67 lines
1.5 KiB
C
67 lines
1.5 KiB
C
---
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author: "Flávio Schiavoni"
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description: Comunicador Alsa MIDI
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---
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <alsa/asoundlib.h>
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int keep_walking;
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static void sigint_handler(int i){
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keep_walking = 0;
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}
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int main(int argc, char *argv[]) {
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int note_time = 1000000; // 1 segundo (em microsegundos)
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// Pega o Ctrl+C ou signal de Kill para a aplicação.
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signal(SIGINT, &sigint_handler);
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signal(SIGTERM, &sigint_handler);
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keep_walking = 1;
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// Crio o dispositivo MIDI
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snd_seq_t *seq_handle;
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int portid;
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if (snd_seq_open(&seq_handle, "hw", SND_SEQ_OPEN_DUPLEX, 0) < 0) {
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fprintf(stderr, "Error opening ALSA sequencer.\n");
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exit(1);
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}
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snd_seq_set_client_name(seq_handle, "My App Midi");
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if ((portid = snd_seq_create_simple_port(seq_handle, "My Midi Port",
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SND_SEQ_PORT_CAP_READ|SND_SEQ_PORT_CAP_SUBS_READ,
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SND_SEQ_PORT_TYPE_APPLICATION)) < 0) {
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fprintf(stderr, "Error creating sequencer port.\n");
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exit(1);
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}
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snd_seq_event_t ev;
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snd_seq_ev_clear(&ev);
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snd_seq_ev_set_source(&ev, 0);
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snd_seq_ev_set_subs(&ev);
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snd_seq_ev_set_direct(&ev);
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int value = 0;
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while (keep_walking) {
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// Note on
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snd_seq_ev_set_controller(&ev, 0, 0, value);
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snd_seq_event_output(seq_handle, &ev);
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snd_seq_drain_output(seq_handle);
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// Duration
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usleep(note_time);
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// value = (value < 127) ? value + 1 : 0;
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}
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snd_seq_close(seq_handle);
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return 0;
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}
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