5d74b1efef
This mixer plugin may be used instead of the traditional global software mixer. It integrates with the "volume" filter plugin, and can control the software volume of an audio output which has no hardware mixer.
87 lines
1.9 KiB
C
87 lines
1.9 KiB
C
/*
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* Copyright (C) 2003-2009 The Music Player Daemon Project
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* http://www.musicpd.org
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include "mixer_control.h"
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#include "mixer_list.h"
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#include "filter_registry.h"
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#include "pcm_volume.h"
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#include <glib.h>
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#include <assert.h>
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#include <string.h>
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#include <unistd.h>
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const struct filter_plugin *
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filter_plugin_by_name(G_GNUC_UNUSED const char *name)
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{
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assert(false);
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return NULL;
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}
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bool
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pcm_volume(G_GNUC_UNUSED void *buffer, G_GNUC_UNUSED int length,
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G_GNUC_UNUSED const struct audio_format *format,
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G_GNUC_UNUSED int volume)
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{
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assert(false);
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return false;
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}
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int main(int argc, G_GNUC_UNUSED char **argv)
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{
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struct mixer *mixer;
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bool success;
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int volume;
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if (argc != 2) {
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g_printerr("Usage: read_mixer PLUGIN\n");
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return 1;
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}
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g_thread_init(NULL);
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mixer = mixer_new(&alsa_mixer, NULL);
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if (mixer == NULL) {
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g_printerr("mixer_new() failed\n");
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return 2;
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}
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success = mixer_open(mixer);
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if (!success) {
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mixer_free(mixer);
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g_printerr("failed to open the mixer\n");
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return 2;
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}
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volume = mixer_get_volume(mixer);
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mixer_close(mixer);
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mixer_free(mixer);
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assert(volume >= -1 && volume <= 100);
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if (volume < 0) {
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g_printerr("failed to read volume\n");
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return 2;
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}
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g_print("%d\n", volume);
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return 0;
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}
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