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 "timecode_renderer.h"
  49 #include "v210_converter.h"
  50 #include "video_encoder.h"
  51
  52 class IDeckLink;
  53 class QOpenGLContext;
  54
  55 using namespace movit;
  56 using namespace std;
  57 using namespace std::chrono;
  58 using namespace std::placeholders;
  59 using namespace bmusb;
  60
  61 Mixer *global_mixer = nullptr;
  62 bool uses_mlock = false;
  63
  64 namespace {
  65
  66 void insert_new_frame(RefCountedFrame frame, unsigned field_num, bool interlaced, unsigned card_index, InputState *input_state)
  67 {
  68         if (interlaced) {
  69                 for (unsigned frame_num = FRAME_HISTORY_LENGTH; frame_num --> 1; ) {  // :-)
  70                         input_state->buffered_frames[card_index][frame_num] =
  71                                 input_state->buffered_frames[card_index][frame_num - 1];
  72                 }
  73                 input_state->buffered_frames[card_index][0] = { frame, field_num };
  74         } else {
  75                 for (unsigned frame_num = 0; frame_num < FRAME_HISTORY_LENGTH; ++frame_num) {
  76                         input_state->buffered_frames[card_index][frame_num] = { frame, field_num };
  77                 }
  78         }
  79 }
  80
  81 void ensure_texture_resolution(PBOFrameAllocator::Userdata *userdata, unsigned field, unsigned width, unsigned height, unsigned v210_width)
  82 {
  83         bool first;
  84         if (global_flags.ten_bit_input) {
  85                 first = userdata->tex_v210[field] == 0 || userdata->tex_444[field] == 0;
  86         } else {
  87                 first = userdata->tex_y[field] == 0 || userdata->tex_cbcr[field] == 0;
  88         }
  89
  90         if (first ||
  91             width != userdata->last_width[field] ||
  92             height != userdata->last_height[field]) {
  93                 // We changed resolution since last use of this texture, so we need to create
  94                 // a new object. Note that this each card has its own PBOFrameAllocator,
  95                 // we don't need to worry about these flip-flopping between resolutions.
  96                 if (global_flags.ten_bit_input) {
  97                         glBindTexture(GL_TEXTURE_2D, userdata->tex_444[field]);
  98                         check_error();
  99                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB10_A2, width, height, 0, GL_RGBA, GL_UNSIGNED_INT_2_10_10_10_REV, nullptr);
 100                         check_error();
 101                 } else {
 102                         size_t cbcr_width = width / 2;
 103
 104                         glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr[field]);
 105                         check_error();
 106                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RG8, cbcr_width, height, 0, GL_RG, GL_UNSIGNED_BYTE, nullptr);
 107                         check_error();
 108                         glBindTexture(GL_TEXTURE_2D, userdata->tex_y[field]);
 109                         check_error();
 110                         glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, width, height, 0, GL_RED, GL_UNSIGNED_BYTE, nullptr);
 111                         check_error();
 112                 }
 113                 userdata->last_width[field] = width;
 114                 userdata->last_height[field] = height;
 115         }
 116         if (global_flags.ten_bit_input &&
 117             (first || v210_width != userdata->last_v210_width[field])) {
 118                 // Same as above; we need to recreate the texture.
 119                 glBindTexture(GL_TEXTURE_2D, userdata->tex_v210[field]);
 120                 check_error();
 121                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB10_A2, v210_width, height, 0, GL_RGBA, GL_UNSIGNED_INT_2_10_10_10_REV, nullptr);
 122                 check_error();
 123                 userdata->last_v210_width[field] = v210_width;
 124         }
 125 }
 126
 127 void upload_texture(GLuint tex, GLuint width, GLuint height, GLuint stride, bool interlaced_stride, GLenum format, GLenum type, GLintptr offset)
 128 {
 129         if (interlaced_stride) {
 130                 stride *= 2;
 131         }
 132         if (global_flags.flush_pbos) {
 133                 glFlushMappedBufferRange(GL_PIXEL_UNPACK_BUFFER, offset, stride * height);
 134                 check_error();
 135         }
 136
 137         glBindTexture(GL_TEXTURE_2D, tex);
 138         check_error();
 139         if (interlaced_stride) {
 140                 glPixelStorei(GL_UNPACK_ROW_LENGTH, width * 2);
 141                 check_error();
 142         } else {
 143                 glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 144                 check_error();
 145         }
 146
 147         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, type, BUFFER_OFFSET(offset));
 148         check_error();
 149         glBindTexture(GL_TEXTURE_2D, 0);
 150         check_error();
 151         glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 152         check_error();
 153 }
 154
 155 }  // namespace
 156
 157 void QueueLengthPolicy::update_policy(unsigned queue_length)
 158 {
 159         if (queue_length == 0) {  // Starvation.
 160                 if (been_at_safe_point_since_last_starvation && safe_queue_length < unsigned(global_flags.max_input_queue_frames)) {
 161                         ++safe_queue_length;
 162                         fprintf(stderr, "Card %u: Starvation, increasing safe limit to %u frame(s)\n",
 163                                 card_index, safe_queue_length);
 164                 }
 165                 frames_with_at_least_one = 0;
 166                 been_at_safe_point_since_last_starvation = false;
 167                 return;
 168         }
 169         if (queue_length >= safe_queue_length) {
 170                 been_at_safe_point_since_last_starvation = true;
 171         }
 172         if (++frames_with_at_least_one >= 1000 && safe_queue_length > 1) {
 173                 --safe_queue_length;
 174                 fprintf(stderr, "Card %u: Spare frames for more than 1000 frames, reducing safe limit to %u frame(s)\n",
 175                         card_index, safe_queue_length);
 176                 frames_with_at_least_one = 0;
 177         }
 178 }
 179
 180 Mixer::Mixer(const QSurfaceFormat &format, unsigned num_cards)
 181         : httpd(),
 182           num_cards(num_cards),
 183           mixer_surface(create_surface(format)),
 184           h264_encoder_surface(create_surface(format)),
 185           decklink_output_surface(create_surface(format)),
 186           audio_mixer(num_cards)
 187 {
 188         CHECK(init_movit(MOVIT_SHADER_DIR, MOVIT_DEBUG_OFF));
 189         check_error();
 190
 191         // Since we allow non-bouncing 4:2:2 YCbCrInputs, effective subpixel precision
 192         // will be halved when sampling them, and we need to compensate here.
 193         movit_texel_subpixel_precision /= 2.0;
 194
 195         resource_pool.reset(new ResourcePool);
 196         theme.reset(new Theme(global_flags.theme_filename, global_flags.theme_dirs, resource_pool.get(), num_cards));
 197         for (unsigned i = 0; i < NUM_OUTPUTS; ++i) {
 198                 output_channel[i].parent = this;
 199                 output_channel[i].channel = i;
 200         }
 201
 202         ImageFormat inout_format;
 203         inout_format.color_space = COLORSPACE_sRGB;
 204         inout_format.gamma_curve = GAMMA_sRGB;
 205
 206         // Display chain; shows the live output produced by the main chain (its RGBA version).
 207         display_chain.reset(new EffectChain(global_flags.width, global_flags.height, resource_pool.get()));
 208         check_error();
 209         display_input = new FlatInput(inout_format, FORMAT_RGB, GL_UNSIGNED_BYTE, global_flags.width, global_flags.height);  // FIXME: GL_UNSIGNED_BYTE is really wrong.
 210         display_chain->add_input(display_input);
 211         display_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
 212         display_chain->set_dither_bits(0);  // Don't bother.
 213         display_chain->finalize();
 214
 215         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));
 216
 217         // Start listening for clients only once VideoEncoder has written its header, if any.
 218         httpd.start(9095);
 219
 220         // First try initializing the then PCI devices, then USB, then
 221         // fill up with fake cards until we have the desired number of cards.
 222         unsigned num_pci_devices = 0;
 223         unsigned card_index = 0;
 224
 225         {
 226                 IDeckLinkIterator *decklink_iterator = CreateDeckLinkIteratorInstance();
 227                 if (decklink_iterator != nullptr) {
 228                         for ( ; card_index < num_cards; ++card_index) {
 229                                 IDeckLink *decklink;
 230                                 if (decklink_iterator->Next(&decklink) != S_OK) {
 231                                         break;
 232                                 }
 233
 234                                 DeckLinkCapture *capture = new DeckLinkCapture(decklink, card_index);
 235                                 DeckLinkOutput *output = new DeckLinkOutput(resource_pool.get(), decklink_output_surface, global_flags.width, global_flags.height, card_index);
 236                                 output->set_device(decklink);
 237                                 configure_card(card_index, capture, /*is_fake_capture=*/false, output);
 238                                 ++num_pci_devices;
 239                         }
 240                         decklink_iterator->Release();
 241                         fprintf(stderr, "Found %u DeckLink PCI card(s).\n", num_pci_devices);
 242                 } else {
 243                         fprintf(stderr, "DeckLink drivers not found. Probing for USB cards only.\n");
 244                 }
 245         }
 246
 247         unsigned num_usb_devices = BMUSBCapture::num_cards();
 248         for (unsigned usb_card_index = 0; usb_card_index < num_usb_devices && card_index < num_cards; ++usb_card_index, ++card_index) {
 249                 BMUSBCapture *capture = new BMUSBCapture(usb_card_index);
 250                 capture->set_card_disconnected_callback(bind(&Mixer::bm_hotplug_remove, this, card_index));
 251                 configure_card(card_index, capture, /*is_fake_capture=*/false, /*output=*/nullptr);
 252         }
 253         fprintf(stderr, "Found %u USB card(s).\n", num_usb_devices);
 254
 255         unsigned num_fake_cards = 0;
 256         for ( ; card_index < num_cards; ++card_index, ++num_fake_cards) {
 257                 FakeCapture *capture = new FakeCapture(global_flags.width, global_flags.height, FAKE_FPS, OUTPUT_FREQUENCY, card_index, global_flags.fake_cards_audio);
 258                 configure_card(card_index, capture, /*is_fake_capture=*/true, /*output=*/nullptr);
 259         }
 260
 261         if (num_fake_cards > 0) {
 262                 fprintf(stderr, "Initialized %u fake cards.\n", num_fake_cards);
 263         }
 264
 265         BMUSBCapture::set_card_connected_callback(bind(&Mixer::bm_hotplug_add, this, _1));
 266         BMUSBCapture::start_bm_thread();
 267
 268         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 269                 cards[card_index].queue_length_policy.reset(card_index);
 270         }
 271
 272         chroma_subsampler.reset(new ChromaSubsampler(resource_pool.get()));
 273
 274         if (global_flags.ten_bit_input) {
 275                 if (!v210Converter::has_hardware_support()) {
 276                         fprintf(stderr, "ERROR: --ten-bit-input requires support for OpenGL compute shaders\n");
 277                         fprintf(stderr, "       (OpenGL 4.3, or GL_ARB_compute_shader + GL_ARB_shader_image_load_store).\n");
 278                         exit(1);
 279                 }
 280                 v210_converter.reset(new v210Converter());
 281
 282                 // These are all the widths listed in the Blackmagic SDK documentation
 283                 // (section 2.7.3, “Display Modes”).
 284                 v210_converter->precompile_shader(720);
 285                 v210_converter->precompile_shader(1280);
 286                 v210_converter->precompile_shader(1920);
 287                 v210_converter->precompile_shader(2048);
 288                 v210_converter->precompile_shader(3840);
 289                 v210_converter->precompile_shader(4096);
 290         }
 291
 292         timecode_renderer.reset(new TimecodeRenderer(resource_pool.get(), global_flags.width, global_flags.height));
 293         display_timecode_in_stream = global_flags.display_timecode_in_stream;
 294         display_timecode_on_stdout = global_flags.display_timecode_on_stdout;
 295
 296         if (global_flags.enable_alsa_output) {
 297                 alsa.reset(new ALSAOutput(OUTPUT_FREQUENCY, /*num_channels=*/2));
 298         }
 299         if (global_flags.output_card != -1) {
 300                 desired_output_card_index = global_flags.output_card;
 301                 set_output_card_internal(global_flags.output_card);
 302         }
 303 }
 304
 305 Mixer::~Mixer()
 306 {
 307         BMUSBCapture::stop_bm_thread();
 308
 309         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 310                 {
 311                         unique_lock<mutex> lock(card_mutex);
 312                         cards[card_index].should_quit = true;  // Unblock thread.
 313                         cards[card_index].new_frames_changed.notify_all();
 314                 }
 315                 cards[card_index].capture->stop_dequeue_thread();
 316                 if (cards[card_index].output) {
 317                         cards[card_index].output->end_output();
 318                         cards[card_index].output.reset();
 319                 }
 320         }
 321
 322         video_encoder.reset(nullptr);
 323 }
 324
 325 void Mixer::configure_card(unsigned card_index, CaptureInterface *capture, bool is_fake_capture, DeckLinkOutput *output)
 326 {
 327         printf("Configuring card %d...\n", card_index);
 328
 329         CaptureCard *card = &cards[card_index];
 330         if (card->capture != nullptr) {
 331                 card->capture->stop_dequeue_thread();
 332         }
 333         card->capture.reset(capture);
 334         card->is_fake_capture = is_fake_capture;
 335         if (card->output.get() != output) {
 336                 card->output.reset(output);
 337         }
 338         card->capture->set_frame_callback(bind(&Mixer::bm_frame, this, card_index, _1, _2, _3, _4, _5, _6, _7));
 339         if (card->frame_allocator == nullptr) {
 340                 card->frame_allocator.reset(new PBOFrameAllocator(8 << 20, global_flags.width, global_flags.height));  // 8 MB.
 341         }
 342         card->capture->set_video_frame_allocator(card->frame_allocator.get());
 343         if (card->surface == nullptr) {
 344                 card->surface = create_surface_with_same_format(mixer_surface);
 345         }
 346         while (!card->new_frames.empty()) card->new_frames.pop_front();
 347         card->last_timecode = -1;
 348         card->capture->set_pixel_format(global_flags.ten_bit_input ? PixelFormat_10BitYCbCr : PixelFormat_8BitYCbCr);
 349         card->capture->configure_card();
 350
 351         // NOTE: start_bm_capture() happens in thread_func().
 352
 353         DeviceSpec device{InputSourceType::CAPTURE_CARD, card_index};
 354         audio_mixer.reset_resampler(device);
 355         audio_mixer.set_display_name(device, card->capture->get_description());
 356         audio_mixer.trigger_state_changed_callback();
 357 }
 358
 359 void Mixer::set_output_card_internal(int card_index)
 360 {
 361         // We don't really need to take card_mutex, since we're in the mixer
 362         // thread and don't mess with any queues (which is the only thing that happens
 363         // from other threads), but it's probably the safest in the long run.
 364         unique_lock<mutex> lock(card_mutex);
 365         if (output_card_index != -1) {
 366                 // Switch the old card from output to input.
 367                 CaptureCard *old_card = &cards[output_card_index];
 368                 old_card->output->end_output();
 369
 370                 // Stop the fake card that we put into place.
 371                 // This needs to _not_ happen under the mutex, to avoid deadlock
 372                 // (delivering the last frame needs to take the mutex).
 373                 bmusb::CaptureInterface *fake_capture = old_card->capture.get();
 374                 lock.unlock();
 375                 fake_capture->stop_dequeue_thread();
 376                 lock.lock();
 377                 old_card->capture = move(old_card->parked_capture);
 378                 old_card->is_fake_capture = false;
 379                 old_card->capture->start_bm_capture();
 380         }
 381         if (card_index != -1) {
 382                 CaptureCard *card = &cards[card_index];
 383                 bmusb::CaptureInterface *capture = card->capture.get();
 384                 // TODO: DeckLinkCapture::stop_dequeue_thread can actually take
 385                 // several seconds to complete (blocking on DisableVideoInput);
 386                 // see if we can maybe do it asynchronously.
 387                 lock.unlock();
 388                 capture->stop_dequeue_thread();
 389                 lock.lock();
 390                 card->parked_capture = move(card->capture);
 391                 bmusb::CaptureInterface *fake_capture = new FakeCapture(global_flags.width, global_flags.height, FAKE_FPS, OUTPUT_FREQUENCY, card_index, global_flags.fake_cards_audio);
 392                 configure_card(card_index, fake_capture, /*is_fake_capture=*/true, card->output.release());
 393                 card->queue_length_policy.reset(card_index);
 394                 card->capture->start_bm_capture();
 395                 desired_output_video_mode = output_video_mode = card->output->pick_video_mode(desired_output_video_mode);
 396                 card->output->start_output(desired_output_video_mode, pts_int);
 397         }
 398         output_card_index = card_index;
 399 }
 400
 401 namespace {
 402
 403 int unwrap_timecode(uint16_t current_wrapped, int last)
 404 {
 405         uint16_t last_wrapped = last & 0xffff;
 406         if (current_wrapped > last_wrapped) {
 407                 return (last & ~0xffff) | current_wrapped;
 408         } else {
 409                 return 0x10000 + ((last & ~0xffff) | current_wrapped);
 410         }
 411 }
 412
 413 }  // namespace
 414
 415 void Mixer::bm_frame(unsigned card_index, uint16_t timecode,
 416                      FrameAllocator::Frame video_frame, size_t video_offset, VideoFormat video_format,
 417                      FrameAllocator::Frame audio_frame, size_t audio_offset, AudioFormat audio_format)
 418 {
 419         DeviceSpec device{InputSourceType::CAPTURE_CARD, card_index};
 420         CaptureCard *card = &cards[card_index];
 421
 422         if (is_mode_scanning[card_index]) {
 423                 if (video_format.has_signal) {
 424                         // Found a stable signal, so stop scanning.
 425                         is_mode_scanning[card_index] = false;
 426                 } else {
 427                         static constexpr double switch_time_s = 0.1;  // Should be enough time for the signal to stabilize.
 428                         steady_clock::time_point now = steady_clock::now();
 429                         double sec_since_last_switch = duration<double>(steady_clock::now() - last_mode_scan_change[card_index]).count();
 430                         if (sec_since_last_switch > switch_time_s) {
 431                                 // It isn't this mode; try the next one.
 432                                 mode_scanlist_index[card_index]++;
 433                                 mode_scanlist_index[card_index] %= mode_scanlist[card_index].size();
 434                                 cards[card_index].capture->set_video_mode(mode_scanlist[card_index][mode_scanlist_index[card_index]]);
 435                                 last_mode_scan_change[card_index] = now;
 436                         }
 437                 }
 438         }
 439
 440         int64_t frame_length = int64_t(TIMEBASE) * video_format.frame_rate_den / video_format.frame_rate_nom;
 441         assert(frame_length > 0);
 442
 443         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;
 444         if (num_samples > OUTPUT_FREQUENCY / 10) {
 445                 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",
 446                         card_index, int(audio_frame.len), int(audio_offset),
 447                         timecode, int(video_frame.len), int(video_offset), video_format.id);
 448                 if (video_frame.owner) {
 449                         video_frame.owner->release_frame(video_frame);
 450                 }
 451                 if (audio_frame.owner) {
 452                         audio_frame.owner->release_frame(audio_frame);
 453                 }
 454                 return;
 455         }
 456
 457         int dropped_frames = 0;
 458         if (card->last_timecode != -1) {
 459                 dropped_frames = unwrap_timecode(timecode, card->last_timecode) - card->last_timecode - 1;
 460         }
 461
 462         // Number of samples per frame if we need to insert silence.
 463         // (Could be nonintegral, but resampling will save us then.)
 464         const int silence_samples = OUTPUT_FREQUENCY * video_format.frame_rate_den / video_format.frame_rate_nom;
 465
 466         if (dropped_frames > MAX_FPS * 2) {
 467                 fprintf(stderr, "Card %d lost more than two seconds (or time code jumping around; from 0x%04x to 0x%04x), resetting resampler\n",
 468                         card_index, card->last_timecode, timecode);
 469                 audio_mixer.reset_resampler(device);
 470                 dropped_frames = 0;
 471         } else if (dropped_frames > 0) {
 472                 // Insert silence as needed.
 473                 fprintf(stderr, "Card %d dropped %d frame(s) (before timecode 0x%04x), inserting silence.\n",
 474                         card_index, dropped_frames, timecode);
 475
 476                 bool success;
 477                 do {
 478                         success = audio_mixer.add_silence(device, silence_samples, dropped_frames, frame_length);
 479                 } while (!success);
 480         }
 481
 482         audio_mixer.add_audio(device, audio_frame.data + audio_offset, num_samples, audio_format, frame_length, audio_frame.received_timestamp);
 483
 484         // Done with the audio, so release it.
 485         if (audio_frame.owner) {
 486                 audio_frame.owner->release_frame(audio_frame);
 487         }
 488
 489         card->last_timecode = timecode;
 490
 491         size_t expected_length = video_format.stride * (video_format.height + video_format.extra_lines_top + video_format.extra_lines_bottom);
 492         if (video_frame.len - video_offset == 0 ||
 493             video_frame.len - video_offset != expected_length) {
 494                 if (video_frame.len != 0) {
 495                         printf("Card %d: Dropping video frame with wrong length (%ld; expected %ld)\n",
 496                                 card_index, video_frame.len - video_offset, expected_length);
 497                 }
 498                 if (video_frame.owner) {
 499                         video_frame.owner->release_frame(video_frame);
 500                 }
 501
 502                 // Still send on the information that we _had_ a frame, even though it's corrupted,
 503                 // so that pts can go up accordingly.
 504                 {
 505                         unique_lock<mutex> lock(card_mutex);
 506                         CaptureCard::NewFrame new_frame;
 507                         new_frame.frame = RefCountedFrame(FrameAllocator::Frame());
 508                         new_frame.length = frame_length;
 509                         new_frame.interlaced = false;
 510                         new_frame.dropped_frames = dropped_frames;
 511                         new_frame.received_timestamp = video_frame.received_timestamp;
 512                         card->new_frames.push_back(move(new_frame));
 513                         card->new_frames_changed.notify_all();
 514                 }
 515                 return;
 516         }
 517
 518         PBOFrameAllocator::Userdata *userdata = (PBOFrameAllocator::Userdata *)video_frame.userdata;
 519
 520         unsigned num_fields = video_format.interlaced ? 2 : 1;
 521         steady_clock::time_point frame_upload_start;
 522         bool interlaced_stride = false;
 523         if (video_format.interlaced) {
 524                 // Send the two fields along as separate frames; the other side will need to add
 525                 // a deinterlacer to actually get this right.
 526                 assert(video_format.height % 2 == 0);
 527                 video_format.height /= 2;
 528                 assert(frame_length % 2 == 0);
 529                 frame_length /= 2;
 530                 num_fields = 2;
 531                 if (video_format.second_field_start == 1) {
 532                         interlaced_stride = true;
 533                 }
 534                 frame_upload_start = steady_clock::now();
 535         }
 536         userdata->last_interlaced = video_format.interlaced;
 537         userdata->last_has_signal = video_format.has_signal;
 538         userdata->last_is_connected = video_format.is_connected;
 539         userdata->last_frame_rate_nom = video_format.frame_rate_nom;
 540         userdata->last_frame_rate_den = video_format.frame_rate_den;
 541         RefCountedFrame frame(video_frame);
 542
 543         // Upload the textures.
 544         const size_t cbcr_width = video_format.width / 2;
 545         const size_t cbcr_offset = video_offset / 2;
 546         const size_t y_offset = video_frame.size / 2 + video_offset / 2;
 547
 548         for (unsigned field = 0; field < num_fields; ++field) {
 549                 // Put the actual texture upload in a lambda that is executed in the main thread.
 550                 // It is entirely possible to do this in the same thread (and it might even be
 551                 // faster, depending on the GPU and driver), but it appears to be trickling
 552                 // driver bugs very easily.
 553                 //
 554                 // Note that this means we must hold on to the actual frame data in <userdata>
 555                 // until the upload command is run, but we hold on to <frame> much longer than that
 556                 // (in fact, all the way until we no longer use the texture in rendering).
 557                 auto upload_func = [this, field, video_format, y_offset, video_offset, cbcr_offset, cbcr_width, interlaced_stride, userdata]() {
 558                         unsigned field_start_line;
 559                         if (field == 1) {
 560                                 field_start_line = video_format.second_field_start;
 561                         } else {
 562                                 field_start_line = video_format.extra_lines_top;
 563                         }
 564
 565                         // For 8-bit input, v210_width will be nonsensical but not used.
 566                         size_t v210_width = video_format.stride / sizeof(uint32_t);
 567                         ensure_texture_resolution(userdata, field, video_format.width, video_format.height, v210_width);
 568
 569                         glBindBuffer(GL_PIXEL_UNPACK_BUFFER, userdata->pbo);
 570                         check_error();
 571
 572                         if (global_flags.ten_bit_input) {
 573                                 size_t field_start = video_offset + video_format.stride * field_start_line;
 574                                 upload_texture(userdata->tex_v210[field], v210_width, video_format.height, video_format.stride, interlaced_stride, GL_RGBA, GL_UNSIGNED_INT_2_10_10_10_REV, field_start);
 575                                 v210_converter->convert(userdata->tex_v210[field], userdata->tex_444[field], video_format.width, video_format.height);
 576                         } else {
 577                                 size_t field_y_start = y_offset + video_format.width * field_start_line;
 578                                 size_t field_cbcr_start = cbcr_offset + cbcr_width * field_start_line * sizeof(uint16_t);
 579
 580                                 // Make up our own strides, since we are interleaving.
 581                                 upload_texture(userdata->tex_y[field], video_format.width, video_format.height, video_format.width, interlaced_stride, GL_RED, GL_UNSIGNED_BYTE, field_y_start);
 582                                 upload_texture(userdata->tex_cbcr[field], cbcr_width, video_format.height, cbcr_width * sizeof(uint16_t), interlaced_stride, GL_RG, GL_UNSIGNED_BYTE, field_cbcr_start);
 583                         }
 584
 585                         glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
 586                         check_error();
 587                 };
 588
 589                 if (field == 1) {
 590                         // Don't upload the second field as fast as we can; wait until
 591                         // the field time has approximately passed. (Otherwise, we could
 592                         // get timing jitter against the other sources, and possibly also
 593                         // against the video display, although the latter is not as critical.)
 594                         // This requires our system clock to be reasonably close to the
 595                         // video clock, but that's not an unreasonable assumption.
 596                         steady_clock::time_point second_field_start = frame_upload_start +
 597                                 nanoseconds(frame_length * 1000000000 / TIMEBASE);
 598                         this_thread::sleep_until(second_field_start);
 599                 }
 600
 601                 {
 602                         unique_lock<mutex> lock(card_mutex);
 603                         CaptureCard::NewFrame new_frame;
 604                         new_frame.frame = frame;
 605                         new_frame.length = frame_length;
 606                         new_frame.field = field;
 607                         new_frame.interlaced = video_format.interlaced;
 608                         new_frame.upload_func = upload_func;
 609                         new_frame.dropped_frames = dropped_frames;
 610                         new_frame.received_timestamp = video_frame.received_timestamp;  // Ignore the audio timestamp.
 611                         card->new_frames.push_back(move(new_frame));
 612                         card->new_frames_changed.notify_all();
 613                 }
 614         }
 615 }
 616
 617 void Mixer::bm_hotplug_add(libusb_device *dev)
 618 {
 619         lock_guard<mutex> lock(hotplug_mutex);
 620         hotplugged_cards.push_back(dev);
 621 }
 622
 623 void Mixer::bm_hotplug_remove(unsigned card_index)
 624 {
 625         cards[card_index].new_frames_changed.notify_all();
 626 }
 627
 628 void Mixer::thread_func()
 629 {
 630         pthread_setname_np(pthread_self(), "Mixer_OpenGL");
 631
 632         eglBindAPI(EGL_OPENGL_API);
 633         QOpenGLContext *context = create_context(mixer_surface);
 634         if (!make_current(context, mixer_surface)) {
 635                 printf("oops\n");
 636                 exit(1);
 637         }
 638
 639         // Start the actual capture. (We don't want to do it before we're actually ready
 640         // to process output frames.)
 641         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 642                 if (int(card_index) != output_card_index) {
 643                         cards[card_index].capture->start_bm_capture();
 644                 }
 645         }
 646
 647         steady_clock::time_point start, now;
 648         start = steady_clock::now();
 649
 650         int stats_dropped_frames = 0;
 651
 652         while (!should_quit) {
 653                 if (desired_output_card_index != output_card_index) {
 654                         set_output_card_internal(desired_output_card_index);
 655                 }
 656                 if (output_card_index != -1 &&
 657                     desired_output_video_mode != output_video_mode) {
 658                         DeckLinkOutput *output = cards[output_card_index].output.get();
 659                         output->end_output();
 660                         desired_output_video_mode = output_video_mode = output->pick_video_mode(desired_output_video_mode);
 661                         output->start_output(desired_output_video_mode, pts_int);
 662                 }
 663
 664                 CaptureCard::NewFrame new_frames[MAX_VIDEO_CARDS];
 665                 bool has_new_frame[MAX_VIDEO_CARDS] = { false };
 666
 667                 bool master_card_is_output;
 668                 unsigned master_card_index;
 669                 if (output_card_index != -1) {
 670                         master_card_is_output = true;
 671                         master_card_index = output_card_index;
 672                 } else {
 673                         master_card_is_output = false;
 674                         master_card_index = theme->map_signal(master_clock_channel);
 675                         assert(master_card_index < num_cards);
 676                 }
 677
 678                 OutputFrameInfo output_frame_info = get_one_frame_from_each_card(master_card_index, master_card_is_output, new_frames, has_new_frame);
 679                 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);
 680                 stats_dropped_frames += output_frame_info.dropped_frames;
 681
 682                 handle_hotplugged_cards();
 683
 684                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 685                         if (card_index == master_card_index || !has_new_frame[card_index]) {
 686                                 continue;
 687                         }
 688                         if (new_frames[card_index].frame->len == 0) {
 689                                 ++new_frames[card_index].dropped_frames;
 690                         }
 691                         if (new_frames[card_index].dropped_frames > 0) {
 692                                 printf("Card %u dropped %d frames before this\n",
 693                                         card_index, int(new_frames[card_index].dropped_frames));
 694                         }
 695                 }
 696
 697                 // If the first card is reporting a corrupted or otherwise dropped frame,
 698                 // just increase the pts (skipping over this frame) and don't try to compute anything new.
 699                 if (!master_card_is_output && new_frames[master_card_index].frame->len == 0) {
 700                         ++stats_dropped_frames;
 701                         pts_int += new_frames[master_card_index].length;
 702                         continue;
 703                 }
 704
 705                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 706                         if (!has_new_frame[card_index] || new_frames[card_index].frame->len == 0)
 707                                 continue;
 708
 709                         CaptureCard::NewFrame *new_frame = &new_frames[card_index];
 710                         assert(new_frame->frame != nullptr);
 711                         insert_new_frame(new_frame->frame, new_frame->field, new_frame->interlaced, card_index, &input_state);
 712                         check_error();
 713
 714                         // The new texture might need uploading before use.
 715                         if (new_frame->upload_func) {
 716                                 new_frame->upload_func();
 717                                 new_frame->upload_func = nullptr;
 718                         }
 719                 }
 720
 721                 int64_t frame_duration = output_frame_info.frame_duration;
 722                 render_one_frame(frame_duration);
 723                 ++frame_num;
 724                 pts_int += frame_duration;
 725
 726                 now = steady_clock::now();
 727                 double elapsed = duration<double>(now - start).count();
 728                 if (frame_num % 100 == 0) {
 729                         printf("%d frames (%d dropped) in %.3f seconds = %.1f fps (%.1f ms/frame)",
 730                                 frame_num, stats_dropped_frames, elapsed, frame_num / elapsed,
 731                                 1e3 * elapsed / frame_num);
 732                 //      chain->print_phase_timing();
 733
 734                         // Check our memory usage, to see if we are close to our mlockall()
 735                         // limit (if at all set).
 736                         rusage used;
 737                         if (getrusage(RUSAGE_SELF, &used) == -1) {
 738                                 perror("getrusage(RUSAGE_SELF)");
 739                                 assert(false);
 740                         }
 741
 742                         if (uses_mlock) {
 743                                 rlimit limit;
 744                                 if (getrlimit(RLIMIT_MEMLOCK, &limit) == -1) {
 745                                         perror("getrlimit(RLIMIT_MEMLOCK)");
 746                                         assert(false);
 747                                 }
 748
 749                                 if (limit.rlim_cur == 0) {
 750                                         printf(", using %ld MB memory (locked)",
 751                                                 long(used.ru_maxrss / 1024));
 752                                 } else {
 753                                         printf(", using %ld / %ld MB lockable memory (%.1f%%)",
 754                                                 long(used.ru_maxrss / 1024),
 755                                                 long(limit.rlim_cur / 1048576),
 756                                                 float(100.0 * (used.ru_maxrss * 1024.0) / limit.rlim_cur));
 757                                 }
 758                         } else {
 759                                 printf(", using %ld MB memory (not locked)",
 760                                         long(used.ru_maxrss / 1024));
 761                         }
 762
 763                         printf("\n");
 764                 }
 765
 766
 767                 if (should_cut.exchange(false)) {  // Test and clear.
 768                         video_encoder->do_cut(frame_num);
 769                 }
 770
 771 #if 0
 772                 // Reset every 100 frames, so that local variations in frame times
 773                 // (especially for the first few frames, when the shaders are
 774                 // compiled etc.) don't make it hard to measure for the entire
 775                 // remaining duration of the program.
 776                 if (frame == 10000) {
 777                         frame = 0;
 778                         start = now;
 779                 }
 780 #endif
 781                 check_error();
 782         }
 783
 784         resource_pool->clean_context();
 785 }
 786
 787 bool Mixer::input_card_is_master_clock(unsigned card_index, unsigned master_card_index) const
 788 {
 789         if (output_card_index != -1) {
 790                 // The output card (ie., cards[output_card_index].output) is the master clock,
 791                 // so no input card (ie., cards[card_index].capture) is.
 792                 return false;
 793         }
 794         return (card_index == master_card_index);
 795 }
 796
 797 void Mixer::trim_queue(CaptureCard *card, unsigned card_index)
 798 {
 799         // Count the number of frames in the queue, including any frames
 800         // we dropped. It's hard to know exactly how we should deal with
 801         // dropped (corrupted) input frames; they don't help our goal of
 802         // avoiding starvation, but they still add to the problem of latency.
 803         // Since dropped frames is going to mean a bump in the signal anyway,
 804         // we err on the side of having more stable latency instead.
 805         unsigned queue_length = 0;
 806         for (const CaptureCard::NewFrame &frame : card->new_frames) {
 807                 queue_length += frame.dropped_frames + 1;
 808         }
 809         card->queue_length_policy.update_policy(queue_length);
 810
 811         // If needed, drop frames until the queue is below the safe limit.
 812         // We prefer to drop from the head, because all else being equal,
 813         // we'd like more recent frames (less latency).
 814         unsigned dropped_frames = 0;
 815         while (queue_length > card->queue_length_policy.get_safe_queue_length()) {
 816                 assert(!card->new_frames.empty());
 817                 assert(queue_length > card->new_frames.front().dropped_frames);
 818                 queue_length -= card->new_frames.front().dropped_frames;
 819
 820                 if (queue_length <= card->queue_length_policy.get_safe_queue_length()) {
 821                         // No need to drop anything.
 822                         break;
 823                 }
 824
 825                 card->new_frames.pop_front();
 826                 card->new_frames_changed.notify_all();
 827                 --queue_length;
 828                 ++dropped_frames;
 829         }
 830
 831         if (dropped_frames > 0) {
 832                 fprintf(stderr, "Card %u dropped %u frame(s) to keep latency down.\n",
 833                         card_index, dropped_frames);
 834         }
 835 }
 836
 837
 838 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])
 839 {
 840         OutputFrameInfo output_frame_info;
 841 start:
 842         unique_lock<mutex> lock(card_mutex, defer_lock);
 843         if (master_card_is_output) {
 844                 // Clocked to the output, so wait for it to be ready for the next frame.
 845                 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);
 846                 lock.lock();
 847         } else {
 848                 // Wait for the master card to have a new frame.
 849                 // TODO: Add a timeout.
 850                 output_frame_info.is_preroll = false;
 851                 lock.lock();
 852                 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(); });
 853         }
 854
 855         if (master_card_is_output) {
 856                 handle_hotplugged_cards();
 857         } else if (cards[master_card_index].new_frames.empty()) {
 858                 // We were woken up, but not due to a new frame. Deal with it
 859                 // and then restart.
 860                 assert(cards[master_card_index].capture->get_disconnected());
 861                 handle_hotplugged_cards();
 862                 goto start;
 863         }
 864
 865         if (!master_card_is_output) {
 866                 output_frame_info.frame_timestamp =
 867                         cards[master_card_index].new_frames.front().received_timestamp;
 868         }
 869
 870         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 871                 CaptureCard *card = &cards[card_index];
 872                 if (input_card_is_master_clock(card_index, master_card_index)) {
 873                         // We don't use the queue length policy for the master card,
 874                         // but we will if it stops being the master. Thus, clear out
 875                         // the policy in case we switch in the future.
 876                         card->queue_length_policy.reset(card_index);
 877                         assert(!card->new_frames.empty());
 878                 } else {
 879                         trim_queue(card, card_index);
 880                 }
 881                 if (!card->new_frames.empty()) {
 882                         new_frames[card_index] = move(card->new_frames.front());
 883                         has_new_frame[card_index] = true;
 884                         card->new_frames.pop_front();
 885                         card->new_frames_changed.notify_all();
 886                 }
 887         }
 888
 889         if (!master_card_is_output) {
 890                 output_frame_info.dropped_frames = new_frames[master_card_index].dropped_frames;
 891                 output_frame_info.frame_duration = new_frames[master_card_index].length;
 892         }
 893
 894         // This might get off by a fractional sample when changing master card
 895         // between ones with different frame rates, but that's fine.
 896         int num_samples_times_timebase = OUTPUT_FREQUENCY * output_frame_info.frame_duration + fractional_samples;
 897         output_frame_info.num_samples = num_samples_times_timebase / TIMEBASE;
 898         fractional_samples = num_samples_times_timebase % TIMEBASE;
 899         assert(output_frame_info.num_samples >= 0);
 900
 901         return output_frame_info;
 902 }
 903
 904 void Mixer::handle_hotplugged_cards()
 905 {
 906         // Check for cards that have been disconnected since last frame.
 907         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 908                 CaptureCard *card = &cards[card_index];
 909                 if (card->capture->get_disconnected()) {
 910                         fprintf(stderr, "Card %u went away, replacing with a fake card.\n", card_index);
 911                         FakeCapture *capture = new FakeCapture(global_flags.width, global_flags.height, FAKE_FPS, OUTPUT_FREQUENCY, card_index, global_flags.fake_cards_audio);
 912                         configure_card(card_index, capture, /*is_fake_capture=*/true, /*output=*/nullptr);
 913                         card->queue_length_policy.reset(card_index);
 914                         card->capture->start_bm_capture();
 915                 }
 916         }
 917
 918         // Check for cards that have been connected since last frame.
 919         vector<libusb_device *> hotplugged_cards_copy;
 920         {
 921                 lock_guard<mutex> lock(hotplug_mutex);
 922                 swap(hotplugged_cards, hotplugged_cards_copy);
 923         }
 924         for (libusb_device *new_dev : hotplugged_cards_copy) {
 925                 // Look for a fake capture card where we can stick this in.
 926                 int free_card_index = -1;
 927                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 928                         if (cards[card_index].is_fake_capture) {
 929                                 free_card_index = card_index;
 930                                 break;
 931                         }
 932                 }
 933
 934                 if (free_card_index == -1) {
 935                         fprintf(stderr, "New card plugged in, but no free slots -- ignoring.\n");
 936                         libusb_unref_device(new_dev);
 937                 } else {
 938                         // BMUSBCapture takes ownership.
 939                         fprintf(stderr, "New card plugged in, choosing slot %d.\n", free_card_index);
 940                         CaptureCard *card = &cards[free_card_index];
 941                         BMUSBCapture *capture = new BMUSBCapture(free_card_index, new_dev);
 942                         configure_card(free_card_index, capture, /*is_fake_capture=*/false, /*output=*/nullptr);
 943                         card->queue_length_policy.reset(free_card_index);
 944                         capture->set_card_disconnected_callback(bind(&Mixer::bm_hotplug_remove, this, free_card_index));
 945                         capture->start_bm_capture();
 946                 }
 947         }
 948 }
 949
 950
 951 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)
 952 {
 953         // Resample the audio as needed, including from previously dropped frames.
 954         assert(num_cards > 0);
 955         for (unsigned frame_num = 0; frame_num < dropped_frames + 1; ++frame_num) {
 956                 const bool dropped_frame = (frame_num != dropped_frames);
 957                 {
 958                         // Signal to the audio thread to process this frame.
 959                         // Note that if the frame is a dropped frame, we signal that
 960                         // we don't want to use this frame as base for adjusting
 961                         // the resampler rate. The reason for this is that the timing
 962                         // of these frames is often way too late; they typically don't
 963                         // “arrive” before we synthesize them. Thus, we could end up
 964                         // in a situation where we have inserted e.g. five audio frames
 965                         // into the queue before we then start pulling five of them
 966                         // back out. This makes ResamplingQueue overestimate the delay,
 967                         // causing undue resampler changes. (We _do_ use the last,
 968                         // non-dropped frame; perhaps we should just discard that as well,
 969                         // since dropped frames are expected to be rare, and it might be
 970                         // better to just wait until we have a slightly more normal situation).
 971                         unique_lock<mutex> lock(audio_mutex);
 972                         bool adjust_rate = !dropped_frame && !is_preroll;
 973                         audio_task_queue.push(AudioTask{pts_int, num_samples_per_frame, adjust_rate, frame_timestamp});
 974                         audio_task_queue_changed.notify_one();
 975                 }
 976                 if (dropped_frame) {
 977                         // For dropped frames, increase the pts. Note that if the format changed
 978                         // in the meantime, we have no way of detecting that; we just have to
 979                         // assume the frame length is always the same.
 980                         pts_int += length_per_frame;
 981                 }
 982         }
 983 }
 984
 985 void Mixer::render_one_frame(int64_t duration)
 986 {
 987         // Determine the time code for this frame before we start rendering.
 988         string timecode_text = timecode_renderer->get_timecode_text(double(pts_int) / TIMEBASE, frame_num);
 989         if (display_timecode_on_stdout) {
 990                 printf("Timecode: '%s'\n", timecode_text.c_str());
 991         }
 992
 993         // Get the main chain from the theme, and set its state immediately.
 994         Theme::Chain theme_main_chain = theme->get_chain(0, pts(), global_flags.width, global_flags.height, input_state);
 995         EffectChain *chain = theme_main_chain.chain;
 996         theme_main_chain.setup_chain();
 997         //theme_main_chain.chain->enable_phase_timing(true);
 998
 999         const int64_t av_delay = lrint(global_flags.audio_queue_length_ms * 0.001 * TIMEBASE);  // Corresponds to the delay in ResamplingQueue.
1000         GLuint y_tex, cbcr_tex;
1001         bool got_frame = video_encoder->begin_frame(pts_int + av_delay, duration, theme_main_chain.input_frames, &y_tex, &cbcr_tex);
1002         assert(got_frame);
1003
1004         // Render main chain.
1005         GLuint cbcr_full_tex = resource_pool->create_2d_texture(GL_RG8, global_flags.width, global_flags.height);
1006         GLuint rgba_tex = resource_pool->create_2d_texture(GL_RGB565, global_flags.width, global_flags.height);  // Saves texture bandwidth, although dithering gets messed up.
1007         GLuint fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex, rgba_tex);
1008         check_error();
1009         chain->render_to_fbo(fbo, global_flags.width, global_flags.height);
1010
1011         if (display_timecode_in_stream) {
1012                 // Render the timecode on top.
1013                 timecode_renderer->render_timecode(fbo, timecode_text);
1014         }
1015
1016         resource_pool->release_fbo(fbo);
1017
1018         chroma_subsampler->subsample_chroma(cbcr_full_tex, global_flags.width, global_flags.height, cbcr_tex);
1019         if (output_card_index != -1) {
1020                 cards[output_card_index].output->send_frame(y_tex, cbcr_full_tex, theme_main_chain.input_frames, pts_int, duration);
1021         }
1022         resource_pool->release_2d_texture(cbcr_full_tex);
1023
1024         // Set the right state for rgba_tex.
1025         glBindFramebuffer(GL_FRAMEBUFFER, 0);
1026         glBindTexture(GL_TEXTURE_2D, rgba_tex);
1027         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1028         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
1029         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
1030
1031         RefCountedGLsync fence = video_encoder->end_frame();
1032
1033         // The live frame just shows the RGBA texture we just rendered.
1034         // It owns rgba_tex now.
1035         DisplayFrame live_frame;
1036         live_frame.chain = display_chain.get();
1037         live_frame.setup_chain = [this, rgba_tex]{
1038                 display_input->set_texture_num(rgba_tex);
1039         };
1040         live_frame.ready_fence = fence;
1041         live_frame.input_frames = {};
1042         live_frame.temp_textures = { rgba_tex };
1043         output_channel[OUTPUT_LIVE].output_frame(live_frame);
1044
1045         // Set up preview and any additional channels.
1046         for (int i = 1; i < theme->get_num_channels() + 2; ++i) {
1047                 DisplayFrame display_frame;
1048                 Theme::Chain chain = theme->get_chain(i, pts(), global_flags.width, global_flags.height, input_state);  // FIXME: dimensions
1049                 display_frame.chain = chain.chain;
1050                 display_frame.setup_chain = chain.setup_chain;
1051                 display_frame.ready_fence = fence;
1052                 display_frame.input_frames = chain.input_frames;
1053                 display_frame.temp_textures = {};
1054                 output_channel[i].output_frame(display_frame);
1055         }
1056 }
1057
1058 void Mixer::audio_thread_func()
1059 {
1060         pthread_setname_np(pthread_self(), "Mixer_Audio");
1061
1062         while (!should_quit) {
1063                 AudioTask task;
1064
1065                 {
1066                         unique_lock<mutex> lock(audio_mutex);
1067                         audio_task_queue_changed.wait(lock, [this]{ return should_quit || !audio_task_queue.empty(); });
1068                         if (should_quit) {
1069                                 return;
1070                         }
1071                         task = audio_task_queue.front();
1072                         audio_task_queue.pop();
1073                 }
1074
1075                 ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy =
1076                         task.adjust_rate ? ResamplingQueue::ADJUST_RATE : ResamplingQueue::DO_NOT_ADJUST_RATE;
1077                 vector<float> samples_out = audio_mixer.get_output(
1078                         task.frame_timestamp,
1079                         task.num_samples,
1080                         rate_adjustment_policy);
1081
1082                 // Send the samples to the sound card, then add them to the output.
1083                 if (alsa) {
1084                         alsa->write(samples_out);
1085                 }
1086                 if (output_card_index != -1) {
1087                         const int64_t av_delay = lrint(global_flags.audio_queue_length_ms * 0.001 * TIMEBASE);  // Corresponds to the delay in ResamplingQueue.
1088                         cards[output_card_index].output->send_audio(task.pts_int + av_delay, samples_out);
1089                 }
1090                 video_encoder->add_audio(task.pts_int, move(samples_out));
1091         }
1092 }
1093
1094 void Mixer::release_display_frame(DisplayFrame *frame)
1095 {
1096         for (GLuint texnum : frame->temp_textures) {
1097                 resource_pool->release_2d_texture(texnum);
1098         }
1099         frame->temp_textures.clear();
1100         frame->ready_fence.reset();
1101         frame->input_frames.clear();
1102 }
1103
1104 void Mixer::start()
1105 {
1106         mixer_thread = thread(&Mixer::thread_func, this);
1107         audio_thread = thread(&Mixer::audio_thread_func, this);
1108 }
1109
1110 void Mixer::quit()
1111 {
1112         should_quit = true;
1113         audio_task_queue_changed.notify_one();
1114         mixer_thread.join();
1115         audio_thread.join();
1116 }
1117
1118 void Mixer::transition_clicked(int transition_num)
1119 {
1120         theme->transition_clicked(transition_num, pts());
1121 }
1122
1123 void Mixer::channel_clicked(int preview_num)
1124 {
1125         theme->channel_clicked(preview_num);
1126 }
1127
1128 void Mixer::start_mode_scanning(unsigned card_index)
1129 {
1130         assert(card_index < num_cards);
1131         if (is_mode_scanning[card_index]) {
1132                 return;
1133         }
1134         is_mode_scanning[card_index] = true;
1135         mode_scanlist[card_index].clear();
1136         for (const auto &mode : cards[card_index].capture->get_available_video_modes()) {
1137                 mode_scanlist[card_index].push_back(mode.first);
1138         }
1139         assert(!mode_scanlist[card_index].empty());
1140         mode_scanlist_index[card_index] = 0;
1141         cards[card_index].capture->set_video_mode(mode_scanlist[card_index][0]);
1142         last_mode_scan_change[card_index] = steady_clock::now();
1143 }
1144
1145 map<uint32_t, bmusb::VideoMode> Mixer::get_available_output_video_modes() const
1146 {
1147         assert(desired_output_card_index != -1);
1148         unique_lock<mutex> lock(card_mutex);
1149         return cards[desired_output_card_index].output->get_available_video_modes();
1150 }
1151
1152 Mixer::OutputChannel::~OutputChannel()
1153 {
1154         if (has_current_frame) {
1155                 parent->release_display_frame(&current_frame);
1156         }
1157         if (has_ready_frame) {
1158                 parent->release_display_frame(&ready_frame);
1159         }
1160 }
1161
1162 void Mixer::OutputChannel::output_frame(DisplayFrame frame)
1163 {
1164         // Store this frame for display. Remove the ready frame if any
1165         // (it was seemingly never used).
1166         {
1167                 unique_lock<mutex> lock(frame_mutex);
1168                 if (has_ready_frame) {
1169                         parent->release_display_frame(&ready_frame);
1170                 }
1171                 ready_frame = frame;
1172                 has_ready_frame = true;
1173         }
1174
1175         if (new_frame_ready_callback) {
1176                 new_frame_ready_callback();
1177         }
1178
1179         // Reduce the number of callbacks by filtering duplicates. The reason
1180         // why we bother doing this is that Qt seemingly can get into a state
1181         // where its builds up an essentially unbounded queue of signals,
1182         // consuming more and more memory, and there's no good way of collapsing
1183         // user-defined signals or limiting the length of the queue.
1184         if (transition_names_updated_callback) {
1185                 vector<string> transition_names = global_mixer->get_transition_names();
1186                 bool changed = false;
1187                 if (transition_names.size() != last_transition_names.size()) {
1188                         changed = true;
1189                 } else {
1190                         for (unsigned i = 0; i < transition_names.size(); ++i) {
1191                                 if (transition_names[i] != last_transition_names[i]) {
1192                                         changed = true;
1193                                         break;
1194                                 }
1195                         }
1196                 }
1197                 if (changed) {
1198                         transition_names_updated_callback(transition_names);
1199                         last_transition_names = transition_names;
1200                 }
1201         }
1202         if (name_updated_callback) {
1203                 string name = global_mixer->get_channel_name(channel);
1204                 if (name != last_name) {
1205                         name_updated_callback(name);
1206                         last_name = name;
1207                 }
1208         }
1209         if (color_updated_callback) {
1210                 string color = global_mixer->get_channel_color(channel);
1211                 if (color != last_color) {
1212                         color_updated_callback(color);
1213                         last_color = color;
1214                 }
1215         }
1216 }
1217
1218 bool Mixer::OutputChannel::get_display_frame(DisplayFrame *frame)
1219 {
1220         unique_lock<mutex> lock(frame_mutex);
1221         if (!has_current_frame && !has_ready_frame) {
1222                 return false;
1223         }
1224
1225         if (has_current_frame && has_ready_frame) {
1226                 // We have a new ready frame. Toss the current one.
1227                 parent->release_display_frame(&current_frame);
1228                 has_current_frame = false;
1229         }
1230         if (has_ready_frame) {
1231                 assert(!has_current_frame);
1232                 current_frame = ready_frame;
1233                 ready_frame.ready_fence.reset();  // Drop the refcount.
1234                 ready_frame.input_frames.clear();  // Drop the refcounts.
1235                 has_current_frame = true;
1236                 has_ready_frame = false;
1237         }
1238
1239         *frame = current_frame;
1240         return true;
1241 }
1242
1243 void Mixer::OutputChannel::set_frame_ready_callback(Mixer::new_frame_ready_callback_t callback)
1244 {
1245         new_frame_ready_callback = callback;
1246 }
1247
1248 void Mixer::OutputChannel::set_transition_names_updated_callback(Mixer::transition_names_updated_callback_t callback)
1249 {
1250         transition_names_updated_callback = callback;
1251 }
1252
1253 void Mixer::OutputChannel::set_name_updated_callback(Mixer::name_updated_callback_t callback)
1254 {
1255         name_updated_callback = callback;
1256 }
1257
1258 void Mixer::OutputChannel::set_color_updated_callback(Mixer::color_updated_callback_t callback)
1259 {
1260         color_updated_callback = callback;
1261 }
1262
1263 mutex RefCountedGLsync::fence_lock;