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

   1 #undef Success
   2
   3 #include "mixer.h"
   4
   5 #include <assert.h>
   6 #include <epoxy/egl.h>
   7 #include <movit/effect_chain.h>
   8 #include <movit/effect_util.h>
   9 #include <movit/flat_input.h>
  10 #include <movit/image_format.h>
  11 #include <movit/init.h>
  12 #include <movit/resource_pool.h>
  13 #include <pthread.h>
  14 #include <stdint.h>
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <sys/resource.h>
  18 #include <algorithm>
  19 #include <chrono>
  20 #include <condition_variable>
  21 #include <cstddef>
  22 #include <cstdint>
  23 #include <memory>
  24 #include <mutex>
  25 #include <ratio>
  26 #include <string>
  27 #include <thread>
  28 #include <utility>
  29 #include <vector>
  30
  31 #include "DeckLinkAPI.h"
  32 #include "LinuxCOM.h"
  33 #include "alsa_output.h"
  34 #include "bmusb/bmusb.h"
  35 #include "bmusb/fake_capture.h"
  36 #include "chroma_subsampler.h"
  37 #include "context.h"
  38 #include "decklink_capture.h"
  39 #include "decklink_output.h"
  40 #include "defs.h"
  41 #include "disk_space_estimator.h"
  42 #include "flags.h"
  43 #include "input_mapping.h"
  44 #include "pbo_frame_allocator.h"
  45 #include "ref_counted_gl_sync.h"
  46 #include "resampling_queue.h"
  47 #include "timebase.h"
  48 #include "video_encoder.h"
  49
  50 class IDeckLink;
  51 class QOpenGLContext;
  52
  53 using namespace movit;
  54 using namespace std;
  55 using namespace std::chrono;
  56 using namespace std::placeholders;
  57 using namespace bmusb;
  58
  59 Mixer *global_mixer = nullptr;
  60 bool uses_mlock = false;
  61
  62 namespace {
  63
  64 void insert_new_frame(RefCountedFrame frame, unsigned field_num, bool interlaced, unsigned card_index, InputState *input_state)
  65 {
  66         if (interlaced) {
  67                 for (unsigned frame_num = FRAME_HISTORY_LENGTH; frame_num --> 1; ) {  // :-)
  68                         input_state->buffered_frames[card_index][frame_num] =
  69                                 input_state->buffered_frames[card_index][frame_num - 1];
  70                 }
  71                 input_state->buffered_frames[card_index][0] = { frame, field_num };
  72         } else {
  73                 for (unsigned frame_num = 0; frame_num < FRAME_HISTORY_LENGTH; ++frame_num) {
  74                         input_state->buffered_frames[card_index][frame_num] = { frame, field_num };
  75                 }
  76         }
  77 }
  78
  79 }  // namespace
  80
  81 void QueueLengthPolicy::update_policy(unsigned queue_length)
  82 {
  83         if (queue_length == 0) {  // Starvation.
  84                 if (been_at_safe_point_since_last_starvation && safe_queue_length < 6) {
  85                         ++safe_queue_length;
  86                         fprintf(stderr, "Card %u: Starvation, increasing safe limit to %u frame(s)\n",
  87                                 card_index, safe_queue_length);
  88                 }
  89                 frames_with_at_least_one = 0;
  90                 been_at_safe_point_since_last_starvation = false;
  91                 return;
  92         }
  93         if (queue_length >= 1) {
  94                 if (queue_length >= safe_queue_length) {
  95                         been_at_safe_point_since_last_starvation = true;
  96                 }
  97                 if (++frames_with_at_least_one >= 1000 && safe_queue_length > 1) {
  98                         --safe_queue_length;
  99                         fprintf(stderr, "Card %u: Spare frames for more than 1000 frames, reducing safe limit to %u frame(s)\n",
 100                                 card_index, safe_queue_length);
 101                         frames_with_at_least_one = 0;
 102                 }
 103         } else {
 104                 frames_with_at_least_one = 0;
 105         }
 106 }
 107
 108 Mixer::Mixer(const QSurfaceFormat &format, unsigned num_cards)
 109         : httpd(),
 110           num_cards(num_cards),
 111           mixer_surface(create_surface(format)),
 112           h264_encoder_surface(create_surface(format)),
 113           decklink_output_surface(create_surface(format)),
 114           audio_mixer(num_cards)
 115 {
 116         CHECK(init_movit(MOVIT_SHADER_DIR, MOVIT_DEBUG_OFF));
 117         check_error();
 118
 119         // Since we allow non-bouncing 4:2:2 YCbCrInputs, effective subpixel precision
 120         // will be halved when sampling them, and we need to compensate here.
 121         movit_texel_subpixel_precision /= 2.0;
 122
 123         resource_pool.reset(new ResourcePool);
 124         theme.reset(new Theme(global_flags.theme_filename, global_flags.theme_dirs, resource_pool.get(), num_cards));
 125         for (unsigned i = 0; i < NUM_OUTPUTS; ++i) {
 126                 output_channel[i].parent = this;
 127                 output_channel[i].channel = i;
 128         }
 129
 130         ImageFormat inout_format;
 131         inout_format.color_space = COLORSPACE_sRGB;
 132         inout_format.gamma_curve = GAMMA_sRGB;
 133
 134         // Display chain; shows the live output produced by the main chain (its RGBA version).
 135         display_chain.reset(new EffectChain(global_flags.width, global_flags.height, resource_pool.get()));
 136         check_error();
 137         display_input = new FlatInput(inout_format, FORMAT_RGB, GL_UNSIGNED_BYTE, global_flags.width, global_flags.height);  // FIXME: GL_UNSIGNED_BYTE is really wrong.
 138         display_chain->add_input(display_input);
 139         display_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
 140         display_chain->set_dither_bits(0);  // Don't bother.
 141         display_chain->finalize();
 142
 143         video_encoder.reset(new VideoEncoder(resource_pool.get(), h264_encoder_surface, global_flags.va_display, global_flags.width, global_flags.height, &httpd, global_disk_space_estimator));
 144
 145         // Start listening for clients only once VideoEncoder has written its header, if any.
 146         httpd.start(9095);
 147
 148         // First try initializing the then PCI devices, then USB, then
 149         // fill up with fake cards until we have the desired number of cards.
 150         unsigned num_pci_devices = 0;
 151         unsigned card_index = 0;
 152
 153         {
 154                 IDeckLinkIterator *decklink_iterator = CreateDeckLinkIteratorInstance();
 155                 if (decklink_iterator != nullptr) {
 156                         for ( ; card_index < num_cards; ++card_index) {
 157                                 IDeckLink *decklink;
 158                                 if (decklink_iterator->Next(&decklink) != S_OK) {
 159                                         break;
 160                                 }
 161
 162                                 DeckLinkCapture *capture = new DeckLinkCapture(decklink, card_index);
 163                                 DeckLinkOutput *output = new DeckLinkOutput(resource_pool.get(), decklink_output_surface, global_flags.width, global_flags.height, card_index);
 164                                 output->set_device(decklink);
 165                                 configure_card(card_index, capture, /*is_fake_capture=*/false, output);
 166                                 ++num_pci_devices;
 167                         }
 168                         decklink_iterator->Release();
 169                         fprintf(stderr, "Found %u DeckLink PCI card(s).\n", num_pci_devices);
 170                 } else {
 171                         fprintf(stderr, "DeckLink drivers not found. Probing for USB cards only.\n");
 172                 }
 173         }
 174
 175         unsigned num_usb_devices = BMUSBCapture::num_cards();
 176         for (unsigned usb_card_index = 0; usb_card_index < num_usb_devices && card_index < num_cards; ++usb_card_index, ++card_index) {
 177                 BMUSBCapture *capture = new BMUSBCapture(usb_card_index);
 178                 capture->set_card_disconnected_callback(bind(&Mixer::bm_hotplug_remove, this, card_index));
 179                 configure_card(card_index, capture, /*is_fake_capture=*/false, /*output=*/nullptr);
 180         }
 181         fprintf(stderr, "Found %u USB card(s).\n", num_usb_devices);
 182
 183         unsigned num_fake_cards = 0;
 184         for ( ; card_index < num_cards; ++card_index, ++num_fake_cards) {
 185                 FakeCapture *capture = new FakeCapture(global_flags.width, global_flags.height, FAKE_FPS, OUTPUT_FREQUENCY, card_index, global_flags.fake_cards_audio);
 186                 configure_card(card_index, capture, /*is_fake_capture=*/true, /*output=*/nullptr);
 187         }
 188
 189         if (num_fake_cards > 0) {
 190                 fprintf(stderr, "Initialized %u fake cards.\n", num_fake_cards);
 191         }
 192
 193         BMUSBCapture::set_card_connected_callback(bind(&Mixer::bm_hotplug_add, this, _1));
 194         BMUSBCapture::start_bm_thread();
 195
 196         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 197                 cards[card_index].queue_length_policy.reset(card_index);
 198         }
 199
 200         chroma_subsampler.reset(new ChromaSubsampler(resource_pool.get()));
 201
 202         if (global_flags.enable_alsa_output) {
 203                 alsa.reset(new ALSAOutput(OUTPUT_FREQUENCY, /*num_channels=*/2));
 204         }
 205         if (global_flags.output_card != -1) {
 206                 desired_output_card_index = global_flags.output_card;
 207                 set_output_card_internal(global_flags.output_card);
 208         }
 209 }
 210
 211 Mixer::~Mixer()
 212 {
 213         BMUSBCapture::stop_bm_thread();
 214
 215         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 216                 {
 217                         unique_lock<mutex> lock(card_mutex);
 218                         cards[card_index].should_quit = true;  // Unblock thread.
 219                         cards[card_index].new_frames_changed.notify_all();
 220                 }
 221                 cards[card_index].capture->stop_dequeue_thread();
 222                 if (cards[card_index].output) {
 223                         cards[card_index].output->end_output();
 224                         cards[card_index].output.reset();
 225                 }
 226         }
 227
 228         video_encoder.reset(nullptr);
 229 }
 230
 231 void Mixer::configure_card(unsigned card_index, CaptureInterface *capture, bool is_fake_capture, DeckLinkOutput *output)
 232 {
 233         printf("Configuring card %d...\n", card_index);
 234
 235         CaptureCard *card = &cards[card_index];
 236         if (card->capture != nullptr) {
 237                 card->capture->stop_dequeue_thread();
 238         }
 239         card->capture.reset(capture);
 240         card->is_fake_capture = is_fake_capture;
 241         if (card->output.get() != output) {
 242                 card->output.reset(output);
 243         }
 244         card->capture->set_frame_callback(bind(&Mixer::bm_frame, this, card_index, _1, _2, _3, _4, _5, _6, _7));
 245         if (card->frame_allocator == nullptr) {
 246                 card->frame_allocator.reset(new PBOFrameAllocator(8 << 20, global_flags.width, global_flags.height));  // 8 MB.
 247         }
 248         card->capture->set_video_frame_allocator(card->frame_allocator.get());
 249         if (card->surface == nullptr) {
 250                 card->surface = create_surface_with_same_format(mixer_surface);
 251         }
 252         while (!card->new_frames.empty()) card->new_frames.pop_front();
 253         card->last_timecode = -1;
 254         card->capture->configure_card();
 255
 256         // NOTE: start_bm_capture() happens in thread_func().
 257
 258         DeviceSpec device{InputSourceType::CAPTURE_CARD, card_index};
 259         audio_mixer.reset_resampler(device);
 260         audio_mixer.set_display_name(device, card->capture->get_description());
 261         audio_mixer.trigger_state_changed_callback();
 262 }
 263
 264 void Mixer::set_output_card_internal(int card_index)
 265 {
 266         // We don't really need to take card_mutex, since we're in the mixer
 267         // thread and don't mess with any queues (which is the only thing that happens
 268         // from other threads), but it's probably the safest in the long run.
 269         unique_lock<mutex> lock(card_mutex);
 270         if (output_card_index != -1) {
 271                 // Switch the old card from output to input.
 272                 CaptureCard *old_card = &cards[output_card_index];
 273                 old_card->output->end_output();
 274
 275                 // Stop the fake card that we put into place.
 276                 // This needs to _not_ happen under the mutex, to avoid deadlock
 277                 // (delivering the last frame needs to take the mutex).
 278                 bmusb::CaptureInterface *fake_capture = old_card->capture.get();
 279                 lock.unlock();
 280                 fake_capture->stop_dequeue_thread();
 281                 lock.lock();
 282                 old_card->capture = move(old_card->parked_capture);
 283                 old_card->is_fake_capture = false;
 284                 old_card->capture->start_bm_capture();
 285         }
 286         if (card_index != -1) {
 287                 CaptureCard *card = &cards[card_index];
 288                 bmusb::CaptureInterface *capture = card->capture.get();
 289                 // TODO: DeckLinkCapture::stop_dequeue_thread can actually take
 290                 // several seconds to complete (blocking on DisableVideoInput);
 291                 // see if we can maybe do it asynchronously.
 292                 lock.unlock();
 293                 capture->stop_dequeue_thread();
 294                 lock.lock();
 295                 card->parked_capture = move(card->capture);
 296                 bmusb::CaptureInterface *fake_capture = new FakeCapture(global_flags.width, global_flags.height, FAKE_FPS, OUTPUT_FREQUENCY, card_index, global_flags.fake_cards_audio);
 297                 configure_card(card_index, fake_capture, /*is_fake_capture=*/true, card->output.release());
 298                 card->queue_length_policy.reset(card_index);
 299                 card->capture->start_bm_capture();
 300                 desired_output_video_mode = output_video_mode = card->output->pick_video_mode(desired_output_video_mode);
 301                 card->output->start_output(desired_output_video_mode, pts_int);
 302         }
 303         output_card_index = card_index;
 304 }
 305
 306 namespace {
 307
 308 int unwrap_timecode(uint16_t current_wrapped, int last)
 309 {
 310         uint16_t last_wrapped = last & 0xffff;
 311         if (current_wrapped > last_wrapped) {
 312                 return (last & ~0xffff) | current_wrapped;
 313         } else {
 314                 return 0x10000 + ((last & ~0xffff) | current_wrapped);
 315         }
 316 }
 317
 318 }  // namespace
 319
 320 void Mixer::bm_frame(unsigned card_index, uint16_t timecode,
 321                      FrameAllocator::Frame video_frame, size_t video_offset, VideoFormat video_format,
 322                      FrameAllocator::Frame audio_frame, size_t audio_offset, AudioFormat audio_format)
 323 {
 324         DeviceSpec device{InputSourceType::CAPTURE_CARD, card_index};
 325         CaptureCard *card = &cards[card_index];
 326
 327         if (is_mode_scanning[card_index]) {
 328                 if (video_format.has_signal) {
 329                         // Found a stable signal, so stop scanning.
 330                         is_mode_scanning[card_index] = false;
 331                 } else {
 332                         static constexpr double switch_time_s = 0.1;  // Should be enough time for the signal to stabilize.
 333                         steady_clock::time_point now = steady_clock::now();
 334                         double sec_since_last_switch = duration<double>(steady_clock::now() - last_mode_scan_change[card_index]).count();
 335                         if (sec_since_last_switch > switch_time_s) {
 336                                 // It isn't this mode; try the next one.
 337                                 mode_scanlist_index[card_index]++;
 338                                 mode_scanlist_index[card_index] %= mode_scanlist[card_index].size();
 339                                 cards[card_index].capture->set_video_mode(mode_scanlist[card_index][mode_scanlist_index[card_index]]);
 340                                 last_mode_scan_change[card_index] = now;
 341                         }
 342                 }
 343         }
 344
 345         int64_t frame_length = int64_t(TIMEBASE) * video_format.frame_rate_den / video_format.frame_rate_nom;
 346         assert(frame_length > 0);
 347
 348         size_t num_samples = (audio_frame.len > audio_offset) ? (audio_frame.len - audio_offset) / audio_format.num_channels / (audio_format.bits_per_sample / 8) : 0;
 349         if (num_samples > OUTPUT_FREQUENCY / 10) {
 350                 printf("Card %d: Dropping frame with implausible audio length (len=%d, offset=%d) [timecode=0x%04x video_len=%d video_offset=%d video_format=%x)\n",
 351                         card_index, int(audio_frame.len), int(audio_offset),
 352                         timecode, int(video_frame.len), int(video_offset), video_format.id);
 353                 if (video_frame.owner) {
 354                         video_frame.owner->release_frame(video_frame);
 355                 }
 356                 if (audio_frame.owner) {
 357                         audio_frame.owner->release_frame(audio_frame);
 358                 }
 359                 return;
 360         }
 361
 362         int dropped_frames = 0;
 363         if (card->last_timecode != -1) {
 364                 dropped_frames = unwrap_timecode(timecode, card->last_timecode) - card->last_timecode - 1;
 365         }
 366
 367         // Number of samples per frame if we need to insert silence.
 368         // (Could be nonintegral, but resampling will save us then.)
 369         const int silence_samples = OUTPUT_FREQUENCY * video_format.frame_rate_den / video_format.frame_rate_nom;
 370
 371         if (dropped_frames > MAX_FPS * 2) {
 372                 fprintf(stderr, "Card %d lost more than two seconds (or time code jumping around; from 0x%04x to 0x%04x), resetting resampler\n",
 373                         card_index, card->last_timecode, timecode);
 374                 audio_mixer.reset_resampler(device);
 375                 dropped_frames = 0;
 376         } else if (dropped_frames > 0) {
 377                 // Insert silence as needed.
 378                 fprintf(stderr, "Card %d dropped %d frame(s) (before timecode 0x%04x), inserting silence.\n",
 379                         card_index, dropped_frames, timecode);
 380
 381                 bool success;
 382                 do {
 383                         success = audio_mixer.add_silence(device, silence_samples, dropped_frames, frame_length);
 384                 } while (!success);
 385         }
 386
 387         audio_mixer.add_audio(device, audio_frame.data + audio_offset, num_samples, audio_format, frame_length, audio_frame.received_timestamp);
 388
 389         // Done with the audio, so release it.
 390         if (audio_frame.owner) {
 391                 audio_frame.owner->release_frame(audio_frame);
 392         }
 393
 394         card->last_timecode = timecode;
 395
 396         size_t expected_length = video_format.width * (video_format.height + video_format.extra_lines_top + video_format.extra_lines_bottom) * 2;
 397         if (video_frame.len - video_offset == 0 ||
 398             video_frame.len - video_offset != expected_length) {
 399                 if (video_frame.len != 0) {
 400                         printf("Card %d: Dropping video frame with wrong length (%ld; expected %ld)\n",
 401                                 card_index, video_frame.len - video_offset, expected_length);
 402                 }
 403                 if (video_frame.owner) {
 404                         video_frame.owner->release_frame(video_frame);
 405                 }
 406
 407                 // Still send on the information that we _had_ a frame, even though it's corrupted,
 408                 // so that pts can go up accordingly.
 409                 {
 410                         unique_lock<mutex> lock(card_mutex);
 411                         CaptureCard::NewFrame new_frame;
 412                         new_frame.frame = RefCountedFrame(FrameAllocator::Frame());
 413                         new_frame.length = frame_length;
 414                         new_frame.interlaced = false;
 415                         new_frame.dropped_frames = dropped_frames;
 416                         card->new_frames.push_back(move(new_frame));
 417                         card->new_frames_changed.notify_all();
 418                 }
 419                 return;
 420         }
 421
 422         PBOFrameAllocator::Userdata *userdata = (PBOFrameAllocator::Userdata *)video_frame.userdata;
 423
 424         unsigned num_fields = video_format.interlaced ? 2 : 1;
 425         steady_clock::time_point frame_upload_start;
 426         bool interlaced_stride = false;
 427         if (video_format.interlaced) {
 428                 // Send the two fields along as separate frames; the other side will need to add
 429                 // a deinterlacer to actually get this right.
 430                 assert(video_format.height % 2 == 0);
 431                 video_format.height /= 2;
 432                 assert(frame_length % 2 == 0);
 433                 frame_length /= 2;
 434                 num_fields = 2;
 435                 if (video_format.second_field_start == 1) {
 436                         interlaced_stride = true;
 437                 }
 438                 frame_upload_start = steady_clock::now();
 439         }
 440         userdata->last_interlaced = video_format.interlaced;
 441         userdata->last_has_signal = video_format.has_signal;
 442         userdata->last_is_connected = video_format.is_connected;
 443         userdata->last_frame_rate_nom = video_format.frame_rate_nom;
 444         userdata->last_frame_rate_den = video_format.frame_rate_den;
 445         RefCountedFrame frame(video_frame);
 446
 447         // Upload the textures.
 448         size_t cbcr_width = video_format.width / 2;
 449         size_t cbcr_offset = video_offset / 2;
 450         size_t y_offset = video_frame.size / 2 + video_offset / 2;
 451
 452         for (unsigned field = 0; field < num_fields; ++field) {
 453                 // Put the actual texture upload in a lambda that is executed in the main thread.
 454                 // It is entirely possible to do this in the same thread (and it might even be
 455                 // faster, depending on the GPU and driver), but it appears to be trickling
 456                 // driver bugs very easily.
 457                 //
 458                 // Note that this means we must hold on to the actual frame data in <userdata>
 459                 // until the upload command is run, but we hold on to <frame> much longer than that
 460                 // (in fact, all the way until we no longer use the texture in rendering).
 461                 auto upload_func = [field, video_format, y_offset, cbcr_offset, cbcr_width, interlaced_stride, userdata]() {
 462                         unsigned field_start_line;
 463                         if (field == 1) {
 464                                 field_start_line = video_format.second_field_start;
 465                         } else {
 466                                 field_start_line = video_format.extra_lines_top;
 467                         }
 468
 469                         if (userdata->tex_y[field] == 0 ||
 470                             userdata->tex_cbcr[field] == 0 ||
 471                             video_format.width != userdata->last_width[field] ||
 472                             video_format.height != userdata->last_height[field]) {
 473                                 // We changed resolution since last use of this texture, so we need to create
 474                                 // a new object. Note that this each card has its own PBOFrameAllocator,
 475                                 // we don't need to worry about these flip-flopping between resolutions.
 476                                 glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr[field]);
 477                                 check_error();
 478                                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RG8, cbcr_width, video_format.height, 0, GL_RG, GL_UNSIGNED_BYTE, nullptr);
 479                                 check_error();
 480                                 glBindTexture(GL_TEXTURE_2D, userdata->tex_y[field]);
 481                                 check_error();
 482                                 glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, video_format.width, video_format.height, 0, GL_RED, GL_UNSIGNED_BYTE, nullptr);
 483                                 check_error();
 484                                 userdata->last_width[field] = video_format.width;
 485                                 userdata->last_height[field] = video_format.height;
 486                         }
 487
 488                         GLuint pbo = userdata->pbo;
 489                         check_error();
 490                         glBindBuffer(GL_PIXEL_UNPACK_BUFFER, pbo);
 491                         check_error();
 492
 493                         size_t field_y_start = y_offset + video_format.width * field_start_line;
 494                         size_t field_cbcr_start = cbcr_offset + cbcr_width * field_start_line * sizeof(uint16_t);
 495
 496                         if (global_flags.flush_pbos) {
 497                                 glFlushMappedBufferRange(GL_PIXEL_UNPACK_BUFFER, field_y_start, video_format.width * video_format.height);
 498                                 check_error();
 499                                 glFlushMappedBufferRange(GL_PIXEL_UNPACK_BUFFER, field_cbcr_start, cbcr_width * video_format.height * sizeof(uint16_t));
 500                                 check_error();
 501                         }
 502
 503                         glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr[field]);
 504                         check_error();
 505                         if (interlaced_stride) {
 506                                 glPixelStorei(GL_UNPACK_ROW_LENGTH, cbcr_width * 2);
 507                                 check_error();
 508                         } else {
 509                                 glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 510                                 check_error();
 511                         }
 512                         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, cbcr_width, video_format.height, GL_RG, GL_UNSIGNED_BYTE, BUFFER_OFFSET(field_cbcr_start));
 513                         check_error();
 514                         glBindTexture(GL_TEXTURE_2D, userdata->tex_y[field]);
 515                         check_error();
 516                         if (interlaced_stride) {
 517                                 glPixelStorei(GL_UNPACK_ROW_LENGTH, video_format.width * 2);
 518                                 check_error();
 519                         } else {
 520                                 glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 521                                 check_error();
 522                         }
 523                         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, video_format.width, video_format.height, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET(field_y_start));
 524                         check_error();
 525                         glBindTexture(GL_TEXTURE_2D, 0);
 526                         check_error();
 527                         glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
 528                         check_error();
 529                         glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 530                         check_error();
 531                 };
 532
 533                 if (field == 1) {
 534                         // Don't upload the second field as fast as we can; wait until
 535                         // the field time has approximately passed. (Otherwise, we could
 536                         // get timing jitter against the other sources, and possibly also
 537                         // against the video display, although the latter is not as critical.)
 538                         // This requires our system clock to be reasonably close to the
 539                         // video clock, but that's not an unreasonable assumption.
 540                         steady_clock::time_point second_field_start = frame_upload_start +
 541                                 nanoseconds(frame_length * 1000000000 / TIMEBASE);
 542                         this_thread::sleep_until(second_field_start);
 543                 }
 544
 545                 {
 546                         unique_lock<mutex> lock(card_mutex);
 547                         CaptureCard::NewFrame new_frame;
 548                         new_frame.frame = frame;
 549                         new_frame.length = frame_length;
 550                         new_frame.field = field;
 551                         new_frame.interlaced = video_format.interlaced;
 552                         new_frame.upload_func = upload_func;
 553                         new_frame.dropped_frames = dropped_frames;
 554                         new_frame.received_timestamp = video_frame.received_timestamp;  // Ignore the audio timestamp.
 555                         card->new_frames.push_back(move(new_frame));
 556                         card->new_frames_changed.notify_all();
 557                 }
 558         }
 559 }
 560
 561 void Mixer::bm_hotplug_add(libusb_device *dev)
 562 {
 563         lock_guard<mutex> lock(hotplug_mutex);
 564         hotplugged_cards.push_back(dev);
 565 }
 566
 567 void Mixer::bm_hotplug_remove(unsigned card_index)
 568 {
 569         cards[card_index].new_frames_changed.notify_all();
 570 }
 571
 572 void Mixer::thread_func()
 573 {
 574         pthread_setname_np(pthread_self(), "Mixer_OpenGL");
 575
 576         eglBindAPI(EGL_OPENGL_API);
 577         QOpenGLContext *context = create_context(mixer_surface);
 578         if (!make_current(context, mixer_surface)) {
 579                 printf("oops\n");
 580                 exit(1);
 581         }
 582
 583         // Start the actual capture. (We don't want to do it before we're actually ready
 584         // to process output frames.)
 585         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 586                 if (int(card_index) != output_card_index) {
 587                         cards[card_index].capture->start_bm_capture();
 588                 }
 589         }
 590
 591         steady_clock::time_point start, now;
 592         start = steady_clock::now();
 593
 594         int frame = 0;
 595         int stats_dropped_frames = 0;
 596
 597         while (!should_quit) {
 598                 if (desired_output_card_index != output_card_index) {
 599                         set_output_card_internal(desired_output_card_index);
 600                 }
 601                 if (output_card_index != -1 &&
 602                     desired_output_video_mode != output_video_mode) {
 603                         DeckLinkOutput *output = cards[output_card_index].output.get();
 604                         output->end_output();
 605                         desired_output_video_mode = output_video_mode = output->pick_video_mode(desired_output_video_mode);
 606                         output->start_output(desired_output_video_mode, pts_int);
 607                 }
 608
 609                 CaptureCard::NewFrame new_frames[MAX_VIDEO_CARDS];
 610                 bool has_new_frame[MAX_VIDEO_CARDS] = { false };
 611
 612                 bool master_card_is_output;
 613                 unsigned master_card_index;
 614                 if (output_card_index != -1) {
 615                         master_card_is_output = true;
 616                         master_card_index = output_card_index;
 617                 } else {
 618                         master_card_is_output = false;
 619                         master_card_index = theme->map_signal(master_clock_channel);
 620                         assert(master_card_index < num_cards);
 621                 }
 622
 623                 OutputFrameInfo output_frame_info = get_one_frame_from_each_card(master_card_index, master_card_is_output, new_frames, has_new_frame);
 624                 schedule_audio_resampling_tasks(output_frame_info.dropped_frames, output_frame_info.num_samples, output_frame_info.frame_duration, output_frame_info.is_preroll, output_frame_info.frame_timestamp);
 625                 stats_dropped_frames += output_frame_info.dropped_frames;
 626
 627                 handle_hotplugged_cards();
 628
 629                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 630                         if (card_index == master_card_index || !has_new_frame[card_index]) {
 631                                 continue;
 632                         }
 633                         if (new_frames[card_index].frame->len == 0) {
 634                                 ++new_frames[card_index].dropped_frames;
 635                         }
 636                         if (new_frames[card_index].dropped_frames > 0) {
 637                                 printf("Card %u dropped %d frames before this\n",
 638                                         card_index, int(new_frames[card_index].dropped_frames));
 639                         }
 640                 }
 641
 642                 // If the first card is reporting a corrupted or otherwise dropped frame,
 643                 // just increase the pts (skipping over this frame) and don't try to compute anything new.
 644                 if (!master_card_is_output && new_frames[master_card_index].frame->len == 0) {
 645                         ++stats_dropped_frames;
 646                         pts_int += new_frames[master_card_index].length;
 647                         continue;
 648                 }
 649
 650                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 651                         if (!has_new_frame[card_index] || new_frames[card_index].frame->len == 0)
 652                                 continue;
 653
 654                         CaptureCard::NewFrame *new_frame = &new_frames[card_index];
 655                         assert(new_frame->frame != nullptr);
 656                         insert_new_frame(new_frame->frame, new_frame->field, new_frame->interlaced, card_index, &input_state);
 657                         check_error();
 658
 659                         // The new texture might need uploading before use.
 660                         if (new_frame->upload_func) {
 661                                 new_frame->upload_func();
 662                                 new_frame->upload_func = nullptr;
 663                         }
 664                 }
 665
 666                 int64_t frame_duration = output_frame_info.frame_duration;
 667                 render_one_frame(frame_duration);
 668                 ++frame;
 669                 pts_int += frame_duration;
 670
 671                 now = steady_clock::now();
 672                 double elapsed = duration<double>(now - start).count();
 673                 if (frame % 100 == 0) {
 674                         printf("%d frames (%d dropped) in %.3f seconds = %.1f fps (%.1f ms/frame)",
 675                                 frame, stats_dropped_frames, elapsed, frame / elapsed,
 676                                 1e3 * elapsed / frame);
 677                 //      chain->print_phase_timing();
 678
 679                         // Check our memory usage, to see if we are close to our mlockall()
 680                         // limit (if at all set).
 681                         rusage used;
 682                         if (getrusage(RUSAGE_SELF, &used) == -1) {
 683                                 perror("getrusage(RUSAGE_SELF)");
 684                                 assert(false);
 685                         }
 686
 687                         if (uses_mlock) {
 688                                 rlimit limit;
 689                                 if (getrlimit(RLIMIT_MEMLOCK, &limit) == -1) {
 690                                         perror("getrlimit(RLIMIT_MEMLOCK)");
 691                                         assert(false);
 692                                 }
 693
 694                                 if (limit.rlim_cur == 0) {
 695                                         printf(", using %ld MB memory (locked)",
 696                                                 long(used.ru_maxrss / 1024));
 697                                 } else {
 698                                         printf(", using %ld / %ld MB lockable memory (%.1f%%)",
 699                                                 long(used.ru_maxrss / 1024),
 700                                                 long(limit.rlim_cur / 1048576),
 701                                                 float(100.0 * (used.ru_maxrss * 1024.0) / limit.rlim_cur));
 702                                 }
 703                         } else {
 704                                 printf(", using %ld MB memory (not locked)",
 705                                         long(used.ru_maxrss / 1024));
 706                         }
 707
 708                         printf("\n");
 709                 }
 710
 711
 712                 if (should_cut.exchange(false)) {  // Test and clear.
 713                         video_encoder->do_cut(frame);
 714                 }
 715
 716 #if 0
 717                 // Reset every 100 frames, so that local variations in frame times
 718                 // (especially for the first few frames, when the shaders are
 719                 // compiled etc.) don't make it hard to measure for the entire
 720                 // remaining duration of the program.
 721                 if (frame == 10000) {
 722                         frame = 0;
 723                         start = now;
 724                 }
 725 #endif
 726                 check_error();
 727         }
 728
 729         resource_pool->clean_context();
 730 }
 731
 732 bool Mixer::input_card_is_master_clock(unsigned card_index, unsigned master_card_index) const
 733 {
 734         if (output_card_index != -1) {
 735                 // The output card (ie., cards[output_card_index].output) is the master clock,
 736                 // so no input card (ie., cards[card_index].capture) is.
 737                 return false;
 738         }
 739         return (card_index == master_card_index);
 740 }
 741
 742 void Mixer::trim_queue(CaptureCard *card, unsigned card_index)
 743 {
 744         // Count the number of frames in the queue, including any frames
 745         // we dropped. It's hard to know exactly how we should deal with
 746         // dropped (corrupted) input frames; they don't help our goal of
 747         // avoiding starvation, but they still add to the problem of latency.
 748         // Since dropped frames is going to mean a bump in the signal anyway,
 749         // we err on the side of having more stable latency instead.
 750         unsigned queue_length = 0;
 751         for (const CaptureCard::NewFrame &frame : card->new_frames) {
 752                 queue_length += frame.dropped_frames + 1;
 753         }
 754         card->queue_length_policy.update_policy(queue_length);
 755
 756         // If needed, drop frames until the queue is below the safe limit.
 757         // We prefer to drop from the head, because all else being equal,
 758         // we'd like more recent frames (less latency).
 759         unsigned dropped_frames = 0;
 760         while (queue_length > card->queue_length_policy.get_safe_queue_length()) {
 761                 assert(!card->new_frames.empty());
 762                 assert(queue_length > card->new_frames.front().dropped_frames);
 763                 queue_length -= card->new_frames.front().dropped_frames;
 764
 765                 if (queue_length <= card->queue_length_policy.get_safe_queue_length()) {
 766                         // No need to drop anything.
 767                         break;
 768                 }
 769
 770                 card->new_frames.pop_front();
 771                 card->new_frames_changed.notify_all();
 772                 --queue_length;
 773                 ++dropped_frames;
 774         }
 775
 776         if (dropped_frames > 0) {
 777                 fprintf(stderr, "Card %u dropped %u frame(s) to keep latency down.\n",
 778                         card_index, dropped_frames);
 779         }
 780 }
 781
 782
 783 Mixer::OutputFrameInfo Mixer::get_one_frame_from_each_card(unsigned master_card_index, bool master_card_is_output, CaptureCard::NewFrame new_frames[MAX_VIDEO_CARDS], bool has_new_frame[MAX_VIDEO_CARDS])
 784 {
 785         OutputFrameInfo output_frame_info;
 786 start:
 787         unique_lock<mutex> lock(card_mutex, defer_lock);
 788         if (master_card_is_output) {
 789                 // Clocked to the output, so wait for it to be ready for the next frame.
 790                 cards[master_card_index].output->wait_for_frame(pts_int, &output_frame_info.dropped_frames, &output_frame_info.frame_duration, &output_frame_info.is_preroll, &output_frame_info.frame_timestamp);
 791                 lock.lock();
 792         } else {
 793                 // Wait for the master card to have a new frame.
 794                 // TODO: Add a timeout.
 795                 output_frame_info.is_preroll = false;
 796                 lock.lock();
 797                 cards[master_card_index].new_frames_changed.wait(lock, [this, master_card_index]{ return !cards[master_card_index].new_frames.empty() || cards[master_card_index].capture->get_disconnected(); });
 798         }
 799
 800         if (master_card_is_output) {
 801                 handle_hotplugged_cards();
 802         } else if (cards[master_card_index].new_frames.empty()) {
 803                 // We were woken up, but not due to a new frame. Deal with it
 804                 // and then restart.
 805                 assert(cards[master_card_index].capture->get_disconnected());
 806                 handle_hotplugged_cards();
 807                 goto start;
 808         }
 809
 810         if (!master_card_is_output) {
 811                 output_frame_info.frame_timestamp =
 812                         cards[master_card_index].new_frames.front().received_timestamp;
 813         }
 814
 815         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 816                 CaptureCard *card = &cards[card_index];
 817                 if (input_card_is_master_clock(card_index, master_card_index)) {
 818                         // We don't use the queue length policy for the master card,
 819                         // but we will if it stops being the master. Thus, clear out
 820                         // the policy in case we switch in the future.
 821                         card->queue_length_policy.reset(card_index);
 822                         assert(!card->new_frames.empty());
 823                 } else {
 824                         trim_queue(card, card_index);
 825                 }
 826                 if (!card->new_frames.empty()) {
 827                         new_frames[card_index] = move(card->new_frames.front());
 828                         has_new_frame[card_index] = true;
 829                         card->new_frames.pop_front();
 830                         card->new_frames_changed.notify_all();
 831                 }
 832         }
 833
 834         if (!master_card_is_output) {
 835                 output_frame_info.dropped_frames = new_frames[master_card_index].dropped_frames;
 836                 output_frame_info.frame_duration = new_frames[master_card_index].length;
 837         }
 838
 839         // This might get off by a fractional sample when changing master card
 840         // between ones with different frame rates, but that's fine.
 841         int num_samples_times_timebase = OUTPUT_FREQUENCY * output_frame_info.frame_duration + fractional_samples;
 842         output_frame_info.num_samples = num_samples_times_timebase / TIMEBASE;
 843         fractional_samples = num_samples_times_timebase % TIMEBASE;
 844         assert(output_frame_info.num_samples >= 0);
 845
 846         return output_frame_info;
 847 }
 848
 849 void Mixer::handle_hotplugged_cards()
 850 {
 851         // Check for cards that have been disconnected since last frame.
 852         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 853                 CaptureCard *card = &cards[card_index];
 854                 if (card->capture->get_disconnected()) {
 855                         fprintf(stderr, "Card %u went away, replacing with a fake card.\n", card_index);
 856                         FakeCapture *capture = new FakeCapture(global_flags.width, global_flags.height, FAKE_FPS, OUTPUT_FREQUENCY, card_index, global_flags.fake_cards_audio);
 857                         configure_card(card_index, capture, /*is_fake_capture=*/true, /*output=*/nullptr);
 858                         card->queue_length_policy.reset(card_index);
 859                         card->capture->start_bm_capture();
 860                 }
 861         }
 862
 863         // Check for cards that have been connected since last frame.
 864         vector<libusb_device *> hotplugged_cards_copy;
 865         {
 866                 lock_guard<mutex> lock(hotplug_mutex);
 867                 swap(hotplugged_cards, hotplugged_cards_copy);
 868         }
 869         for (libusb_device *new_dev : hotplugged_cards_copy) {
 870                 // Look for a fake capture card where we can stick this in.
 871                 int free_card_index = -1;
 872                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 873                         if (cards[card_index].is_fake_capture) {
 874                                 free_card_index = card_index;
 875                                 break;
 876                         }
 877                 }
 878
 879                 if (free_card_index == -1) {
 880                         fprintf(stderr, "New card plugged in, but no free slots -- ignoring.\n");
 881                         libusb_unref_device(new_dev);
 882                 } else {
 883                         // BMUSBCapture takes ownership.
 884                         fprintf(stderr, "New card plugged in, choosing slot %d.\n", free_card_index);
 885                         CaptureCard *card = &cards[free_card_index];
 886                         BMUSBCapture *capture = new BMUSBCapture(free_card_index, new_dev);
 887                         configure_card(free_card_index, capture, /*is_fake_capture=*/false, /*output=*/nullptr);
 888                         card->queue_length_policy.reset(free_card_index);
 889                         capture->set_card_disconnected_callback(bind(&Mixer::bm_hotplug_remove, this, free_card_index));
 890                         capture->start_bm_capture();
 891                 }
 892         }
 893 }
 894
 895
 896 void Mixer::schedule_audio_resampling_tasks(unsigned dropped_frames, int num_samples_per_frame, int length_per_frame, bool is_preroll, steady_clock::time_point frame_timestamp)
 897 {
 898         // Resample the audio as needed, including from previously dropped frames.
 899         assert(num_cards > 0);
 900         for (unsigned frame_num = 0; frame_num < dropped_frames + 1; ++frame_num) {
 901                 const bool dropped_frame = (frame_num != dropped_frames);
 902                 {
 903                         // Signal to the audio thread to process this frame.
 904                         // Note that if the frame is a dropped frame, we signal that
 905                         // we don't want to use this frame as base for adjusting
 906                         // the resampler rate. The reason for this is that the timing
 907                         // of these frames is often way too late; they typically don't
 908                         // “arrive” before we synthesize them. Thus, we could end up
 909                         // in a situation where we have inserted e.g. five audio frames
 910                         // into the queue before we then start pulling five of them
 911                         // back out. This makes ResamplingQueue overestimate the delay,
 912                         // causing undue resampler changes. (We _do_ use the last,
 913                         // non-dropped frame; perhaps we should just discard that as well,
 914                         // since dropped frames are expected to be rare, and it might be
 915                         // better to just wait until we have a slightly more normal situation).
 916                         unique_lock<mutex> lock(audio_mutex);
 917                         bool adjust_rate = !dropped_frame && !is_preroll;
 918                         audio_task_queue.push(AudioTask{pts_int, num_samples_per_frame, adjust_rate, frame_timestamp});
 919                         audio_task_queue_changed.notify_one();
 920                 }
 921                 if (dropped_frame) {
 922                         // For dropped frames, increase the pts. Note that if the format changed
 923                         // in the meantime, we have no way of detecting that; we just have to
 924                         // assume the frame length is always the same.
 925                         pts_int += length_per_frame;
 926                 }
 927         }
 928 }
 929
 930 void Mixer::render_one_frame(int64_t duration)
 931 {
 932         // Get the main chain from the theme, and set its state immediately.
 933         Theme::Chain theme_main_chain = theme->get_chain(0, pts(), global_flags.width, global_flags.height, input_state);
 934         EffectChain *chain = theme_main_chain.chain;
 935         theme_main_chain.setup_chain();
 936         //theme_main_chain.chain->enable_phase_timing(true);
 937
 938         GLuint y_tex, cbcr_tex;
 939         bool got_frame = video_encoder->begin_frame(&y_tex, &cbcr_tex);
 940         assert(got_frame);
 941
 942         // Render main chain.
 943         GLuint cbcr_full_tex = resource_pool->create_2d_texture(GL_RG8, global_flags.width, global_flags.height);
 944         GLuint rgba_tex = resource_pool->create_2d_texture(GL_RGB565, global_flags.width, global_flags.height);  // Saves texture bandwidth, although dithering gets messed up.
 945         GLuint fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex, rgba_tex);
 946         check_error();
 947         chain->render_to_fbo(fbo, global_flags.width, global_flags.height);
 948         resource_pool->release_fbo(fbo);
 949
 950         chroma_subsampler->subsample_chroma(cbcr_full_tex, global_flags.width, global_flags.height, cbcr_tex);
 951         if (output_card_index != -1) {
 952                 cards[output_card_index].output->send_frame(y_tex, cbcr_full_tex, theme_main_chain.input_frames, pts_int, duration);
 953         }
 954         resource_pool->release_2d_texture(cbcr_full_tex);
 955
 956         // Set the right state for rgba_tex.
 957         glBindFramebuffer(GL_FRAMEBUFFER, 0);
 958         glBindTexture(GL_TEXTURE_2D, rgba_tex);
 959         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 960         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 961         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 962
 963         const int64_t av_delay = lrint(global_flags.audio_queue_length_ms * 0.001 * TIMEBASE);  // Corresponds to the delay in ResamplingQueue.
 964         RefCountedGLsync fence = video_encoder->end_frame(pts_int + av_delay, duration, theme_main_chain.input_frames);
 965
 966         // The live frame just shows the RGBA texture we just rendered.
 967         // It owns rgba_tex now.
 968         DisplayFrame live_frame;
 969         live_frame.chain = display_chain.get();
 970         live_frame.setup_chain = [this, rgba_tex]{
 971                 display_input->set_texture_num(rgba_tex);
 972         };
 973         live_frame.ready_fence = fence;
 974         live_frame.input_frames = {};
 975         live_frame.temp_textures = { rgba_tex };
 976         output_channel[OUTPUT_LIVE].output_frame(live_frame);
 977
 978         // Set up preview and any additional channels.
 979         for (int i = 1; i < theme->get_num_channels() + 2; ++i) {
 980                 DisplayFrame display_frame;
 981                 Theme::Chain chain = theme->get_chain(i, pts(), global_flags.width, global_flags.height, input_state);  // FIXME: dimensions
 982                 display_frame.chain = chain.chain;
 983                 display_frame.setup_chain = chain.setup_chain;
 984                 display_frame.ready_fence = fence;
 985                 display_frame.input_frames = chain.input_frames;
 986                 display_frame.temp_textures = {};
 987                 output_channel[i].output_frame(display_frame);
 988         }
 989 }
 990
 991 void Mixer::audio_thread_func()
 992 {
 993         pthread_setname_np(pthread_self(), "Mixer_Audio");
 994
 995         while (!should_quit) {
 996                 AudioTask task;
 997
 998                 {
 999                         unique_lock<mutex> lock(audio_mutex);
1000                         audio_task_queue_changed.wait(lock, [this]{ return should_quit || !audio_task_queue.empty(); });
1001                         if (should_quit) {
1002                                 return;
1003                         }
1004                         task = audio_task_queue.front();
1005                         audio_task_queue.pop();
1006                 }
1007
1008                 ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy =
1009                         task.adjust_rate ? ResamplingQueue::ADJUST_RATE : ResamplingQueue::DO_NOT_ADJUST_RATE;
1010                 vector<float> samples_out = audio_mixer.get_output(
1011                         task.frame_timestamp,
1012                         task.num_samples,
1013                         rate_adjustment_policy);
1014
1015                 // Send the samples to the sound card, then add them to the output.
1016                 if (alsa) {
1017                         alsa->write(samples_out);
1018                 }
1019                 if (output_card_index != -1) {
1020                         const int64_t av_delay = lrint(global_flags.audio_queue_length_ms * 0.001 * TIMEBASE);  // Corresponds to the delay in ResamplingQueue.
1021                         cards[output_card_index].output->send_audio(task.pts_int + av_delay, samples_out);
1022                 }
1023                 video_encoder->add_audio(task.pts_int, move(samples_out));
1024         }
1025 }
1026
1027 void Mixer::release_display_frame(DisplayFrame *frame)
1028 {
1029         for (GLuint texnum : frame->temp_textures) {
1030                 resource_pool->release_2d_texture(texnum);
1031         }
1032         frame->temp_textures.clear();
1033         frame->ready_fence.reset();
1034         frame->input_frames.clear();
1035 }
1036
1037 void Mixer::start()
1038 {
1039         mixer_thread = thread(&Mixer::thread_func, this);
1040         audio_thread = thread(&Mixer::audio_thread_func, this);
1041 }
1042
1043 void Mixer::quit()
1044 {
1045         should_quit = true;
1046         audio_task_queue_changed.notify_one();
1047         mixer_thread.join();
1048         audio_thread.join();
1049 }
1050
1051 void Mixer::transition_clicked(int transition_num)
1052 {
1053         theme->transition_clicked(transition_num, pts());
1054 }
1055
1056 void Mixer::channel_clicked(int preview_num)
1057 {
1058         theme->channel_clicked(preview_num);
1059 }
1060
1061 void Mixer::start_mode_scanning(unsigned card_index)
1062 {
1063         assert(card_index < num_cards);
1064         if (is_mode_scanning[card_index]) {
1065                 return;
1066         }
1067         is_mode_scanning[card_index] = true;
1068         mode_scanlist[card_index].clear();
1069         for (const auto &mode : cards[card_index].capture->get_available_video_modes()) {
1070                 mode_scanlist[card_index].push_back(mode.first);
1071         }
1072         assert(!mode_scanlist[card_index].empty());
1073         mode_scanlist_index[card_index] = 0;
1074         cards[card_index].capture->set_video_mode(mode_scanlist[card_index][0]);
1075         last_mode_scan_change[card_index] = steady_clock::now();
1076 }
1077
1078 map<uint32_t, bmusb::VideoMode> Mixer::get_available_output_video_modes() const
1079 {
1080         assert(desired_output_card_index != -1);
1081         unique_lock<mutex> lock(card_mutex);
1082         return cards[desired_output_card_index].output->get_available_video_modes();
1083 }
1084
1085 Mixer::OutputChannel::~OutputChannel()
1086 {
1087         if (has_current_frame) {
1088                 parent->release_display_frame(&current_frame);
1089         }
1090         if (has_ready_frame) {
1091                 parent->release_display_frame(&ready_frame);
1092         }
1093 }
1094
1095 void Mixer::OutputChannel::output_frame(DisplayFrame frame)
1096 {
1097         // Store this frame for display. Remove the ready frame if any
1098         // (it was seemingly never used).
1099         {
1100                 unique_lock<mutex> lock(frame_mutex);
1101                 if (has_ready_frame) {
1102                         parent->release_display_frame(&ready_frame);
1103                 }
1104                 ready_frame = frame;
1105                 has_ready_frame = true;
1106         }
1107
1108         if (new_frame_ready_callback) {
1109                 new_frame_ready_callback();
1110         }
1111
1112         // Reduce the number of callbacks by filtering duplicates. The reason
1113         // why we bother doing this is that Qt seemingly can get into a state
1114         // where its builds up an essentially unbounded queue of signals,
1115         // consuming more and more memory, and there's no good way of collapsing
1116         // user-defined signals or limiting the length of the queue.
1117         if (transition_names_updated_callback) {
1118                 vector<string> transition_names = global_mixer->get_transition_names();
1119                 bool changed = false;
1120                 if (transition_names.size() != last_transition_names.size()) {
1121                         changed = true;
1122                 } else {
1123                         for (unsigned i = 0; i < transition_names.size(); ++i) {
1124                                 if (transition_names[i] != last_transition_names[i]) {
1125                                         changed = true;
1126                                         break;
1127                                 }
1128                         }
1129                 }
1130                 if (changed) {
1131                         transition_names_updated_callback(transition_names);
1132                         last_transition_names = transition_names;
1133                 }
1134         }
1135         if (name_updated_callback) {
1136                 string name = global_mixer->get_channel_name(channel);
1137                 if (name != last_name) {
1138                         name_updated_callback(name);
1139                         last_name = name;
1140                 }
1141         }
1142         if (color_updated_callback) {
1143                 string color = global_mixer->get_channel_color(channel);
1144                 if (color != last_color) {
1145                         color_updated_callback(color);
1146                         last_color = color;
1147                 }
1148         }
1149 }
1150
1151 bool Mixer::OutputChannel::get_display_frame(DisplayFrame *frame)
1152 {
1153         unique_lock<mutex> lock(frame_mutex);
1154         if (!has_current_frame && !has_ready_frame) {
1155                 return false;
1156         }
1157
1158         if (has_current_frame && has_ready_frame) {
1159                 // We have a new ready frame. Toss the current one.
1160                 parent->release_display_frame(&current_frame);
1161                 has_current_frame = false;
1162         }
1163         if (has_ready_frame) {
1164                 assert(!has_current_frame);
1165                 current_frame = ready_frame;
1166                 ready_frame.ready_fence.reset();  // Drop the refcount.
1167                 ready_frame.input_frames.clear();  // Drop the refcounts.
1168                 has_current_frame = true;
1169                 has_ready_frame = false;
1170         }
1171
1172         *frame = current_frame;
1173         return true;
1174 }
1175
1176 void Mixer::OutputChannel::set_frame_ready_callback(Mixer::new_frame_ready_callback_t callback)
1177 {
1178         new_frame_ready_callback = callback;
1179 }
1180
1181 void Mixer::OutputChannel::set_transition_names_updated_callback(Mixer::transition_names_updated_callback_t callback)
1182 {
1183         transition_names_updated_callback = callback;
1184 }
1185
1186 void Mixer::OutputChannel::set_name_updated_callback(Mixer::name_updated_callback_t callback)
1187 {
1188         name_updated_callback = callback;
1189 }
1190
1191 void Mixer::OutputChannel::set_color_updated_callback(Mixer::color_updated_callback_t callback)
1192 {
1193         color_updated_callback = callback;
1194 }
1195
1196 mutex RefCountedGLsync::fence_lock;