88 lines
2.7 KiB
C
88 lines
2.7 KiB
C
/*
|
|
|
|
Copyright 2009, 2011 Sebastian Gesemann. All rights reserved.
|
|
|
|
Redistribution and use in source and binary forms, with or without modification, are
|
|
permitted provided that the following conditions are met:
|
|
|
|
1. Redistributions of source code must retain the above copyright notice, this list of
|
|
conditions and the following disclaimer.
|
|
|
|
2. Redistributions in binary form must reproduce the above copyright notice, this list
|
|
of conditions and the following disclaimer in the documentation and/or other materials
|
|
provided with the distribution.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY SEBASTIAN GESEMANN ''AS IS'' AND ANY EXPRESS OR IMPLIED
|
|
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
|
|
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SEBASTIAN GESEMANN OR
|
|
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
|
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
|
|
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
|
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
|
|
ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
The views and conclusions contained in the software and documentation are those of the
|
|
authors and should not be interpreted as representing official policies, either expressed
|
|
or implied, of Sebastian Gesemann.
|
|
|
|
*/
|
|
|
|
#ifndef NOISE_SHAPE_H_INCLUDED
|
|
#define NOISE_SHAPE_H_INCLUDED
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
typedef struct noise_shape_ctx_s {
|
|
int sos_count; /* number of second order sections */
|
|
const float *bbaa; /* filter coefficients, owned by user */
|
|
float *t1, *t2; /* filter state, owned by ns library */
|
|
} noise_shape_ctx;
|
|
|
|
/**
|
|
* initializes a noise_shaper context
|
|
* returns an error code or 0
|
|
*/
|
|
extern int noise_shape_init(
|
|
noise_shape_ctx *ctx,
|
|
int sos_count,
|
|
const float *coeffs);
|
|
|
|
/**
|
|
* destroys a noise_shaper context
|
|
*/
|
|
extern void noise_shape_destroy(
|
|
noise_shape_ctx *ctx);
|
|
|
|
/**
|
|
* initializes a noise_shaper context so that its state
|
|
* is a copy of a given context
|
|
* returns an error code or 0
|
|
*/
|
|
extern int noise_shape_clone(
|
|
const noise_shape_ctx *from, noise_shape_ctx *to);
|
|
|
|
/**
|
|
* computes the next "noise shaping sample". Note: This call
|
|
* alters the internal state. xxx_get and xxx_update must be
|
|
* called in an alternating manner.
|
|
*/
|
|
extern float noise_shape_get(
|
|
noise_shape_ctx *ctx);
|
|
|
|
/**
|
|
* updates the noise shaper's state with the
|
|
* last quantization error
|
|
*/
|
|
extern void noise_shape_update(
|
|
noise_shape_ctx *ctx, float qerror);
|
|
|
|
#ifdef __cplusplus
|
|
} /* extern "C" */
|
|
#endif
|
|
|
|
#endif /* NOISE_SHAPE_H_INCLUDED */
|
|
|