/***************************************************************************** * volume.c : helper for software audio amplification ***************************************************************************** * Copyright (C) 2012 RĂ©mi Denis-Courmont * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program; if not, write to the Free Software Foundation, * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA. *****************************************************************************/ #ifdef HAVE_CONFIG_H # include #endif #include #include #include #include #define add_sw_gain() \ add_float(MODULE_STRING"-gain", 1., N_("Software gain"), \ N_("This linear gain will be applied in software."), true) \ change_float_range(0., 8.) static int aout_SoftVolumeSet(audio_output_t *aout, float volume) { aout_sys_t *sys = aout->sys; /* * Cubic mapping from software volume to amplification factor. * This provides a good tradeoff between low and high volume ranges. * * This code is only used for the VLC software mixer. If you change this * formula, be sure to update the volume-capable plugins also. */ float gain = volume * volume * volume; if (!sys->soft_mute && aout_GainRequest(aout, gain)) return -1; sys->soft_gain = gain; if (var_InheritBool(aout, "volume-save")) config_PutFloat(aout, MODULE_STRING"-gain", gain); aout_VolumeReport(aout, volume); return 0; } static int aout_SoftMuteSet (audio_output_t *aout, bool mute) { aout_sys_t *sys = aout->sys; if (aout_GainRequest(aout, mute ? 0.f : sys->soft_gain)) return -1; sys->soft_mute = mute; aout_MuteReport(aout, mute); return 0; } static void aout_SoftVolumeInit(audio_output_t *aout) { aout_sys_t *sys = aout->sys; float gain = var_InheritFloat(aout, MODULE_STRING"-gain"); bool mute = var_InheritBool(aout, "mute"); aout->volume_set = aout_SoftVolumeSet; aout->mute_set = aout_SoftMuteSet; sys->soft_gain = gain; sys->soft_mute = mute; aout_MuteReport(aout, mute); aout_VolumeReport(aout, cbrtf(gain)); } static void aout_SoftVolumeStart (audio_output_t *aout) { aout_sys_t *sys = aout->sys; if (aout_GainRequest(aout, sys->soft_mute ? 0.f : sys->soft_gain)) { aout_MuteReport(aout, false); aout_VolumeReport(aout, 1.f); } }