| /* 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. |
| */ |
| |
| #include <stddef.h> |
| #include <stdlib.h> |
| |
| #include "cras_volume_curve.h" |
| #include "softvol_curve.h" |
| |
| /* This is a ramp that increases 0.5dB per step, for a total range of 50dB. */ |
| const float softvol_scalers[101] = { |
| 0.003162, /* volume 0 */ |
| 0.003350, |
| 0.003548, |
| 0.003758, |
| 0.003981, |
| 0.004217, |
| 0.004467, |
| 0.004732, |
| 0.005012, |
| 0.005309, |
| 0.005623, |
| 0.005957, |
| 0.006310, |
| 0.006683, |
| 0.007079, |
| 0.007499, |
| 0.007943, |
| 0.008414, |
| 0.008913, |
| 0.009441, |
| 0.010000, |
| 0.010593, |
| 0.011220, |
| 0.011885, |
| 0.012589, |
| 0.013335, |
| 0.014125, |
| 0.014962, |
| 0.015849, |
| 0.016788, |
| 0.017783, |
| 0.018836, |
| 0.019953, |
| 0.021135, |
| 0.022387, |
| 0.023714, |
| 0.025119, |
| 0.026607, |
| 0.028184, |
| 0.029854, |
| 0.031623, |
| 0.033497, |
| 0.035481, |
| 0.037584, |
| 0.039811, |
| 0.042170, |
| 0.044668, |
| 0.047315, |
| 0.050119, |
| 0.053088, |
| 0.056234, |
| 0.059566, |
| 0.063096, |
| 0.066834, |
| 0.070795, |
| 0.074989, |
| 0.079433, |
| 0.084140, |
| 0.089125, |
| 0.094406, |
| 0.100000, |
| 0.105925, |
| 0.112202, |
| 0.118850, |
| 0.125893, |
| 0.133352, |
| 0.141254, |
| 0.149624, |
| 0.158489, |
| 0.167880, |
| 0.177828, |
| 0.188365, |
| 0.199526, |
| 0.211349, |
| 0.223872, |
| 0.237137, |
| 0.251189, |
| 0.266073, |
| 0.281838, |
| 0.298538, |
| 0.316228, |
| 0.334965, |
| 0.354813, |
| 0.375837, |
| 0.398107, |
| 0.421697, |
| 0.446684, |
| 0.473151, |
| 0.501187, |
| 0.530884, |
| 0.562341, |
| 0.595662, |
| 0.630957, |
| 0.668344, |
| 0.707946, |
| 0.749894, |
| 0.794328, |
| 0.841395, |
| 0.891251, |
| 0.944061, |
| 1.000000, /* volume 100 */ |
| }; |
| |
| float *softvol_build_from_curve(const struct cras_volume_curve *curve) |
| { |
| float *scalers; |
| unsigned int volume; |
| |
| if (!curve) |
| return NULL; |
| |
| scalers = (float *)malloc(NUM_VOLUME_STEPS * sizeof(float)); |
| if (!scalers) |
| return NULL; |
| |
| /* When software volume is used, it is assumed all volume curve values |
| * are relative to 0 dBFS when converting to scale. If a positive dBFS |
| * value is specified in curve config, it will be treated as invalid |
| * and clip to 1.0 in scale. |
| */ |
| for (volume = 0; volume <= MAX_VOLUME; volume++) { |
| scalers[volume] = convert_softvol_scaler_from_dB( |
| curve->get_dBFS(curve, volume)); |
| if (scalers[volume] > 1.0) |
| scalers[volume] = 1.0; |
| } |
| |
| return scalers; |
| } |