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 "ffmpeg_capture.h"
  43 #include "flags.h"
  44 #include "input_mapping.h"
  45 #include "metrics.h"
  46 #include "pbo_frame_allocator.h"
  47 #include "ref_counted_gl_sync.h"
  48 #include "resampling_queue.h"
  49 #include "timebase.h"
  50 #include "timecode_renderer.h"
  51 #include "v210_converter.h"
  52 #include "video_encoder.h"
  53
  54 class IDeckLink;
  55 class QOpenGLContext;
  56
  57 using namespace movit;
  58 using namespace std;
  59 using namespace std::chrono;
  60 using namespace std::placeholders;
  61 using namespace bmusb;
  62
  63 Mixer *global_mixer = nullptr;
  64 bool uses_mlock = false;
  65
  66 namespace {
  67
  68 void insert_new_frame(RefCountedFrame frame, unsigned field_num, bool interlaced, unsigned card_index, InputState *input_state)
  69 {
  70         if (interlaced) {
  71                 for (unsigned frame_num = FRAME_HISTORY_LENGTH; frame_num --> 1; ) {  // :-)
  72                         input_state->buffered_frames[card_index][frame_num] =
  73                                 input_state->buffered_frames[card_index][frame_num - 1];
  74                 }
  75                 input_state->buffered_frames[card_index][0] = { frame, field_num };
  76         } else {
  77                 for (unsigned frame_num = 0; frame_num < FRAME_HISTORY_LENGTH; ++frame_num) {
  78                         input_state->buffered_frames[card_index][frame_num] = { frame, field_num };
  79                 }
  80         }
  81 }
  82
  83 void ensure_texture_resolution(PBOFrameAllocator::Userdata *userdata, unsigned field, unsigned width, unsigned height, unsigned cbcr_width, unsigned cbcr_height, unsigned v210_width)
  84 {
  85         bool first;
  86         switch (userdata->pixel_format) {
  87         case PixelFormat_10BitYCbCr:
  88                 first = userdata->tex_v210[field] == 0 || userdata->tex_444[field] == 0;
  89                 break;
  90         case PixelFormat_8BitYCbCr:
  91                 first = userdata->tex_y[field] == 0 || userdata->tex_cbcr[field] == 0;
  92                 break;
  93         case PixelFormat_8BitBGRA:
  94                 first = userdata->tex_rgba[field] == 0;
  95                 break;
  96         case PixelFormat_8BitYCbCrPlanar:
  97                 first = userdata->tex_y[field] == 0 || userdata->tex_cb[field] == 0 || userdata->tex_cr[field] == 0;
  98                 break;
  99         default:
 100                 assert(false);
 101         }
 102
 103         if (first ||
 104             width != userdata->last_width[field] ||
 105             height != userdata->last_height[field] ||
 106             cbcr_width != userdata->last_cbcr_width[field] ||
 107             cbcr_height != userdata->last_cbcr_height[field]) {
 108                 // We changed resolution since last use of this texture, so we need to create
 109                 // a new object. Note that this each card has its own PBOFrameAllocator,
 110                 // we don't need to worry about these flip-flopping between resolutions.
 111                 switch (userdata->pixel_format) {
 112                 case PixelFormat_10BitYCbCr:
 113                         glBindTexture(GL_TEXTURE_2D, userdata->tex_444[field]);
 114                         check_error();
 115                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB10_A2, width, height, 0, GL_RGBA, GL_UNSIGNED_INT_2_10_10_10_REV, nullptr);
 116                         check_error();
 117                         break;
 118                 case PixelFormat_8BitYCbCr: {
 119                         glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr[field]);
 120                         check_error();
 121                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RG8, cbcr_width, height, 0, GL_RG, GL_UNSIGNED_BYTE, nullptr);
 122                         check_error();
 123                         glBindTexture(GL_TEXTURE_2D, userdata->tex_y[field]);
 124                         check_error();
 125                         glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, width, height, 0, GL_RED, GL_UNSIGNED_BYTE, nullptr);
 126                         check_error();
 127                         break;
 128                 }
 129                 case PixelFormat_8BitYCbCrPlanar: {
 130                         glBindTexture(GL_TEXTURE_2D, userdata->tex_y[field]);
 131                         check_error();
 132                         glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, width, height, 0, GL_RED, GL_UNSIGNED_BYTE, nullptr);
 133                         check_error();
 134                         glBindTexture(GL_TEXTURE_2D, userdata->tex_cb[field]);
 135                         check_error();
 136                         glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, cbcr_width, cbcr_height, 0, GL_RED, GL_UNSIGNED_BYTE, nullptr);
 137                         check_error();
 138                         glBindTexture(GL_TEXTURE_2D, userdata->tex_cr[field]);
 139                         check_error();
 140                         glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, cbcr_width, cbcr_height, 0, GL_RED, GL_UNSIGNED_BYTE, nullptr);
 141                         check_error();
 142                         break;
 143                 }
 144                 case PixelFormat_8BitBGRA:
 145                         glBindTexture(GL_TEXTURE_2D, userdata->tex_rgba[field]);
 146                         check_error();
 147                         if (global_flags.can_disable_srgb_decoder) {  // See the comments in tweaked_inputs.h.
 148                                 glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB8_ALPHA8, width, height, 0, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, nullptr);
 149                         } else {
 150                                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, nullptr);
 151                         }
 152                         check_error();
 153                         break;
 154                 }
 155                 userdata->last_width[field] = width;
 156                 userdata->last_height[field] = height;
 157                 userdata->last_cbcr_width[field] = cbcr_width;
 158                 userdata->last_cbcr_height[field] = cbcr_height;
 159         }
 160         if (global_flags.ten_bit_input &&
 161             (first || v210_width != userdata->last_v210_width[field])) {
 162                 // Same as above; we need to recreate the texture.
 163                 glBindTexture(GL_TEXTURE_2D, userdata->tex_v210[field]);
 164                 check_error();
 165                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB10_A2, v210_width, height, 0, GL_RGBA, GL_UNSIGNED_INT_2_10_10_10_REV, nullptr);
 166                 check_error();
 167                 userdata->last_v210_width[field] = v210_width;
 168         }
 169 }
 170
 171 void upload_texture(GLuint tex, GLuint width, GLuint height, GLuint stride, bool interlaced_stride, GLenum format, GLenum type, GLintptr offset)
 172 {
 173         if (interlaced_stride) {
 174                 stride *= 2;
 175         }
 176         if (global_flags.flush_pbos) {
 177                 glFlushMappedBufferRange(GL_PIXEL_UNPACK_BUFFER, offset, stride * height);
 178                 check_error();
 179         }
 180
 181         glBindTexture(GL_TEXTURE_2D, tex);
 182         check_error();
 183         if (interlaced_stride) {
 184                 glPixelStorei(GL_UNPACK_ROW_LENGTH, width * 2);
 185                 check_error();
 186         } else {
 187                 glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 188                 check_error();
 189         }
 190
 191         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, type, BUFFER_OFFSET(offset));
 192         check_error();
 193         glBindTexture(GL_TEXTURE_2D, 0);
 194         check_error();
 195         glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 196         check_error();
 197 }
 198
 199 }  // namespace
 200
 201 void QueueLengthPolicy::register_metrics(const vector<pair<string, string>> &labels)
 202 {
 203         global_metrics.add("input_queue_length_frames", labels, &metric_input_queue_length_frames, Metrics::TYPE_GAUGE);
 204         global_metrics.add("input_queue_safe_length_frames", labels, &metric_input_queue_safe_length_frames, Metrics::TYPE_GAUGE);
 205         global_metrics.add("input_queue_duped_frames", labels, &metric_input_duped_frames);
 206 }
 207
 208 void QueueLengthPolicy::update_policy(unsigned queue_length)
 209 {
 210         metric_input_queue_length_frames = queue_length;
 211
 212         if (queue_length == 0) {  // Starvation.
 213                 if (been_at_safe_point_since_last_starvation && safe_queue_length < unsigned(global_flags.max_input_queue_frames)) {
 214                         ++safe_queue_length;
 215                         fprintf(stderr, "Card %u: Starvation, increasing safe limit to %u frame(s)\n",
 216                                 card_index, safe_queue_length);
 217                 }
 218                 frames_with_at_least_one = 0;
 219                 been_at_safe_point_since_last_starvation = false;
 220                 ++metric_input_duped_frames;
 221                 metric_input_queue_safe_length_frames = safe_queue_length;
 222                 return;
 223         }
 224         if (queue_length >= safe_queue_length) {
 225                 been_at_safe_point_since_last_starvation = true;
 226         }
 227         if (++frames_with_at_least_one >= 1000 && safe_queue_length > 1) {
 228                 --safe_queue_length;
 229                 metric_input_queue_safe_length_frames = safe_queue_length;
 230                 fprintf(stderr, "Card %u: Spare frames for more than 1000 frames, reducing safe limit to %u frame(s)\n",
 231                         card_index, safe_queue_length);
 232                 frames_with_at_least_one = 0;
 233         }
 234 }
 235
 236 Mixer::Mixer(const QSurfaceFormat &format, unsigned num_cards)
 237         : httpd(),
 238           num_cards(num_cards),
 239           mixer_surface(create_surface(format)),
 240           h264_encoder_surface(create_surface(format)),
 241           decklink_output_surface(create_surface(format)),
 242           ycbcr_interpretation(global_flags.ycbcr_interpretation),
 243           audio_mixer(num_cards)
 244 {
 245         CHECK(init_movit(MOVIT_SHADER_DIR, MOVIT_DEBUG_OFF));
 246         check_error();
 247
 248         // This nearly always should be true.
 249         global_flags.can_disable_srgb_decoder =
 250                 epoxy_has_gl_extension("GL_EXT_texture_sRGB_decode") &&
 251                 epoxy_has_gl_extension("GL_ARB_sampler_objects");
 252
 253         // Since we allow non-bouncing 4:2:2 YCbCrInputs, effective subpixel precision
 254         // will be halved when sampling them, and we need to compensate here.
 255         movit_texel_subpixel_precision /= 2.0;
 256
 257         resource_pool.reset(new ResourcePool);
 258         for (unsigned i = 0; i < NUM_OUTPUTS; ++i) {
 259                 output_channel[i].parent = this;
 260                 output_channel[i].channel = i;
 261         }
 262
 263         ImageFormat inout_format;
 264         inout_format.color_space = COLORSPACE_sRGB;
 265         inout_format.gamma_curve = GAMMA_sRGB;
 266
 267         // Matches the 4:2:0 format created by the main chain.
 268         YCbCrFormat ycbcr_format;
 269         ycbcr_format.chroma_subsampling_x = 2;
 270         ycbcr_format.chroma_subsampling_y = 2;
 271         if (global_flags.ycbcr_rec709_coefficients) {
 272                 ycbcr_format.luma_coefficients = YCBCR_REC_709;
 273         } else {
 274                 ycbcr_format.luma_coefficients = YCBCR_REC_601;
 275         }
 276         ycbcr_format.full_range = false;
 277         ycbcr_format.num_levels = 1 << global_flags.x264_bit_depth;
 278         ycbcr_format.cb_x_position = 0.0f;
 279         ycbcr_format.cr_x_position = 0.0f;
 280         ycbcr_format.cb_y_position = 0.5f;
 281         ycbcr_format.cr_y_position = 0.5f;
 282
 283         // Display chain; shows the live output produced by the main chain (or rather, a copy of it).
 284         display_chain.reset(new EffectChain(global_flags.width, global_flags.height, resource_pool.get()));
 285         check_error();
 286         GLenum type = global_flags.x264_bit_depth > 8 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_BYTE;
 287         display_input = new YCbCrInput(inout_format, ycbcr_format, global_flags.width, global_flags.height, YCBCR_INPUT_SPLIT_Y_AND_CBCR, type);
 288         display_chain->add_input(display_input);
 289         display_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
 290         display_chain->set_dither_bits(0);  // Don't bother.
 291         display_chain->finalize();
 292
 293         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));
 294
 295         // Must be instantiated after VideoEncoder has initialized global_flags.use_zerocopy.
 296         theme.reset(new Theme(global_flags.theme_filename, global_flags.theme_dirs, resource_pool.get(), num_cards));
 297
 298         // Start listening for clients only once VideoEncoder has written its header, if any.
 299         httpd.start(9095);
 300
 301         // First try initializing the then PCI devices, then USB, then
 302         // fill up with fake cards until we have the desired number of cards.
 303         unsigned num_pci_devices = 0;
 304         unsigned card_index = 0;
 305
 306         {
 307                 IDeckLinkIterator *decklink_iterator = CreateDeckLinkIteratorInstance();
 308                 if (decklink_iterator != nullptr) {
 309                         for ( ; card_index < num_cards; ++card_index) {
 310                                 IDeckLink *decklink;
 311                                 if (decklink_iterator->Next(&decklink) != S_OK) {
 312                                         break;
 313                                 }
 314
 315                                 DeckLinkCapture *capture = new DeckLinkCapture(decklink, card_index);
 316                                 DeckLinkOutput *output = new DeckLinkOutput(resource_pool.get(), decklink_output_surface, global_flags.width, global_flags.height, card_index);
 317                                 output->set_device(decklink);
 318                                 configure_card(card_index, capture, CardType::LIVE_CARD, output);
 319                                 ++num_pci_devices;
 320                         }
 321                         decklink_iterator->Release();
 322                         fprintf(stderr, "Found %u DeckLink PCI card(s).\n", num_pci_devices);
 323                 } else {
 324                         fprintf(stderr, "DeckLink drivers not found. Probing for USB cards only.\n");
 325                 }
 326         }
 327
 328         unsigned num_usb_devices = BMUSBCapture::num_cards();
 329         for (unsigned usb_card_index = 0; usb_card_index < num_usb_devices && card_index < num_cards; ++usb_card_index, ++card_index) {
 330                 BMUSBCapture *capture = new BMUSBCapture(usb_card_index);
 331                 capture->set_card_disconnected_callback(bind(&Mixer::bm_hotplug_remove, this, card_index));
 332                 configure_card(card_index, capture, CardType::LIVE_CARD, /*output=*/nullptr);
 333         }
 334         fprintf(stderr, "Found %u USB card(s).\n", num_usb_devices);
 335
 336         unsigned num_fake_cards = 0;
 337         for ( ; card_index < num_cards; ++card_index, ++num_fake_cards) {
 338                 FakeCapture *capture = new FakeCapture(global_flags.width, global_flags.height, FAKE_FPS, OUTPUT_FREQUENCY, card_index, global_flags.fake_cards_audio);
 339                 configure_card(card_index, capture, CardType::FAKE_CAPTURE, /*output=*/nullptr);
 340         }
 341
 342         if (num_fake_cards > 0) {
 343                 fprintf(stderr, "Initialized %u fake cards.\n", num_fake_cards);
 344         }
 345
 346         // Initialize all video inputs the theme asked for. Note that these are
 347         // all put _after_ the regular cards, which stop at <num_cards> - 1.
 348         std::vector<FFmpegCapture *> video_inputs = theme->get_video_inputs();
 349         for (unsigned video_card_index = 0; video_card_index < video_inputs.size(); ++card_index, ++video_card_index) {
 350                 if (card_index >= MAX_VIDEO_CARDS) {
 351                         fprintf(stderr, "ERROR: Not enough card slots available for the videos the theme requested.\n");
 352                         exit(1);
 353                 }
 354                 configure_card(card_index, video_inputs[video_card_index], CardType::FFMPEG_INPUT, /*output=*/nullptr);
 355                 video_inputs[video_card_index]->set_card_index(card_index);
 356         }
 357         num_video_inputs = video_inputs.size();
 358
 359         BMUSBCapture::set_card_connected_callback(bind(&Mixer::bm_hotplug_add, this, _1));
 360         BMUSBCapture::start_bm_thread();
 361
 362         for (unsigned card_index = 0; card_index < num_cards + num_video_inputs; ++card_index) {
 363                 cards[card_index].queue_length_policy.reset(card_index);
 364         }
 365
 366         chroma_subsampler.reset(new ChromaSubsampler(resource_pool.get()));
 367
 368         if (global_flags.ten_bit_input) {
 369                 if (!v210Converter::has_hardware_support()) {
 370                         fprintf(stderr, "ERROR: --ten-bit-input requires support for OpenGL compute shaders\n");
 371                         fprintf(stderr, "       (OpenGL 4.3, or GL_ARB_compute_shader + GL_ARB_shader_image_load_store).\n");
 372                         exit(1);
 373                 }
 374                 v210_converter.reset(new v210Converter());
 375
 376                 // These are all the widths listed in the Blackmagic SDK documentation
 377                 // (section 2.7.3, “Display Modes”).
 378                 v210_converter->precompile_shader(720);
 379                 v210_converter->precompile_shader(1280);
 380                 v210_converter->precompile_shader(1920);
 381                 v210_converter->precompile_shader(2048);
 382                 v210_converter->precompile_shader(3840);
 383                 v210_converter->precompile_shader(4096);
 384         }
 385         if (global_flags.ten_bit_output) {
 386                 if (!v210Converter::has_hardware_support()) {
 387                         fprintf(stderr, "ERROR: --ten-bit-output requires support for OpenGL compute shaders\n");
 388                         fprintf(stderr, "       (OpenGL 4.3, or GL_ARB_compute_shader + GL_ARB_shader_image_load_store).\n");
 389                         exit(1);
 390                 }
 391         }
 392
 393         timecode_renderer.reset(new TimecodeRenderer(resource_pool.get(), global_flags.width, global_flags.height));
 394         display_timecode_in_stream = global_flags.display_timecode_in_stream;
 395         display_timecode_on_stdout = global_flags.display_timecode_on_stdout;
 396
 397         if (global_flags.enable_alsa_output) {
 398                 alsa.reset(new ALSAOutput(OUTPUT_FREQUENCY, /*num_channels=*/2));
 399         }
 400         if (global_flags.output_card != -1) {
 401                 desired_output_card_index = global_flags.output_card;
 402                 set_output_card_internal(global_flags.output_card);
 403         }
 404
 405         metric_start_time_seconds = get_timestamp_for_metrics();
 406
 407         global_metrics.add("frames_output_total", &metric_frames_output_total);
 408         global_metrics.add("frames_output_dropped", &metric_frames_output_dropped);
 409         global_metrics.add("start_time_seconds", &metric_start_time_seconds, Metrics::TYPE_GAUGE);
 410         global_metrics.add("memory_used_bytes", &metrics_memory_used_bytes);
 411         global_metrics.add("metrics_memory_locked_limit_bytes", &metrics_memory_locked_limit_bytes);
 412 }
 413
 414 Mixer::~Mixer()
 415 {
 416         BMUSBCapture::stop_bm_thread();
 417
 418         for (unsigned card_index = 0; card_index < num_cards + num_video_inputs; ++card_index) {
 419                 {
 420                         unique_lock<mutex> lock(card_mutex);
 421                         cards[card_index].should_quit = true;  // Unblock thread.
 422                         cards[card_index].new_frames_changed.notify_all();
 423                 }
 424                 cards[card_index].capture->stop_dequeue_thread();
 425                 if (cards[card_index].output) {
 426                         cards[card_index].output->end_output();
 427                         cards[card_index].output.reset();
 428                 }
 429         }
 430
 431         video_encoder.reset(nullptr);
 432 }
 433
 434 void Mixer::configure_card(unsigned card_index, CaptureInterface *capture, CardType card_type, DeckLinkOutput *output)
 435 {
 436         printf("Configuring card %d...\n", card_index);
 437
 438         CaptureCard *card = &cards[card_index];
 439         if (card->capture != nullptr) {
 440                 card->capture->stop_dequeue_thread();
 441         }
 442         card->capture.reset(capture);
 443         card->is_fake_capture = (card_type == CardType::FAKE_CAPTURE);
 444         card->type = card_type;
 445         if (card->output.get() != output) {
 446                 card->output.reset(output);
 447         }
 448
 449         PixelFormat pixel_format;
 450         if (card_type == CardType::FFMPEG_INPUT) {
 451                 pixel_format = capture->get_current_pixel_format();
 452         } else if (global_flags.ten_bit_input) {
 453                 pixel_format = PixelFormat_10BitYCbCr;
 454         } else {
 455                 pixel_format = PixelFormat_8BitYCbCr;
 456         }
 457
 458         card->capture->set_frame_callback(bind(&Mixer::bm_frame, this, card_index, _1, _2, _3, _4, _5, _6, _7));
 459         if (card->frame_allocator == nullptr) {
 460                 card->frame_allocator.reset(new PBOFrameAllocator(pixel_format, 8 << 20, global_flags.width, global_flags.height));  // 8 MB.
 461         }
 462         card->capture->set_video_frame_allocator(card->frame_allocator.get());
 463         if (card->surface == nullptr) {
 464                 card->surface = create_surface_with_same_format(mixer_surface);
 465         }
 466         while (!card->new_frames.empty()) card->new_frames.pop_front();
 467         card->last_timecode = -1;
 468         card->capture->set_pixel_format(pixel_format);
 469         card->capture->configure_card();
 470
 471         // NOTE: start_bm_capture() happens in thread_func().
 472
 473         DeviceSpec device{InputSourceType::CAPTURE_CARD, card_index};
 474         audio_mixer.reset_resampler(device);
 475         audio_mixer.set_display_name(device, card->capture->get_description());
 476         audio_mixer.trigger_state_changed_callback();
 477
 478         // Register metrics.
 479         vector<pair<string, string>> labels;
 480         char card_name[64];
 481         snprintf(card_name, sizeof(card_name), "%d", card_index);
 482         labels.emplace_back("card", card_name);
 483
 484         switch (card_type) {
 485         case CardType::LIVE_CARD:
 486                 labels.emplace_back("cardtype", "live");
 487                 break;
 488         case CardType::FAKE_CAPTURE:
 489                 labels.emplace_back("cardtype", "fake");
 490                 break;
 491         case CardType::FFMPEG_INPUT:
 492                 labels.emplace_back("cardtype", "ffmpeg");
 493                 break;
 494         default:
 495                 assert(false);
 496         }
 497         card->queue_length_policy.register_metrics(labels);
 498         global_metrics.add("input_dropped_frames_jitter", labels, &card->metric_input_dropped_frames_jitter);
 499         global_metrics.add("input_dropped_frames_error", labels, &card->metric_input_dropped_frames_error);
 500         global_metrics.add("input_dropped_frames_resets", labels, &card->metric_input_resets);
 501
 502         global_metrics.add("input_has_signal_bool", labels, &card->metric_input_has_signal_bool, Metrics::TYPE_GAUGE);
 503         global_metrics.add("input_is_connected_bool", labels, &card->metric_input_is_connected_bool, Metrics::TYPE_GAUGE);
 504         global_metrics.add("input_interlaced_bool", labels, &card->metric_input_interlaced_bool, Metrics::TYPE_GAUGE);
 505         global_metrics.add("input_width_pixels", labels, &card->metric_input_width_pixels, Metrics::TYPE_GAUGE);
 506         global_metrics.add("input_height_pixels", labels, &card->metric_input_height_pixels, Metrics::TYPE_GAUGE);
 507         global_metrics.add("input_frame_rate_nom", labels, &card->metric_input_frame_rate_nom, Metrics::TYPE_GAUGE);
 508         global_metrics.add("input_frame_rate_den", labels, &card->metric_input_frame_rate_den, Metrics::TYPE_GAUGE);
 509         global_metrics.add("input_sample_rate_hz", labels, &card->metric_input_sample_rate_hz, Metrics::TYPE_GAUGE);
 510 }
 511
 512 void Mixer::set_output_card_internal(int card_index)
 513 {
 514         // We don't really need to take card_mutex, since we're in the mixer
 515         // thread and don't mess with any queues (which is the only thing that happens
 516         // from other threads), but it's probably the safest in the long run.
 517         unique_lock<mutex> lock(card_mutex);
 518         if (output_card_index != -1) {
 519                 // Switch the old card from output to input.
 520                 CaptureCard *old_card = &cards[output_card_index];
 521                 old_card->output->end_output();
 522
 523                 // Stop the fake card that we put into place.
 524                 // This needs to _not_ happen under the mutex, to avoid deadlock
 525                 // (delivering the last frame needs to take the mutex).
 526                 CaptureInterface *fake_capture = old_card->capture.get();
 527                 lock.unlock();
 528                 fake_capture->stop_dequeue_thread();
 529                 lock.lock();
 530                 old_card->capture = move(old_card->parked_capture);
 531                 old_card->is_fake_capture = false;
 532                 old_card->capture->start_bm_capture();
 533         }
 534         if (card_index != -1) {
 535                 CaptureCard *card = &cards[card_index];
 536                 CaptureInterface *capture = card->capture.get();
 537                 // TODO: DeckLinkCapture::stop_dequeue_thread can actually take
 538                 // several seconds to complete (blocking on DisableVideoInput);
 539                 // see if we can maybe do it asynchronously.
 540                 lock.unlock();
 541                 capture->stop_dequeue_thread();
 542                 lock.lock();
 543                 card->parked_capture = move(card->capture);
 544                 CaptureInterface *fake_capture = new FakeCapture(global_flags.width, global_flags.height, FAKE_FPS, OUTPUT_FREQUENCY, card_index, global_flags.fake_cards_audio);
 545                 configure_card(card_index, fake_capture, CardType::FAKE_CAPTURE, card->output.release());
 546                 card->queue_length_policy.reset(card_index);
 547                 card->capture->start_bm_capture();
 548                 desired_output_video_mode = output_video_mode = card->output->pick_video_mode(desired_output_video_mode);
 549                 card->output->start_output(desired_output_video_mode, pts_int);
 550         }
 551         output_card_index = card_index;
 552 }
 553
 554 namespace {
 555
 556 int unwrap_timecode(uint16_t current_wrapped, int last)
 557 {
 558         uint16_t last_wrapped = last & 0xffff;
 559         if (current_wrapped > last_wrapped) {
 560                 return (last & ~0xffff) | current_wrapped;
 561         } else {
 562                 return 0x10000 + ((last & ~0xffff) | current_wrapped);
 563         }
 564 }
 565
 566 }  // namespace
 567
 568 void Mixer::bm_frame(unsigned card_index, uint16_t timecode,
 569                      FrameAllocator::Frame video_frame, size_t video_offset, VideoFormat video_format,
 570                      FrameAllocator::Frame audio_frame, size_t audio_offset, AudioFormat audio_format)
 571 {
 572         DeviceSpec device{InputSourceType::CAPTURE_CARD, card_index};
 573         CaptureCard *card = &cards[card_index];
 574
 575         card->metric_input_has_signal_bool = video_format.has_signal;
 576         card->metric_input_is_connected_bool = video_format.is_connected;
 577         card->metric_input_interlaced_bool = video_format.interlaced;
 578         card->metric_input_width_pixels = video_format.width;
 579         card->metric_input_height_pixels = video_format.height;
 580         card->metric_input_frame_rate_nom = video_format.frame_rate_nom;
 581         card->metric_input_frame_rate_den = video_format.frame_rate_den;
 582         card->metric_input_sample_rate_hz = audio_format.sample_rate;
 583
 584         if (is_mode_scanning[card_index]) {
 585                 if (video_format.has_signal) {
 586                         // Found a stable signal, so stop scanning.
 587                         is_mode_scanning[card_index] = false;
 588                 } else {
 589                         static constexpr double switch_time_s = 0.1;  // Should be enough time for the signal to stabilize.
 590                         steady_clock::time_point now = steady_clock::now();
 591                         double sec_since_last_switch = duration<double>(steady_clock::now() - last_mode_scan_change[card_index]).count();
 592                         if (sec_since_last_switch > switch_time_s) {
 593                                 // It isn't this mode; try the next one.
 594                                 mode_scanlist_index[card_index]++;
 595                                 mode_scanlist_index[card_index] %= mode_scanlist[card_index].size();
 596                                 cards[card_index].capture->set_video_mode(mode_scanlist[card_index][mode_scanlist_index[card_index]]);
 597                                 last_mode_scan_change[card_index] = now;
 598                         }
 599                 }
 600         }
 601
 602         int64_t frame_length = int64_t(TIMEBASE) * video_format.frame_rate_den / video_format.frame_rate_nom;
 603         assert(frame_length > 0);
 604
 605         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;
 606         if (num_samples > OUTPUT_FREQUENCY / 10) {
 607                 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",
 608                         card_index, int(audio_frame.len), int(audio_offset),
 609                         timecode, int(video_frame.len), int(video_offset), video_format.id);
 610                 if (video_frame.owner) {
 611                         video_frame.owner->release_frame(video_frame);
 612                 }
 613                 if (audio_frame.owner) {
 614                         audio_frame.owner->release_frame(audio_frame);
 615                 }
 616                 return;
 617         }
 618
 619         int dropped_frames = 0;
 620         if (card->last_timecode != -1) {
 621                 dropped_frames = unwrap_timecode(timecode, card->last_timecode) - card->last_timecode - 1;
 622         }
 623
 624         // Number of samples per frame if we need to insert silence.
 625         // (Could be nonintegral, but resampling will save us then.)
 626         const int silence_samples = OUTPUT_FREQUENCY * video_format.frame_rate_den / video_format.frame_rate_nom;
 627
 628         if (dropped_frames > MAX_FPS * 2) {
 629                 fprintf(stderr, "Card %d lost more than two seconds (or time code jumping around; from 0x%04x to 0x%04x), resetting resampler\n",
 630                         card_index, card->last_timecode, timecode);
 631                 audio_mixer.reset_resampler(device);
 632                 dropped_frames = 0;
 633                 ++card->metric_input_resets;
 634         } else if (dropped_frames > 0) {
 635                 // Insert silence as needed.
 636                 fprintf(stderr, "Card %d dropped %d frame(s) (before timecode 0x%04x), inserting silence.\n",
 637                         card_index, dropped_frames, timecode);
 638                 card->metric_input_dropped_frames_error += dropped_frames;
 639
 640                 bool success;
 641                 do {
 642                         success = audio_mixer.add_silence(device, silence_samples, dropped_frames, frame_length);
 643                 } while (!success);
 644         }
 645
 646         audio_mixer.add_audio(device, audio_frame.data + audio_offset, num_samples, audio_format, frame_length, audio_frame.received_timestamp);
 647
 648         // Done with the audio, so release it.
 649         if (audio_frame.owner) {
 650                 audio_frame.owner->release_frame(audio_frame);
 651         }
 652
 653         card->last_timecode = timecode;
 654
 655         PBOFrameAllocator::Userdata *userdata = (PBOFrameAllocator::Userdata *)video_frame.userdata;
 656
 657         size_t cbcr_width, cbcr_height, cbcr_offset, y_offset;
 658         size_t expected_length = video_format.stride * (video_format.height + video_format.extra_lines_top + video_format.extra_lines_bottom);
 659         if (userdata != nullptr && userdata->pixel_format == PixelFormat_8BitYCbCrPlanar) {
 660                 // The calculation above is wrong for planar Y'CbCr, so just override it.
 661                 assert(card->type == CardType::FFMPEG_INPUT);
 662                 assert(video_offset == 0);
 663                 expected_length = video_frame.len;
 664
 665                 userdata->ycbcr_format = (static_cast<FFmpegCapture *>(card->capture.get()))->get_current_frame_ycbcr_format();
 666                 cbcr_width = video_format.width / userdata->ycbcr_format.chroma_subsampling_x;
 667                 cbcr_height = video_format.height / userdata->ycbcr_format.chroma_subsampling_y;
 668                 cbcr_offset = video_format.width * video_format.height;
 669                 y_offset = 0;
 670         } else {
 671                 // All the other Y'CbCr formats are 4:2:2.
 672                 cbcr_width = video_format.width / 2;
 673                 cbcr_height = video_format.height;
 674                 cbcr_offset = video_offset / 2;
 675                 y_offset = video_frame.size / 2 + video_offset / 2;
 676         }
 677         if (video_frame.len - video_offset == 0 ||
 678             video_frame.len - video_offset != expected_length) {
 679                 if (video_frame.len != 0) {
 680                         printf("Card %d: Dropping video frame with wrong length (%ld; expected %ld)\n",
 681                                 card_index, video_frame.len - video_offset, expected_length);
 682                 }
 683                 if (video_frame.owner) {
 684                         video_frame.owner->release_frame(video_frame);
 685                 }
 686
 687                 // Still send on the information that we _had_ a frame, even though it's corrupted,
 688                 // so that pts can go up accordingly.
 689                 {
 690                         unique_lock<mutex> lock(card_mutex);
 691                         CaptureCard::NewFrame new_frame;
 692                         new_frame.frame = RefCountedFrame(FrameAllocator::Frame());
 693                         new_frame.length = frame_length;
 694                         new_frame.interlaced = false;
 695                         new_frame.dropped_frames = dropped_frames;
 696                         new_frame.received_timestamp = video_frame.received_timestamp;
 697                         card->new_frames.push_back(move(new_frame));
 698                         card->new_frames_changed.notify_all();
 699                 }
 700                 return;
 701         }
 702
 703         unsigned num_fields = video_format.interlaced ? 2 : 1;
 704         steady_clock::time_point frame_upload_start;
 705         bool interlaced_stride = false;
 706         if (video_format.interlaced) {
 707                 // Send the two fields along as separate frames; the other side will need to add
 708                 // a deinterlacer to actually get this right.
 709                 assert(video_format.height % 2 == 0);
 710                 video_format.height /= 2;
 711                 cbcr_height /= 2;
 712                 assert(frame_length % 2 == 0);
 713                 frame_length /= 2;
 714                 num_fields = 2;
 715                 if (video_format.second_field_start == 1) {
 716                         interlaced_stride = true;
 717                 }
 718                 frame_upload_start = steady_clock::now();
 719         }
 720         userdata->last_interlaced = video_format.interlaced;
 721         userdata->last_has_signal = video_format.has_signal;
 722         userdata->last_is_connected = video_format.is_connected;
 723         userdata->last_frame_rate_nom = video_format.frame_rate_nom;
 724         userdata->last_frame_rate_den = video_format.frame_rate_den;
 725         RefCountedFrame frame(video_frame);
 726
 727         // Upload the textures.
 728         for (unsigned field = 0; field < num_fields; ++field) {
 729                 // Put the actual texture upload in a lambda that is executed in the main thread.
 730                 // It is entirely possible to do this in the same thread (and it might even be
 731                 // faster, depending on the GPU and driver), but it appears to be trickling
 732                 // driver bugs very easily.
 733                 //
 734                 // Note that this means we must hold on to the actual frame data in <userdata>
 735                 // until the upload command is run, but we hold on to <frame> much longer than that
 736                 // (in fact, all the way until we no longer use the texture in rendering).
 737                 auto upload_func = [this, field, video_format, y_offset, video_offset, cbcr_offset, cbcr_width, cbcr_height, interlaced_stride, userdata]() {
 738                         unsigned field_start_line;
 739                         if (field == 1) {
 740                                 field_start_line = video_format.second_field_start;
 741                         } else {
 742                                 field_start_line = video_format.extra_lines_top;
 743                         }
 744
 745                         // For anything not FRAME_FORMAT_YCBCR_10BIT, v210_width will be nonsensical but not used.
 746                         size_t v210_width = video_format.stride / sizeof(uint32_t);
 747                         ensure_texture_resolution(userdata, field, video_format.width, video_format.height, cbcr_width, cbcr_height, v210_width);
 748
 749                         glBindBuffer(GL_PIXEL_UNPACK_BUFFER, userdata->pbo);
 750                         check_error();
 751
 752                         switch (userdata->pixel_format) {
 753                         case PixelFormat_10BitYCbCr: {
 754                                 size_t field_start = video_offset + video_format.stride * field_start_line;
 755                                 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);
 756                                 v210_converter->convert(userdata->tex_v210[field], userdata->tex_444[field], video_format.width, video_format.height);
 757                                 break;
 758                         }
 759                         case PixelFormat_8BitYCbCr: {
 760                                 size_t field_y_start = y_offset + video_format.width * field_start_line;
 761                                 size_t field_cbcr_start = cbcr_offset + cbcr_width * field_start_line * sizeof(uint16_t);
 762
 763                                 // Make up our own strides, since we are interleaving.
 764                                 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);
 765                                 upload_texture(userdata->tex_cbcr[field], cbcr_width, cbcr_height, cbcr_width * sizeof(uint16_t), interlaced_stride, GL_RG, GL_UNSIGNED_BYTE, field_cbcr_start);
 766                                 break;
 767                         }
 768                         case PixelFormat_8BitYCbCrPlanar: {
 769                                 assert(field_start_line == 0);  // We don't really support interlaced here.
 770                                 size_t field_y_start = y_offset;
 771                                 size_t field_cb_start = cbcr_offset;
 772                                 size_t field_cr_start = cbcr_offset + cbcr_width * cbcr_height;
 773
 774                                 // Make up our own strides, since we are interleaving.
 775                                 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);
 776                                 upload_texture(userdata->tex_cb[field], cbcr_width, cbcr_height, cbcr_width, interlaced_stride, GL_RED, GL_UNSIGNED_BYTE, field_cb_start);
 777                                 upload_texture(userdata->tex_cr[field], cbcr_width, cbcr_height, cbcr_width, interlaced_stride, GL_RED, GL_UNSIGNED_BYTE, field_cr_start);
 778                                 break;
 779                         }
 780                         case PixelFormat_8BitBGRA: {
 781                                 size_t field_start = video_offset + video_format.stride * field_start_line;
 782                                 upload_texture(userdata->tex_rgba[field], video_format.width, video_format.height, video_format.stride, interlaced_stride, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, field_start);
 783                                 // These could be asked to deliver mipmaps at any time.
 784                                 glBindTexture(GL_TEXTURE_2D, userdata->tex_rgba[field]);
 785                                 check_error();
 786                                 glGenerateMipmap(GL_TEXTURE_2D);
 787                                 check_error();
 788                                 glBindTexture(GL_TEXTURE_2D, 0);
 789                                 check_error();
 790                                 break;
 791                         }
 792                         default:
 793                                 assert(false);
 794                         }
 795
 796                         glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
 797                         check_error();
 798                 };
 799
 800                 if (field == 1) {
 801                         // Don't upload the second field as fast as we can; wait until
 802                         // the field time has approximately passed. (Otherwise, we could
 803                         // get timing jitter against the other sources, and possibly also
 804                         // against the video display, although the latter is not as critical.)
 805                         // This requires our system clock to be reasonably close to the
 806                         // video clock, but that's not an unreasonable assumption.
 807                         steady_clock::time_point second_field_start = frame_upload_start +
 808                                 nanoseconds(frame_length * 1000000000 / TIMEBASE);
 809                         this_thread::sleep_until(second_field_start);
 810                 }
 811
 812                 {
 813                         unique_lock<mutex> lock(card_mutex);
 814                         CaptureCard::NewFrame new_frame;
 815                         new_frame.frame = frame;
 816                         new_frame.length = frame_length;
 817                         new_frame.field = field;
 818                         new_frame.interlaced = video_format.interlaced;
 819                         new_frame.upload_func = upload_func;
 820                         new_frame.dropped_frames = dropped_frames;
 821                         new_frame.received_timestamp = video_frame.received_timestamp;  // Ignore the audio timestamp.
 822                         card->new_frames.push_back(move(new_frame));
 823                         card->new_frames_changed.notify_all();
 824                 }
 825         }
 826 }
 827
 828 void Mixer::bm_hotplug_add(libusb_device *dev)
 829 {
 830         lock_guard<mutex> lock(hotplug_mutex);
 831         hotplugged_cards.push_back(dev);
 832 }
 833
 834 void Mixer::bm_hotplug_remove(unsigned card_index)
 835 {
 836         cards[card_index].new_frames_changed.notify_all();
 837 }
 838
 839 void Mixer::thread_func()
 840 {
 841         pthread_setname_np(pthread_self(), "Mixer_OpenGL");
 842
 843         eglBindAPI(EGL_OPENGL_API);
 844         QOpenGLContext *context = create_context(mixer_surface);
 845         if (!make_current(context, mixer_surface)) {
 846                 printf("oops\n");
 847                 exit(1);
 848         }
 849
 850         // Start the actual capture. (We don't want to do it before we're actually ready
 851         // to process output frames.)
 852         for (unsigned card_index = 0; card_index < num_cards + num_video_inputs; ++card_index) {
 853                 if (int(card_index) != output_card_index) {
 854                         cards[card_index].capture->start_bm_capture();
 855                 }
 856         }
 857
 858         steady_clock::time_point start, now;
 859         start = steady_clock::now();
 860
 861         int stats_dropped_frames = 0;
 862
 863         while (!should_quit) {
 864                 if (desired_output_card_index != output_card_index) {
 865                         set_output_card_internal(desired_output_card_index);
 866                 }
 867                 if (output_card_index != -1 &&
 868                     desired_output_video_mode != output_video_mode) {
 869                         DeckLinkOutput *output = cards[output_card_index].output.get();
 870                         output->end_output();
 871                         desired_output_video_mode = output_video_mode = output->pick_video_mode(desired_output_video_mode);
 872                         output->start_output(desired_output_video_mode, pts_int);
 873                 }
 874
 875                 CaptureCard::NewFrame new_frames[MAX_VIDEO_CARDS];
 876                 bool has_new_frame[MAX_VIDEO_CARDS] = { false };
 877
 878                 bool master_card_is_output;
 879                 unsigned master_card_index;
 880                 if (output_card_index != -1) {
 881                         master_card_is_output = true;
 882                         master_card_index = output_card_index;
 883                 } else {
 884                         master_card_is_output = false;
 885                         master_card_index = theme->map_signal(master_clock_channel);
 886                         assert(master_card_index < num_cards);
 887                 }
 888
 889                 OutputFrameInfo output_frame_info = get_one_frame_from_each_card(master_card_index, master_card_is_output, new_frames, has_new_frame);
 890                 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);
 891                 stats_dropped_frames += output_frame_info.dropped_frames;
 892
 893                 handle_hotplugged_cards();
 894
 895                 for (unsigned card_index = 0; card_index < num_cards + num_video_inputs; ++card_index) {
 896                         if (card_index == master_card_index || !has_new_frame[card_index]) {
 897                                 continue;
 898                         }
 899                         if (new_frames[card_index].frame->len == 0) {
 900                                 ++new_frames[card_index].dropped_frames;
 901                         }
 902                         if (new_frames[card_index].dropped_frames > 0) {
 903                                 printf("Card %u dropped %d frames before this\n",
 904                                         card_index, int(new_frames[card_index].dropped_frames));
 905                         }
 906                 }
 907
 908                 // If the first card is reporting a corrupted or otherwise dropped frame,
 909                 // just increase the pts (skipping over this frame) and don't try to compute anything new.
 910                 if (!master_card_is_output && new_frames[master_card_index].frame->len == 0) {
 911                         ++stats_dropped_frames;
 912                         pts_int += new_frames[master_card_index].length;
 913                         continue;
 914                 }
 915
 916                 for (unsigned card_index = 0; card_index < num_cards + num_video_inputs; ++card_index) {
 917                         if (!has_new_frame[card_index] || new_frames[card_index].frame->len == 0)
 918                                 continue;
 919
 920                         CaptureCard::NewFrame *new_frame = &new_frames[card_index];
 921                         assert(new_frame->frame != nullptr);
 922                         insert_new_frame(new_frame->frame, new_frame->field, new_frame->interlaced, card_index, &input_state);
 923                         check_error();
 924
 925                         // The new texture might need uploading before use.
 926                         if (new_frame->upload_func) {
 927                                 new_frame->upload_func();
 928                                 new_frame->upload_func = nullptr;
 929                         }
 930                 }
 931
 932                 int64_t frame_duration = output_frame_info.frame_duration;
 933                 render_one_frame(frame_duration);
 934                 ++frame_num;
 935                 pts_int += frame_duration;
 936
 937                 now = steady_clock::now();
 938                 double elapsed = duration<double>(now - start).count();
 939
 940                 metric_frames_output_total = frame_num;
 941                 metric_frames_output_dropped = stats_dropped_frames;
 942
 943                 if (frame_num % 100 == 0) {
 944                         printf("%d frames (%d dropped) in %.3f seconds = %.1f fps (%.1f ms/frame)",
 945                                 frame_num, stats_dropped_frames, elapsed, frame_num / elapsed,
 946                                 1e3 * elapsed / frame_num);
 947                 //      chain->print_phase_timing();
 948
 949                         // Check our memory usage, to see if we are close to our mlockall()
 950                         // limit (if at all set).
 951                         rusage used;
 952                         if (getrusage(RUSAGE_SELF, &used) == -1) {
 953                                 perror("getrusage(RUSAGE_SELF)");
 954                                 assert(false);
 955                         }
 956
 957                         if (uses_mlock) {
 958                                 rlimit limit;
 959                                 if (getrlimit(RLIMIT_MEMLOCK, &limit) == -1) {
 960                                         perror("getrlimit(RLIMIT_MEMLOCK)");
 961                                         assert(false);
 962                                 }
 963
 964                                 if (limit.rlim_cur == 0) {
 965                                         printf(", using %ld MB memory (locked)",
 966                                                 long(used.ru_maxrss / 1024));
 967                                 } else {
 968                                         printf(", using %ld / %ld MB lockable memory (%.1f%%)",
 969                                                 long(used.ru_maxrss / 1024),
 970                                                 long(limit.rlim_cur / 1048576),
 971                                                 float(100.0 * (used.ru_maxrss * 1024.0) / limit.rlim_cur));
 972                                 }
 973                                 metrics_memory_locked_limit_bytes = limit.rlim_cur;
 974                         } else {
 975                                 printf(", using %ld MB memory (not locked)",
 976                                         long(used.ru_maxrss / 1024));
 977                                 metrics_memory_locked_limit_bytes = 0.0 / 0.0;
 978                         }
 979
 980                         printf("\n");
 981
 982                         metrics_memory_used_bytes = used.ru_maxrss;
 983                 }
 984
 985
 986                 if (should_cut.exchange(false)) {  // Test and clear.
 987                         video_encoder->do_cut(frame_num);
 988                 }
 989
 990 #if 0
 991                 // Reset every 100 frames, so that local variations in frame times
 992                 // (especially for the first few frames, when the shaders are
 993                 // compiled etc.) don't make it hard to measure for the entire
 994                 // remaining duration of the program.
 995                 if (frame == 10000) {
 996                         frame = 0;
 997                         start = now;
 998                 }
 999 #endif
1000                 check_error();
1001         }
1002
1003         resource_pool->clean_context();
1004 }
1005
1006 bool Mixer::input_card_is_master_clock(unsigned card_index, unsigned master_card_index) const
1007 {
1008         if (output_card_index != -1) {
1009                 // The output card (ie., cards[output_card_index].output) is the master clock,
1010                 // so no input card (ie., cards[card_index].capture) is.
1011                 return false;
1012         }
1013         return (card_index == master_card_index);
1014 }
1015
1016 void Mixer::trim_queue(CaptureCard *card, unsigned card_index)
1017 {
1018         // Count the number of frames in the queue, including any frames
1019         // we dropped. It's hard to know exactly how we should deal with
1020         // dropped (corrupted) input frames; they don't help our goal of
1021         // avoiding starvation, but they still add to the problem of latency.
1022         // Since dropped frames is going to mean a bump in the signal anyway,
1023         // we err on the side of having more stable latency instead.
1024         unsigned queue_length = 0;
1025         for (const CaptureCard::NewFrame &frame : card->new_frames) {
1026                 queue_length += frame.dropped_frames + 1;
1027         }
1028         card->queue_length_policy.update_policy(queue_length);
1029
1030         // If needed, drop frames until the queue is below the safe limit.
1031         // We prefer to drop from the head, because all else being equal,
1032         // we'd like more recent frames (less latency).
1033         unsigned dropped_frames = 0;
1034         while (queue_length > card->queue_length_policy.get_safe_queue_length()) {
1035                 assert(!card->new_frames.empty());
1036                 assert(queue_length > card->new_frames.front().dropped_frames);
1037                 queue_length -= card->new_frames.front().dropped_frames;
1038
1039                 if (queue_length <= card->queue_length_policy.get_safe_queue_length()) {
1040                         // No need to drop anything.
1041                         break;
1042                 }
1043
1044                 card->new_frames.pop_front();
1045                 card->new_frames_changed.notify_all();
1046                 --queue_length;
1047                 ++dropped_frames;
1048         }
1049
1050         card->metric_input_dropped_frames_jitter += dropped_frames;
1051
1052 #if 0
1053         if (dropped_frames > 0) {
1054                 fprintf(stderr, "Card %u dropped %u frame(s) to keep latency down.\n",
1055                         card_index, dropped_frames);
1056         }
1057 #endif
1058 }
1059
1060
1061 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])
1062 {
1063         OutputFrameInfo output_frame_info;
1064 start:
1065         unique_lock<mutex> lock(card_mutex, defer_lock);
1066         if (master_card_is_output) {
1067                 // Clocked to the output, so wait for it to be ready for the next frame.
1068                 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);
1069                 lock.lock();
1070         } else {
1071                 // Wait for the master card to have a new frame.
1072                 // TODO: Add a timeout.
1073                 output_frame_info.is_preroll = false;
1074                 lock.lock();
1075                 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(); });
1076         }
1077
1078         if (master_card_is_output) {
1079                 handle_hotplugged_cards();
1080         } else if (cards[master_card_index].new_frames.empty()) {
1081                 // We were woken up, but not due to a new frame. Deal with it
1082                 // and then restart.
1083                 assert(cards[master_card_index].capture->get_disconnected());
1084                 handle_hotplugged_cards();
1085                 goto start;
1086         }
1087
1088         if (!master_card_is_output) {
1089                 output_frame_info.frame_timestamp =
1090                         cards[master_card_index].new_frames.front().received_timestamp;
1091         }
1092
1093         for (unsigned card_index = 0; card_index < num_cards + num_video_inputs; ++card_index) {
1094                 CaptureCard *card = &cards[card_index];
1095                 if (input_card_is_master_clock(card_index, master_card_index)) {
1096                         // We don't use the queue length policy for the master card,
1097                         // but we will if it stops being the master. Thus, clear out
1098                         // the policy in case we switch in the future.
1099                         card->queue_length_policy.reset(card_index);
1100                         assert(!card->new_frames.empty());
1101                 } else {
1102                         trim_queue(card, card_index);
1103                 }
1104                 if (!card->new_frames.empty()) {
1105                         new_frames[card_index] = move(card->new_frames.front());
1106                         has_new_frame[card_index] = true;
1107                         card->new_frames.pop_front();
1108                         card->new_frames_changed.notify_all();
1109                 }
1110         }
1111
1112         if (!master_card_is_output) {
1113                 output_frame_info.dropped_frames = new_frames[master_card_index].dropped_frames;
1114                 output_frame_info.frame_duration = new_frames[master_card_index].length;
1115         }
1116
1117         // This might get off by a fractional sample when changing master card
1118         // between ones with different frame rates, but that's fine.
1119         int num_samples_times_timebase = OUTPUT_FREQUENCY * output_frame_info.frame_duration + fractional_samples;
1120         output_frame_info.num_samples = num_samples_times_timebase / TIMEBASE;
1121         fractional_samples = num_samples_times_timebase % TIMEBASE;
1122         assert(output_frame_info.num_samples >= 0);
1123
1124         return output_frame_info;
1125 }
1126
1127 void Mixer::handle_hotplugged_cards()
1128 {
1129         // Check for cards that have been disconnected since last frame.
1130         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
1131                 CaptureCard *card = &cards[card_index];
1132                 if (card->capture->get_disconnected()) {
1133                         fprintf(stderr, "Card %u went away, replacing with a fake card.\n", card_index);
1134                         FakeCapture *capture = new FakeCapture(global_flags.width, global_flags.height, FAKE_FPS, OUTPUT_FREQUENCY, card_index, global_flags.fake_cards_audio);
1135                         configure_card(card_index, capture, CardType::FAKE_CAPTURE, /*output=*/nullptr);
1136                         card->queue_length_policy.reset(card_index);
1137                         card->capture->start_bm_capture();
1138                 }
1139         }
1140
1141         // Check for cards that have been connected since last frame.
1142         vector<libusb_device *> hotplugged_cards_copy;
1143         {
1144                 lock_guard<mutex> lock(hotplug_mutex);
1145                 swap(hotplugged_cards, hotplugged_cards_copy);
1146         }
1147         for (libusb_device *new_dev : hotplugged_cards_copy) {
1148                 // Look for a fake capture card where we can stick this in.
1149                 int free_card_index = -1;
1150                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
1151                         if (cards[card_index].is_fake_capture) {
1152                                 free_card_index = card_index;
1153                                 break;
1154                         }
1155                 }
1156
1157                 if (free_card_index == -1) {
1158                         fprintf(stderr, "New card plugged in, but no free slots -- ignoring.\n");
1159                         libusb_unref_device(new_dev);
1160                 } else {
1161                         // BMUSBCapture takes ownership.
1162                         fprintf(stderr, "New card plugged in, choosing slot %d.\n", free_card_index);
1163                         CaptureCard *card = &cards[free_card_index];
1164                         BMUSBCapture *capture = new BMUSBCapture(free_card_index, new_dev);
1165                         configure_card(free_card_index, capture, CardType::LIVE_CARD, /*output=*/nullptr);
1166                         card->queue_length_policy.reset(free_card_index);
1167                         capture->set_card_disconnected_callback(bind(&Mixer::bm_hotplug_remove, this, free_card_index));
1168                         capture->start_bm_capture();
1169                 }
1170         }
1171 }
1172
1173
1174 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)
1175 {
1176         // Resample the audio as needed, including from previously dropped frames.
1177         assert(num_cards > 0);
1178         for (unsigned frame_num = 0; frame_num < dropped_frames + 1; ++frame_num) {
1179                 const bool dropped_frame = (frame_num != dropped_frames);
1180                 {
1181                         // Signal to the audio thread to process this frame.
1182                         // Note that if the frame is a dropped frame, we signal that
1183                         // we don't want to use this frame as base for adjusting
1184                         // the resampler rate. The reason for this is that the timing
1185                         // of these frames is often way too late; they typically don't
1186                         // “arrive” before we synthesize them. Thus, we could end up
1187                         // in a situation where we have inserted e.g. five audio frames
1188                         // into the queue before we then start pulling five of them
1189                         // back out. This makes ResamplingQueue overestimate the delay,
1190                         // causing undue resampler changes. (We _do_ use the last,
1191                         // non-dropped frame; perhaps we should just discard that as well,
1192                         // since dropped frames are expected to be rare, and it might be
1193                         // better to just wait until we have a slightly more normal situation).
1194                         unique_lock<mutex> lock(audio_mutex);
1195                         bool adjust_rate = !dropped_frame && !is_preroll;
1196                         audio_task_queue.push(AudioTask{pts_int, num_samples_per_frame, adjust_rate, frame_timestamp});
1197                         audio_task_queue_changed.notify_one();
1198                 }
1199                 if (dropped_frame) {
1200                         // For dropped frames, increase the pts. Note that if the format changed
1201                         // in the meantime, we have no way of detecting that; we just have to
1202                         // assume the frame length is always the same.
1203                         pts_int += length_per_frame;
1204                 }
1205         }
1206 }
1207
1208 void Mixer::render_one_frame(int64_t duration)
1209 {
1210         // Determine the time code for this frame before we start rendering.
1211         string timecode_text = timecode_renderer->get_timecode_text(double(pts_int) / TIMEBASE, frame_num);
1212         if (display_timecode_on_stdout) {
1213                 printf("Timecode: '%s'\n", timecode_text.c_str());
1214         }
1215
1216         // Update Y'CbCr settings for all cards.
1217         {
1218                 unique_lock<mutex> lock(card_mutex);
1219                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
1220                         YCbCrInterpretation *interpretation = &ycbcr_interpretation[card_index];
1221                         input_state.ycbcr_coefficients_auto[card_index] = interpretation->ycbcr_coefficients_auto;
1222                         input_state.ycbcr_coefficients[card_index] = interpretation->ycbcr_coefficients;
1223                         input_state.full_range[card_index] = interpretation->full_range;
1224                 }
1225         }
1226
1227         // Get the main chain from the theme, and set its state immediately.
1228         Theme::Chain theme_main_chain = theme->get_chain(0, pts(), global_flags.width, global_flags.height, input_state);
1229         EffectChain *chain = theme_main_chain.chain;
1230         theme_main_chain.setup_chain();
1231         //theme_main_chain.chain->enable_phase_timing(true);
1232
1233         // The theme can't (or at least shouldn't!) call connect_signal() on
1234         // each FFmpeg input, so we'll do it here.
1235         for (const pair<LiveInputWrapper *, FFmpegCapture *> &conn : theme->get_signal_connections()) {
1236                 conn.first->connect_signal_raw(conn.second->get_card_index());
1237         }
1238
1239         // If HDMI/SDI output is active and the user has requested auto mode,
1240         // its mode overrides the existing Y'CbCr setting for the chain.
1241         YCbCrLumaCoefficients ycbcr_output_coefficients;
1242         if (global_flags.ycbcr_auto_coefficients && output_card_index != -1) {
1243                 ycbcr_output_coefficients = cards[output_card_index].output->preferred_ycbcr_coefficients();
1244         } else {
1245                 ycbcr_output_coefficients = global_flags.ycbcr_rec709_coefficients ? YCBCR_REC_709 : YCBCR_REC_601;
1246         }
1247
1248         // TODO: Reduce the duplication against theme.cpp.
1249         YCbCrFormat output_ycbcr_format;
1250         output_ycbcr_format.chroma_subsampling_x = 1;
1251         output_ycbcr_format.chroma_subsampling_y = 1;
1252         output_ycbcr_format.luma_coefficients = ycbcr_output_coefficients;
1253         output_ycbcr_format.full_range = false;
1254         output_ycbcr_format.num_levels = 1 << global_flags.x264_bit_depth;
1255         chain->change_ycbcr_output_format(output_ycbcr_format);
1256
1257         // Render main chain. If we're using zerocopy Quick Sync encoding
1258         // (the default case), we take an extra copy of the created outputs,
1259         // so that we can display it back to the screen later (it's less memory
1260         // bandwidth than writing and reading back an RGBA texture, even at 16-bit).
1261         // Ideally, we'd like to avoid taking copies and just use the main textures
1262         // for display as well, but they're just views into VA-API memory and must be
1263         // unmapped during encoding, so we can't use them for display, unfortunately.
1264         GLuint y_tex, cbcr_full_tex, cbcr_tex;
1265         GLuint y_copy_tex, cbcr_copy_tex = 0;
1266         GLuint y_display_tex, cbcr_display_tex;
1267         GLenum y_type = (global_flags.x264_bit_depth > 8) ? GL_R16 : GL_R8;
1268         GLenum cbcr_type = (global_flags.x264_bit_depth > 8) ? GL_RG16 : GL_RG8;
1269         const bool is_zerocopy = video_encoder->is_zerocopy();
1270         if (is_zerocopy) {
1271                 cbcr_full_tex = resource_pool->create_2d_texture(cbcr_type, global_flags.width, global_flags.height);
1272                 y_copy_tex = resource_pool->create_2d_texture(y_type, global_flags.width, global_flags.height);
1273                 cbcr_copy_tex = resource_pool->create_2d_texture(cbcr_type, global_flags.width / 2, global_flags.height / 2);
1274
1275                 y_display_tex = y_copy_tex;
1276                 cbcr_display_tex = cbcr_copy_tex;
1277
1278                 // y_tex and cbcr_tex will be given by VideoEncoder.
1279         } else {
1280                 cbcr_full_tex = resource_pool->create_2d_texture(cbcr_type, global_flags.width, global_flags.height);
1281                 y_tex = resource_pool->create_2d_texture(y_type, global_flags.width, global_flags.height);
1282                 cbcr_tex = resource_pool->create_2d_texture(cbcr_type, global_flags.width / 2, global_flags.height / 2);
1283
1284                 y_display_tex = y_tex;
1285                 cbcr_display_tex = cbcr_tex;
1286         }
1287
1288         const int64_t av_delay = lrint(global_flags.audio_queue_length_ms * 0.001 * TIMEBASE);  // Corresponds to the delay in ResamplingQueue.
1289         bool got_frame = video_encoder->begin_frame(pts_int + av_delay, duration, ycbcr_output_coefficients, theme_main_chain.input_frames, &y_tex, &cbcr_tex);
1290         assert(got_frame);
1291
1292         GLuint fbo;
1293         if (is_zerocopy) {
1294                 fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex, y_copy_tex);
1295         } else {
1296                 fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex);
1297         }
1298         check_error();
1299         chain->render_to_fbo(fbo, global_flags.width, global_flags.height);
1300
1301         if (display_timecode_in_stream) {
1302                 // Render the timecode on top.
1303                 timecode_renderer->render_timecode(fbo, timecode_text);
1304         }
1305
1306         resource_pool->release_fbo(fbo);
1307
1308         if (is_zerocopy) {
1309                 chroma_subsampler->subsample_chroma(cbcr_full_tex, global_flags.width, global_flags.height, cbcr_tex, cbcr_copy_tex);
1310         } else {
1311                 chroma_subsampler->subsample_chroma(cbcr_full_tex, global_flags.width, global_flags.height, cbcr_tex);
1312         }
1313         if (output_card_index != -1) {
1314                 cards[output_card_index].output->send_frame(y_tex, cbcr_full_tex, ycbcr_output_coefficients, theme_main_chain.input_frames, pts_int, duration);
1315         }
1316         resource_pool->release_2d_texture(cbcr_full_tex);
1317
1318         // Set the right state for the Y' and CbCr textures we use for display.
1319         glBindFramebuffer(GL_FRAMEBUFFER, 0);
1320         glBindTexture(GL_TEXTURE_2D, y_display_tex);
1321         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1322         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
1323         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
1324
1325         glBindTexture(GL_TEXTURE_2D, cbcr_display_tex);
1326         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1327         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
1328         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
1329
1330         RefCountedGLsync fence = video_encoder->end_frame();
1331
1332         // The live frame pieces the Y'CbCr texture copies back into RGB and displays them.
1333         // It owns y_display_tex and cbcr_display_tex now (whichever textures they are).
1334         DisplayFrame live_frame;
1335         live_frame.chain = display_chain.get();
1336         live_frame.setup_chain = [this, y_display_tex, cbcr_display_tex]{
1337                 display_input->set_texture_num(0, y_display_tex);
1338                 display_input->set_texture_num(1, cbcr_display_tex);
1339         };
1340         live_frame.ready_fence = fence;
1341         live_frame.input_frames = {};
1342         live_frame.temp_textures = { y_display_tex, cbcr_display_tex };
1343         output_channel[OUTPUT_LIVE].output_frame(live_frame);
1344
1345         // Set up preview and any additional channels.
1346         for (int i = 1; i < theme->get_num_channels() + 2; ++i) {
1347                 DisplayFrame display_frame;
1348                 Theme::Chain chain = theme->get_chain(i, pts(), global_flags.width, global_flags.height, input_state);  // FIXME: dimensions
1349                 display_frame.chain = chain.chain;
1350                 display_frame.setup_chain = chain.setup_chain;
1351                 display_frame.ready_fence = fence;
1352                 display_frame.input_frames = chain.input_frames;
1353                 display_frame.temp_textures = {};
1354                 output_channel[i].output_frame(display_frame);
1355         }
1356 }
1357
1358 void Mixer::audio_thread_func()
1359 {
1360         pthread_setname_np(pthread_self(), "Mixer_Audio");
1361
1362         while (!should_quit) {
1363                 AudioTask task;
1364
1365                 {
1366                         unique_lock<mutex> lock(audio_mutex);
1367                         audio_task_queue_changed.wait(lock, [this]{ return should_quit || !audio_task_queue.empty(); });
1368                         if (should_quit) {
1369                                 return;
1370                         }
1371                         task = audio_task_queue.front();
1372                         audio_task_queue.pop();
1373                 }
1374
1375                 ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy =
1376                         task.adjust_rate ? ResamplingQueue::ADJUST_RATE : ResamplingQueue::DO_NOT_ADJUST_RATE;
1377                 vector<float> samples_out = audio_mixer.get_output(
1378                         task.frame_timestamp,
1379                         task.num_samples,
1380                         rate_adjustment_policy);
1381
1382                 // Send the samples to the sound card, then add them to the output.
1383                 if (alsa) {
1384                         alsa->write(samples_out);
1385                 }
1386                 if (output_card_index != -1) {
1387                         const int64_t av_delay = lrint(global_flags.audio_queue_length_ms * 0.001 * TIMEBASE);  // Corresponds to the delay in ResamplingQueue.
1388                         cards[output_card_index].output->send_audio(task.pts_int + av_delay, samples_out);
1389                 }
1390                 video_encoder->add_audio(task.pts_int, move(samples_out));
1391         }
1392 }
1393
1394 void Mixer::release_display_frame(DisplayFrame *frame)
1395 {
1396         for (GLuint texnum : frame->temp_textures) {
1397                 resource_pool->release_2d_texture(texnum);
1398         }
1399         frame->temp_textures.clear();
1400         frame->ready_fence.reset();
1401         frame->input_frames.clear();
1402 }
1403
1404 void Mixer::start()
1405 {
1406         mixer_thread = thread(&Mixer::thread_func, this);
1407         audio_thread = thread(&Mixer::audio_thread_func, this);
1408 }
1409
1410 void Mixer::quit()
1411 {
1412         should_quit = true;
1413         audio_task_queue_changed.notify_one();
1414         mixer_thread.join();
1415         audio_thread.join();
1416 }
1417
1418 void Mixer::transition_clicked(int transition_num)
1419 {
1420         theme->transition_clicked(transition_num, pts());
1421 }
1422
1423 void Mixer::channel_clicked(int preview_num)
1424 {
1425         theme->channel_clicked(preview_num);
1426 }
1427
1428 YCbCrInterpretation Mixer::get_input_ycbcr_interpretation(unsigned card_index) const
1429 {
1430         unique_lock<mutex> lock(card_mutex);
1431         return ycbcr_interpretation[card_index];
1432 }
1433
1434 void Mixer::set_input_ycbcr_interpretation(unsigned card_index, const YCbCrInterpretation &interpretation)
1435 {
1436         unique_lock<mutex> lock(card_mutex);
1437         ycbcr_interpretation[card_index] = interpretation;
1438 }
1439
1440 void Mixer::start_mode_scanning(unsigned card_index)
1441 {
1442         assert(card_index < num_cards);
1443         if (is_mode_scanning[card_index]) {
1444                 return;
1445         }
1446         is_mode_scanning[card_index] = true;
1447         mode_scanlist[card_index].clear();
1448         for (const auto &mode : cards[card_index].capture->get_available_video_modes()) {
1449                 mode_scanlist[card_index].push_back(mode.first);
1450         }
1451         assert(!mode_scanlist[card_index].empty());
1452         mode_scanlist_index[card_index] = 0;
1453         cards[card_index].capture->set_video_mode(mode_scanlist[card_index][0]);
1454         last_mode_scan_change[card_index] = steady_clock::now();
1455 }
1456
1457 map<uint32_t, VideoMode> Mixer::get_available_output_video_modes() const
1458 {
1459         assert(desired_output_card_index != -1);
1460         unique_lock<mutex> lock(card_mutex);
1461         return cards[desired_output_card_index].output->get_available_video_modes();
1462 }
1463
1464 Mixer::OutputChannel::~OutputChannel()
1465 {
1466         if (has_current_frame) {
1467                 parent->release_display_frame(&current_frame);
1468         }
1469         if (has_ready_frame) {
1470                 parent->release_display_frame(&ready_frame);
1471         }
1472 }
1473
1474 void Mixer::OutputChannel::output_frame(DisplayFrame frame)
1475 {
1476         // Store this frame for display. Remove the ready frame if any
1477         // (it was seemingly never used).
1478         {
1479                 unique_lock<mutex> lock(frame_mutex);
1480                 if (has_ready_frame) {
1481                         parent->release_display_frame(&ready_frame);
1482                 }
1483                 ready_frame = frame;
1484                 has_ready_frame = true;
1485
1486                 // Call the callbacks under the mutex (they should be short),
1487                 // so that we don't race against a callback removal.
1488                 for (const auto &key_and_callback : new_frame_ready_callbacks) {
1489                         key_and_callback.second();
1490                 }
1491         }
1492
1493         // Reduce the number of callbacks by filtering duplicates. The reason
1494         // why we bother doing this is that Qt seemingly can get into a state
1495         // where its builds up an essentially unbounded queue of signals,
1496         // consuming more and more memory, and there's no good way of collapsing
1497         // user-defined signals or limiting the length of the queue.
1498         if (transition_names_updated_callback) {
1499                 vector<string> transition_names = global_mixer->get_transition_names();
1500                 bool changed = false;
1501                 if (transition_names.size() != last_transition_names.size()) {
1502                         changed = true;
1503                 } else {
1504                         for (unsigned i = 0; i < transition_names.size(); ++i) {
1505                                 if (transition_names[i] != last_transition_names[i]) {
1506                                         changed = true;
1507                                         break;
1508                                 }
1509                         }
1510                 }
1511                 if (changed) {
1512                         transition_names_updated_callback(transition_names);
1513                         last_transition_names = transition_names;
1514                 }
1515         }
1516         if (name_updated_callback) {
1517                 string name = global_mixer->get_channel_name(channel);
1518                 if (name != last_name) {
1519                         name_updated_callback(name);
1520                         last_name = name;
1521                 }
1522         }
1523         if (color_updated_callback) {
1524                 string color = global_mixer->get_channel_color(channel);
1525                 if (color != last_color) {
1526                         color_updated_callback(color);
1527                         last_color = color;
1528                 }
1529         }
1530 }
1531
1532 bool Mixer::OutputChannel::get_display_frame(DisplayFrame *frame)
1533 {
1534         unique_lock<mutex> lock(frame_mutex);
1535         if (!has_current_frame && !has_ready_frame) {
1536                 return false;
1537         }
1538
1539         if (has_current_frame && has_ready_frame) {
1540                 // We have a new ready frame. Toss the current one.
1541                 parent->release_display_frame(&current_frame);
1542                 has_current_frame = false;
1543         }
1544         if (has_ready_frame) {
1545                 assert(!has_current_frame);
1546                 current_frame = ready_frame;
1547                 ready_frame.ready_fence.reset();  // Drop the refcount.
1548                 ready_frame.input_frames.clear();  // Drop the refcounts.
1549                 has_current_frame = true;
1550                 has_ready_frame = false;
1551         }
1552
1553         *frame = current_frame;
1554         return true;
1555 }
1556
1557 void Mixer::OutputChannel::add_frame_ready_callback(void *key, Mixer::new_frame_ready_callback_t callback)
1558 {
1559         unique_lock<mutex> lock(frame_mutex);
1560         new_frame_ready_callbacks[key] = callback;
1561 }
1562
1563 void Mixer::OutputChannel::remove_frame_ready_callback(void *key)
1564 {
1565         unique_lock<mutex> lock(frame_mutex);
1566         new_frame_ready_callbacks.erase(key);
1567 }
1568
1569 void Mixer::OutputChannel::set_transition_names_updated_callback(Mixer::transition_names_updated_callback_t callback)
1570 {
1571         transition_names_updated_callback = callback;
1572 }
1573
1574 void Mixer::OutputChannel::set_name_updated_callback(Mixer::name_updated_callback_t callback)
1575 {
1576         name_updated_callback = callback;
1577 }
1578
1579 void Mixer::OutputChannel::set_color_updated_callback(Mixer::color_updated_callback_t callback)
1580 {
1581         color_updated_callback = callback;
1582 }
1583
1584 mutex RefCountedGLsync::fence_lock;