241 lines
7.2 KiB
C
241 lines
7.2 KiB
C
// cppcheck-suppress missingIncludeSystem
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#include "looper.h"
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#include "channel.h"
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#include "midi.h"
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#include <jack/jack.h>
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#include <jack/midiport.h>
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#include <math.h>
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#include <stdatomic.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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/* Global state (shared across files) */
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struct channel_t channels[MAX_CHANNELS];
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atomic_int channel_count = 0;
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int next_channel_id = 1;
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atomic_int cmd_add = 0;
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atomic_int cmd_remove = 0;
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jack_port_t *midi_control_port = NULL;
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jack_port_t *midi_clock_port = NULL;
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atomic_int control_key_active = 0;
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atomic_int bind_channel = 0;
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/* Deferred removal index (1 second grace) */
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static int pending_unregister_idx = -1;
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/* ----------------------------------------------------------------
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* process callback
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* ---------------------------------------------------------------- */
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int process_callback(jack_nframes_t nframes, void *arg) {
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(void)arg;
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if (midi_control_port) {
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void *midi_ctrl_buf = jack_port_get_buffer(midi_control_port, nframes);
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if (midi_ctrl_buf) {
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midi_handle_events(midi_ctrl_buf, nframes);
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}
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}
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/* process each active channel */
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for (int c = 0; c < MAX_CHANNELS; c++) {
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if (!atomic_load(&channels[c].active))
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continue;
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/* Guard against NULL ports (e.g. if port registration failed) */
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if (!channels[c].audio_in || !channels[c].audio_out) {
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fprintf(stderr, "WARN: channel %d has NULL audio port(s), skipping\n", c);
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continue;
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}
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const jack_default_audio_sample_t *in =
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(const jack_default_audio_sample_t *)jack_port_get_buffer(
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channels[c].audio_in, nframes);
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jack_default_audio_sample_t *out =
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(jack_default_audio_sample_t *)jack_port_get_buffer(
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channels[c].audio_out, nframes);
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if (!out)
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continue;
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int state = atomic_load(&channels[c].state);
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if (state != channels[c].prev_state) {
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switch (state) {
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case STATE_RECORD:
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channels[c].record_pos = 0;
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channels[c].loop_count = 0;
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break;
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case STATE_LOOPING:
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if (channels[c].record_pos > 0)
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channels[c].loop_count = channels[c].record_pos;
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channels[c].playback_pos = 0;
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break;
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default:
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break;
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}
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}
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jack_nframes_t i;
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switch (state) {
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case STATE_RECORD:
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if (in) {
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for (i = 0; i < nframes; i++) {
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if (channels[c].record_pos < LOOP_BUF_SIZE)
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channels[c].loop_buffer[channels[c].record_pos++] =
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((const float *)in)[i];
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((float *)out)[i] = ((const float *)in)[i]; // cppcheck-suppress unreadVariable
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}
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} else {
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memset(out, 0, sizeof(jack_default_audio_sample_t) * nframes);
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}
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break;
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case STATE_LOOPING:
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if (channels[c].loop_count > 0) {
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float *outf = (float *)out;
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for (i = 0; i < nframes; i++) {
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outf[i] = channels[c].loop_buffer[channels[c].playback_pos];
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channels[c].playback_pos =
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(channels[c].playback_pos + 1) % channels[c].loop_count;
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}
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} else {
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memset(out, 0, sizeof(jack_default_audio_sample_t) * nframes);
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}
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break;
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case STATE_PAUSED:
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memset(out, 0, sizeof(jack_default_audio_sample_t) * nframes);
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break;
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default: /* IDLE */
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if (in) {
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memcpy(out, in, sizeof(jack_default_audio_sample_t) * nframes);
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} else {
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memset(out, 0, sizeof(jack_default_audio_sample_t) * nframes);
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}
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break;
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}
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channels[c].prev_state = state;
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}
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/* MIDI clock events – affect channel 0 only */
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if (midi_clock_port) {
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void *midi_clock_buf = jack_port_get_buffer(midi_clock_port, nframes);
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if (midi_clock_buf) {
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jack_nframes_t n_clock_events = jack_midi_get_event_count(midi_clock_buf);
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jack_midi_event_t cev;
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for (jack_nframes_t j = 0; j < n_clock_events; j++) {
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if (jack_midi_event_get(&cev, midi_clock_buf, j) != 0)
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continue;
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if (cev.size >= 1) {
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unsigned char msg = cev.buffer[0];
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switch (msg) {
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case 0xFA: {
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int s = atomic_load(&channels[0].state);
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if (s == STATE_IDLE)
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atomic_store(&channels[0].state, STATE_RECORD);
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break;
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}
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case 0xFC:
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atomic_store(&channels[0].state, STATE_IDLE);
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break;
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case 0xFB: {
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int s = atomic_load(&channels[0].state);
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if (s == STATE_PAUSED)
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atomic_store(&channels[0].state, STATE_LOOPING);
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break;
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}
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default:
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break;
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}
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}
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}
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}
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}
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return 0;
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}
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/* ----------------------------------------------------------------
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* shutdown callback
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* ---------------------------------------------------------------- */
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void jack_shutdown_cb(void *arg) {
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(void)arg;
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fprintf(stderr, "JACK shutdown\n");
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exit(0);
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}
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/* ----------------------------------------------------------------
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* looper initialisation
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* ---------------------------------------------------------------- */
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int looper_init(jack_client_t *client) {
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/* channel 0 */
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channels[0].active = 1;
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atomic_store(&channels[0].state, STATE_IDLE);
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channels[0].prev_state = -1;
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channels[0].loop_count = 0;
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channels[0].record_pos = 0;
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channels[0].playback_pos = 0;
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channels[0].audio_in = jack_port_register(
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client, "input", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0);
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channels[0].audio_out = jack_port_register(
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client, "output", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0);
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if (!channels[0].audio_in || !channels[0].audio_out) {
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fprintf(stderr, "Could not create audio ports for channel 0\n");
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return -1;
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}
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channel_count = 1;
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midi_control_port = jack_port_register(
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client, "control", JACK_DEFAULT_MIDI_TYPE, JackPortIsInput, 0);
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midi_clock_port = jack_port_register(client, "clock", JACK_DEFAULT_MIDI_TYPE,
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JackPortIsInput, 0);
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if (!midi_control_port || !midi_clock_port) {
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fprintf(stderr, "Could not create MIDI ports\n");
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return -1;
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}
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return 0;
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}
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/* ----------------------------------------------------------------
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* main‑loop command processing
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* ---------------------------------------------------------------- */
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void looper_process_commands(jack_client_t *client) {
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/* Unregister any ports that were marked for deferred removal.
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By now the real‑time thread has had at least one full cycle
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to see the `active = 0` store. */
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if (pending_unregister_idx != -1) {
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int idx = pending_unregister_idx;
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if (channels[idx].audio_in)
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jack_port_unregister(client, channels[idx].audio_in);
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if (channels[idx].audio_out)
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jack_port_unregister(client, channels[idx].audio_out);
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pending_unregister_idx = -1;
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}
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if (atomic_exchange(&cmd_add, 0)) {
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int idx;
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for (idx = 0; idx < MAX_CHANNELS; idx++)
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if (!channels[idx].active)
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break;
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if (idx < MAX_CHANNELS) {
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channel_add(client, idx);
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}
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}
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if (atomic_exchange(&cmd_remove, 0)) {
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int remove_idx = -1;
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for (int idx = 1; idx < MAX_CHANNELS; idx++)
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if (channels[idx].active)
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remove_idx = idx;
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if (remove_idx != -1) {
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/* Mark inactive now; ports will be unregistered next round */
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channel_remove(client, remove_idx);
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pending_unregister_idx = remove_idx;
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}
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}
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}
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