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