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 <algorithm>
  18 #include <chrono>
  19 #include <condition_variable>
  20 #include <cstddef>
  21 #include <cstdint>
  22 #include <memory>
  23 #include <mutex>
  24 #include <ratio>
  25 #include <string>
  26 #include <thread>
  27 #include <utility>
  28 #include <vector>
  29
  30 #include "DeckLinkAPI.h"
  31 #include "LinuxCOM.h"
  32 #include "alsa_output.h"
  33 #include "basic_stats.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 #undef Status
  55 #include <google/protobuf/util/json_util.h>
  56 #include "json.pb.h"
  57
  58 class IDeckLink;
  59 class QOpenGLContext;
  60
  61 using namespace movit;
  62 using namespace std;
  63 using namespace std::chrono;
  64 using namespace std::placeholders;
  65 using namespace bmusb;
  66
  67 Mixer *global_mixer = nullptr;
  68
  69 namespace {
  70
  71 void insert_new_frame(RefCountedFrame frame, unsigned field_num, bool interlaced, unsigned card_index, InputState *input_state)
  72 {
  73         if (interlaced) {
  74                 for (unsigned frame_num = FRAME_HISTORY_LENGTH; frame_num --> 1; ) {  // :-)
  75                         input_state->buffered_frames[card_index][frame_num] =
  76                                 input_state->buffered_frames[card_index][frame_num - 1];
  77                 }
  78                 input_state->buffered_frames[card_index][0] = { frame, field_num };
  79         } else {
  80                 for (unsigned frame_num = 0; frame_num < FRAME_HISTORY_LENGTH; ++frame_num) {
  81                         input_state->buffered_frames[card_index][frame_num] = { frame, field_num };
  82                 }
  83         }
  84 }
  85
  86 void ensure_texture_resolution(PBOFrameAllocator::Userdata *userdata, unsigned field, unsigned width, unsigned height, unsigned cbcr_width, unsigned cbcr_height, unsigned v210_width)
  87 {
  88         bool first;
  89         switch (userdata->pixel_format) {
  90         case PixelFormat_10BitYCbCr:
  91                 first = userdata->tex_v210[field] == 0 || userdata->tex_444[field] == 0;
  92                 break;
  93         case PixelFormat_8BitYCbCr:
  94                 first = userdata->tex_y[field] == 0 || userdata->tex_cbcr[field] == 0;
  95                 break;
  96         case PixelFormat_8BitBGRA:
  97                 first = userdata->tex_rgba[field] == 0;
  98                 break;
  99         case PixelFormat_8BitYCbCrPlanar:
 100                 first = userdata->tex_y[field] == 0 || userdata->tex_cb[field] == 0 || userdata->tex_cr[field] == 0;
 101                 break;
 102         default:
 103                 assert(false);
 104         }
 105
 106         if (first ||
 107             width != userdata->last_width[field] ||
 108             height != userdata->last_height[field] ||
 109             cbcr_width != userdata->last_cbcr_width[field] ||
 110             cbcr_height != userdata->last_cbcr_height[field]) {
 111                 // We changed resolution since last use of this texture, so we need to create
 112                 // a new object. Note that this each card has its own PBOFrameAllocator,
 113                 // we don't need to worry about these flip-flopping between resolutions.
 114                 switch (userdata->pixel_format) {
 115                 case PixelFormat_10BitYCbCr:
 116                         glBindTexture(GL_TEXTURE_2D, userdata->tex_444[field]);
 117                         check_error();
 118                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB10_A2, width, height, 0, GL_RGBA, GL_UNSIGNED_INT_2_10_10_10_REV, nullptr);
 119                         check_error();
 120                         break;
 121                 case PixelFormat_8BitYCbCr: {
 122                         glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr[field]);
 123                         check_error();
 124                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RG8, cbcr_width, height, 0, GL_RG, GL_UNSIGNED_BYTE, nullptr);
 125                         check_error();
 126                         glBindTexture(GL_TEXTURE_2D, userdata->tex_y[field]);
 127                         check_error();
 128                         glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, width, height, 0, GL_RED, GL_UNSIGNED_BYTE, nullptr);
 129                         check_error();
 130                         break;
 131                 }
 132                 case PixelFormat_8BitYCbCrPlanar: {
 133                         glBindTexture(GL_TEXTURE_2D, userdata->tex_y[field]);
 134                         check_error();
 135                         glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, width, height, 0, GL_RED, GL_UNSIGNED_BYTE, nullptr);
 136                         check_error();
 137                         glBindTexture(GL_TEXTURE_2D, userdata->tex_cb[field]);
 138                         check_error();
 139                         glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, cbcr_width, cbcr_height, 0, GL_RED, GL_UNSIGNED_BYTE, nullptr);
 140                         check_error();
 141                         glBindTexture(GL_TEXTURE_2D, userdata->tex_cr[field]);
 142                         check_error();
 143                         glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, cbcr_width, cbcr_height, 0, GL_RED, GL_UNSIGNED_BYTE, nullptr);
 144                         check_error();
 145                         break;
 146                 }
 147                 case PixelFormat_8BitBGRA:
 148                         glBindTexture(GL_TEXTURE_2D, userdata->tex_rgba[field]);
 149                         check_error();
 150                         if (global_flags.can_disable_srgb_decoder) {  // See the comments in tweaked_inputs.h.
 151                                 glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB8_ALPHA8, width, height, 0, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, nullptr);
 152                         } else {
 153                                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, nullptr);
 154                         }
 155                         check_error();
 156                         break;
 157                 }
 158                 userdata->last_width[field] = width;
 159                 userdata->last_height[field] = height;
 160                 userdata->last_cbcr_width[field] = cbcr_width;
 161                 userdata->last_cbcr_height[field] = cbcr_height;
 162         }
 163         if (global_flags.ten_bit_input &&
 164             (first || v210_width != userdata->last_v210_width[field])) {
 165                 // Same as above; we need to recreate the texture.
 166                 glBindTexture(GL_TEXTURE_2D, userdata->tex_v210[field]);
 167                 check_error();
 168                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB10_A2, v210_width, height, 0, GL_RGBA, GL_UNSIGNED_INT_2_10_10_10_REV, nullptr);
 169                 check_error();
 170                 userdata->last_v210_width[field] = v210_width;
 171         }
 172 }
 173
 174 void upload_texture(GLuint tex, GLuint width, GLuint height, GLuint stride, bool interlaced_stride, GLenum format, GLenum type, GLintptr offset)
 175 {
 176         if (interlaced_stride) {
 177                 stride *= 2;
 178         }
 179         if (global_flags.flush_pbos) {
 180                 glFlushMappedBufferRange(GL_PIXEL_UNPACK_BUFFER, offset, stride * height);
 181                 check_error();
 182         }
 183
 184         glBindTexture(GL_TEXTURE_2D, tex);
 185         check_error();
 186         if (interlaced_stride) {
 187                 glPixelStorei(GL_UNPACK_ROW_LENGTH, width * 2);
 188                 check_error();
 189         } else {
 190                 glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 191                 check_error();
 192         }
 193
 194         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, type, BUFFER_OFFSET(offset));
 195         check_error();
 196         glBindTexture(GL_TEXTURE_2D, 0);
 197         check_error();
 198         glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 199         check_error();
 200 }
 201
 202 }  // namespace
 203
 204 void JitterHistory::register_metrics(const vector<pair<string, string>> &labels)
 205 {
 206         global_metrics.add("input_underestimated_jitter_frames", labels, &metric_input_underestimated_jitter_frames);
 207         global_metrics.add("input_estimated_max_jitter_seconds", labels, &metric_input_estimated_max_jitter_seconds, Metrics::TYPE_GAUGE);
 208 }
 209
 210 void JitterHistory::unregister_metrics(const vector<pair<string, string>> &labels)
 211 {
 212         global_metrics.remove("input_underestimated_jitter_frames", labels);
 213         global_metrics.remove("input_estimated_max_jitter_seconds", labels);
 214 }
 215
 216 void JitterHistory::frame_arrived(steady_clock::time_point now, int64_t frame_duration, size_t dropped_frames)
 217 {
 218         if (expected_timestamp > steady_clock::time_point::min()) {
 219                 expected_timestamp += dropped_frames * nanoseconds(frame_duration * 1000000000 / TIMEBASE);
 220                 double jitter_seconds = fabs(duration<double>(expected_timestamp - now).count());
 221                 history.push_back(orders.insert(jitter_seconds));
 222                 if (jitter_seconds > estimate_max_jitter()) {
 223                         ++metric_input_underestimated_jitter_frames;
 224                 }
 225
 226                 metric_input_estimated_max_jitter_seconds = estimate_max_jitter();
 227
 228                 if (history.size() > history_length) {
 229                         orders.erase(history.front());
 230                         history.pop_front();
 231                 }
 232                 assert(history.size() <= history_length);
 233         }
 234         expected_timestamp = now + nanoseconds(frame_duration * 1000000000 / TIMEBASE);
 235 }
 236
 237 double JitterHistory::estimate_max_jitter() const
 238 {
 239         if (orders.empty()) {
 240                 return 0.0;
 241         }
 242         size_t elem_idx = lrint((orders.size() - 1) * percentile);
 243         if (percentile <= 0.5) {
 244                 return *next(orders.begin(), elem_idx) * multiplier;
 245         } else {
 246                 return *prev(orders.end(), orders.size() - elem_idx) * multiplier;
 247         }
 248 }
 249
 250 void QueueLengthPolicy::register_metrics(const vector<pair<string, string>> &labels)
 251 {
 252         global_metrics.add("input_queue_safe_length_frames", labels, &metric_input_queue_safe_length_frames, Metrics::TYPE_GAUGE);
 253 }
 254
 255 void QueueLengthPolicy::unregister_metrics(const vector<pair<string, string>> &labels)
 256 {
 257         global_metrics.remove("input_queue_safe_length_frames", labels);
 258 }
 259
 260 void QueueLengthPolicy::update_policy(steady_clock::time_point now,
 261                                       steady_clock::time_point expected_next_frame,
 262                                       int64_t input_frame_duration,
 263                                       int64_t master_frame_duration,
 264                                       double max_input_card_jitter_seconds,
 265                                       double max_master_card_jitter_seconds)
 266 {
 267         double input_frame_duration_seconds = input_frame_duration / double(TIMEBASE);
 268         double master_frame_duration_seconds = master_frame_duration / double(TIMEBASE);
 269
 270         // Figure out when we can expect the next frame for this card, assuming
 271         // worst-case jitter (ie., the frame is maximally late).
 272         double seconds_until_next_frame = max(duration<double>(expected_next_frame - now).count() + max_input_card_jitter_seconds, 0.0);
 273
 274         // How many times are the master card expected to tick in that time?
 275         // We assume the master clock has worst-case jitter but not any rate
 276         // discrepancy, ie., it ticks as early as possible every time, but not
 277         // cumulatively.
 278         double frames_needed = (seconds_until_next_frame + max_master_card_jitter_seconds) / master_frame_duration_seconds;
 279
 280         // As a special case, if the master card ticks faster than the input card,
 281         // we expect the queue to drain by itself even without dropping. But if
 282         // the difference is small (e.g. 60 Hz master and 59.94 input), it would
 283         // go slowly enough that the effect wouldn't really be appreciable.
 284         // We account for this by looking at the situation five frames ahead,
 285         // assuming everything else is the same.
 286         double frames_allowed;
 287         if (master_frame_duration < input_frame_duration) {
 288                 frames_allowed = frames_needed + 5 * (input_frame_duration_seconds - master_frame_duration_seconds) / master_frame_duration_seconds;
 289         } else {
 290                 frames_allowed = frames_needed;
 291         }
 292
 293         safe_queue_length = max<int>(floor(frames_allowed), 0);
 294         metric_input_queue_safe_length_frames = safe_queue_length;
 295 }
 296
 297 Mixer::Mixer(const QSurfaceFormat &format, unsigned num_cards)
 298         : httpd(),
 299           num_cards(num_cards),
 300           mixer_surface(create_surface(format)),
 301           h264_encoder_surface(create_surface(format)),
 302           decklink_output_surface(create_surface(format)),
 303           audio_mixer(num_cards)
 304 {
 305         memcpy(ycbcr_interpretation, global_flags.ycbcr_interpretation, sizeof(ycbcr_interpretation));
 306         CHECK(init_movit(MOVIT_SHADER_DIR, MOVIT_DEBUG_OFF));
 307         check_error();
 308
 309         // This nearly always should be true.
 310         global_flags.can_disable_srgb_decoder =
 311                 epoxy_has_gl_extension("GL_EXT_texture_sRGB_decode") &&
 312                 epoxy_has_gl_extension("GL_ARB_sampler_objects");
 313
 314         // Since we allow non-bouncing 4:2:2 YCbCrInputs, effective subpixel precision
 315         // will be halved when sampling them, and we need to compensate here.
 316         movit_texel_subpixel_precision /= 2.0;
 317
 318         resource_pool.reset(new ResourcePool);
 319         for (unsigned i = 0; i < NUM_OUTPUTS; ++i) {
 320                 output_channel[i].parent = this;
 321                 output_channel[i].channel = i;
 322         }
 323
 324         ImageFormat inout_format;
 325         inout_format.color_space = COLORSPACE_sRGB;
 326         inout_format.gamma_curve = GAMMA_sRGB;
 327
 328         // Matches the 4:2:0 format created by the main chain.
 329         YCbCrFormat ycbcr_format;
 330         ycbcr_format.chroma_subsampling_x = 2;
 331         ycbcr_format.chroma_subsampling_y = 2;
 332         if (global_flags.ycbcr_rec709_coefficients) {
 333                 ycbcr_format.luma_coefficients = YCBCR_REC_709;
 334         } else {
 335                 ycbcr_format.luma_coefficients = YCBCR_REC_601;
 336         }
 337         ycbcr_format.full_range = false;
 338         ycbcr_format.num_levels = 1 << global_flags.x264_bit_depth;
 339         ycbcr_format.cb_x_position = 0.0f;
 340         ycbcr_format.cr_x_position = 0.0f;
 341         ycbcr_format.cb_y_position = 0.5f;
 342         ycbcr_format.cr_y_position = 0.5f;
 343
 344         // Display chain; shows the live output produced by the main chain (or rather, a copy of it).
 345         display_chain.reset(new EffectChain(global_flags.width, global_flags.height, resource_pool.get()));
 346         check_error();
 347         GLenum type = global_flags.x264_bit_depth > 8 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_BYTE;
 348         display_input = new YCbCrInput(inout_format, ycbcr_format, global_flags.width, global_flags.height, YCBCR_INPUT_SPLIT_Y_AND_CBCR, type);
 349         display_chain->add_input(display_input);
 350         display_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
 351         display_chain->set_dither_bits(0);  // Don't bother.
 352         display_chain->finalize();
 353
 354         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));
 355
 356         // Must be instantiated after VideoEncoder has initialized global_flags.use_zerocopy.
 357         theme.reset(new Theme(global_flags.theme_filename, global_flags.theme_dirs, resource_pool.get(), num_cards));
 358
 359         httpd.add_endpoint("/channels", bind(&Mixer::get_channels_json, this), HTTPD::ALLOW_ALL_ORIGINS);
 360         for (int channel_idx = 2; channel_idx < theme->get_num_channels(); ++channel_idx) {
 361                 char url[256];
 362                 snprintf(url, sizeof(url), "/channels/%d/color", channel_idx);
 363                 httpd.add_endpoint(url, bind(&Mixer::get_channel_color_http, this, unsigned(channel_idx)), HTTPD::ALLOW_ALL_ORIGINS);
 364         }
 365
 366         // Start listening for clients only once VideoEncoder has written its header, if any.
 367         httpd.start(global_flags.http_port);
 368
 369         // First try initializing the then PCI devices, then USB, then
 370         // fill up with fake cards until we have the desired number of cards.
 371         unsigned num_pci_devices = 0;
 372         unsigned card_index = 0;
 373
 374         {
 375                 IDeckLinkIterator *decklink_iterator = CreateDeckLinkIteratorInstance();
 376                 if (decklink_iterator != nullptr) {
 377                         for ( ; card_index < num_cards; ++card_index) {
 378                                 IDeckLink *decklink;
 379                                 if (decklink_iterator->Next(&decklink) != S_OK) {
 380                                         break;
 381                                 }
 382
 383                                 DeckLinkCapture *capture = new DeckLinkCapture(decklink, card_index);
 384                                 DeckLinkOutput *output = new DeckLinkOutput(resource_pool.get(), decklink_output_surface, global_flags.width, global_flags.height, card_index);
 385                                 if (!output->set_device(decklink)) {
 386                                         delete output;
 387                                         output = nullptr;
 388                                 }
 389                                 configure_card(card_index, capture, CardType::LIVE_CARD, output);
 390                                 ++num_pci_devices;
 391                         }
 392                         decklink_iterator->Release();
 393                         fprintf(stderr, "Found %u DeckLink PCI card(s).\n", num_pci_devices);
 394                 } else {
 395                         fprintf(stderr, "DeckLink drivers not found. Probing for USB cards only.\n");
 396                 }
 397         }
 398
 399         unsigned num_usb_devices = BMUSBCapture::num_cards();
 400         for (unsigned usb_card_index = 0; usb_card_index < num_usb_devices && card_index < num_cards; ++usb_card_index, ++card_index) {
 401                 BMUSBCapture *capture = new BMUSBCapture(usb_card_index);
 402                 capture->set_card_disconnected_callback(bind(&Mixer::bm_hotplug_remove, this, card_index));
 403                 configure_card(card_index, capture, CardType::LIVE_CARD, /*output=*/nullptr);
 404         }
 405         fprintf(stderr, "Found %u USB card(s).\n", num_usb_devices);
 406
 407         unsigned num_fake_cards = 0;
 408         for ( ; card_index < num_cards; ++card_index, ++num_fake_cards) {
 409                 FakeCapture *capture = new FakeCapture(global_flags.width, global_flags.height, FAKE_FPS, OUTPUT_FREQUENCY, card_index, global_flags.fake_cards_audio);
 410                 configure_card(card_index, capture, CardType::FAKE_CAPTURE, /*output=*/nullptr);
 411         }
 412
 413         if (num_fake_cards > 0) {
 414                 fprintf(stderr, "Initialized %u fake cards.\n", num_fake_cards);
 415         }
 416
 417         // Initialize all video inputs the theme asked for. Note that these are
 418         // all put _after_ the regular cards, which stop at <num_cards> - 1.
 419         std::vector<FFmpegCapture *> video_inputs = theme->get_video_inputs();
 420         for (unsigned video_card_index = 0; video_card_index < video_inputs.size(); ++card_index, ++video_card_index) {
 421                 if (card_index >= MAX_VIDEO_CARDS) {
 422                         fprintf(stderr, "ERROR: Not enough card slots available for the videos the theme requested.\n");
 423                         exit(1);
 424                 }
 425                 configure_card(card_index, video_inputs[video_card_index], CardType::FFMPEG_INPUT, /*output=*/nullptr);
 426                 video_inputs[video_card_index]->set_card_index(card_index);
 427         }
 428         num_video_inputs = video_inputs.size();
 429
 430         BMUSBCapture::set_card_connected_callback(bind(&Mixer::bm_hotplug_add, this, _1));
 431         BMUSBCapture::start_bm_thread();
 432
 433         for (unsigned card_index = 0; card_index < num_cards + num_video_inputs; ++card_index) {
 434                 cards[card_index].queue_length_policy.reset(card_index);
 435         }
 436
 437         chroma_subsampler.reset(new ChromaSubsampler(resource_pool.get()));
 438
 439         if (global_flags.ten_bit_input) {
 440                 if (!v210Converter::has_hardware_support()) {
 441                         fprintf(stderr, "ERROR: --ten-bit-input requires support for OpenGL compute shaders\n");
 442                         fprintf(stderr, "       (OpenGL 4.3, or GL_ARB_compute_shader + GL_ARB_shader_image_load_store).\n");
 443                         exit(1);
 444                 }
 445                 v210_converter.reset(new v210Converter());
 446
 447                 // These are all the widths listed in the Blackmagic SDK documentation
 448                 // (section 2.7.3, “Display Modes”).
 449                 v210_converter->precompile_shader(720);
 450                 v210_converter->precompile_shader(1280);
 451                 v210_converter->precompile_shader(1920);
 452                 v210_converter->precompile_shader(2048);
 453                 v210_converter->precompile_shader(3840);
 454                 v210_converter->precompile_shader(4096);
 455         }
 456         if (global_flags.ten_bit_output) {
 457                 if (!v210Converter::has_hardware_support()) {
 458                         fprintf(stderr, "ERROR: --ten-bit-output requires support for OpenGL compute shaders\n");
 459                         fprintf(stderr, "       (OpenGL 4.3, or GL_ARB_compute_shader + GL_ARB_shader_image_load_store).\n");
 460                         exit(1);
 461                 }
 462         }
 463
 464         timecode_renderer.reset(new TimecodeRenderer(resource_pool.get(), global_flags.width, global_flags.height));
 465         display_timecode_in_stream = global_flags.display_timecode_in_stream;
 466         display_timecode_on_stdout = global_flags.display_timecode_on_stdout;
 467
 468         if (global_flags.enable_alsa_output) {
 469                 alsa.reset(new ALSAOutput(OUTPUT_FREQUENCY, /*num_channels=*/2));
 470         }
 471         if (global_flags.output_card != -1) {
 472                 desired_output_card_index = global_flags.output_card;
 473                 set_output_card_internal(global_flags.output_card);
 474         }
 475
 476         output_jitter_history.register_metrics({{ "card", "output" }});
 477 }
 478
 479 Mixer::~Mixer()
 480 {
 481         BMUSBCapture::stop_bm_thread();
 482
 483         for (unsigned card_index = 0; card_index < num_cards + num_video_inputs; ++card_index) {
 484                 {
 485                         unique_lock<mutex> lock(card_mutex);
 486                         cards[card_index].should_quit = true;  // Unblock thread.
 487                         cards[card_index].new_frames_changed.notify_all();
 488                 }
 489                 cards[card_index].capture->stop_dequeue_thread();
 490                 if (cards[card_index].output) {
 491                         cards[card_index].output->end_output();
 492                         cards[card_index].output.reset();
 493                 }
 494         }
 495
 496         video_encoder.reset(nullptr);
 497 }
 498
 499 void Mixer::configure_card(unsigned card_index, CaptureInterface *capture, CardType card_type, DeckLinkOutput *output)
 500 {
 501         printf("Configuring card %d...\n", card_index);
 502
 503         CaptureCard *card = &cards[card_index];
 504         if (card->capture != nullptr) {
 505                 card->capture->stop_dequeue_thread();
 506         }
 507         card->capture.reset(capture);
 508         card->is_fake_capture = (card_type == CardType::FAKE_CAPTURE);
 509         card->type = card_type;
 510         if (card->output.get() != output) {
 511                 card->output.reset(output);
 512         }
 513
 514         PixelFormat pixel_format;
 515         if (card_type == CardType::FFMPEG_INPUT) {
 516                 pixel_format = capture->get_current_pixel_format();
 517         } else if (global_flags.ten_bit_input) {
 518                 pixel_format = PixelFormat_10BitYCbCr;
 519         } else {
 520                 pixel_format = PixelFormat_8BitYCbCr;
 521         }
 522
 523         card->capture->set_frame_callback(bind(&Mixer::bm_frame, this, card_index, _1, _2, _3, _4, _5, _6, _7));
 524         if (card->frame_allocator == nullptr) {
 525                 card->frame_allocator.reset(new PBOFrameAllocator(pixel_format, 8 << 20, global_flags.width, global_flags.height));  // 8 MB.
 526         }
 527         card->capture->set_video_frame_allocator(card->frame_allocator.get());
 528         if (card->surface == nullptr) {
 529                 card->surface = create_surface_with_same_format(mixer_surface);
 530         }
 531         while (!card->new_frames.empty()) card->new_frames.pop_front();
 532         card->last_timecode = -1;
 533         card->capture->set_pixel_format(pixel_format);
 534         card->capture->configure_card();
 535
 536         // NOTE: start_bm_capture() happens in thread_func().
 537
 538         DeviceSpec device{InputSourceType::CAPTURE_CARD, card_index};
 539         audio_mixer.reset_resampler(device);
 540         audio_mixer.set_display_name(device, card->capture->get_description());
 541         audio_mixer.trigger_state_changed_callback();
 542
 543         // Unregister old metrics, if any.
 544         if (!card->labels.empty()) {
 545                 const vector<pair<string, string>> &labels = card->labels;
 546                 card->jitter_history.unregister_metrics(labels);
 547                 card->queue_length_policy.unregister_metrics(labels);
 548                 global_metrics.remove("input_received_frames", labels);
 549                 global_metrics.remove("input_dropped_frames_jitter", labels);
 550                 global_metrics.remove("input_dropped_frames_error", labels);
 551                 global_metrics.remove("input_dropped_frames_resets", labels);
 552                 global_metrics.remove("input_queue_length_frames", labels);
 553                 global_metrics.remove("input_queue_duped_frames", labels);
 554
 555                 global_metrics.remove("input_has_signal_bool", labels);
 556                 global_metrics.remove("input_is_connected_bool", labels);
 557                 global_metrics.remove("input_interlaced_bool", labels);
 558                 global_metrics.remove("input_width_pixels", labels);
 559                 global_metrics.remove("input_height_pixels", labels);
 560                 global_metrics.remove("input_frame_rate_nom", labels);
 561                 global_metrics.remove("input_frame_rate_den", labels);
 562                 global_metrics.remove("input_sample_rate_hz", labels);
 563         }
 564
 565         // Register metrics.
 566         vector<pair<string, string>> labels;
 567         char card_name[64];
 568         snprintf(card_name, sizeof(card_name), "%d", card_index);
 569         labels.emplace_back("card", card_name);
 570
 571         switch (card_type) {
 572         case CardType::LIVE_CARD:
 573                 labels.emplace_back("cardtype", "live");
 574                 break;
 575         case CardType::FAKE_CAPTURE:
 576                 labels.emplace_back("cardtype", "fake");
 577                 break;
 578         case CardType::FFMPEG_INPUT:
 579                 labels.emplace_back("cardtype", "ffmpeg");
 580                 break;
 581         default:
 582                 assert(false);
 583         }
 584         card->jitter_history.register_metrics(labels);
 585         card->queue_length_policy.register_metrics(labels);
 586         global_metrics.add("input_received_frames", labels, &card->metric_input_received_frames);
 587         global_metrics.add("input_dropped_frames_jitter", labels, &card->metric_input_dropped_frames_jitter);
 588         global_metrics.add("input_dropped_frames_error", labels, &card->metric_input_dropped_frames_error);
 589         global_metrics.add("input_dropped_frames_resets", labels, &card->metric_input_resets);
 590         global_metrics.add("input_queue_length_frames", labels, &card->metric_input_queue_length_frames, Metrics::TYPE_GAUGE);
 591         global_metrics.add("input_queue_duped_frames", labels, &card->metric_input_duped_frames);
 592
 593         global_metrics.add("input_has_signal_bool", labels, &card->metric_input_has_signal_bool, Metrics::TYPE_GAUGE);
 594         global_metrics.add("input_is_connected_bool", labels, &card->metric_input_is_connected_bool, Metrics::TYPE_GAUGE);
 595         global_metrics.add("input_interlaced_bool", labels, &card->metric_input_interlaced_bool, Metrics::TYPE_GAUGE);
 596         global_metrics.add("input_width_pixels", labels, &card->metric_input_width_pixels, Metrics::TYPE_GAUGE);
 597         global_metrics.add("input_height_pixels", labels, &card->metric_input_height_pixels, Metrics::TYPE_GAUGE);
 598         global_metrics.add("input_frame_rate_nom", labels, &card->metric_input_frame_rate_nom, Metrics::TYPE_GAUGE);
 599         global_metrics.add("input_frame_rate_den", labels, &card->metric_input_frame_rate_den, Metrics::TYPE_GAUGE);
 600         global_metrics.add("input_sample_rate_hz", labels, &card->metric_input_sample_rate_hz, Metrics::TYPE_GAUGE);
 601         card->labels = labels;
 602 }
 603
 604 void Mixer::set_output_card_internal(int card_index)
 605 {
 606         // We don't really need to take card_mutex, since we're in the mixer
 607         // thread and don't mess with any queues (which is the only thing that happens
 608         // from other threads), but it's probably the safest in the long run.
 609         unique_lock<mutex> lock(card_mutex);
 610         if (output_card_index != -1) {
 611                 // Switch the old card from output to input.
 612                 CaptureCard *old_card = &cards[output_card_index];
 613                 old_card->output->end_output();
 614
 615                 // Stop the fake card that we put into place.
 616                 // This needs to _not_ happen under the mutex, to avoid deadlock
 617                 // (delivering the last frame needs to take the mutex).
 618                 CaptureInterface *fake_capture = old_card->capture.get();
 619                 lock.unlock();
 620                 fake_capture->stop_dequeue_thread();
 621                 lock.lock();
 622                 old_card->capture = move(old_card->parked_capture);  // TODO: reset the metrics
 623                 old_card->is_fake_capture = false;
 624                 old_card->capture->start_bm_capture();
 625         }
 626         if (card_index != -1) {
 627                 CaptureCard *card = &cards[card_index];
 628                 CaptureInterface *capture = card->capture.get();
 629                 // TODO: DeckLinkCapture::stop_dequeue_thread can actually take
 630                 // several seconds to complete (blocking on DisableVideoInput);
 631                 // see if we can maybe do it asynchronously.
 632                 lock.unlock();
 633                 capture->stop_dequeue_thread();
 634                 lock.lock();
 635                 card->parked_capture = move(card->capture);
 636                 CaptureInterface *fake_capture = new FakeCapture(global_flags.width, global_flags.height, FAKE_FPS, OUTPUT_FREQUENCY, card_index, global_flags.fake_cards_audio);
 637                 configure_card(card_index, fake_capture, CardType::FAKE_CAPTURE, card->output.release());
 638                 card->queue_length_policy.reset(card_index);
 639                 card->capture->start_bm_capture();
 640                 desired_output_video_mode = output_video_mode = card->output->pick_video_mode(desired_output_video_mode);
 641                 card->output->start_output(desired_output_video_mode, pts_int);
 642         }
 643         output_card_index = card_index;
 644         output_jitter_history.clear();
 645 }
 646
 647 namespace {
 648
 649 int unwrap_timecode(uint16_t current_wrapped, int last)
 650 {
 651         uint16_t last_wrapped = last & 0xffff;
 652         if (current_wrapped > last_wrapped) {
 653                 return (last & ~0xffff) | current_wrapped;
 654         } else {
 655                 return 0x10000 + ((last & ~0xffff) | current_wrapped);
 656         }
 657 }
 658
 659 }  // namespace
 660
 661 void Mixer::bm_frame(unsigned card_index, uint16_t timecode,
 662                      FrameAllocator::Frame video_frame, size_t video_offset, VideoFormat video_format,
 663                      FrameAllocator::Frame audio_frame, size_t audio_offset, AudioFormat audio_format)
 664 {
 665         DeviceSpec device{InputSourceType::CAPTURE_CARD, card_index};
 666         CaptureCard *card = &cards[card_index];
 667
 668         ++card->metric_input_received_frames;
 669         card->metric_input_has_signal_bool = video_format.has_signal;
 670         card->metric_input_is_connected_bool = video_format.is_connected;
 671         card->metric_input_interlaced_bool = video_format.interlaced;
 672         card->metric_input_width_pixels = video_format.width;
 673         card->metric_input_height_pixels = video_format.height;
 674         card->metric_input_frame_rate_nom = video_format.frame_rate_nom;
 675         card->metric_input_frame_rate_den = video_format.frame_rate_den;
 676         card->metric_input_sample_rate_hz = audio_format.sample_rate;
 677
 678         if (is_mode_scanning[card_index]) {
 679                 if (video_format.has_signal) {
 680                         // Found a stable signal, so stop scanning.
 681                         is_mode_scanning[card_index] = false;
 682                 } else {
 683                         static constexpr double switch_time_s = 0.1;  // Should be enough time for the signal to stabilize.
 684                         steady_clock::time_point now = steady_clock::now();
 685                         double sec_since_last_switch = duration<double>(steady_clock::now() - last_mode_scan_change[card_index]).count();
 686                         if (sec_since_last_switch > switch_time_s) {
 687                                 // It isn't this mode; try the next one.
 688                                 mode_scanlist_index[card_index]++;
 689                                 mode_scanlist_index[card_index] %= mode_scanlist[card_index].size();
 690                                 cards[card_index].capture->set_video_mode(mode_scanlist[card_index][mode_scanlist_index[card_index]]);
 691                                 last_mode_scan_change[card_index] = now;
 692                         }
 693                 }
 694         }
 695
 696         int64_t frame_length = int64_t(TIMEBASE) * video_format.frame_rate_den / video_format.frame_rate_nom;
 697         assert(frame_length > 0);
 698
 699         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;
 700         if (num_samples > OUTPUT_FREQUENCY / 10) {
 701                 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",
 702                         card_index, int(audio_frame.len), int(audio_offset),
 703                         timecode, int(video_frame.len), int(video_offset), video_format.id);
 704                 if (video_frame.owner) {
 705                         video_frame.owner->release_frame(video_frame);
 706                 }
 707                 if (audio_frame.owner) {
 708                         audio_frame.owner->release_frame(audio_frame);
 709                 }
 710                 return;
 711         }
 712
 713         int dropped_frames = 0;
 714         if (card->last_timecode != -1) {
 715                 dropped_frames = unwrap_timecode(timecode, card->last_timecode) - card->last_timecode - 1;
 716         }
 717
 718         // Number of samples per frame if we need to insert silence.
 719         // (Could be nonintegral, but resampling will save us then.)
 720         const int silence_samples = OUTPUT_FREQUENCY * video_format.frame_rate_den / video_format.frame_rate_nom;
 721
 722         if (dropped_frames > MAX_FPS * 2) {
 723                 fprintf(stderr, "Card %d lost more than two seconds (or time code jumping around; from 0x%04x to 0x%04x), resetting resampler\n",
 724                         card_index, card->last_timecode, timecode);
 725                 audio_mixer.reset_resampler(device);
 726                 dropped_frames = 0;
 727                 ++card->metric_input_resets;
 728         } else if (dropped_frames > 0) {
 729                 // Insert silence as needed.
 730                 fprintf(stderr, "Card %d dropped %d frame(s) (before timecode 0x%04x), inserting silence.\n",
 731                         card_index, dropped_frames, timecode);
 732                 card->metric_input_dropped_frames_error += dropped_frames;
 733
 734                 bool success;
 735                 do {
 736                         success = audio_mixer.add_silence(device, silence_samples, dropped_frames, frame_length);
 737                 } while (!success);
 738         }
 739
 740         if (num_samples > 0) {
 741                 audio_mixer.add_audio(device, audio_frame.data + audio_offset, num_samples, audio_format, frame_length, audio_frame.received_timestamp);
 742         }
 743
 744         // Done with the audio, so release it.
 745         if (audio_frame.owner) {
 746                 audio_frame.owner->release_frame(audio_frame);
 747         }
 748
 749         card->last_timecode = timecode;
 750
 751         PBOFrameAllocator::Userdata *userdata = (PBOFrameAllocator::Userdata *)video_frame.userdata;
 752
 753         size_t cbcr_width, cbcr_height, cbcr_offset, y_offset;
 754         size_t expected_length = video_format.stride * (video_format.height + video_format.extra_lines_top + video_format.extra_lines_bottom);
 755         if (userdata != nullptr && userdata->pixel_format == PixelFormat_8BitYCbCrPlanar) {
 756                 // The calculation above is wrong for planar Y'CbCr, so just override it.
 757                 assert(card->type == CardType::FFMPEG_INPUT);
 758                 assert(video_offset == 0);
 759                 expected_length = video_frame.len;
 760
 761                 userdata->ycbcr_format = (static_cast<FFmpegCapture *>(card->capture.get()))->get_current_frame_ycbcr_format();
 762                 cbcr_width = video_format.width / userdata->ycbcr_format.chroma_subsampling_x;
 763                 cbcr_height = video_format.height / userdata->ycbcr_format.chroma_subsampling_y;
 764                 cbcr_offset = video_format.width * video_format.height;
 765                 y_offset = 0;
 766         } else {
 767                 // All the other Y'CbCr formats are 4:2:2.
 768                 cbcr_width = video_format.width / 2;
 769                 cbcr_height = video_format.height;
 770                 cbcr_offset = video_offset / 2;
 771                 y_offset = video_frame.size / 2 + video_offset / 2;
 772         }
 773         if (video_frame.len - video_offset == 0 ||
 774             video_frame.len - video_offset != expected_length) {
 775                 if (video_frame.len != 0) {
 776                         printf("Card %d: Dropping video frame with wrong length (%ld; expected %ld)\n",
 777                                 card_index, video_frame.len - video_offset, expected_length);
 778                 }
 779                 if (video_frame.owner) {
 780                         video_frame.owner->release_frame(video_frame);
 781                 }
 782
 783                 // Still send on the information that we _had_ a frame, even though it's corrupted,
 784                 // so that pts can go up accordingly.
 785                 {
 786                         unique_lock<mutex> lock(card_mutex);
 787                         CaptureCard::NewFrame new_frame;
 788                         new_frame.frame = RefCountedFrame(FrameAllocator::Frame());
 789                         new_frame.length = frame_length;
 790                         new_frame.interlaced = false;
 791                         new_frame.dropped_frames = dropped_frames;
 792                         new_frame.received_timestamp = video_frame.received_timestamp;
 793                         card->new_frames.push_back(move(new_frame));
 794                         card->jitter_history.frame_arrived(video_frame.received_timestamp, frame_length, dropped_frames);
 795                 }
 796                 card->new_frames_changed.notify_all();
 797                 return;
 798         }
 799
 800         unsigned num_fields = video_format.interlaced ? 2 : 1;
 801         steady_clock::time_point frame_upload_start;
 802         bool interlaced_stride = false;
 803         if (video_format.interlaced) {
 804                 // Send the two fields along as separate frames; the other side will need to add
 805                 // a deinterlacer to actually get this right.
 806                 assert(video_format.height % 2 == 0);
 807                 video_format.height /= 2;
 808                 cbcr_height /= 2;
 809                 assert(frame_length % 2 == 0);
 810                 frame_length /= 2;
 811                 num_fields = 2;
 812                 if (video_format.second_field_start == 1) {
 813                         interlaced_stride = true;
 814                 }
 815                 frame_upload_start = steady_clock::now();
 816         }
 817         userdata->last_interlaced = video_format.interlaced;
 818         userdata->last_has_signal = video_format.has_signal;
 819         userdata->last_is_connected = video_format.is_connected;
 820         userdata->last_frame_rate_nom = video_format.frame_rate_nom;
 821         userdata->last_frame_rate_den = video_format.frame_rate_den;
 822         RefCountedFrame frame(video_frame);
 823
 824         // Upload the textures.
 825         for (unsigned field = 0; field < num_fields; ++field) {
 826                 // Put the actual texture upload in a lambda that is executed in the main thread.
 827                 // It is entirely possible to do this in the same thread (and it might even be
 828                 // faster, depending on the GPU and driver), but it appears to be trickling
 829                 // driver bugs very easily.
 830                 //
 831                 // Note that this means we must hold on to the actual frame data in <userdata>
 832                 // until the upload command is run, but we hold on to <frame> much longer than that
 833                 // (in fact, all the way until we no longer use the texture in rendering).
 834                 auto upload_func = [this, field, video_format, y_offset, video_offset, cbcr_offset, cbcr_width, cbcr_height, interlaced_stride, userdata]() {
 835                         unsigned field_start_line;
 836                         if (field == 1) {
 837                                 field_start_line = video_format.second_field_start;
 838                         } else {
 839                                 field_start_line = video_format.extra_lines_top;
 840                         }
 841
 842                         // For anything not FRAME_FORMAT_YCBCR_10BIT, v210_width will be nonsensical but not used.
 843                         size_t v210_width = video_format.stride / sizeof(uint32_t);
 844                         ensure_texture_resolution(userdata, field, video_format.width, video_format.height, cbcr_width, cbcr_height, v210_width);
 845
 846                         glBindBuffer(GL_PIXEL_UNPACK_BUFFER, userdata->pbo);
 847                         check_error();
 848
 849                         switch (userdata->pixel_format) {
 850                         case PixelFormat_10BitYCbCr: {
 851                                 size_t field_start = video_offset + video_format.stride * field_start_line;
 852                                 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);
 853                                 v210_converter->convert(userdata->tex_v210[field], userdata->tex_444[field], video_format.width, video_format.height);
 854                                 break;
 855                         }
 856                         case PixelFormat_8BitYCbCr: {
 857                                 size_t field_y_start = y_offset + video_format.width * field_start_line;
 858                                 size_t field_cbcr_start = cbcr_offset + cbcr_width * field_start_line * sizeof(uint16_t);
 859
 860                                 // Make up our own strides, since we are interleaving.
 861                                 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);
 862                                 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);
 863                                 break;
 864                         }
 865                         case PixelFormat_8BitYCbCrPlanar: {
 866                                 assert(field_start_line == 0);  // We don't really support interlaced here.
 867                                 size_t field_y_start = y_offset;
 868                                 size_t field_cb_start = cbcr_offset;
 869                                 size_t field_cr_start = cbcr_offset + cbcr_width * cbcr_height;
 870
 871                                 // Make up our own strides, since we are interleaving.
 872                                 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);
 873                                 upload_texture(userdata->tex_cb[field], cbcr_width, cbcr_height, cbcr_width, interlaced_stride, GL_RED, GL_UNSIGNED_BYTE, field_cb_start);
 874                                 upload_texture(userdata->tex_cr[field], cbcr_width, cbcr_height, cbcr_width, interlaced_stride, GL_RED, GL_UNSIGNED_BYTE, field_cr_start);
 875                                 break;
 876                         }
 877                         case PixelFormat_8BitBGRA: {
 878                                 size_t field_start = video_offset + video_format.stride * field_start_line;
 879                                 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);
 880                                 // These could be asked to deliver mipmaps at any time.
 881                                 glBindTexture(GL_TEXTURE_2D, userdata->tex_rgba[field]);
 882                                 check_error();
 883                                 glGenerateMipmap(GL_TEXTURE_2D);
 884                                 check_error();
 885                                 glBindTexture(GL_TEXTURE_2D, 0);
 886                                 check_error();
 887                                 break;
 888                         }
 889                         default:
 890                                 assert(false);
 891                         }
 892
 893                         glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
 894                         check_error();
 895                 };
 896
 897                 if (field == 1) {
 898                         // Don't upload the second field as fast as we can; wait until
 899                         // the field time has approximately passed. (Otherwise, we could
 900                         // get timing jitter against the other sources, and possibly also
 901                         // against the video display, although the latter is not as critical.)
 902                         // This requires our system clock to be reasonably close to the
 903                         // video clock, but that's not an unreasonable assumption.
 904                         steady_clock::time_point second_field_start = frame_upload_start +
 905                                 nanoseconds(frame_length * 1000000000 / TIMEBASE);
 906                         this_thread::sleep_until(second_field_start);
 907                 }
 908
 909                 {
 910                         unique_lock<mutex> lock(card_mutex);
 911                         CaptureCard::NewFrame new_frame;
 912                         new_frame.frame = frame;
 913                         new_frame.length = frame_length;
 914                         new_frame.field = field;
 915                         new_frame.interlaced = video_format.interlaced;
 916                         new_frame.upload_func = upload_func;
 917                         new_frame.dropped_frames = dropped_frames;
 918                         new_frame.received_timestamp = video_frame.received_timestamp;  // Ignore the audio timestamp.
 919                         card->new_frames.push_back(move(new_frame));
 920                         card->jitter_history.frame_arrived(video_frame.received_timestamp, frame_length, dropped_frames);
 921                 }
 922                 card->new_frames_changed.notify_all();
 923         }
 924 }
 925
 926 void Mixer::bm_hotplug_add(libusb_device *dev)
 927 {
 928         lock_guard<mutex> lock(hotplug_mutex);
 929         hotplugged_cards.push_back(dev);
 930 }
 931
 932 void Mixer::bm_hotplug_remove(unsigned card_index)
 933 {
 934         cards[card_index].new_frames_changed.notify_all();
 935 }
 936
 937 void Mixer::thread_func()
 938 {
 939         pthread_setname_np(pthread_self(), "Mixer_OpenGL");
 940
 941         eglBindAPI(EGL_OPENGL_API);
 942         QOpenGLContext *context = create_context(mixer_surface);
 943         if (!make_current(context, mixer_surface)) {
 944                 printf("oops\n");
 945                 exit(1);
 946         }
 947
 948         // Start the actual capture. (We don't want to do it before we're actually ready
 949         // to process output frames.)
 950         for (unsigned card_index = 0; card_index < num_cards + num_video_inputs; ++card_index) {
 951                 if (int(card_index) != output_card_index) {
 952                         cards[card_index].capture->start_bm_capture();
 953                 }
 954         }
 955
 956         BasicStats basic_stats(/*verbose=*/true);
 957         int stats_dropped_frames = 0;
 958
 959         while (!should_quit) {
 960                 if (desired_output_card_index != output_card_index) {
 961                         set_output_card_internal(desired_output_card_index);
 962                 }
 963                 if (output_card_index != -1 &&
 964                     desired_output_video_mode != output_video_mode) {
 965                         DeckLinkOutput *output = cards[output_card_index].output.get();
 966                         output->end_output();
 967                         desired_output_video_mode = output_video_mode = output->pick_video_mode(desired_output_video_mode);
 968                         output->start_output(desired_output_video_mode, pts_int);
 969                 }
 970
 971                 CaptureCard::NewFrame new_frames[MAX_VIDEO_CARDS];
 972                 bool has_new_frame[MAX_VIDEO_CARDS] = { false };
 973
 974                 bool master_card_is_output;
 975                 unsigned master_card_index;
 976                 if (output_card_index != -1) {
 977                         master_card_is_output = true;
 978                         master_card_index = output_card_index;
 979                 } else {
 980                         master_card_is_output = false;
 981                         master_card_index = theme->map_signal(master_clock_channel);
 982                         assert(master_card_index < num_cards);
 983                 }
 984
 985                 OutputFrameInfo output_frame_info = get_one_frame_from_each_card(master_card_index, master_card_is_output, new_frames, has_new_frame);
 986                 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);
 987                 stats_dropped_frames += output_frame_info.dropped_frames;
 988
 989                 handle_hotplugged_cards();
 990
 991                 for (unsigned card_index = 0; card_index < num_cards + num_video_inputs; ++card_index) {
 992                         if (card_index == master_card_index || !has_new_frame[card_index]) {
 993                                 continue;
 994                         }
 995                         if (new_frames[card_index].frame->len == 0) {
 996                                 ++new_frames[card_index].dropped_frames;
 997                         }
 998                         if (new_frames[card_index].dropped_frames > 0) {
 999                                 printf("Card %u dropped %d frames before this\n",
1000                                         card_index, int(new_frames[card_index].dropped_frames));
1001                         }
1002                 }
1003
1004                 // If the first card is reporting a corrupted or otherwise dropped frame,
1005                 // just increase the pts (skipping over this frame) and don't try to compute anything new.
1006                 if (!master_card_is_output && new_frames[master_card_index].frame->len == 0) {
1007                         ++stats_dropped_frames;
1008                         pts_int += new_frames[master_card_index].length;
1009                         continue;
1010                 }
1011
1012                 for (unsigned card_index = 0; card_index < num_cards + num_video_inputs; ++card_index) {
1013                         if (!has_new_frame[card_index] || new_frames[card_index].frame->len == 0)
1014                                 continue;
1015
1016                         CaptureCard::NewFrame *new_frame = &new_frames[card_index];
1017                         assert(new_frame->frame != nullptr);
1018                         insert_new_frame(new_frame->frame, new_frame->field, new_frame->interlaced, card_index, &input_state);
1019                         check_error();
1020
1021                         // The new texture might need uploading before use.
1022                         if (new_frame->upload_func) {
1023                                 new_frame->upload_func();
1024                                 new_frame->upload_func = nullptr;
1025                         }
1026                 }
1027
1028                 int64_t frame_duration = output_frame_info.frame_duration;
1029                 render_one_frame(frame_duration);
1030                 ++frame_num;
1031                 pts_int += frame_duration;
1032
1033                 basic_stats.update(frame_num, stats_dropped_frames);
1034                 // if (frame_num % 100 == 0) chain->print_phase_timing();
1035
1036                 if (should_cut.exchange(false)) {  // Test and clear.
1037                         video_encoder->do_cut(frame_num);
1038                 }
1039
1040 #if 0
1041                 // Reset every 100 frames, so that local variations in frame times
1042                 // (especially for the first few frames, when the shaders are
1043                 // compiled etc.) don't make it hard to measure for the entire
1044                 // remaining duration of the program.
1045                 if (frame == 10000) {
1046                         frame = 0;
1047                         start = now;
1048                 }
1049 #endif
1050                 check_error();
1051         }
1052
1053         resource_pool->clean_context();
1054 }
1055
1056 bool Mixer::input_card_is_master_clock(unsigned card_index, unsigned master_card_index) const
1057 {
1058         if (output_card_index != -1) {
1059                 // The output card (ie., cards[output_card_index].output) is the master clock,
1060                 // so no input card (ie., cards[card_index].capture) is.
1061                 return false;
1062         }
1063         return (card_index == master_card_index);
1064 }
1065
1066 void Mixer::trim_queue(CaptureCard *card, size_t safe_queue_length)
1067 {
1068         // Count the number of frames in the queue, including any frames
1069         // we dropped. It's hard to know exactly how we should deal with
1070         // dropped (corrupted) input frames; they don't help our goal of
1071         // avoiding starvation, but they still add to the problem of latency.
1072         // Since dropped frames is going to mean a bump in the signal anyway,
1073         // we err on the side of having more stable latency instead.
1074         unsigned queue_length = 0;
1075         for (const CaptureCard::NewFrame &frame : card->new_frames) {
1076                 queue_length += frame.dropped_frames + 1;
1077         }
1078
1079         // If needed, drop frames until the queue is below the safe limit.
1080         // We prefer to drop from the head, because all else being equal,
1081         // we'd like more recent frames (less latency).
1082         unsigned dropped_frames = 0;
1083         while (queue_length > safe_queue_length) {
1084                 assert(!card->new_frames.empty());
1085                 assert(queue_length > card->new_frames.front().dropped_frames);
1086                 queue_length -= card->new_frames.front().dropped_frames;
1087
1088                 if (queue_length <= safe_queue_length) {
1089                         // No need to drop anything.
1090                         break;
1091                 }
1092
1093                 card->new_frames.pop_front();
1094                 card->new_frames_changed.notify_all();
1095                 --queue_length;
1096                 ++dropped_frames;
1097         }
1098
1099         card->metric_input_dropped_frames_jitter += dropped_frames;
1100         card->metric_input_queue_length_frames = queue_length;
1101
1102 #if 0
1103         if (dropped_frames > 0) {
1104                 fprintf(stderr, "Card %u dropped %u frame(s) to keep latency down.\n",
1105                         card_index, dropped_frames);
1106         }
1107 #endif
1108 }
1109
1110 pair<string, string> Mixer::get_channels_json()
1111 {
1112         Channels ret;
1113         for (int channel_idx = 2; channel_idx < theme->get_num_channels(); ++channel_idx) {
1114                 Channel *channel = ret.add_channel();
1115                 channel->set_index(channel_idx);
1116                 channel->set_name(theme->get_channel_name(channel_idx));
1117                 channel->set_color(theme->get_channel_color(channel_idx));
1118         }
1119         string contents;
1120         google::protobuf::util::MessageToJsonString(ret, &contents);  // Ignore any errors.
1121         return make_pair(contents, "text/json");
1122 }
1123
1124 pair<string, string> Mixer::get_channel_color_http(unsigned channel_idx)
1125 {
1126         return make_pair(theme->get_channel_color(channel_idx), "text/plain");
1127 }
1128
1129 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])
1130 {
1131         OutputFrameInfo output_frame_info;
1132 start:
1133         unique_lock<mutex> lock(card_mutex, defer_lock);
1134         if (master_card_is_output) {
1135                 // Clocked to the output, so wait for it to be ready for the next frame.
1136                 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);
1137                 lock.lock();
1138         } else {
1139                 // Wait for the master card to have a new frame.
1140                 // TODO: Add a timeout.
1141                 output_frame_info.is_preroll = false;
1142                 lock.lock();
1143                 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(); });
1144         }
1145
1146         if (master_card_is_output) {
1147                 handle_hotplugged_cards();
1148         } else if (cards[master_card_index].new_frames.empty()) {
1149                 // We were woken up, but not due to a new frame. Deal with it
1150                 // and then restart.
1151                 assert(cards[master_card_index].capture->get_disconnected());
1152                 handle_hotplugged_cards();
1153                 lock.unlock();
1154                 goto start;
1155         }
1156
1157         for (unsigned card_index = 0; card_index < num_cards + num_video_inputs; ++card_index) {
1158                 CaptureCard *card = &cards[card_index];
1159                 if (card->new_frames.empty()) {  // Starvation.
1160                         ++card->metric_input_duped_frames;
1161                 } else {
1162                         new_frames[card_index] = move(card->new_frames.front());
1163                         has_new_frame[card_index] = true;
1164                         card->new_frames.pop_front();
1165                         card->new_frames_changed.notify_all();
1166                 }
1167         }
1168
1169         if (!master_card_is_output) {
1170                 output_frame_info.frame_timestamp = new_frames[master_card_index].received_timestamp;
1171                 output_frame_info.dropped_frames = new_frames[master_card_index].dropped_frames;
1172                 output_frame_info.frame_duration = new_frames[master_card_index].length;
1173         }
1174
1175         if (!output_frame_info.is_preroll) {
1176                 output_jitter_history.frame_arrived(output_frame_info.frame_timestamp, output_frame_info.frame_duration, output_frame_info.dropped_frames);
1177         }
1178
1179         for (unsigned card_index = 0; card_index < num_cards + num_video_inputs; ++card_index) {
1180                 CaptureCard *card = &cards[card_index];
1181                 if (has_new_frame[card_index] &&
1182                     !input_card_is_master_clock(card_index, master_card_index) &&
1183                     !output_frame_info.is_preroll) {
1184                         card->queue_length_policy.update_policy(
1185                                 output_frame_info.frame_timestamp,
1186                                 card->jitter_history.get_expected_next_frame(),
1187                                 new_frames[master_card_index].length,
1188                                 output_frame_info.frame_duration,
1189                                 card->jitter_history.estimate_max_jitter(),
1190                                 output_jitter_history.estimate_max_jitter());
1191                         trim_queue(card, min<int>(global_flags.max_input_queue_frames,
1192                                                   card->queue_length_policy.get_safe_queue_length()));
1193                 }
1194         }
1195
1196         // This might get off by a fractional sample when changing master card
1197         // between ones with different frame rates, but that's fine.
1198         int num_samples_times_timebase = OUTPUT_FREQUENCY * output_frame_info.frame_duration + fractional_samples;
1199         output_frame_info.num_samples = num_samples_times_timebase / TIMEBASE;
1200         fractional_samples = num_samples_times_timebase % TIMEBASE;
1201         assert(output_frame_info.num_samples >= 0);
1202
1203         return output_frame_info;
1204 }
1205
1206 void Mixer::handle_hotplugged_cards()
1207 {
1208         // Check for cards that have been disconnected since last frame.
1209         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
1210                 CaptureCard *card = &cards[card_index];
1211                 if (card->capture->get_disconnected()) {
1212                         fprintf(stderr, "Card %u went away, replacing with a fake card.\n", card_index);
1213                         FakeCapture *capture = new FakeCapture(global_flags.width, global_flags.height, FAKE_FPS, OUTPUT_FREQUENCY, card_index, global_flags.fake_cards_audio);
1214                         configure_card(card_index, capture, CardType::FAKE_CAPTURE, /*output=*/nullptr);
1215                         card->queue_length_policy.reset(card_index);
1216                         card->capture->start_bm_capture();
1217                 }
1218         }
1219
1220         // Check for cards that have been connected since last frame.
1221         vector<libusb_device *> hotplugged_cards_copy;
1222         {
1223                 lock_guard<mutex> lock(hotplug_mutex);
1224                 swap(hotplugged_cards, hotplugged_cards_copy);
1225         }
1226         for (libusb_device *new_dev : hotplugged_cards_copy) {
1227                 // Look for a fake capture card where we can stick this in.
1228                 int free_card_index = -1;
1229                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
1230                         if (cards[card_index].is_fake_capture) {
1231                                 free_card_index = card_index;
1232                                 break;
1233                         }
1234                 }
1235
1236                 if (free_card_index == -1) {
1237                         fprintf(stderr, "New card plugged in, but no free slots -- ignoring.\n");
1238                         libusb_unref_device(new_dev);
1239                 } else {
1240                         // BMUSBCapture takes ownership.
1241                         fprintf(stderr, "New card plugged in, choosing slot %d.\n", free_card_index);
1242                         CaptureCard *card = &cards[free_card_index];
1243                         BMUSBCapture *capture = new BMUSBCapture(free_card_index, new_dev);
1244                         configure_card(free_card_index, capture, CardType::LIVE_CARD, /*output=*/nullptr);
1245                         card->queue_length_policy.reset(free_card_index);
1246                         capture->set_card_disconnected_callback(bind(&Mixer::bm_hotplug_remove, this, free_card_index));
1247                         capture->start_bm_capture();
1248                 }
1249         }
1250 }
1251
1252
1253 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)
1254 {
1255         // Resample the audio as needed, including from previously dropped frames.
1256         assert(num_cards > 0);
1257         for (unsigned frame_num = 0; frame_num < dropped_frames + 1; ++frame_num) {
1258                 const bool dropped_frame = (frame_num != dropped_frames);
1259                 {
1260                         // Signal to the audio thread to process this frame.
1261                         // Note that if the frame is a dropped frame, we signal that
1262                         // we don't want to use this frame as base for adjusting
1263                         // the resampler rate. The reason for this is that the timing
1264                         // of these frames is often way too late; they typically don't
1265                         // “arrive” before we synthesize them. Thus, we could end up
1266                         // in a situation where we have inserted e.g. five audio frames
1267                         // into the queue before we then start pulling five of them
1268                         // back out. This makes ResamplingQueue overestimate the delay,
1269                         // causing undue resampler changes. (We _do_ use the last,
1270                         // non-dropped frame; perhaps we should just discard that as well,
1271                         // since dropped frames are expected to be rare, and it might be
1272                         // better to just wait until we have a slightly more normal situation).
1273                         unique_lock<mutex> lock(audio_mutex);
1274                         bool adjust_rate = !dropped_frame && !is_preroll;
1275                         audio_task_queue.push(AudioTask{pts_int, num_samples_per_frame, adjust_rate, frame_timestamp});
1276                         audio_task_queue_changed.notify_one();
1277                 }
1278                 if (dropped_frame) {
1279                         // For dropped frames, increase the pts. Note that if the format changed
1280                         // in the meantime, we have no way of detecting that; we just have to
1281                         // assume the frame length is always the same.
1282                         pts_int += length_per_frame;
1283                 }
1284         }
1285 }
1286
1287 void Mixer::render_one_frame(int64_t duration)
1288 {
1289         // Determine the time code for this frame before we start rendering.
1290         string timecode_text = timecode_renderer->get_timecode_text(double(pts_int) / TIMEBASE, frame_num);
1291         if (display_timecode_on_stdout) {
1292                 printf("Timecode: '%s'\n", timecode_text.c_str());
1293         }
1294
1295         // Update Y'CbCr settings for all cards.
1296         {
1297                 unique_lock<mutex> lock(card_mutex);
1298                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
1299                         YCbCrInterpretation *interpretation = &ycbcr_interpretation[card_index];
1300                         input_state.ycbcr_coefficients_auto[card_index] = interpretation->ycbcr_coefficients_auto;
1301                         input_state.ycbcr_coefficients[card_index] = interpretation->ycbcr_coefficients;
1302                         input_state.full_range[card_index] = interpretation->full_range;
1303                 }
1304         }
1305
1306         // Get the main chain from the theme, and set its state immediately.
1307         Theme::Chain theme_main_chain = theme->get_chain(0, pts(), global_flags.width, global_flags.height, input_state);
1308         EffectChain *chain = theme_main_chain.chain;
1309         theme_main_chain.setup_chain();
1310         //theme_main_chain.chain->enable_phase_timing(true);
1311
1312         // The theme can't (or at least shouldn't!) call connect_signal() on
1313         // each FFmpeg input, so we'll do it here.
1314         for (const pair<LiveInputWrapper *, FFmpegCapture *> &conn : theme->get_signal_connections()) {
1315                 conn.first->connect_signal_raw(conn.second->get_card_index(), input_state);
1316         }
1317
1318         // If HDMI/SDI output is active and the user has requested auto mode,
1319         // its mode overrides the existing Y'CbCr setting for the chain.
1320         YCbCrLumaCoefficients ycbcr_output_coefficients;
1321         if (global_flags.ycbcr_auto_coefficients && output_card_index != -1) {
1322                 ycbcr_output_coefficients = cards[output_card_index].output->preferred_ycbcr_coefficients();
1323         } else {
1324                 ycbcr_output_coefficients = global_flags.ycbcr_rec709_coefficients ? YCBCR_REC_709 : YCBCR_REC_601;
1325         }
1326
1327         // TODO: Reduce the duplication against theme.cpp.
1328         YCbCrFormat output_ycbcr_format;
1329         output_ycbcr_format.chroma_subsampling_x = 1;
1330         output_ycbcr_format.chroma_subsampling_y = 1;
1331         output_ycbcr_format.luma_coefficients = ycbcr_output_coefficients;
1332         output_ycbcr_format.full_range = false;
1333         output_ycbcr_format.num_levels = 1 << global_flags.x264_bit_depth;
1334         chain->change_ycbcr_output_format(output_ycbcr_format);
1335
1336         // Render main chain. If we're using zerocopy Quick Sync encoding
1337         // (the default case), we take an extra copy of the created outputs,
1338         // so that we can display it back to the screen later (it's less memory
1339         // bandwidth than writing and reading back an RGBA texture, even at 16-bit).
1340         // Ideally, we'd like to avoid taking copies and just use the main textures
1341         // for display as well, but they're just views into VA-API memory and must be
1342         // unmapped during encoding, so we can't use them for display, unfortunately.
1343         GLuint y_tex, cbcr_full_tex, cbcr_tex;
1344         GLuint y_copy_tex, cbcr_copy_tex = 0;
1345         GLuint y_display_tex, cbcr_display_tex;
1346         GLenum y_type = (global_flags.x264_bit_depth > 8) ? GL_R16 : GL_R8;
1347         GLenum cbcr_type = (global_flags.x264_bit_depth > 8) ? GL_RG16 : GL_RG8;
1348         const bool is_zerocopy = video_encoder->is_zerocopy();
1349         if (is_zerocopy) {
1350                 cbcr_full_tex = resource_pool->create_2d_texture(cbcr_type, global_flags.width, global_flags.height);
1351                 y_copy_tex = resource_pool->create_2d_texture(y_type, global_flags.width, global_flags.height);
1352                 cbcr_copy_tex = resource_pool->create_2d_texture(cbcr_type, global_flags.width / 2, global_flags.height / 2);
1353
1354                 y_display_tex = y_copy_tex;
1355                 cbcr_display_tex = cbcr_copy_tex;
1356
1357                 // y_tex and cbcr_tex will be given by VideoEncoder.
1358         } else {
1359                 cbcr_full_tex = resource_pool->create_2d_texture(cbcr_type, global_flags.width, global_flags.height);
1360                 y_tex = resource_pool->create_2d_texture(y_type, global_flags.width, global_flags.height);
1361                 cbcr_tex = resource_pool->create_2d_texture(cbcr_type, global_flags.width / 2, global_flags.height / 2);
1362
1363                 y_display_tex = y_tex;
1364                 cbcr_display_tex = cbcr_tex;
1365         }
1366
1367         const int64_t av_delay = lrint(global_flags.audio_queue_length_ms * 0.001 * TIMEBASE);  // Corresponds to the delay in ResamplingQueue.
1368         bool got_frame = video_encoder->begin_frame(pts_int + av_delay, duration, ycbcr_output_coefficients, theme_main_chain.input_frames, &y_tex, &cbcr_tex);
1369         assert(got_frame);
1370
1371         GLuint fbo;
1372         if (is_zerocopy) {
1373                 fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex, y_copy_tex);
1374         } else {
1375                 fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex);
1376         }
1377         check_error();
1378         chain->render_to_fbo(fbo, global_flags.width, global_flags.height);
1379
1380         if (display_timecode_in_stream) {
1381                 // Render the timecode on top.
1382                 timecode_renderer->render_timecode(fbo, timecode_text);
1383         }
1384
1385         resource_pool->release_fbo(fbo);
1386
1387         if (is_zerocopy) {
1388                 chroma_subsampler->subsample_chroma(cbcr_full_tex, global_flags.width, global_flags.height, cbcr_tex, cbcr_copy_tex);
1389         } else {
1390                 chroma_subsampler->subsample_chroma(cbcr_full_tex, global_flags.width, global_flags.height, cbcr_tex);
1391         }
1392         if (output_card_index != -1) {
1393                 cards[output_card_index].output->send_frame(y_tex, cbcr_full_tex, ycbcr_output_coefficients, theme_main_chain.input_frames, pts_int, duration);
1394         }
1395         resource_pool->release_2d_texture(cbcr_full_tex);
1396
1397         // Set the right state for the Y' and CbCr textures we use for display.
1398         glBindFramebuffer(GL_FRAMEBUFFER, 0);
1399         glBindTexture(GL_TEXTURE_2D, y_display_tex);
1400         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1401         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
1402         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
1403
1404         glBindTexture(GL_TEXTURE_2D, cbcr_display_tex);
1405         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1406         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
1407         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
1408
1409         RefCountedGLsync fence = video_encoder->end_frame();
1410
1411         // The live frame pieces the Y'CbCr texture copies back into RGB and displays them.
1412         // It owns y_display_tex and cbcr_display_tex now (whichever textures they are).
1413         DisplayFrame live_frame;
1414         live_frame.chain = display_chain.get();
1415         live_frame.setup_chain = [this, y_display_tex, cbcr_display_tex]{
1416                 display_input->set_texture_num(0, y_display_tex);
1417                 display_input->set_texture_num(1, cbcr_display_tex);
1418         };
1419         live_frame.ready_fence = fence;
1420         live_frame.input_frames = {};
1421         live_frame.temp_textures = { y_display_tex, cbcr_display_tex };
1422         output_channel[OUTPUT_LIVE].output_frame(move(live_frame));
1423
1424         // Set up preview and any additional channels.
1425         for (int i = 1; i < theme->get_num_channels() + 2; ++i) {
1426                 DisplayFrame display_frame;
1427                 Theme::Chain chain = theme->get_chain(i, pts(), global_flags.width, global_flags.height, input_state);  // FIXME: dimensions
1428                 display_frame.chain = move(chain.chain);
1429                 display_frame.setup_chain = move(chain.setup_chain);
1430                 display_frame.ready_fence = fence;
1431                 display_frame.input_frames = move(chain.input_frames);
1432                 display_frame.temp_textures = {};
1433                 output_channel[i].output_frame(move(display_frame));
1434         }
1435 }
1436
1437 void Mixer::audio_thread_func()
1438 {
1439         pthread_setname_np(pthread_self(), "Mixer_Audio");
1440
1441         while (!should_quit) {
1442                 AudioTask task;
1443
1444                 {
1445                         unique_lock<mutex> lock(audio_mutex);
1446                         audio_task_queue_changed.wait(lock, [this]{ return should_quit || !audio_task_queue.empty(); });
1447                         if (should_quit) {
1448                                 return;
1449                         }
1450                         task = audio_task_queue.front();
1451                         audio_task_queue.pop();
1452                 }
1453
1454                 ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy =
1455                         task.adjust_rate ? ResamplingQueue::ADJUST_RATE : ResamplingQueue::DO_NOT_ADJUST_RATE;
1456                 vector<float> samples_out = audio_mixer.get_output(
1457                         task.frame_timestamp,
1458                         task.num_samples,
1459                         rate_adjustment_policy);
1460
1461                 // Send the samples to the sound card, then add them to the output.
1462                 if (alsa) {
1463                         alsa->write(samples_out);
1464                 }
1465                 if (output_card_index != -1) {
1466                         const int64_t av_delay = lrint(global_flags.audio_queue_length_ms * 0.001 * TIMEBASE);  // Corresponds to the delay in ResamplingQueue.
1467                         cards[output_card_index].output->send_audio(task.pts_int + av_delay, samples_out);
1468                 }
1469                 video_encoder->add_audio(task.pts_int, move(samples_out));
1470         }
1471 }
1472
1473 void Mixer::release_display_frame(DisplayFrame *frame)
1474 {
1475         for (GLuint texnum : frame->temp_textures) {
1476                 resource_pool->release_2d_texture(texnum);
1477         }
1478         frame->temp_textures.clear();
1479         frame->ready_fence.reset();
1480         frame->input_frames.clear();
1481 }
1482
1483 void Mixer::start()
1484 {
1485         mixer_thread = thread(&Mixer::thread_func, this);
1486         audio_thread = thread(&Mixer::audio_thread_func, this);
1487 }
1488
1489 void Mixer::quit()
1490 {
1491         should_quit = true;
1492         audio_task_queue_changed.notify_one();
1493         mixer_thread.join();
1494         audio_thread.join();
1495 }
1496
1497 void Mixer::transition_clicked(int transition_num)
1498 {
1499         theme->transition_clicked(transition_num, pts());
1500 }
1501
1502 void Mixer::channel_clicked(int preview_num)
1503 {
1504         theme->channel_clicked(preview_num);
1505 }
1506
1507 YCbCrInterpretation Mixer::get_input_ycbcr_interpretation(unsigned card_index) const
1508 {
1509         unique_lock<mutex> lock(card_mutex);
1510         return ycbcr_interpretation[card_index];
1511 }
1512
1513 void Mixer::set_input_ycbcr_interpretation(unsigned card_index, const YCbCrInterpretation &interpretation)
1514 {
1515         unique_lock<mutex> lock(card_mutex);
1516         ycbcr_interpretation[card_index] = interpretation;
1517 }
1518
1519 void Mixer::start_mode_scanning(unsigned card_index)
1520 {
1521         assert(card_index < num_cards);
1522         if (is_mode_scanning[card_index]) {
1523                 return;
1524         }
1525         is_mode_scanning[card_index] = true;
1526         mode_scanlist[card_index].clear();
1527         for (const auto &mode : cards[card_index].capture->get_available_video_modes()) {
1528                 mode_scanlist[card_index].push_back(mode.first);
1529         }
1530         assert(!mode_scanlist[card_index].empty());
1531         mode_scanlist_index[card_index] = 0;
1532         cards[card_index].capture->set_video_mode(mode_scanlist[card_index][0]);
1533         last_mode_scan_change[card_index] = steady_clock::now();
1534 }
1535
1536 map<uint32_t, VideoMode> Mixer::get_available_output_video_modes() const
1537 {
1538         assert(desired_output_card_index != -1);
1539         unique_lock<mutex> lock(card_mutex);
1540         return cards[desired_output_card_index].output->get_available_video_modes();
1541 }
1542
1543 Mixer::OutputChannel::~OutputChannel()
1544 {
1545         if (has_current_frame) {
1546                 parent->release_display_frame(&current_frame);
1547         }
1548         if (has_ready_frame) {
1549                 parent->release_display_frame(&ready_frame);
1550         }
1551 }
1552
1553 void Mixer::OutputChannel::output_frame(DisplayFrame &&frame)
1554 {
1555         // Store this frame for display. Remove the ready frame if any
1556         // (it was seemingly never used).
1557         {
1558                 unique_lock<mutex> lock(frame_mutex);
1559                 if (has_ready_frame) {
1560                         parent->release_display_frame(&ready_frame);
1561                 }
1562                 ready_frame = move(frame);
1563                 has_ready_frame = true;
1564
1565                 // Call the callbacks under the mutex (they should be short),
1566                 // so that we don't race against a callback removal.
1567                 for (const auto &key_and_callback : new_frame_ready_callbacks) {
1568                         key_and_callback.second();
1569                 }
1570         }
1571
1572         // Reduce the number of callbacks by filtering duplicates. The reason
1573         // why we bother doing this is that Qt seemingly can get into a state
1574         // where its builds up an essentially unbounded queue of signals,
1575         // consuming more and more memory, and there's no good way of collapsing
1576         // user-defined signals or limiting the length of the queue.
1577         if (transition_names_updated_callback) {
1578                 vector<string> transition_names = global_mixer->get_transition_names();
1579                 bool changed = false;
1580                 if (transition_names.size() != last_transition_names.size()) {
1581                         changed = true;
1582                 } else {
1583                         for (unsigned i = 0; i < transition_names.size(); ++i) {
1584                                 if (transition_names[i] != last_transition_names[i]) {
1585                                         changed = true;
1586                                         break;
1587                                 }
1588                         }
1589                 }
1590                 if (changed) {
1591                         transition_names_updated_callback(transition_names);
1592                         last_transition_names = transition_names;
1593                 }
1594         }
1595         if (name_updated_callback) {
1596                 string name = global_mixer->get_channel_name(channel);
1597                 if (name != last_name) {
1598                         name_updated_callback(name);
1599                         last_name = name;
1600                 }
1601         }
1602         if (color_updated_callback) {
1603                 string color = global_mixer->get_channel_color(channel);
1604                 if (color != last_color) {
1605                         color_updated_callback(color);
1606                         last_color = color;
1607                 }
1608         }
1609 }
1610
1611 bool Mixer::OutputChannel::get_display_frame(DisplayFrame *frame)
1612 {
1613         unique_lock<mutex> lock(frame_mutex);
1614         if (!has_current_frame && !has_ready_frame) {
1615                 return false;
1616         }
1617
1618         if (has_current_frame && has_ready_frame) {
1619                 // We have a new ready frame. Toss the current one.
1620                 parent->release_display_frame(&current_frame);
1621                 has_current_frame = false;
1622         }
1623         if (has_ready_frame) {
1624                 assert(!has_current_frame);
1625                 current_frame = move(ready_frame);
1626                 ready_frame.ready_fence.reset();  // Drop the refcount.
1627                 ready_frame.input_frames.clear();  // Drop the refcounts.
1628                 has_current_frame = true;
1629                 has_ready_frame = false;
1630         }
1631
1632         *frame = current_frame;
1633         return true;
1634 }
1635
1636 void Mixer::OutputChannel::add_frame_ready_callback(void *key, Mixer::new_frame_ready_callback_t callback)
1637 {
1638         unique_lock<mutex> lock(frame_mutex);
1639         new_frame_ready_callbacks[key] = callback;
1640 }
1641
1642 void Mixer::OutputChannel::remove_frame_ready_callback(void *key)
1643 {
1644         unique_lock<mutex> lock(frame_mutex);
1645         new_frame_ready_callbacks.erase(key);
1646 }
1647
1648 void Mixer::OutputChannel::set_transition_names_updated_callback(Mixer::transition_names_updated_callback_t callback)
1649 {
1650         transition_names_updated_callback = callback;
1651 }
1652
1653 void Mixer::OutputChannel::set_name_updated_callback(Mixer::name_updated_callback_t callback)
1654 {
1655         name_updated_callback = callback;
1656 }
1657
1658 void Mixer::OutputChannel::set_color_updated_callback(Mixer::color_updated_callback_t callback)
1659 {
1660         color_updated_callback = callback;
1661 }
1662
1663 mutex RefCountedGLsync::fence_lock;