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[nageru] / nageru / midi_mapper.cpp
index 3b22192b3b8b0670356ebdb9230a8133777b0983..1dccd8e2edc039a6da15ecaa4d87433b6d6c62d2 100644 (file)
 #include <thread>
 
 #include "audio_mixer.h"
-#include "midi_mapping.pb.h"
+#include "nageru_midi_mapping.pb.h"
+#include "shared/midi_device.h"
+#include "shared/midi_mapper_util.h"
+#include "shared/text_proto.h"
 
 using namespace google::protobuf;
 using namespace std;
 using namespace std::placeholders;
 
-namespace {
-
-double map_controller_to_float(int val)
-{
-       // Slightly hackish mapping so that we can represent exactly 0.0, 0.5 and 1.0.
-       if (val <= 0) {
-               return 0.0;
-       } else if (val >= 127) {
-               return 1.0;
-       } else {
-               return (val + 0.5) / 127.0;
-       }
-}
-
-}  // namespace
-
 MIDIMapper::MIDIMapper(ControllerReceiver *receiver)
-       : receiver(receiver), mapping_proto(new MIDIMappingProto)
+       : receiver(receiver), mapping_proto(new MIDIMappingProto), midi_device(this)
 {
-       should_quit_fd = eventfd(/*initval=*/0, /*flags=*/0);
-       assert(should_quit_fd != -1);
 }
 
-MIDIMapper::~MIDIMapper()
-{
-       should_quit = true;
-       const uint64_t one = 1;
-       if (write(should_quit_fd, &one, sizeof(one)) != sizeof(one)) {
-               perror("write(should_quit_fd)");
-               exit(1);
-       }
-       midi_thread.join();
-       close(should_quit_fd);
-}
+MIDIMapper::~MIDIMapper() {}
 
 bool load_midi_mapping_from_file(const string &filename, MIDIMappingProto *new_mapping)
 {
-       // Read and parse the protobuf from disk.
-       int fd = open(filename.c_str(), O_RDONLY);
-       if (fd == -1) {
-               perror(filename.c_str());
-               return false;
-       }
-       io::FileInputStream input(fd);  // Takes ownership of fd.
-       if (!TextFormat::Parse(&input, new_mapping)) {
-               input.Close();
-               return false;
-       }
-       input.Close();
-       return true;
+       return load_proto_from_file(filename, new_mapping);
 }
 
 bool save_midi_mapping_to_file(const MIDIMappingProto &mapping_proto, const string &filename)
 {
-       // Save to disk. We use the text format because it's friendlier
-       // for a user to look at and edit.
-       int fd = open(filename.c_str(), O_WRONLY | O_TRUNC | O_CREAT, 0666);
-       if (fd == -1) {
-               perror(filename.c_str());
-               return false;
-       }
-       io::FileOutputStream output(fd);  // Takes ownership of fd.
-       if (!TextFormat::Print(mapping_proto, &output)) {
-               // TODO: Don't overwrite the old file (if any) on error.
-               output.Close();
-               return false;
-       }
-
-       output.Close();
-       return true;
+       return save_proto_to_file(mapping_proto, filename);
 }
 
 void MIDIMapper::set_midi_mapping(const MIDIMappingProto &new_mapping)
@@ -115,7 +63,7 @@ void MIDIMapper::set_midi_mapping(const MIDIMappingProto &new_mapping)
 
 void MIDIMapper::start_thread()
 {
-       midi_thread = thread(&MIDIMapper::thread_func, this);
+       midi_device.start_thread();
 }
 
 const MIDIMappingProto &MIDIMapper::get_current_mapping() const
@@ -131,299 +79,124 @@ ControllerReceiver *MIDIMapper::set_receiver(ControllerReceiver *new_receiver)
        return new_receiver;  // Now old receiver.
 }
 
-#define RETURN_ON_ERROR(msg, expr) do {                            \
-       int err = (expr);                                          \
-       if (err < 0) {                                             \
-               fprintf(stderr, msg ": %s\n", snd_strerror(err));  \
-               return;                                            \
-       }                                                          \
-} while (false)
-
-#define WARN_ON_ERROR(msg, expr) do {                              \
-       int err = (expr);                                          \
-       if (err < 0) {                                             \
-               fprintf(stderr, msg ": %s\n", snd_strerror(err));  \
-       }                                                          \
-} while (false)
-
-
-void MIDIMapper::thread_func()
+void MIDIMapper::controller_received(int controller, int value_int)
 {
-       pthread_setname_np(pthread_self(), "MIDIMapper");
-
-       snd_seq_t *seq;
-       int err;
-
-       RETURN_ON_ERROR("snd_seq_open", snd_seq_open(&seq, "default", SND_SEQ_OPEN_DUPLEX, 0));
-       RETURN_ON_ERROR("snd_seq_nonblock", snd_seq_nonblock(seq, 1));
-       RETURN_ON_ERROR("snd_seq_client_name", snd_seq_set_client_name(seq, "nageru"));
-       RETURN_ON_ERROR("snd_seq_create_simple_port",
-               snd_seq_create_simple_port(seq, "nageru",
-                       SND_SEQ_PORT_CAP_READ |
-                               SND_SEQ_PORT_CAP_SUBS_READ |
-                               SND_SEQ_PORT_CAP_WRITE |
-                               SND_SEQ_PORT_CAP_SUBS_WRITE,
-                       SND_SEQ_PORT_TYPE_MIDI_GENERIC |
-                               SND_SEQ_PORT_TYPE_APPLICATION));
-
-       int queue_id = snd_seq_alloc_queue(seq);
-       RETURN_ON_ERROR("snd_seq_create_queue", queue_id);
-       RETURN_ON_ERROR("snd_seq_start_queue", snd_seq_start_queue(seq, queue_id, nullptr));
-
-       // The sequencer object is now ready to be used from other threads.
-       {
-               lock_guard<mutex> lock(mu);
-               alsa_seq = seq;
-               alsa_queue_id = queue_id;
-       }
-
-       // Listen to the announce port (0:1), which will tell us about new ports.
-       RETURN_ON_ERROR("snd_seq_connect_from", snd_seq_connect_from(seq, 0, /*client=*/0, /*port=*/1));
-
-       // Now go through all ports and subscribe to them.
-       snd_seq_client_info_t *cinfo;
-       snd_seq_client_info_alloca(&cinfo);
+       const float value = map_controller_to_float(controller, value_int);
 
-       snd_seq_client_info_set_client(cinfo, -1);
-       while (snd_seq_query_next_client(seq, cinfo) >= 0) {
-               int client = snd_seq_client_info_get_client(cinfo);
+       receiver->controller_changed(controller);
 
-               snd_seq_port_info_t *pinfo;
-               snd_seq_port_info_alloca(&pinfo);
-
-               snd_seq_port_info_set_client(pinfo, client);
-               snd_seq_port_info_set_port(pinfo, -1);
-               while (snd_seq_query_next_port(seq, pinfo) >= 0) {
-                       constexpr int mask = SND_SEQ_PORT_CAP_READ | SND_SEQ_PORT_CAP_SUBS_READ;
-                       if ((snd_seq_port_info_get_capability(pinfo) & mask) == mask) {
-                               lock_guard<mutex> lock(mu);
-                               subscribe_to_port_lock_held(seq, *snd_seq_port_info_get_addr(pinfo));
-                       }
-               }
-       }
-
-       int num_alsa_fds = snd_seq_poll_descriptors_count(seq, POLLIN);
-       unique_ptr<pollfd[]> fds(new pollfd[num_alsa_fds + 1]);
+       // Global controllers.
+       match_controller(controller, MIDIMappingBusProto::kLocutFieldNumber, MIDIMappingProto::kLocutBankFieldNumber,
+               value, bind(&ControllerReceiver::set_locut, receiver, _2));
+       match_controller(controller, MIDIMappingBusProto::kLimiterThresholdFieldNumber, MIDIMappingProto::kLimiterThresholdBankFieldNumber,
+               value, bind(&ControllerReceiver::set_limiter_threshold, receiver, _2));
+       match_controller(controller, MIDIMappingBusProto::kMakeupGainFieldNumber, MIDIMappingProto::kMakeupGainBankFieldNumber,
+               value, bind(&ControllerReceiver::set_makeup_gain, receiver, _2));
+
+       // Bus controllers.
+       match_controller(controller, MIDIMappingBusProto::kStereoWidthFieldNumber, MIDIMappingProto::kStereoWidthBankFieldNumber,
+               value, bind(&ControllerReceiver::set_stereo_width, receiver, _1, _2));
+       match_controller(controller, MIDIMappingBusProto::kTrebleFieldNumber, MIDIMappingProto::kTrebleBankFieldNumber,
+               value, bind(&ControllerReceiver::set_treble, receiver, _1, _2));
+       match_controller(controller, MIDIMappingBusProto::kMidFieldNumber, MIDIMappingProto::kMidBankFieldNumber,
+               value, bind(&ControllerReceiver::set_mid, receiver, _1, _2));
+       match_controller(controller, MIDIMappingBusProto::kBassFieldNumber, MIDIMappingProto::kBassBankFieldNumber,
+               value, bind(&ControllerReceiver::set_bass, receiver, _1, _2));
+       match_controller(controller, MIDIMappingBusProto::kGainFieldNumber, MIDIMappingProto::kGainBankFieldNumber,
+               value, bind(&ControllerReceiver::set_gain, receiver, _1, _2));
+       match_controller(controller, MIDIMappingBusProto::kCompressorThresholdFieldNumber, MIDIMappingProto::kCompressorThresholdBankFieldNumber,
+               value, bind(&ControllerReceiver::set_compressor_threshold, receiver, _1, _2));
+       match_controller(controller, MIDIMappingBusProto::kFaderFieldNumber, MIDIMappingProto::kFaderBankFieldNumber,
+               value, bind(&ControllerReceiver::set_fader, receiver, _1, _2));
+}
 
-       while (!should_quit) {
-               snd_seq_poll_descriptors(seq, fds.get(), num_alsa_fds, POLLIN);
-               fds[num_alsa_fds].fd = should_quit_fd;
-               fds[num_alsa_fds].events = POLLIN;
-               fds[num_alsa_fds].revents = 0;
+void MIDIMapper::note_on_received(int note)
+{
+       lock_guard<mutex> lock(mu);
+       receiver->note_on(note);
 
-               err = poll(fds.get(), num_alsa_fds + 1, -1);
-               if (err == 0 || (err == -1 && errno == EINTR)) {
-                       continue;
+       for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
+               const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
+               if (bus_mapping.has_prev_bank() &&
+                   bus_mapping.prev_bank().note_number() == note) {
+                       current_controller_bank = (current_controller_bank + num_controller_banks - 1) % num_controller_banks;
+                       update_highlights();
+                       update_lights_lock_held();
                }
-               if (err == -1) {
-                       perror("poll");
-                       break;
+               if (bus_mapping.has_next_bank() &&
+                   bus_mapping.next_bank().note_number() == note) {
+                       current_controller_bank = (current_controller_bank + 1) % num_controller_banks;
+                       update_highlights();
+                       update_lights_lock_held();
                }
-               if (fds[num_alsa_fds].revents) {
-                       // Activity on should_quit_fd.
-                       break;
+               if (bus_mapping.has_select_bank_1() &&
+                   bus_mapping.select_bank_1().note_number() == note) {
+                       current_controller_bank = 0;
+                       update_highlights();
+                       update_lights_lock_held();
                }
-
-               // Seemingly we can get multiple events in a single poll,
-               // and if we don't handle them all, poll will _not_ alert us!
-               while (!should_quit) {
-                       snd_seq_event_t *event;
-                       err = snd_seq_event_input(seq, &event);
-                       if (err < 0) {
-                               if (err == -EINTR) continue;
-                               if (err == -EAGAIN) break;
-                               if (err == -ENOSPC) {
-                                       fprintf(stderr, "snd_seq_event_input: Some events were lost.\n");
-                                       continue;
-                               }
-                               fprintf(stderr, "snd_seq_event_input: %s\n", snd_strerror(err));
-                               return;
-                       }
-                       if (event) {
-                               handle_event(seq, event);
-                       }
+               if (bus_mapping.has_select_bank_2() &&
+                   bus_mapping.select_bank_2().note_number() == note &&
+                   num_controller_banks >= 2) {
+                       current_controller_bank = 1;
+                       update_highlights();
+                       update_lights_lock_held();
                }
-       }
-}
-
-void MIDIMapper::handle_event(snd_seq_t *seq, snd_seq_event_t *event)
-{
-       if (event->source.client == snd_seq_client_id(seq)) {
-               // Ignore events we sent out ourselves.
-               return;
-       }
-
-       lock_guard<mutex> lock(mu);
-       switch (event->type) {
-       case SND_SEQ_EVENT_CONTROLLER: {
-               const int controller = event->data.control.param;
-               const float value = map_controller_to_float(event->data.control.value);
-
-               receiver->controller_changed(controller);
-
-               // Global controllers.
-               match_controller(controller, MIDIMappingBusProto::kLocutFieldNumber, MIDIMappingProto::kLocutBankFieldNumber,
-                       value, bind(&ControllerReceiver::set_locut, receiver, _2));
-               match_controller(controller, MIDIMappingBusProto::kLimiterThresholdFieldNumber, MIDIMappingProto::kLimiterThresholdBankFieldNumber,
-                       value, bind(&ControllerReceiver::set_limiter_threshold, receiver, _2));
-               match_controller(controller, MIDIMappingBusProto::kMakeupGainFieldNumber, MIDIMappingProto::kMakeupGainBankFieldNumber,
-                       value, bind(&ControllerReceiver::set_makeup_gain, receiver, _2));
-
-               // Bus controllers.
-               match_controller(controller, MIDIMappingBusProto::kStereoWidthFieldNumber, MIDIMappingProto::kStereoWidthBankFieldNumber,
-                       value, bind(&ControllerReceiver::set_stereo_width, receiver, _1, _2));
-               match_controller(controller, MIDIMappingBusProto::kTrebleFieldNumber, MIDIMappingProto::kTrebleBankFieldNumber,
-                       value, bind(&ControllerReceiver::set_treble, receiver, _1, _2));
-               match_controller(controller, MIDIMappingBusProto::kMidFieldNumber, MIDIMappingProto::kMidBankFieldNumber,
-                       value, bind(&ControllerReceiver::set_mid, receiver, _1, _2));
-               match_controller(controller, MIDIMappingBusProto::kBassFieldNumber, MIDIMappingProto::kBassBankFieldNumber,
-                       value, bind(&ControllerReceiver::set_bass, receiver, _1, _2));
-               match_controller(controller, MIDIMappingBusProto::kGainFieldNumber, MIDIMappingProto::kGainBankFieldNumber,
-                       value, bind(&ControllerReceiver::set_gain, receiver, _1, _2));
-               match_controller(controller, MIDIMappingBusProto::kCompressorThresholdFieldNumber, MIDIMappingProto::kCompressorThresholdBankFieldNumber,
-                       value, bind(&ControllerReceiver::set_compressor_threshold, receiver, _1, _2));
-               match_controller(controller, MIDIMappingBusProto::kFaderFieldNumber, MIDIMappingProto::kFaderBankFieldNumber,
-                       value, bind(&ControllerReceiver::set_fader, receiver, _1, _2));
-               break;
-       }
-       case SND_SEQ_EVENT_NOTEON: {
-               const int note = event->data.note.note;
-
-               receiver->note_on(note);
-
-               for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
-                       const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
-                       if (bus_mapping.has_prev_bank() &&
-                           bus_mapping.prev_bank().note_number() == note) {
-                               current_controller_bank = (current_controller_bank + num_controller_banks - 1) % num_controller_banks;
-                               update_highlights();
-                               update_lights_lock_held();
-                       }
-                       if (bus_mapping.has_next_bank() &&
-                           bus_mapping.next_bank().note_number() == note) {
-                               current_controller_bank = (current_controller_bank + 1) % num_controller_banks;
-                               update_highlights();
-                               update_lights_lock_held();
-                       }
-                       if (bus_mapping.has_select_bank_1() &&
-                           bus_mapping.select_bank_1().note_number() == note) {
-                               current_controller_bank = 0;
-                               update_highlights();
-                               update_lights_lock_held();
-                       }
-                       if (bus_mapping.has_select_bank_2() &&
-                           bus_mapping.select_bank_2().note_number() == note &&
-                           num_controller_banks >= 2) {
-                               current_controller_bank = 1;
-                               update_highlights();
-                               update_lights_lock_held();
-                       }
-                       if (bus_mapping.has_select_bank_3() &&
-                           bus_mapping.select_bank_3().note_number() == note &&
-                           num_controller_banks >= 3) {
-                               current_controller_bank = 2;
-                               update_highlights();
-                               update_lights_lock_held();
-                       }
-                       if (bus_mapping.has_select_bank_4() &&
-                           bus_mapping.select_bank_4().note_number() == note &&
-                           num_controller_banks >= 4) {
-                               current_controller_bank = 3;
-                               update_highlights();
-                               update_lights_lock_held();
-                       }
-                       if (bus_mapping.has_select_bank_5() &&
-                           bus_mapping.select_bank_5().note_number() == note &&
-                           num_controller_banks >= 5) {
-                               current_controller_bank = 4;
-                               update_highlights();
-                               update_lights_lock_held();
-                       }
+               if (bus_mapping.has_select_bank_3() &&
+                   bus_mapping.select_bank_3().note_number() == note &&
+                   num_controller_banks >= 3) {
+                       current_controller_bank = 2;
+                       update_highlights();
+                       update_lights_lock_held();
                }
-
-               match_button(note, MIDIMappingBusProto::kToggleLocutFieldNumber, MIDIMappingProto::kToggleLocutBankFieldNumber,
-                       bind(&ControllerReceiver::toggle_locut, receiver, _1));
-               match_button(note, MIDIMappingBusProto::kToggleAutoGainStagingFieldNumber, MIDIMappingProto::kToggleAutoGainStagingBankFieldNumber,
-                       bind(&ControllerReceiver::toggle_auto_gain_staging, receiver, _1));
-               match_button(note, MIDIMappingBusProto::kToggleCompressorFieldNumber, MIDIMappingProto::kToggleCompressorBankFieldNumber,
-                       bind(&ControllerReceiver::toggle_compressor, receiver, _1));
-               match_button(note, MIDIMappingBusProto::kClearPeakFieldNumber, MIDIMappingProto::kClearPeakBankFieldNumber,
-                       bind(&ControllerReceiver::clear_peak, receiver, _1));
-               match_button(note, MIDIMappingBusProto::kToggleMuteFieldNumber, MIDIMappingProto::kClearPeakBankFieldNumber,
-                       bind(&ControllerReceiver::toggle_mute, receiver, _1));
-               match_button(note, MIDIMappingBusProto::kToggleLimiterFieldNumber, MIDIMappingProto::kToggleLimiterBankFieldNumber,
-                       bind(&ControllerReceiver::toggle_limiter, receiver));
-               match_button(note, MIDIMappingBusProto::kToggleAutoMakeupGainFieldNumber, MIDIMappingProto::kToggleAutoMakeupGainBankFieldNumber,
-                       bind(&ControllerReceiver::toggle_auto_makeup_gain, receiver));
-               break;
-       }
-       case SND_SEQ_EVENT_PORT_START:
-               subscribe_to_port_lock_held(seq, event->data.addr);
-               break;
-       case SND_SEQ_EVENT_PORT_EXIT:
-               printf("MIDI port %d:%d went away.\n", event->data.addr.client, event->data.addr.port);
-               break;
-       case SND_SEQ_EVENT_PORT_SUBSCRIBED:
-               if (event->data.connect.sender.client != 0 &&  // Ignore system senders.
-                   event->data.connect.sender.client != snd_seq_client_id(seq) &&
-                   event->data.connect.dest.client == snd_seq_client_id(seq)) {
-                       ++num_subscribed_ports;
+               if (bus_mapping.has_select_bank_4() &&
+                   bus_mapping.select_bank_4().note_number() == note &&
+                   num_controller_banks >= 4) {
+                       current_controller_bank = 3;
                        update_highlights();
+                       update_lights_lock_held();
                }
-               break;
-       case SND_SEQ_EVENT_PORT_UNSUBSCRIBED:
-               if (event->data.connect.sender.client != 0 &&  // Ignore system senders.
-                   event->data.connect.sender.client != snd_seq_client_id(seq) &&
-                   event->data.connect.dest.client == snd_seq_client_id(seq)) {
-                       --num_subscribed_ports;
+               if (bus_mapping.has_select_bank_5() &&
+                   bus_mapping.select_bank_5().note_number() == note &&
+                   num_controller_banks >= 5) {
+                       current_controller_bank = 4;
                        update_highlights();
+                       update_lights_lock_held();
                }
-               break;
-       case SND_SEQ_EVENT_NOTEOFF:
-       case SND_SEQ_EVENT_CLIENT_START:
-       case SND_SEQ_EVENT_CLIENT_EXIT:
-       case SND_SEQ_EVENT_CLIENT_CHANGE:
-       case SND_SEQ_EVENT_PORT_CHANGE:
-               break;
-       default:
-               printf("Ignoring MIDI event of unknown type %d.\n", event->type);
        }
+
+       match_button(note, MIDIMappingBusProto::kToggleLocutFieldNumber, MIDIMappingProto::kToggleLocutBankFieldNumber,
+               bind(&ControllerReceiver::toggle_locut, receiver, _1));
+       match_button(note, MIDIMappingBusProto::kToggleAutoGainStagingFieldNumber, MIDIMappingProto::kToggleAutoGainStagingBankFieldNumber,
+               bind(&ControllerReceiver::toggle_auto_gain_staging, receiver, _1));
+       match_button(note, MIDIMappingBusProto::kToggleCompressorFieldNumber, MIDIMappingProto::kToggleCompressorBankFieldNumber,
+               bind(&ControllerReceiver::toggle_compressor, receiver, _1));
+       match_button(note, MIDIMappingBusProto::kClearPeakFieldNumber, MIDIMappingProto::kClearPeakBankFieldNumber,
+               bind(&ControllerReceiver::clear_peak, receiver, _1));
+       match_button(note, MIDIMappingBusProto::kToggleMuteFieldNumber, MIDIMappingProto::kClearPeakBankFieldNumber,
+               bind(&ControllerReceiver::toggle_mute, receiver, _1));
+       match_button(note, MIDIMappingBusProto::kToggleLimiterFieldNumber, MIDIMappingProto::kToggleLimiterBankFieldNumber,
+               bind(&ControllerReceiver::toggle_limiter, receiver));
+       match_button(note, MIDIMappingBusProto::kToggleAutoMakeupGainFieldNumber, MIDIMappingProto::kToggleAutoMakeupGainBankFieldNumber,
+               bind(&ControllerReceiver::toggle_auto_makeup_gain, receiver));
+       match_button(note, MIDIMappingBusProto::kSwitchVideoChannelFieldNumber, MIDIMappingProto::kSwitchVideoChannelBankFieldNumber,
+               bind(&ControllerReceiver::switch_video_channel, receiver, _1));
+       match_button(note, MIDIMappingBusProto::kApplyTransitionFieldNumber, MIDIMappingProto::kApplyTransitionBankFieldNumber,
+               bind(&ControllerReceiver::apply_transition, receiver, _1));
+       match_button(note, MIDIMappingBusProto::kPrevAudioViewFieldNumber, MIDIMappingProto::kPrevAudioViewBankFieldNumber,
+               bind(&ControllerReceiver::prev_audio_view, receiver));
+       match_button(note, MIDIMappingBusProto::kNextAudioViewFieldNumber, MIDIMappingProto::kNextAudioViewBankFieldNumber,
+               bind(&ControllerReceiver::prev_audio_view, receiver));
+       match_button(note, MIDIMappingBusProto::kBeginNewVideoSegmentFieldNumber, MIDIMappingProto::kBeginNewVideoSegmentBankFieldNumber,
+               bind(&ControllerReceiver::begin_new_segment, receiver));
+       match_button(note, MIDIMappingBusProto::kExitFieldNumber, MIDIMappingProto::kExitBankFieldNumber,
+               bind(&ControllerReceiver::exit, receiver));
 }
 
-void MIDIMapper::subscribe_to_port_lock_held(snd_seq_t *seq, const snd_seq_addr_t &addr)
+void MIDIMapper::update_num_subscribers(unsigned num_subscribers)
 {
-       // Client 0 (SNDRV_SEQ_CLIENT_SYSTEM) is basically the system; ignore it.
-       // MIDI through (SNDRV_SEQ_CLIENT_DUMMY) echoes back what we give it, so ignore that, too.
-       if (addr.client == 0 || addr.client == 14) {
-               return;
-       }
-
-       // Don't listen to ourselves.
-       if (addr.client == snd_seq_client_id(seq)) {
-               return;
-       }
-
-       int err = snd_seq_connect_from(seq, 0, addr.client, addr.port);
-       if (err < 0) {
-               // Just print out a warning (i.e., don't die); it could
-               // very well just be e.g. another application.
-               printf("Couldn't subscribe to MIDI port %d:%d (%s).\n",
-                       addr.client, addr.port, snd_strerror(err));
-       } else {
-               printf("Subscribed to MIDI port %d:%d.\n", addr.client, addr.port);
-       }
-
-       // For sending data back.
-       err = snd_seq_connect_to(seq, 0, addr.client, addr.port);
-       if (err < 0) {
-               printf("Couldn't subscribe MIDI port %d:%d (%s) to us.\n",
-                       addr.client, addr.port, snd_strerror(err));
-       } else {
-               printf("Subscribed MIDI port %d:%d to us.\n", addr.client, addr.port);
-       }
-
-       current_light_status.clear();  // The current state of the device is unknown.
-       update_lights_lock_held();
+       num_subscribed_ports = num_subscribers;
+       update_highlights();
 }
 
 void MIDIMapper::match_controller(int controller, int field_number, int bank_field_number, float value, function<void(unsigned, float)> func)
@@ -434,15 +207,7 @@ void MIDIMapper::match_controller(int controller, int field_number, int bank_fie
 
        for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
                const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
-
-               const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
-               const Reflection *bus_reflection = bus_mapping.GetReflection();
-               if (!bus_reflection->HasField(bus_mapping, descriptor)) {
-                       continue;
-               }
-               const MIDIControllerProto &controller_proto =
-                       static_cast<const MIDIControllerProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
-               if (controller_proto.controller_number() == controller) {
+               if (match_controller_helper(bus_mapping, field_number, controller)) {
                        func(bus_idx, value);
                }
        }
@@ -456,15 +221,7 @@ void MIDIMapper::match_button(int note, int field_number, int bank_field_number,
 
        for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
                const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
-
-               const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
-               const Reflection *bus_reflection = bus_mapping.GetReflection();
-               if (!bus_reflection->HasField(bus_mapping, descriptor)) {
-                       continue;
-               }
-               const MIDIButtonProto &button_proto =
-                       static_cast<const MIDIButtonProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
-               if (button_proto.note_number() == note) {
+               if (match_button_helper(bus_mapping, field_number, note)) {
                        func(bus_idx);
                }
        }
@@ -484,10 +241,7 @@ bool MIDIMapper::has_active_controller(unsigned bus_idx, int field_number, int b
 
 bool MIDIMapper::bank_mismatch(int bank_field_number)
 {
-       const FieldDescriptor *bank_descriptor = mapping_proto->GetDescriptor()->FindFieldByNumber(bank_field_number);
-       const Reflection *reflection = mapping_proto->GetReflection();
-       return (reflection->HasField(*mapping_proto, bank_descriptor) &&
-               reflection->GetInt32(*mapping_proto, bank_descriptor) != current_controller_bank);
+       return !match_bank_helper(*mapping_proto, bank_field_number, current_controller_bank);
 }
 
 void MIDIMapper::refresh_highlights()
@@ -572,11 +326,11 @@ void MIDIMapper::update_highlights()
 
 void MIDIMapper::update_lights_lock_held()
 {
-       if (alsa_seq == nullptr || global_audio_mixer == nullptr) {
+       if (global_audio_mixer == nullptr) {
                return;
        }
 
-       set<unsigned> active_lights;  // Desired state.
+       map<MIDIDevice::LightKey, uint8_t> active_lights;  // Desired state.
        if (current_controller_bank == 0) {
                activate_lights_all_buses(MIDIMappingBusProto::kBank1IsSelectedFieldNumber, &active_lights);
        }
@@ -600,77 +354,31 @@ void MIDIMapper::update_lights_lock_held()
        }
        unsigned num_buses = min<unsigned>(global_audio_mixer->num_buses(), mapping_proto->bus_mapping_size());
        for (unsigned bus_idx = 0; bus_idx < num_buses; ++bus_idx) {
+               const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
                if (global_audio_mixer->get_mute(bus_idx)) {
-                       activate_lights(bus_idx, MIDIMappingBusProto::kIsMutedFieldNumber, &active_lights);
+                       activate_mapped_light(bus_mapping, MIDIMappingBusProto::kIsMutedFieldNumber, &active_lights);
                }
                if (global_audio_mixer->get_locut_enabled(bus_idx)) {
-                       activate_lights(bus_idx, MIDIMappingBusProto::kLocutIsOnFieldNumber, &active_lights);
+                       activate_mapped_light(bus_mapping, MIDIMappingBusProto::kLocutIsOnFieldNumber, &active_lights);
                }
                if (global_audio_mixer->get_gain_staging_auto(bus_idx)) {
-                       activate_lights(bus_idx, MIDIMappingBusProto::kAutoGainStagingIsOnFieldNumber, &active_lights);
+                       activate_mapped_light(bus_mapping, MIDIMappingBusProto::kAutoGainStagingIsOnFieldNumber, &active_lights);
                }
                if (global_audio_mixer->get_compressor_enabled(bus_idx)) {
-                       activate_lights(bus_idx, MIDIMappingBusProto::kCompressorIsOnFieldNumber, &active_lights);
+                       activate_mapped_light(bus_mapping, MIDIMappingBusProto::kCompressorIsOnFieldNumber, &active_lights);
                }
                if (has_peaked[bus_idx]) {
-                       activate_lights(bus_idx, MIDIMappingBusProto::kHasPeakedFieldNumber, &active_lights);
+                       activate_mapped_light(bus_mapping, MIDIMappingBusProto::kHasPeakedFieldNumber, &active_lights);
                }
        }
 
-       unsigned num_events = 0;
-       for (unsigned note_num = 1; note_num <= 127; ++note_num) {
-               bool active = active_lights.count(note_num);
-               if (current_light_status.count(note_num) &&
-                   current_light_status[note_num] == active) {
-                       // Already known to be in the desired state.
-                       continue;
-               }
-
-               snd_seq_event_t ev;
-               snd_seq_ev_clear(&ev);
-
-               // Some devices drop events if we throw them onto them
-               // too quickly. Add a 1 ms delay for each.
-               snd_seq_real_time_t tm{0, num_events++ * 1000000};
-               snd_seq_ev_schedule_real(&ev, alsa_queue_id, true, &tm);
-               snd_seq_ev_set_source(&ev, 0);
-               snd_seq_ev_set_subs(&ev);
-
-               // For some reason, not all devices respond to note off.
-               // Use note-on with velocity of 0 (which is equivalent) instead.
-               snd_seq_ev_set_noteon(&ev, /*channel=*/0, note_num, active ? 127 : 0);
-               WARN_ON_ERROR("snd_seq_event_output", snd_seq_event_output(alsa_seq, &ev));
-               current_light_status[note_num] = active;
-       }
-       WARN_ON_ERROR("snd_seq_drain_output", snd_seq_drain_output(alsa_seq));
+       midi_device.update_lights(active_lights);
 }
 
-void MIDIMapper::activate_lights(unsigned bus_idx, int field_number, set<unsigned> *active_lights)
-{
-       const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
-
-       const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
-       const Reflection *bus_reflection = bus_mapping.GetReflection();
-       if (!bus_reflection->HasField(bus_mapping, descriptor)) {
-               return;
-       }
-       const MIDILightProto &light_proto =
-               static_cast<const MIDILightProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
-       active_lights->insert(light_proto.note_number());
-}
-
-void MIDIMapper::activate_lights_all_buses(int field_number, set<unsigned> *active_lights)
+void MIDIMapper::activate_lights_all_buses(int field_number, map<MIDIDevice::LightKey, uint8_t> *active_lights)
 {
        for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
                const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
-
-               const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
-               const Reflection *bus_reflection = bus_mapping.GetReflection();
-               if (!bus_reflection->HasField(bus_mapping, descriptor)) {
-                       continue;
-               }
-               const MIDILightProto &light_proto =
-                       static_cast<const MIDILightProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
-               active_lights->insert(light_proto.note_number());
+               activate_mapped_light(bus_mapping, field_number, active_lights);
        }
 }