mirror of
https://gitlab.freedesktop.org/pipewire/pipewire.git
synced 2025-11-13 13:30:05 -05:00
934ab3036e
SPDX tags make the licensing information easy to understand and clear, and they are machine parseable. See https://spdx.dev for more information.
51 lines
1,018 B
C
51 lines
1,018 B
C
/* Simple DLL */
|
|
/* SPDX-FileCopyrightText: Copyright © 2019 Wim Taymans */
|
|
/* SPDX-License-Identifier: MIT */
|
|
|
|
#ifndef SPA_DLL_H
|
|
#define SPA_DLL_H
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
#include <stddef.h>
|
|
#include <math.h>
|
|
|
|
#define SPA_DLL_BW_MAX 0.128
|
|
#define SPA_DLL_BW_MIN 0.016
|
|
|
|
struct spa_dll {
|
|
double bw;
|
|
double z1, z2, z3;
|
|
double w0, w1, w2;
|
|
};
|
|
|
|
static inline void spa_dll_init(struct spa_dll *dll)
|
|
{
|
|
dll->bw = 0.0;
|
|
dll->z1 = dll->z2 = dll->z3 = 0.0;
|
|
}
|
|
|
|
static inline void spa_dll_set_bw(struct spa_dll *dll, double bw, unsigned period, unsigned rate)
|
|
{
|
|
double w = 2 * M_PI * bw * period / rate;
|
|
dll->w0 = 1.0 - exp (-20.0 * w);
|
|
dll->w1 = w * 1.5 / period;
|
|
dll->w2 = w / 1.5;
|
|
dll->bw = bw;
|
|
}
|
|
|
|
static inline double spa_dll_update(struct spa_dll *dll, double err)
|
|
{
|
|
dll->z1 += dll->w0 * (dll->w1 * err - dll->z1);
|
|
dll->z2 += dll->w0 * (dll->z1 - dll->z2);
|
|
dll->z3 += dll->w2 * dll->z2;
|
|
return 1.0 - (dll->z2 + dll->z3);
|
|
}
|
|
|
|
#ifdef __cplusplus
|
|
} /* extern "C" */
|
|
#endif
|
|
|
|
#endif /* SPA_DLL_H */
|