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Diffstat (limited to 'cras/src/dsp/crossover.h')
-rw-r--r-- | cras/src/dsp/crossover.h | 70 |
1 files changed, 0 insertions, 70 deletions
diff --git a/cras/src/dsp/crossover.h b/cras/src/dsp/crossover.h deleted file mode 100644 index 99a601c1..00000000 --- a/cras/src/dsp/crossover.h +++ /dev/null @@ -1,70 +0,0 @@ -/* 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_ - -#ifdef __cplusplus -extern "C" { -#endif - -/* 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 { - float b0, b1, b2; - float a1, a2; - float x1, x2; - float y1, y2; - float z1, z2; -}; - -/* Three bands crossover filter: - * - * INPUT --+-- lp0 --+-- lp1 --+---> LOW (0) - * | | | - * | \-- hp1 --/ - * | - * \-- hp0 --+-- lp2 ------> MID (1) - * | - * \-- hp2 ------> HIGH (2) - * - * [f0] [f1] - * - * Each lp or hp is an LR4 filter, which consists of two second-order - * lowpass or highpass butterworth filters. - */ -struct crossover { - struct lr4 lp[3], hp[3]; -}; - -/* Initializes a crossover filter - * Args: - * xo - The crossover filter we want to initialize. - * freq1 - The normalized frequency splits low and mid band. - * freq2 - The normalized frequency splits mid and high band. - */ -void crossover_init(struct crossover *xo, float freq1, float freq2); - -/* Splits input samples to three bands. - * Args: - * xo - The crossover filter to use. - * count - The number of input samples. - * data0 - The input samples, also the place to store low band output. - * data1 - The place to store mid band output. - * data2 - The place to store high band output. - */ -void crossover_process(struct crossover *xo, int count, float *data0, - float *data1, float *data2); - -#ifdef __cplusplus -} /* extern "C" */ -#endif - -#endif /* CROSSOVER_H_ */ |