/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved. * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #ifndef CROSSOVER_H_ #define CROSSOVER_H_ #include #include "biquad.h" /* An LR4 filter is two biquads with the same parameters connected in series: * * x -- [BIQUAD] -- y -- [BIQUAD] -- z * * Both biquad filter has the same parameter b[012] and a[12], * The variable [xyz][12] keep the history values. */ struct lr4 { struct biquad bq; float x1, x2; float y1, y2; float z1, z2; bool active; }; void lr4_set(struct lr4 *lr4, enum biquad_type type, float freq); void lr4_process(struct lr4 *lr4, float *dst, const float *src, const float vol, int samples); #endif /* CROSSOVER_H_ */