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 struct BFormatDec {
  38     static constexpr size_t NumBands{2};
  39
  40     ALuint Enabled; /* Bitfield of enabled channels. */
  41
  42     union {
  43         alignas(16) ALfloat Dual[MAX_OUTPUT_CHANNELS][NumBands][MAX_AMBI_COEFFS];
  44         alignas(16) ALfloat Single[MAX_OUTPUT_CHANNELS][MAX_AMBI_COEFFS];
  45     } Matrix;
  46
  47     /* NOTE: BandSplitter filters are unused with single-band decoding */
  48     BandSplitter XOver[MAX_AMBI_COEFFS];
  49
  50     al::vector<std::array<ALfloat,BUFFERSIZE>, 16> Samples;
  51     /* These two alias into Samples */
  52     std::array<ALfloat,BUFFERSIZE> *SamplesHF;
  53     std::array<ALfloat,BUFFERSIZE> *SamplesLF;
  54
  55     alignas(16) ALfloat ChannelMix[BUFFERSIZE];
  56
  57     struct {
  58         BandSplitter XOver;
  59         ALfloat Gains[NumBands];
  60     } UpSampler[4];
  61
  62     ALsizei NumChannels;
  63     ALboolean DualBand;
  64
  65     DEF_NEWDEL(BFormatDec)
  66 };
  67
  68 void bformatdec_reset(BFormatDec *dec, 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 bformatdec_process(BFormatDec *dec, ALfloat (*RESTRICT OutBuffer)[BUFFERSIZE], ALsizei OutChannels, const ALfloat (*RESTRICT InSamples)[BUFFERSIZE], ALsizei SamplesToDo);
  72
  73 /* Up-samples a first-order input to the decoder's configuration. */
  74 void bformatdec_upSample(BFormatDec *dec, ALfloat (*RESTRICT OutBuffer)[BUFFERSIZE], const ALfloat (*RESTRICT InSamples)[BUFFERSIZE], ALsizei InChannels, ALsizei SamplesToDo);
  75
  76
  77 /* Stand-alone first-order upsampler. Kept here because it shares some stuff
  78  * with bformatdec. Assumes a periphonic (4-channel) input mix!
  79  */
  80 struct AmbiUpsampler {
  81     static constexpr size_t NumBands{2};
  82
  83     alignas(16) ALfloat Samples[NumBands][BUFFERSIZE];
  84
  85     BandSplitter XOver[4];
  86
  87     ALfloat Gains[4][MAX_OUTPUT_CHANNELS][NumBands];
  88
  89     DEF_NEWDEL(AmbiUpsampler)
  90 };
  91
  92 void ambiup_reset(AmbiUpsampler *ambiup, const ALCdevice *device, ALfloat w_scale, ALfloat xyz_scale);
  93 void ambiup_process(AmbiUpsampler *ambiup, ALfloat (*RESTRICT OutBuffer)[BUFFERSIZE], ALsizei OutChannels, const ALfloat (*RESTRICT InSamples)[BUFFERSIZE], ALsizei SamplesToDo);
  94
  95 #endif /* BFORMATDEC_H */