core/bs2b.h

   1 /*-
   2  * Copyright (c) 2005 Boris Mikhaylov
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining
   5  * a copy of this software and associated documentation files (the
   6  * "Software"), to deal in the Software without restriction, including
   7  * without limitation the rights to use, copy, modify, merge, publish,
   8  * distribute, sublicense, and/or sell copies of the Software, and to
   9  * permit persons to whom the Software is furnished to do so, subject to
  10  * the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be
  13  * included in all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  18  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
  19  * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  20  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  21  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 #ifndef CORE_BS2B_H
  25 #define CORE_BS2B_H
  26
  27 #include "almalloc.h"
  28
  29 /* Number of crossfeed levels */
  30 #define BS2B_CLEVELS           3
  31
  32 /* Normal crossfeed levels */
  33 #define BS2B_HIGH_CLEVEL       3
  34 #define BS2B_MIDDLE_CLEVEL     2
  35 #define BS2B_LOW_CLEVEL        1
  36
  37 /* Easy crossfeed levels */
  38 #define BS2B_HIGH_ECLEVEL      BS2B_HIGH_CLEVEL    + BS2B_CLEVELS
  39 #define BS2B_MIDDLE_ECLEVEL    BS2B_MIDDLE_CLEVEL  + BS2B_CLEVELS
  40 #define BS2B_LOW_ECLEVEL       BS2B_LOW_CLEVEL     + BS2B_CLEVELS
  41
  42 /* Default crossfeed levels */
  43 #define BS2B_DEFAULT_CLEVEL    BS2B_HIGH_ECLEVEL
  44 /* Default sample rate (Hz) */
  45 #define BS2B_DEFAULT_SRATE     44100
  46
  47 struct bs2b {
  48     int level;  /* Crossfeed level */
  49     int srate;   /* Sample rate (Hz) */
  50
  51     /* Lowpass IIR filter coefficients */
  52     float a0_lo;
  53     float b1_lo;
  54
  55     /* Highboost IIR filter coefficients */
  56     float a0_hi;
  57     float a1_hi;
  58     float b1_hi;
  59
  60     /* Buffer of filter history
  61      * [0] - first channel, [1] - second channel
  62      */
  63     struct t_last_sample {
  64         float lo;
  65         float hi;
  66     } history[2];
  67
  68     DEF_NEWDEL(bs2b)
  69 };
  70
  71 /* Clear buffers and set new coefficients with new crossfeed level and sample
  72  * rate values.
  73  * level - crossfeed level of *LEVEL values.
  74  * srate - sample rate by Hz.
  75  */
  76 void bs2b_set_params(bs2b *bs2b, int level, int srate);
  77
  78 /* Return current crossfeed level value */
  79 int bs2b_get_level(bs2b *bs2b);
  80
  81 /* Return current sample rate value */
  82 int bs2b_get_srate(bs2b *bs2b);
  83
  84 /* Clear buffer */
  85 void bs2b_clear(bs2b *bs2b);
  86
  87 void bs2b_cross_feed(bs2b *bs2b, float *Left, float *Right, size_t SamplesToDo);
  88
  89 #endif /* CORE_BS2B_H */