Alc/bformatdec.h

   1 #ifndef BFORMATDEC_H
   2 #define BFORMATDEC_H
   3
   4 #include "alMain.h"
   5
   6
   7 /* These are the necessary scales for first-order HF responses to play over
   8  * higher-order 2D (non-periphonic) decoders.
   9  */
  10 #define W_SCALE2D_SECOND   1.224744871f /* sqrt(1.5) */
  11 #define XYZ_SCALE2D_SECOND 1.0f
  12 #define W_SCALE2D_THIRD   1.414213562f /* sqrt(2) */
  13 #define XYZ_SCALE2D_THIRD 1.082392196f
  14
  15 /* These are the necessary scales for first-order HF responses to play over
  16  * higher-order 3D (periphonic) decoders.
  17  */
  18 #define W_SCALE3D_SECOND   1.341640787f /* sqrt(1.8) */
  19 #define XYZ_SCALE3D_SECOND 1.0f
  20 #define W_SCALE3D_THIRD   1.695486018f
  21 #define XYZ_SCALE3D_THIRD 1.136697713f
  22
  23
  24 struct AmbDecConf;
  25 struct BFormatDec;
  26 struct AmbiUpsampler;
  27
  28
  29 struct BFormatDec *bformatdec_alloc();
  30 void bformatdec_free(struct BFormatDec *dec);
  31 void bformatdec_reset(struct BFormatDec *dec, const struct AmbDecConf *conf, ALsizei chancount, ALuint srate, const ALsizei chanmap[MAX_OUTPUT_CHANNELS]);
  32
  33 /* Decodes the ambisonic input to the given output channels. */
  34 void bformatdec_process(struct BFormatDec *dec, ALfloat (*restrict OutBuffer)[BUFFERSIZE], ALsizei OutChannels, const ALfloat (*restrict InSamples)[BUFFERSIZE], ALsizei SamplesToDo);
  35
  36 /* Up-samples a first-order input to the decoder's configuration. */
  37 void bformatdec_upSample(struct BFormatDec *dec, ALfloat (*restrict OutBuffer)[BUFFERSIZE], const ALfloat (*restrict InSamples)[BUFFERSIZE], ALsizei InChannels, ALsizei SamplesToDo);
  38
  39
  40 /* Stand-alone first-order upsampler. Kept here because it shares some stuff
  41  * with bformatdec.
  42  */
  43 struct AmbiUpsampler *ambiup_alloc();
  44 void ambiup_free(struct AmbiUpsampler *ambiup);
  45 void ambiup_reset(struct AmbiUpsampler *ambiup, const ALCdevice *device);
  46
  47 void ambiup_process(struct AmbiUpsampler *ambiup, ALfloat (*restrict OutBuffer)[BUFFERSIZE], ALsizei OutChannels, const ALfloat (*restrict InSamples)[BUFFERSIZE], ALsizei SamplesToDo);
  48
  49
  50 /* Band splitter. Splits a signal into two phase-matching frequency bands. */
  51 typedef struct BandSplitter {
  52     ALfloat coeff;
  53     ALfloat lp_z1;
  54     ALfloat lp_z2;
  55     ALfloat hp_z1;
  56 } BandSplitter;
  57
  58 void bandsplit_init(BandSplitter *splitter, ALfloat freq_mult);
  59 void bandsplit_clear(BandSplitter *splitter);
  60 void bandsplit_process(BandSplitter *splitter, ALfloat *restrict hpout, ALfloat *restrict lpout,
  61                        const ALfloat *input, ALsizei count);
  62
  63 /* The all-pass portion of the band splitter. Applies the same phase shift
  64  * without splitting the signal.
  65  */
  66 typedef struct SplitterAllpass {
  67     ALfloat coeff;
  68     ALfloat z1;
  69 } SplitterAllpass;
  70
  71 void splitterap_init(SplitterAllpass *splitter, ALfloat freq_mult);
  72 void splitterap_clear(SplitterAllpass *splitter);
  73 void splitterap_process(SplitterAllpass *splitter, ALfloat *restrict samples, ALsizei count);
  74
  75
  76 typedef struct FrontStablizer {
  77     SplitterAllpass APFilter[MAX_OUTPUT_CHANNELS];
  78     BandSplitter LFilter, RFilter;
  79     alignas(16) ALfloat LSplit[2][BUFFERSIZE];
  80     alignas(16) ALfloat RSplit[2][BUFFERSIZE];
  81 } FrontStablizer;
  82
  83 #endif /* BFORMATDEC_H */