rlm@0: /*-
rlm@0:  * Copyright (c) 2005 Boris Mikhaylov
rlm@0:  *
rlm@0:  * Permission is hereby granted, free of charge, to any person obtaining
rlm@0:  * a copy of this software and associated documentation files (the
rlm@0:  * "Software"), to deal in the Software without restriction, including
rlm@0:  * without limitation the rights to use, copy, modify, merge, publish,
rlm@0:  * distribute, sublicense, and/or sell copies of the Software, and to
rlm@0:  * permit persons to whom the Software is furnished to do so, subject to
rlm@0:  * the following conditions:
rlm@0:  *
rlm@0:  * The above copyright notice and this permission notice shall be
rlm@0:  * included in all copies or substantial portions of the Software.
rlm@0:  *
rlm@0:  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
rlm@0:  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
rlm@0:  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
rlm@0:  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
rlm@0:  * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
rlm@0:  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
rlm@0:  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
rlm@0:  */
rlm@0: 
rlm@0: #ifndef BS2B_H
rlm@0: #define BS2B_H
rlm@0: 
rlm@0: /* Number of crossfeed levels */
rlm@0: #define BS2B_CLEVELS           3
rlm@0: 
rlm@0: /* Normal crossfeed levels */
rlm@0: #define BS2B_HIGH_CLEVEL       3
rlm@0: #define BS2B_MIDDLE_CLEVEL     2
rlm@0: #define BS2B_LOW_CLEVEL        1
rlm@0: 
rlm@0: /* Easy crossfeed levels */
rlm@0: #define BS2B_HIGH_ECLEVEL      BS2B_HIGH_CLEVEL    + BS2B_CLEVELS
rlm@0: #define BS2B_MIDDLE_ECLEVEL    BS2B_MIDDLE_CLEVEL  + BS2B_CLEVELS
rlm@0: #define BS2B_LOW_ECLEVEL       BS2B_LOW_CLEVEL     + BS2B_CLEVELS
rlm@0: 
rlm@0: /* Default crossfeed levels */
rlm@0: #define BS2B_DEFAULT_CLEVEL    BS2B_HIGH_ECLEVEL
rlm@0: /* Default sample rate (Hz) */
rlm@0: #define BS2B_DEFAULT_SRATE     44100
rlm@0: 
rlm@0: #ifdef __cplusplus
rlm@0: extern "C" {
rlm@0: #endif /* __cplusplus */
rlm@0: 
rlm@0: struct bs2b {
rlm@0:     int level;  /* Crossfeed level */
rlm@0:     int srate;   /* Sample rate (Hz) */
rlm@0: 
rlm@0:     /* Lowpass IIR filter coefficients */
rlm@0:     double a0_lo;
rlm@0:     double b1_lo;
rlm@0: 
rlm@0:     /* Highboost IIR filter coefficients */
rlm@0:     double a0_hi;
rlm@0:     double a1_hi;
rlm@0:     double b1_hi;
rlm@0: 
rlm@0:     /* Global gain against overloading */
rlm@0:     double gain;
rlm@0: 
rlm@0:     /* Buffer of last filtered sample.
rlm@0:      * [0] - first channel, [1] - second channel
rlm@0:      */
rlm@0:     struct t_last_sample {
rlm@0:         double asis[2];
rlm@0:         double lo[2];
rlm@0:         double hi[2];
rlm@0:     } last_sample;
rlm@0: };
rlm@0: 
rlm@0: /* Clear buffers and set new coefficients with new crossfeed level value.
rlm@0:  * level - crossfeed level of *LEVEL values.
rlm@0:  */
rlm@0: void bs2b_set_level(struct bs2b *bs2b, int level);
rlm@0: 
rlm@0: /* Return current crossfeed level value */
rlm@0: int bs2b_get_level(struct bs2b *bs2b);
rlm@0: 
rlm@0: /* Clear buffers and set new coefficients with new sample rate value.
rlm@0:  * srate - sample rate by Hz.
rlm@0:  */
rlm@0: void bs2b_set_srate(struct bs2b *bs2b, int srate);
rlm@0: 
rlm@0: /* Return current sample rate value */
rlm@0: int bs2b_get_srate(struct bs2b *bs2b);
rlm@0: 
rlm@0: /* Clear buffer */
rlm@0: void bs2b_clear(struct bs2b *bs2b);
rlm@0: 
rlm@0: /* Return 1 if buffer is clear */
rlm@0: int bs2b_is_clear(struct bs2b *bs2b);
rlm@0: 
rlm@0: /* Crossfeeds one stereo sample that are pointed by sample.
rlm@0:  * [0] - first channel, [1] - second channel.
rlm@0:  * Returns crossfided samle by sample pointer.
rlm@0:  */
rlm@0: 
rlm@0: /* sample poits to floats */
rlm@0: void bs2b_cross_feed(struct bs2b *bs2b, float *sample);
rlm@0: 
rlm@0: #ifdef __cplusplus
rlm@0: }    /* extern "C" */
rlm@0: #endif /* __cplusplus */
rlm@0: 
rlm@0: #endif /* BS2B_H */