65 lines
1.5 KiB
C
65 lines
1.5 KiB
C
#include <alsa/asoundlib.h>
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#include <log.h>
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#include <stdlib.h>
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#include "types.h"
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#include "config.h"
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void midi_open(MidiDevice *device, const char *name) {
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strlcpy(device->name, name, STR_LEN);
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device->input = NULL;
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device->output = NULL;
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snd_rawmidi_open(&device->input, &device->output, name, SND_RAWMIDI_NONBLOCK);
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device->error = device->input == NULL || device->output == NULL;
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log_info("(%s) MIDI open", name);
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}
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void midi_write(const MidiDevice *device, unsigned char code,
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unsigned char value) {
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if (device->error) {
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return;
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}
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unsigned char buffer[3];
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buffer[0] = 0xB0;
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buffer[1] = code;
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buffer[2] = value;
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snd_rawmidi_write(device->output, buffer, 3);
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}
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bool midi_background_listen(const MidiDevice *device,
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const SharedContext *context,
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void (*event_callback)(unsigned char code,
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unsigned char value)) {
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pid_t pid;
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int bytes_read;
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unsigned char buffer[3];
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pid = fork();
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if (pid < 0) {
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log_error("Could not create subprocess");
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return false;
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}
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if (pid == 0) {
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return true;
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}
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log_info("(%s) background acquisition started (pid: %d)", device->name, pid);
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while (!context->stop) {
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bytes_read = snd_rawmidi_read(device->input, buffer, 3);
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if (bytes_read == 3) {
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event_callback(buffer[1], buffer[2]);
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}
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}
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log_info("(%s) background acquisition stopped by main thread (pid: %d)",
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device->name, pid);
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exit(EXIT_SUCCESS);
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}
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