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diff --git a/cras/src/dsp/crossover.h b/cras/src/dsp/crossover.h
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-/* 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_ */