. */
  71     void process(ALfloat (*RESTRICT OutBuffer)[BUFFERSIZE], const ALsizei OutChannels, const ALfloat (*RESTRICT InSamples)[BUFFERSIZE], const ALsizei SamplesToDo);
  72
  73     /* Up-samples a first-order input to the decoder's configuration. */
  74     void upSample(ALfloat (*RESTRICT OutBuffer)[BUFFERSIZE], const ALfloat (*RESTRICT InSamples)[BUFFERSIZE], const ALsizei InChannels, const ALsizei SamplesToDo);
  75
  76     DEF_NEWDEL(BFormatDec)
  77 };
  78
  79
  80 /* Stand-alone first-order upsampler. Kept here because it shares some stuff
  81  * with bformatdec. Assumes a periphonic (4-channel) input mix!
  82  */
  83 class AmbiUpsampler {
  84 public:
  85     static constexpr size_t sNumBands{2};
  86
  87 private:
  88     alignas(16) ALfloat mSamples[sNumBands][BUFFERSIZE];
  89
  90     BandSplitter mXOver[4];
  91
  92     ALfloat mGains[4][MAX_OUTPUT_CHANNELS][sNumBands];
  93
  94 public:
  95     void reset(const ALCdevice *device, const ALfloat w_scale, const ALfloat xyz_scale);
  96     void process(ALfloat (*RESTRICT OutBuffer)[BUFFERSIZE], const ALsizei OutChannels, const ALfloat (*RESTRICT InSamples)[BUFFERSIZE], const ALsizei SamplesToDo);
  97
  98     DEF_NEWDEL(AmbiUpsampler)
  99 };
 100
 101 #endif /* BFORMATDEC_H */