third_party_alsa-utils/bat/bat-signal.h
Lu, Han e1b7a5f376 alsabat: add a single channel sine wave generator
Add function generate_sine_wave_raw_mono(). It serves as a single
channel sine wave generator, to provide data for calculation (e.g.
for noise analysis).
The function is similar to generate_sine_wave(), but a lite revision.
It has no dependency on bat channels and target frequency, no malloc
inside, no data conversion from float to integer samples, and supports
one channel only.

Signed-off-by: Lu, Han <han.lu@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-06-08 15:14:06 +02:00

32 lines
1.2 KiB
C

/*
* Copyright (C) 2015 Caleb Crome
* Copyright (C) 2013-2015 Intel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
/*
* Here's a generic sine wave generator that will work indefinitely
* for any frequency.
*
* Note: the state & phasor are stored as doubles (and updated as
* doubles) because after a million samples the magnitude drifts a
* bit. If we really need floats, it can be done with periodic
* renormalization of the state_real+state_imag magnitudes.
*/
int sin_generator_init(struct sin_generator *, float, float, float);
float sin_generator_next_sample(struct sin_generator *);
void sin_generator_vfill(struct sin_generator *, float *, int);
int generate_sine_wave(struct bat *, int, void *);
int generate_sine_wave_raw_mono(struct bat *, float *, float, int);