git.sesse.net Git - nageru/blob - mainwindow.cpp

   1 #include "mainwindow.h"
   2
   3 #include <math.h>
   4 #include <stdio.h>
   5 #include <signal.h>
   6 #include <algorithm>
   7 #include <chrono>
   8 #include <string>
   9 #include <vector>
  10 #include <QBoxLayout>
  11 #include <QInputDialog>
  12 #include <QKeySequence>
  13 #include <QLabel>
  14 #include <QMetaType>
  15 #include <QPushButton>
  16 #include <QResizeEvent>
  17 #include <QShortcut>
  18 #include <QSize>
  19 #include <QString>
  20
  21 #include "aboutdialog.h"
  22 #include "disk_space_estimator.h"
  23 #include "flags.h"
  24 #include "glwidget.h"
  25 #include "input_mapping_dialog.h"
  26 #include "lrameter.h"
  27 #include "mixer.h"
  28 #include "post_to_main_thread.h"
  29 #include "ui_audio_miniview.h"
  30 #include "ui_display.h"
  31 #include "ui_mainwindow.h"
  32 #include "vumeter.h"
  33
  34 class QResizeEvent;
  35
  36 using namespace std;
  37 using namespace std::chrono;
  38 using namespace std::placeholders;
  39
  40 Q_DECLARE_METATYPE(std::string);
  41 Q_DECLARE_METATYPE(std::vector<std::string>);
  42
  43 MainWindow *global_mainwindow = nullptr;
  44
  45 namespace {
  46
  47 void schedule_cut_signal(int ignored)
  48 {
  49         global_mixer->schedule_cut();
  50 }
  51
  52 void quit_signal(int ignored)
  53 {
  54         global_mainwindow->close();
  55 }
  56
  57 constexpr unsigned DB_NO_FLAGS = 0x0;
  58 constexpr unsigned DB_WITH_SIGN = 0x1;
  59 constexpr unsigned DB_BARE = 0x2;
  60
  61 string format_db(double db, unsigned flags)
  62 {
  63         string text;
  64         if (flags & DB_WITH_SIGN) {
  65                 if (isfinite(db)) {
  66                         char buf[256];
  67                         snprintf(buf, sizeof(buf), "%+.1f", db);
  68                         text = buf;
  69                 } else if (db < 0.0) {
  70                         text = "-∞";
  71                 } else {
  72                         // Should never happen, really.
  73                         text = "+∞";
  74                 }
  75         } else {
  76                 if (isfinite(db)) {
  77                         char buf[256];
  78                         snprintf(buf, sizeof(buf), "%.1f", db);
  79                         text = buf;
  80                 } else if (db < 0.0) {
  81                         text = "-∞";
  82                 } else {
  83                         // Should never happen, really.
  84                         text = "∞";
  85                 }
  86         }
  87         if (!(flags & DB_BARE)) {
  88                 text += " dB";
  89         }
  90         return text;
  91 }
  92
  93 }  // namespace
  94
  95 MainWindow::MainWindow()
  96         : ui(new Ui::MainWindow)
  97 {
  98         global_mainwindow = this;
  99         ui->setupUi(this);
 100
 101         global_disk_space_estimator = new DiskSpaceEstimator(bind(&MainWindow::report_disk_space, this, _1, _2));
 102         disk_free_label = new QLabel(this);
 103         disk_free_label->setStyleSheet("QLabel {padding-right: 5px;}");
 104         ui->menuBar->setCornerWidget(disk_free_label);
 105
 106         ui->me_live->set_output(Mixer::OUTPUT_LIVE);
 107         ui->me_preview->set_output(Mixer::OUTPUT_PREVIEW);
 108
 109         // The menus.
 110         connect(ui->cut_action, &QAction::triggered, this, &MainWindow::cut_triggered);
 111         connect(ui->exit_action, &QAction::triggered, this, &MainWindow::exit_triggered);
 112         connect(ui->about_action, &QAction::triggered, this, &MainWindow::about_triggered);
 113         connect(ui->input_mapping_action, &QAction::triggered, this, &MainWindow::input_mapping_triggered);
 114
 115         if (global_flags.x264_video_to_http) {
 116                 connect(ui->x264_bitrate_action, &QAction::triggered, this, &MainWindow::x264_bitrate_triggered);
 117         } else {
 118                 ui->x264_bitrate_action->setEnabled(false);
 119         }
 120
 121         // Hook up the transition buttons. (Keyboard shortcuts are set in set_transition_names().)
 122         // TODO: Make them dynamic.
 123         connect(ui->transition_btn1, &QPushButton::clicked, bind(&MainWindow::transition_clicked, this, 0));
 124         connect(ui->transition_btn2, &QPushButton::clicked, bind(&MainWindow::transition_clicked, this, 1));
 125         connect(ui->transition_btn3, &QPushButton::clicked, bind(&MainWindow::transition_clicked, this, 2));
 126
 127         // Aiee...
 128         transition_btn1 = ui->transition_btn1;
 129         transition_btn2 = ui->transition_btn2;
 130         transition_btn3 = ui->transition_btn3;
 131         qRegisterMetaType<string>("std::string");
 132         qRegisterMetaType<vector<string>>("std::vector<std::string>");
 133         connect(ui->me_live, &GLWidget::transition_names_updated, this, &MainWindow::set_transition_names);
 134         qRegisterMetaType<Mixer::Output>("Mixer::Output");
 135
 136         // Hook up the prev/next buttons on the audio views.
 137         connect(ui->compact_prev_page, &QAbstractButton::clicked, bind(&QStackedWidget::setCurrentIndex, ui->audio_views, 1));
 138         connect(ui->compact_next_page, &QAbstractButton::clicked, bind(&QStackedWidget::setCurrentIndex, ui->audio_views, 1));
 139         connect(ui->full_prev_page, &QAbstractButton::clicked, bind(&QStackedWidget::setCurrentIndex, ui->audio_views, 0));
 140         connect(ui->full_next_page, &QAbstractButton::clicked, bind(&QStackedWidget::setCurrentIndex, ui->audio_views, 0));
 141
 142         last_audio_level_callback = steady_clock::now() - seconds(1);
 143 }
 144
 145 void MainWindow::resizeEvent(QResizeEvent* event)
 146 {
 147         QMainWindow::resizeEvent(event);
 148
 149         // Ask for a relayout, but only after the event loop is done doing relayout
 150         // on everything else.
 151         QMetaObject::invokeMethod(this, "relayout", Qt::QueuedConnection);
 152 }
 153
 154 void MainWindow::mixer_created(Mixer *mixer)
 155 {
 156         // Make the previews.
 157         unsigned num_previews = mixer->get_num_channels();
 158
 159         for (unsigned i = 0; i < num_previews; ++i) {
 160                 Mixer::Output output = Mixer::Output(Mixer::OUTPUT_INPUT0 + i);
 161
 162                 QWidget *preview = new QWidget(this);
 163                 Ui::Display *ui_display = new Ui::Display;
 164                 ui_display->setupUi(preview);
 165                 ui_display->label->setText(mixer->get_channel_name(output).c_str());
 166                 ui_display->display->set_output(output);
 167                 ui->preview_displays->insertWidget(previews.size(), preview, 1);
 168                 previews.push_back(ui_display);
 169
 170                 // Hook up the click.
 171                 connect(ui_display->display, &GLWidget::clicked, bind(&MainWindow::channel_clicked, this, i));
 172
 173                 // Let the theme update the text whenever the resolution or color changed.
 174                 connect(ui_display->display, &GLWidget::name_updated, this, &MainWindow::update_channel_name);
 175                 connect(ui_display->display, &GLWidget::color_updated, this, &MainWindow::update_channel_color);
 176
 177                 // Hook up the keyboard key.
 178                 QShortcut *shortcut = new QShortcut(QKeySequence(Qt::Key_1 + i), this);
 179                 connect(shortcut, &QShortcut::activated, bind(&MainWindow::channel_clicked, this, i));
 180
 181                 // Hook up the white balance button (irrelevant if invisible).
 182                 ui_display->wb_button->setVisible(mixer->get_supports_set_wb(output));
 183                 connect(ui_display->wb_button, &QPushButton::clicked, bind(&MainWindow::wb_button_clicked, this, i));
 184         }
 185
 186         setup_audio_miniview();
 187
 188         // TODO: Fetch all of the values these for completeness,
 189         // not just the enable knobs implied by flags.
 190         ui->locut_enabled->setChecked(global_mixer->get_audio_mixer()->get_locut_enabled());
 191         ui->gainstaging_knob->setValue(global_mixer->get_audio_mixer()->get_gain_staging_db());
 192         ui->gainstaging_auto_checkbox->setChecked(global_mixer->get_audio_mixer()->get_gain_staging_auto());
 193         ui->compressor_enabled->setChecked(global_mixer->get_audio_mixer()->get_compressor_enabled());
 194         ui->limiter_enabled->setChecked(global_mixer->get_audio_mixer()->get_limiter_enabled());
 195         ui->makeup_gain_auto_checkbox->setChecked(global_mixer->get_audio_mixer()->get_final_makeup_gain_auto());
 196
 197         ui->limiter_threshold_db_display->setText(
 198                 QString::fromStdString(format_db(mixer->get_audio_mixer()->get_limiter_threshold_dbfs(), DB_WITH_SIGN)));
 199         ui->compressor_threshold_db_display->setText(
 200                 QString::fromStdString(format_db(mixer->get_audio_mixer()->get_compressor_threshold_dbfs(), DB_WITH_SIGN)));
 201
 202         connect(ui->locut_cutoff_knob, &QDial::valueChanged, this, &MainWindow::cutoff_knob_changed);
 203         cutoff_knob_changed(ui->locut_cutoff_knob->value());
 204         connect(ui->locut_enabled, &QCheckBox::stateChanged, [this](int state){
 205                 global_mixer->get_audio_mixer()->set_locut_enabled(state == Qt::Checked);
 206         });
 207
 208         connect(ui->gainstaging_knob, &QAbstractSlider::valueChanged, this, &MainWindow::gain_staging_knob_changed);
 209         connect(ui->gainstaging_auto_checkbox, &QCheckBox::stateChanged, [this](int state){
 210                 global_mixer->get_audio_mixer()->set_gain_staging_auto(state == Qt::Checked);
 211         });
 212         connect(ui->makeup_gain_knob, &QAbstractSlider::valueChanged, this, &MainWindow::final_makeup_gain_knob_changed);
 213         connect(ui->makeup_gain_auto_checkbox, &QCheckBox::stateChanged, [this](int state){
 214                 global_mixer->get_audio_mixer()->set_final_makeup_gain_auto(state == Qt::Checked);
 215         });
 216
 217         connect(ui->limiter_threshold_knob, &QDial::valueChanged, this, &MainWindow::limiter_threshold_knob_changed);
 218         connect(ui->compressor_threshold_knob, &QDial::valueChanged, this, &MainWindow::compressor_threshold_knob_changed);
 219         connect(ui->limiter_enabled, &QCheckBox::stateChanged, [this](int state){
 220                 global_mixer->get_audio_mixer()->set_limiter_enabled(state == Qt::Checked);
 221         });
 222         connect(ui->compressor_enabled, &QCheckBox::stateChanged, [this](int state){
 223                 global_mixer->get_audio_mixer()->set_compressor_enabled(state == Qt::Checked);
 224         });
 225         connect(ui->reset_meters_button, &QPushButton::clicked, this, &MainWindow::reset_meters_button_clicked);
 226         mixer->get_audio_mixer()->set_audio_level_callback(bind(&MainWindow::audio_level_callback, this, _1, _2, _3, _4, _5, _6, _7, _8, _9));
 227
 228         struct sigaction act;
 229         memset(&act, 0, sizeof(act));
 230         act.sa_handler = schedule_cut_signal;
 231         act.sa_flags = SA_RESTART;
 232         sigaction(SIGHUP, &act, nullptr);
 233
 234         // Mostly for debugging. Don't override SIGINT, that's so evil if
 235         // shutdown isn't instant.
 236         memset(&act, 0, sizeof(act));
 237         act.sa_handler = quit_signal;
 238         act.sa_flags = SA_RESTART;
 239         sigaction(SIGUSR1, &act, nullptr);
 240 }
 241
 242 void MainWindow::setup_audio_miniview()
 243 {
 244         // Remove any existing channels.
 245         for (QLayoutItem *item; (item = ui->faders->takeAt(0)) != nullptr; ) {
 246                 delete item->widget();
 247                 delete item;
 248         }
 249         audio_miniviews.clear();
 250
 251         // Set up brand new ones from the input mapping.
 252         InputMapping mapping = global_mixer->get_audio_mixer()->get_input_mapping();
 253         audio_miniviews.resize(mapping.buses.size());
 254         for (unsigned bus_index = 0; bus_index < mapping.buses.size(); ++bus_index) {
 255                 QWidget *channel = new QWidget(this);
 256                 Ui::AudioMiniView *ui_audio_miniview = new Ui::AudioMiniView;
 257                 ui_audio_miniview->setupUi(channel);
 258                 ui_audio_miniview->bus_desc_label->setFullText(
 259                         QString::fromStdString(mapping.buses[bus_index].name));
 260                 audio_miniviews[bus_index] = ui_audio_miniview;
 261                 // TODO: Set the fader position.
 262                 ui->faders->addWidget(channel);
 263
 264                 connect(ui_audio_miniview->fader, &NonLinearFader::dbValueChanged,
 265                         bind(&MainWindow::mini_fader_changed, this, ui_audio_miniview, bus_index, _1));
 266         }
 267 }
 268
 269 void MainWindow::mixer_shutting_down()
 270 {
 271         ui->me_live->clean_context();
 272         ui->me_preview->clean_context();
 273         for (Ui::Display *display : previews) {
 274                 display->display->clean_context();
 275         }
 276 }
 277
 278 void MainWindow::cut_triggered()
 279 {
 280         global_mixer->schedule_cut();
 281 }
 282
 283 void MainWindow::x264_bitrate_triggered()
 284 {
 285         bool ok;
 286         int new_bitrate = QInputDialog::getInt(this, "Change x264 bitrate", "Choose new bitrate for x264 HTTP output (from 100–100,000 kbit/sec):", global_flags.x264_bitrate, /*min=*/100, /*max=*/100000, /*step=*/100, &ok);
 287         if (ok && new_bitrate >= 100 && new_bitrate <= 100000) {
 288                 global_flags.x264_bitrate = new_bitrate;
 289                 global_mixer->change_x264_bitrate(new_bitrate);
 290         }
 291 }
 292
 293 void MainWindow::exit_triggered()
 294 {
 295         close();
 296 }
 297
 298 void MainWindow::about_triggered()
 299 {
 300         AboutDialog().exec();
 301 }
 302
 303 void MainWindow::input_mapping_triggered()
 304 {
 305         if (InputMappingDialog().exec() == QDialog::Accepted) {
 306                 setup_audio_miniview();
 307         }
 308 }
 309
 310 void MainWindow::gain_staging_knob_changed(int value)
 311 {
 312         ui->gainstaging_auto_checkbox->setCheckState(Qt::Unchecked);
 313
 314         float gain_db = value * 0.1f;
 315         global_mixer->get_audio_mixer()->set_gain_staging_db(gain_db);
 316
 317         // The label will be updated by the audio level callback.
 318 }
 319
 320 void MainWindow::final_makeup_gain_knob_changed(int value)
 321 {
 322         ui->makeup_gain_auto_checkbox->setCheckState(Qt::Unchecked);
 323
 324         float gain_db = value * 0.1f;
 325         global_mixer->get_audio_mixer()->set_final_makeup_gain_db(gain_db);
 326
 327         // The label will be updated by the audio level callback.
 328 }
 329
 330 void MainWindow::cutoff_knob_changed(int value)
 331 {
 332         float octaves = value * 0.1f;
 333         float cutoff_hz = 20.0 * pow(2.0, octaves);
 334         global_mixer->get_audio_mixer()->set_locut_cutoff(cutoff_hz);
 335
 336         char buf[256];
 337         snprintf(buf, sizeof(buf), "%ld Hz", lrintf(cutoff_hz));
 338         ui->locut_cutoff_display->setText(buf);
 339 }
 340
 341 void MainWindow::report_disk_space(off_t free_bytes, double estimated_seconds_left)
 342 {
 343         char time_str[256];
 344         if (estimated_seconds_left < 60.0) {
 345                 strcpy(time_str, "<font color=\"red\">Less than a minute</font>");
 346         } else if (estimated_seconds_left < 1800.0) {  // Less than half an hour: Xm Ys (red).
 347                 int s = lrintf(estimated_seconds_left);
 348                 int m = s / 60;
 349                 s %= 60;
 350                 snprintf(time_str, sizeof(time_str), "<font color=\"red\">%dm %ds</font>", m, s);
 351         } else if (estimated_seconds_left < 3600.0) {  // Less than an hour: Xm.
 352                 int m = lrintf(estimated_seconds_left / 60.0);
 353                 snprintf(time_str, sizeof(time_str), "%dm", m);
 354         } else if (estimated_seconds_left < 36000.0) {  // Less than ten hours: Xh Ym.
 355                 int m = lrintf(estimated_seconds_left / 60.0);
 356                 int h = m / 60;
 357                 m %= 60;
 358                 snprintf(time_str, sizeof(time_str), "%dh %dm", h, m);
 359         } else {  // More than ten hours: Xh.
 360                 int h = lrintf(estimated_seconds_left / 3600.0);
 361                 snprintf(time_str, sizeof(time_str), "%dh", h);
 362         }
 363         char buf[256];
 364         snprintf(buf, sizeof(buf), "Disk free: %'.0f MB (approx. %s)", free_bytes / 1048576.0, time_str);
 365
 366         std::string label = buf;
 367
 368         post_to_main_thread([this, label]{
 369                 disk_free_label->setText(QString::fromStdString(label));
 370                 ui->menuBar->setCornerWidget(disk_free_label);  // Need to set this again for the sizing to get right.
 371         });
 372 }
 373
 374 void MainWindow::limiter_threshold_knob_changed(int value)
 375 {
 376         float threshold_dbfs = value * 0.1f;
 377         global_mixer->get_audio_mixer()->set_limiter_threshold_dbfs(threshold_dbfs);
 378         ui->limiter_threshold_db_display->setText(
 379                 QString::fromStdString(format_db(threshold_dbfs, DB_WITH_SIGN)));
 380 }
 381
 382 void MainWindow::compressor_threshold_knob_changed(int value)
 383 {
 384         float threshold_dbfs = value * 0.1f;
 385         global_mixer->get_audio_mixer()->set_compressor_threshold_dbfs(threshold_dbfs);
 386         ui->compressor_threshold_db_display->setText(
 387                 QString::fromStdString(format_db(threshold_dbfs, DB_WITH_SIGN)));
 388 }
 389
 390 void MainWindow::mini_fader_changed(Ui::AudioMiniView *ui, int channel, double volume_db)
 391 {
 392         char buf[256];
 393         if (isfinite(volume_db)) {
 394                 snprintf(buf, sizeof(buf), "%+.1f dB", volume_db);
 395                 ui->fader_label->setText(buf);
 396         } else {
 397                 ui->fader_label->setText("-∞ dB");
 398         }
 399
 400         global_mixer->get_audio_mixer()->set_fader_volume(channel, volume_db);
 401 }
 402
 403 void MainWindow::reset_meters_button_clicked()
 404 {
 405         global_mixer->get_audio_mixer()->reset_meters();
 406         ui->peak_display->setText(QString::fromStdString(format_db(-HUGE_VAL, DB_WITH_SIGN | DB_BARE)));
 407         ui->peak_display->setStyleSheet("");
 408 }
 409
 410 void MainWindow::audio_level_callback(float level_lufs, float peak_db, vector<float> bus_level_lufs,
 411                                       float global_level_lufs,
 412                                       float range_low_lufs, float range_high_lufs,
 413                                       float gain_staging_db, float final_makeup_gain_db,
 414                                       float correlation)
 415 {
 416         steady_clock::time_point now = steady_clock::now();
 417
 418         // The meters are somewhat inefficient to update. Only update them
 419         // every 100 ms or so (we get updates every 5–20 ms).
 420         double last_update_age = duration<double>(now - last_audio_level_callback).count();
 421         if (last_update_age < 0.100) {
 422                 return;
 423         }
 424         last_audio_level_callback = now;
 425
 426         post_to_main_thread([=]() {
 427                 ui->vu_meter->set_level(level_lufs);
 428                 for (unsigned bus_index = 0; bus_index < bus_level_lufs.size(); ++bus_index) {
 429                         if (bus_index < audio_miniviews.size()) {
 430                                 audio_miniviews[bus_index]->vu_meter_meter->set_level(
 431                                         bus_level_lufs[bus_index]);
 432                         }
 433                 }
 434                 ui->lra_meter->set_levels(global_level_lufs, range_low_lufs, range_high_lufs);
 435                 ui->correlation_meter->set_correlation(correlation);
 436
 437                 ui->peak_display->setText(QString::fromStdString(format_db(peak_db, DB_BARE)));
 438                 if (peak_db > -0.1f) {  // -0.1 dBFS is EBU peak limit.
 439                         ui->peak_display->setStyleSheet("QLabel { background-color: red; color: white; }");
 440                 } else {
 441                         ui->peak_display->setStyleSheet("");
 442                 }
 443
 444                 ui->gainstaging_knob->blockSignals(true);
 445                 ui->gainstaging_knob->setValue(lrintf(gain_staging_db * 10.0f));
 446                 ui->gainstaging_knob->blockSignals(false);
 447                 ui->gainstaging_db_display->setText(
 448                         QString::fromStdString(format_db(gain_staging_db, DB_WITH_SIGN)));
 449
 450                 ui->makeup_gain_knob->blockSignals(true);
 451                 ui->makeup_gain_knob->setValue(lrintf(final_makeup_gain_db * 10.0f));
 452                 ui->makeup_gain_knob->blockSignals(false);
 453                 ui->makeup_gain_db_display->setText(
 454                         QString::fromStdString(format_db(final_makeup_gain_db, DB_WITH_SIGN)));
 455         });
 456 }
 457
 458 void MainWindow::relayout()
 459 {
 460         int height = ui->vertical_layout->geometry().height();
 461
 462         double remaining_height = height;
 463
 464         // Allocate the height; the most important part is to keep the main displays
 465         // at 16:9 if at all possible.
 466         double me_width = ui->me_preview->width();
 467         double me_height = me_width * 9.0 / 16.0 + ui->label_preview->height() + ui->preview_vertical_layout->spacing();
 468
 469         // TODO: Scale the widths when we need to do this.
 470         if (me_height / double(height) > 0.8) {
 471                 me_height = height * 0.8;
 472         }
 473         remaining_height -= me_height + ui->vertical_layout->spacing();
 474
 475         // Space between the M/E displays and the audio strip.
 476         remaining_height -= ui->vertical_layout->spacing();
 477
 478         // The label above the audio strip.
 479         double compact_label_height = ui->compact_label->geometry().height() +
 480                 ui->compact_audio_layout->spacing();
 481         remaining_height -= compact_label_height;
 482
 483         // The previews will be constrained by the remaining height, and the width.
 484         double preview_label_height = previews[0]->title_bar->geometry().height() +
 485                 previews[0]->main_vertical_layout->spacing();
 486         int preview_total_width = ui->preview_displays->geometry().width() - (previews.size() - 1) * ui->preview_displays->spacing();
 487         double preview_height = min(remaining_height - preview_label_height, (preview_total_width / double(previews.size())) * 9.0 / 16.0);
 488         remaining_height -= preview_height + preview_label_height + ui->vertical_layout->spacing();
 489
 490         ui->vertical_layout->setStretch(0, lrintf(me_height));
 491         ui->vertical_layout->setStretch(1,
 492                 lrintf(compact_label_height) +
 493                 lrintf(remaining_height) +
 494                 lrintf(preview_height + preview_label_height));  // Audio strip and previews together.
 495
 496         ui->compact_audio_layout->setStretch(0, lrintf(compact_label_height));
 497         ui->compact_audio_layout->setStretch(1, lrintf(remaining_height));  // Audio strip.
 498         ui->compact_audio_layout->setStretch(2, lrintf(preview_height + preview_label_height));
 499
 500         // Set the widths for the previews.
 501         double preview_width = preview_height * 16.0 / 9.0;
 502         for (unsigned i = 0; i < previews.size(); ++i) {
 503                 ui->preview_displays->setStretch(i, lrintf(preview_width));
 504         }
 505
 506         // The preview horizontal spacer.
 507         double remaining_preview_width = preview_total_width - previews.size() * preview_width;
 508         ui->preview_displays->setStretch(previews.size(), lrintf(remaining_preview_width));
 509 }
 510
 511 void MainWindow::set_transition_names(vector<string> transition_names)
 512 {
 513         if (transition_names.size() < 1 || transition_names[0].empty()) {
 514                 transition_btn1->setText(QString(""));
 515         } else {
 516                 transition_btn1->setText(QString::fromStdString(transition_names[0] + " (J)"));
 517                 ui->transition_btn1->setShortcut(QKeySequence("J"));
 518         }
 519         if (transition_names.size() < 2 || transition_names[1].empty()) {
 520                 transition_btn2->setText(QString(""));
 521         } else {
 522                 transition_btn2->setText(QString::fromStdString(transition_names[1] + " (K)"));
 523                 ui->transition_btn2->setShortcut(QKeySequence("K"));
 524         }
 525         if (transition_names.size() < 3 || transition_names[2].empty()) {
 526                 transition_btn3->setText(QString(""));
 527         } else {
 528                 transition_btn3->setText(QString::fromStdString(transition_names[2] + " (L)"));
 529                 ui->transition_btn3->setShortcut(QKeySequence("L"));
 530         }
 531 }
 532
 533 void MainWindow::update_channel_name(Mixer::Output output, const string &name)
 534 {
 535         if (output >= Mixer::OUTPUT_INPUT0) {
 536                 unsigned channel = output - Mixer::OUTPUT_INPUT0;
 537                 previews[channel]->label->setText(name.c_str());
 538         }
 539 }
 540
 541 void MainWindow::update_channel_color(Mixer::Output output, const string &color)
 542 {
 543         if (output >= Mixer::OUTPUT_INPUT0) {
 544                 unsigned channel = output - Mixer::OUTPUT_INPUT0;
 545                 previews[channel]->frame->setStyleSheet(QString::fromStdString("background-color:" + color));
 546         }
 547 }
 548
 549 void MainWindow::transition_clicked(int transition_number)
 550 {
 551         global_mixer->transition_clicked(transition_number);
 552 }
 553
 554 void MainWindow::channel_clicked(int channel_number)
 555 {
 556         if (current_wb_pick_display == channel_number) {
 557                 // The picking was already done from eventFilter(), since we don't get
 558                 // the mouse pointer here.
 559         } else {
 560                 global_mixer->channel_clicked(channel_number);
 561         }
 562 }
 563
 564 void MainWindow::wb_button_clicked(int channel_number)
 565 {
 566         current_wb_pick_display = channel_number;
 567         QApplication::setOverrideCursor(Qt::CrossCursor);
 568 }
 569
 570 bool MainWindow::eventFilter(QObject *watched, QEvent *event)
 571 {
 572         if (current_wb_pick_display != -1 &&
 573             event->type() == QEvent::MouseButtonRelease &&
 574             watched->isWidgetType()) {
 575                 QApplication::restoreOverrideCursor();
 576                 if (watched == previews[current_wb_pick_display]->display) {
 577                         const QMouseEvent *mouse_event = (QMouseEvent *)event;
 578                         set_white_balance(current_wb_pick_display, mouse_event->x(), mouse_event->y());
 579                 } else {
 580                         // The user clicked on something else, give up.
 581                         // (The click goes through, which might not be ideal, but, yes.)
 582                         current_wb_pick_display = -1;
 583                 }
 584         }
 585         return false;
 586 }
 587
 588 namespace {
 589
 590 double srgb_to_linear(double x)
 591 {
 592         if (x < 0.04045) {
 593                 return x / 12.92;
 594         } else {
 595                 return pow((x + 0.055) / 1.055, 2.4);
 596         }
 597 }
 598
 599 }  // namespace
 600
 601 void MainWindow::set_white_balance(int channel_number, int x, int y)
 602 {
 603         // Set the white balance to neutral for the grab. It's probably going to
 604         // flicker a bit, but hopefully this display is not live anyway.
 605         global_mixer->set_wb(Mixer::OUTPUT_INPUT0 + channel_number, 0.5, 0.5, 0.5);
 606         previews[channel_number]->display->updateGL();
 607         QRgb reference_color = previews[channel_number]->display->grabFrameBuffer().pixel(x, y);
 608
 609         double r = srgb_to_linear(qRed(reference_color) / 255.0);
 610         double g = srgb_to_linear(qGreen(reference_color) / 255.0);
 611         double b = srgb_to_linear(qBlue(reference_color) / 255.0);
 612         global_mixer->set_wb(Mixer::OUTPUT_INPUT0 + channel_number, r, g, b);
 613         previews[channel_number]->display->updateGL();
 614 }