| /* 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 SOFTVOL_CURVE_H_ |
| #define SOFTVOL_CURVE_H_ |
| |
| #include <math.h> |
| |
| #define LOG_10 2.302585 |
| |
| struct cras_volume_curve; |
| |
| extern const float softvol_scalers[101]; |
| |
| /* Returns the volume scaler in the soft volume curve for the given index. */ |
| static inline float softvol_get_scaler(unsigned int volume_index) |
| { |
| return softvol_scalers[volume_index]; |
| } |
| |
| /* convert dBFS to softvol scaler */ |
| static inline float convert_softvol_scaler_from_dB(long dBFS) |
| { |
| return expf(LOG_10 * dBFS / 2000); |
| } |
| |
| /* Builds software volume scalers from volume curve. */ |
| float *softvol_build_from_curve(const struct cras_volume_curve *curve); |
| |
| #endif /* SOFTVOL_CURVE_H_ */ |
