Mercurial > audio-send

     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 BS2B_H

    25 #define BS2B_H

    26 

    27 /* Number of crossfeed levels */

    28 #define BS2B_CLEVELS           3

    29 

    30 /* Normal crossfeed levels */

    31 #define BS2B_HIGH_CLEVEL       3

    32 #define BS2B_MIDDLE_CLEVEL     2

    33 #define BS2B_LOW_CLEVEL        1

    34 

    35 /* Easy crossfeed levels */

    36 #define BS2B_HIGH_ECLEVEL      BS2B_HIGH_CLEVEL    + BS2B_CLEVELS

    37 #define BS2B_MIDDLE_ECLEVEL    BS2B_MIDDLE_CLEVEL  + BS2B_CLEVELS

    38 #define BS2B_LOW_ECLEVEL       BS2B_LOW_CLEVEL     + BS2B_CLEVELS

    39 

    40 /* Default crossfeed levels */

    41 #define BS2B_DEFAULT_CLEVEL    BS2B_HIGH_ECLEVEL

    42 /* Default sample rate (Hz) */

    43 #define BS2B_DEFAULT_SRATE     44100

    44 

    45 #ifdef __cplusplus

    46 extern "C" {

    47 #endif /* __cplusplus */

    48 

    49 struct bs2b {

    50     int level;  /* Crossfeed level */

    51     int srate;   /* Sample rate (Hz) */

    52 

    53     /* Lowpass IIR filter coefficients */

    54     double a0_lo;

    55     double b1_lo;

    56 

    57     /* Highboost IIR filter coefficients */

    58     double a0_hi;

    59     double a1_hi;

    60     double b1_hi;

    61 

    62     /* Global gain against overloading */

    63     double gain;

    64 

    65     /* Buffer of last filtered sample.

    66      * [0] - first channel, [1] - second channel

    67      */

    68     struct t_last_sample {

    69         double asis[2];

    70         double lo[2];

    71         double hi[2];

    72     } last_sample;

    73 };

    74 

    75 /* Clear buffers and set new coefficients with new crossfeed level value.

    76  * level - crossfeed level of *LEVEL values.

    77  */

    78 void bs2b_set_level(struct bs2b *bs2b, int level);

    79 

    80 /* Return current crossfeed level value */

    81 int bs2b_get_level(struct bs2b *bs2b);

    82 

    83 /* Clear buffers and set new coefficients with new sample rate value.

    84  * srate - sample rate by Hz.

    85  */

    86 void bs2b_set_srate(struct bs2b *bs2b, int srate);

    87 

    88 /* Return current sample rate value */

    89 int bs2b_get_srate(struct bs2b *bs2b);

    90 

    91 /* Clear buffer */

    92 void bs2b_clear(struct bs2b *bs2b);

    93 

    94 /* Return 1 if buffer is clear */

    95 int bs2b_is_clear(struct bs2b *bs2b);

    96 

    97 /* Crossfeeds one stereo sample that are pointed by sample.

    98  * [0] - first channel, [1] - second channel.

    99  * Returns crossfided samle by sample pointer.

   100  */

   101 

   102 /* sample poits to floats */

   103 void bs2b_cross_feed(struct bs2b *bs2b, float *sample);

   104 

   105 #ifdef __cplusplus

   106 }    /* extern "C" */

   107 #endif /* __cplusplus */

   108 

   109 #endif /* BS2B_H */
author	Robert McIntyre <rlm@mit.edu>
date	Sat, 04 Feb 2012 01:43:33 -0700
parents	f9476ff7637e
children