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Diffstat (limited to '')
-rw-r--r-- | src/mixer/Volume.cxx | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/src/mixer/Volume.cxx b/src/mixer/Volume.cxx new file mode 100644 index 000000000..4c897b21f --- /dev/null +++ b/src/mixer/Volume.cxx @@ -0,0 +1,130 @@ +/* + * Copyright (C) 2003-2014 The Music Player Daemon Project + * http://www.musicpd.org + * + * 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. + * + * You should have received a copy of the GNU 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. + */ + +#include "config.h" +#include "Volume.hxx" +#include "MixerAll.hxx" +#include "Idle.hxx" +#include "GlobalEvents.hxx" +#include "util/StringUtil.hxx" +#include "util/Domain.hxx" +#include "system/PeriodClock.hxx" +#include "Log.hxx" + +#include <assert.h> +#include <stdlib.h> + +#define SW_VOLUME_STATE "sw_volume: " + +static constexpr Domain volume_domain("volume"); + +static unsigned volume_software_set = 100; + +/** the cached hardware mixer value; invalid if negative */ +static int last_hardware_volume = -1; +/** the age of #last_hardware_volume */ +static PeriodClock hardware_volume_clock; + +/** + * Handler for #GlobalEvents::MIXER. + */ +static void +mixer_event_callback(void) +{ + /* flush the hardware volume cache */ + last_hardware_volume = -1; + + /* notify clients */ + idle_add(IDLE_MIXER); +} + +void volume_init(void) +{ + GlobalEvents::Register(GlobalEvents::MIXER, mixer_event_callback); +} + +int volume_level_get(void) +{ + if (last_hardware_volume >= 0 && + !hardware_volume_clock.CheckUpdate(1000)) + /* throttle access to hardware mixers */ + return last_hardware_volume; + + last_hardware_volume = mixer_all_get_volume(); + return last_hardware_volume; +} + +static bool software_volume_change(unsigned volume) +{ + assert(volume <= 100); + + volume_software_set = volume; + mixer_all_set_software_volume(volume); + + return true; +} + +static bool hardware_volume_change(unsigned volume) +{ + /* reset the cache */ + last_hardware_volume = -1; + + return mixer_all_set_volume(volume); +} + +bool volume_level_change(unsigned volume) +{ + assert(volume <= 100); + + volume_software_set = volume; + + idle_add(IDLE_MIXER); + + return hardware_volume_change(volume); +} + +bool +read_sw_volume_state(const char *line) +{ + char *end = nullptr; + long int sv; + + if (!StringStartsWith(line, SW_VOLUME_STATE)) + return false; + + line += sizeof(SW_VOLUME_STATE) - 1; + sv = strtol(line, &end, 10); + if (*end == 0 && sv >= 0 && sv <= 100) + software_volume_change(sv); + else + FormatWarning(volume_domain, + "Can't parse software volume: %s", line); + return true; +} + +void save_sw_volume_state(FILE *fp) +{ + fprintf(fp, SW_VOLUME_STATE "%u\n", volume_software_set); +} + +unsigned +sw_volume_state_get_hash(void) +{ + return volume_software_set; +} |