150 lines
3.1 KiB
C
150 lines
3.1 KiB
C
/**
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* Based on alsactl/monitor.c (by Takashi Iwai <tiwai@suse.de>) from alsa-utils
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* http://git.alsa-project.org/?p=alsa-utils.git;a=blob_plain;f=alsactl/monitor.c;hb=HEAD
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*
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* Inspired by kbdd
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*/
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#include <stdio.h>
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#include <alsa/asoundlib.h>
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#include <dbus/dbus.h>
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int notify(DBusConnection *conn)
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{
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DBusMessage *msg;
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dbus_uint32_t serial = 0;
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msg = dbus_message_new_signal("/com/ch1p/Object", "com.ch1p.avm", "valueChanged");
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if (NULL == msg) {
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fprintf(stderr, "DBus: Message Null\n");
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return 1;
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}
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if (!dbus_connection_send(conn, msg, &serial)) {
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fprintf(stderr, "DBus send: Out Of Memory!\n");
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return 1;
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}
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dbus_connection_flush(conn);
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dbus_message_unref(msg);
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return 0;
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}
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int open_ctl(const char *name, snd_ctl_t **ctlp)
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{
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snd_ctl_t *ctl;
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int err;
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err = snd_ctl_open(&ctl, name, SND_CTL_READONLY);
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if (err < 0) {
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fprintf(stderr, "Cannot open ctl %s\n", name);
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return err;
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}
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err = snd_ctl_subscribe_events(ctl, 1);
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if (err < 0) {
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fprintf(stderr, "Cannot open subscribe events to ctl %s\n", name);
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snd_ctl_close(ctl);
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return err;
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}
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*ctlp = ctl;
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return 0;
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}
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int check_event(snd_ctl_t *ctl, DBusConnection *conn)
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{
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snd_ctl_event_t *event;
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unsigned int mask;
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int err;
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snd_ctl_event_alloca(&event);
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err = snd_ctl_read(ctl, event);
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if (err < 0)
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return err;
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if (snd_ctl_event_get_type(event) != SND_CTL_EVENT_ELEM)
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return 0;
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mask = snd_ctl_event_elem_get_mask(event);
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if (!(mask & SND_CTL_EVENT_MASK_VALUE))
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return 0;
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notify(conn);
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return 0;
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}
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#define MAX_CARDS 256
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int monitor(const char *name, DBusConnection *conn) {
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snd_ctl_t *ctl;
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int err = 0;
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err = open_ctl(name, &ctl);
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if (err < 0)
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goto error;
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while (1) {
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struct pollfd fd;
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snd_ctl_poll_descriptors(ctl, &fd, 1);
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err = poll(&fd, 1, -1);
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if (err <= 0) {
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err = 0;
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break;
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}
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unsigned short revents;
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snd_ctl_poll_descriptors_revents(ctl, &fd, 1,
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&revents);
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if (revents & POLLIN)
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check_event(ctl, conn);
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}
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error:
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snd_ctl_close(ctl);
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return err;
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}
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void usage()
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{
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fprintf(stderr,
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"Usage:\n"
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" alsa-volume-monitor <card name>\n\n"
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"Example:\n"
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" alsa-volume-monitor hw:0\n");
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exit(1);
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}
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int main(int argc, char *argv[])
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{
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if (argc < 2)
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usage();
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DBusConnection *connection;
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DBusError err;
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dbus_error_init(&err);
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connection = dbus_bus_get(DBUS_BUS_SESSION, &err);
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if (dbus_error_is_set(&err)) {
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fprintf(stderr, "DBus Connection Error (%s)\n", err.message);
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dbus_error_free(&err);
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}
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if (!connection) {
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return 1;
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}
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dbus_bus_request_name(connection, "com.ch1p.avm",
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DBUS_NAME_FLAG_REPLACE_EXISTING , &err);
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if (dbus_error_is_set(&err)) {
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fprintf(stderr, "DBus Name Error (%s)\n", err.message);
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dbus_error_free(&err);
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}
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monitor(argv[1], connection);
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return 0;
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}
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