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 <movit/util.h>
  14 #include <stdint.h>
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <sys/time.h>
  18 #include <time.h>
  19 #include <algorithm>
  20 #include <cmath>
  21 #include <condition_variable>
  22 #include <cstddef>
  23 #include <memory>
  24 #include <mutex>
  25 #include <string>
  26 #include <thread>
  27 #include <utility>
  28 #include <vector>
  29 #include <arpa/inet.h>
  30
  31 #include "bmusb/bmusb.h"
  32 #include "context.h"
  33 #include "decklink_capture.h"
  34 #include "defs.h"
  35 #include "flags.h"
  36 #include "h264encode.h"
  37 #include "pbo_frame_allocator.h"
  38 #include "ref_counted_gl_sync.h"
  39 #include "timebase.h"
  40
  41 class QOpenGLContext;
  42
  43 using namespace movit;
  44 using namespace std;
  45 using namespace std::placeholders;
  46
  47 Mixer *global_mixer = nullptr;
  48
  49 namespace {
  50
  51 void convert_fixed24_to_fp32(float *dst, size_t out_channels, const uint8_t *src, size_t in_channels, size_t num_samples)
  52 {
  53         assert(in_channels >= out_channels);
  54         for (size_t i = 0; i < num_samples; ++i) {
  55                 for (size_t j = 0; j < out_channels; ++j) {
  56                         uint32_t s1 = *src++;
  57                         uint32_t s2 = *src++;
  58                         uint32_t s3 = *src++;
  59                         uint32_t s = s1 | (s1 << 8) | (s2 << 16) | (s3 << 24);
  60                         dst[i * out_channels + j] = int(s) * (1.0f / 4294967296.0f);
  61                 }
  62                 src += 3 * (in_channels - out_channels);
  63         }
  64 }
  65
  66 void convert_fixed32_to_fp32(float *dst, size_t out_channels, const uint8_t *src, size_t in_channels, size_t num_samples)
  67 {
  68         assert(in_channels >= out_channels);
  69         for (size_t i = 0; i < num_samples; ++i) {
  70                 for (size_t j = 0; j < out_channels; ++j) {
  71                         // Note: Assumes little-endian.
  72                         int32_t s = *(int32_t *)src;
  73                         dst[i * out_channels + j] = s * (1.0f / 4294967296.0f);
  74                         src += 4;
  75                 }
  76                 src += 4 * (in_channels - out_channels);
  77         }
  78 }
  79
  80 void insert_new_frame(RefCountedFrame frame, unsigned field_num, bool interlaced, unsigned card_index, InputState *input_state)
  81 {
  82         if (interlaced) {
  83                 for (unsigned frame_num = FRAME_HISTORY_LENGTH; frame_num --> 1; ) {  // :-)
  84                         input_state->buffered_frames[card_index][frame_num] =
  85                                 input_state->buffered_frames[card_index][frame_num - 1];
  86                 }
  87                 input_state->buffered_frames[card_index][0] = { frame, field_num };
  88         } else {
  89                 for (unsigned frame_num = 0; frame_num < FRAME_HISTORY_LENGTH; ++frame_num) {
  90                         input_state->buffered_frames[card_index][frame_num] = { frame, field_num };
  91                 }
  92         }
  93 }
  94
  95 string generate_local_dump_filename(int frame)
  96 {
  97         time_t now = time(NULL);
  98         tm now_tm;
  99         localtime_r(&now, &now_tm);
 100
 101         char timestamp[256];
 102         strftime(timestamp, sizeof(timestamp), "%F-%T%z", &now_tm);
 103
 104         // Use the frame number to disambiguate between two cuts starting
 105         // on the same second.
 106         char filename[256];
 107         snprintf(filename, sizeof(filename), "%s%s-f%02d%s",
 108                 LOCAL_DUMP_PREFIX, timestamp, frame % 100, LOCAL_DUMP_SUFFIX);
 109         return filename;
 110 }
 111
 112 }  // namespace
 113
 114 void QueueLengthPolicy::update_policy(int queue_length)
 115 {
 116         if (queue_length < 0) {  // Starvation.
 117                 if (been_at_safe_point_since_last_starvation && safe_queue_length < 5) {
 118                         ++safe_queue_length;
 119                         fprintf(stderr, "Card %u: Starvation, increasing safe limit to %u frames\n",
 120                                 card_index, safe_queue_length);
 121                 }
 122                 frames_with_at_least_one = 0;
 123                 been_at_safe_point_since_last_starvation = false;
 124                 return;
 125         }
 126         if (queue_length > 0) {
 127                 if (queue_length >= int(safe_queue_length)) {
 128                         been_at_safe_point_since_last_starvation = true;
 129                 }
 130                 if (++frames_with_at_least_one >= 50 && safe_queue_length > 0) {
 131                         --safe_queue_length;
 132                         fprintf(stderr, "Card %u: Spare frames for more than 50 frames, reducing safe limit to %u frames\n",
 133                                 card_index, safe_queue_length);
 134                         frames_with_at_least_one = 0;
 135                 }
 136         } else {
 137                 frames_with_at_least_one = 0;
 138         }
 139 }
 140
 141 Mixer::Mixer(const QSurfaceFormat &format, unsigned num_cards)
 142         : httpd(WIDTH, HEIGHT),
 143           num_cards(num_cards),
 144           mixer_surface(create_surface(format)),
 145           h264_encoder_surface(create_surface(format)),
 146           correlation(OUTPUT_FREQUENCY),
 147           level_compressor(OUTPUT_FREQUENCY),
 148           limiter(OUTPUT_FREQUENCY),
 149           compressor(OUTPUT_FREQUENCY)
 150 {
 151         httpd.open_output_file(generate_local_dump_filename(/*frame=*/0).c_str());
 152         httpd.start(9095);
 153
 154         CHECK(init_movit(MOVIT_SHADER_DIR, MOVIT_DEBUG_OFF));
 155         check_error();
 156
 157         // Since we allow non-bouncing 4:2:2 YCbCrInputs, effective subpixel precision
 158         // will be halved when sampling them, and we need to compensate here.
 159         movit_texel_subpixel_precision /= 2.0;
 160
 161         resource_pool.reset(new ResourcePool);
 162         theme.reset(new Theme(global_flags.theme_filename.c_str(), resource_pool.get(), num_cards));
 163         for (unsigned i = 0; i < NUM_OUTPUTS; ++i) {
 164                 output_channel[i].parent = this;
 165         }
 166
 167         ImageFormat inout_format;
 168         inout_format.color_space = COLORSPACE_sRGB;
 169         inout_format.gamma_curve = GAMMA_sRGB;
 170
 171         // Display chain; shows the live output produced by the main chain (its RGBA version).
 172         display_chain.reset(new EffectChain(WIDTH, HEIGHT, resource_pool.get()));
 173         check_error();
 174         display_input = new FlatInput(inout_format, FORMAT_RGB, GL_UNSIGNED_BYTE, WIDTH, HEIGHT);  // FIXME: GL_UNSIGNED_BYTE is really wrong.
 175         display_chain->add_input(display_input);
 176         display_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
 177         display_chain->set_dither_bits(0);  // Don't bother.
 178         display_chain->finalize();
 179
 180         h264_encoder.reset(new H264Encoder(h264_encoder_surface, global_flags.va_display, WIDTH, HEIGHT, &httpd));
 181
 182         // First try initializing the PCI devices, then USB, until we have the desired number of cards.
 183         unsigned num_pci_devices = 0, num_usb_devices = 0;
 184         unsigned card_index = 0;
 185
 186         IDeckLinkIterator *decklink_iterator = CreateDeckLinkIteratorInstance();
 187         if (decklink_iterator != nullptr) {
 188                 for ( ; card_index < num_cards; ++card_index) {
 189                         IDeckLink *decklink;
 190                         if (decklink_iterator->Next(&decklink) != S_OK) {
 191                                 break;
 192                         }
 193
 194                         configure_card(card_index, format, new DeckLinkCapture(decklink, card_index));
 195                         ++num_pci_devices;
 196                 }
 197                 decklink_iterator->Release();
 198                 fprintf(stderr, "Found %d DeckLink PCI card(s).\n", num_pci_devices);
 199         } else {
 200                 fprintf(stderr, "DeckLink drivers not found. Probing for USB cards only.\n");
 201         }
 202         for ( ; card_index < num_cards; ++card_index) {
 203                 configure_card(card_index, format, new BMUSBCapture(card_index - num_pci_devices));
 204                 ++num_usb_devices;
 205         }
 206
 207         if (num_usb_devices > 0) {
 208                 BMUSBCapture::start_bm_thread();
 209         }
 210
 211         for (card_index = 0; card_index < num_cards; ++card_index) {
 212                 cards[card_index].queue_length_policy.reset(card_index);
 213                 cards[card_index].capture->start_bm_capture();
 214         }
 215
 216         // Set up stuff for NV12 conversion.
 217
 218         // Cb/Cr shader.
 219         string cbcr_vert_shader =
 220                 "#version 130 \n"
 221                 " \n"
 222                 "in vec2 position; \n"
 223                 "in vec2 texcoord; \n"
 224                 "out vec2 tc0; \n"
 225                 "uniform vec2 foo_chroma_offset_0; \n"
 226                 " \n"
 227                 "void main() \n"
 228                 "{ \n"
 229                 "    // The result of glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0) is: \n"
 230                 "    // \n"
 231                 "    //   2.000  0.000  0.000 -1.000 \n"
 232                 "    //   0.000  2.000  0.000 -1.000 \n"
 233                 "    //   0.000  0.000 -2.000 -1.000 \n"
 234                 "    //   0.000  0.000  0.000  1.000 \n"
 235                 "    gl_Position = vec4(2.0 * position.x - 1.0, 2.0 * position.y - 1.0, -1.0, 1.0); \n"
 236                 "    vec2 flipped_tc = texcoord; \n"
 237                 "    tc0 = flipped_tc + foo_chroma_offset_0; \n"
 238                 "} \n";
 239         string cbcr_frag_shader =
 240                 "#version 130 \n"
 241                 "in vec2 tc0; \n"
 242                 "uniform sampler2D cbcr_tex; \n"
 243                 "out vec4 FragColor; \n"
 244                 "void main() { \n"
 245                 "    FragColor = texture(cbcr_tex, tc0); \n"
 246                 "} \n";
 247         vector<string> frag_shader_outputs;
 248         cbcr_program_num = resource_pool->compile_glsl_program(cbcr_vert_shader, cbcr_frag_shader, frag_shader_outputs);
 249
 250         float vertices[] = {
 251                 0.0f, 2.0f,
 252                 0.0f, 0.0f,
 253                 2.0f, 0.0f
 254         };
 255         cbcr_vbo = generate_vbo(2, GL_FLOAT, sizeof(vertices), vertices);
 256         cbcr_position_attribute_index = glGetAttribLocation(cbcr_program_num, "position");
 257         cbcr_texcoord_attribute_index = glGetAttribLocation(cbcr_program_num, "texcoord");
 258
 259         r128.init(2, OUTPUT_FREQUENCY);
 260         r128.integr_start();
 261
 262         locut.init(FILTER_HPF, 2);
 263
 264         // If --flat-audio is given, turn off everything that messes with the sound,
 265         // except the final makeup gain.
 266         if (global_flags.flat_audio) {
 267                 set_locut_enabled(false);
 268                 set_limiter_enabled(false);
 269                 set_compressor_enabled(false);
 270         }
 271
 272         // hlen=16 is pretty low quality, but we use quite a bit of CPU otherwise,
 273         // and there's a limit to how important the peak meter is.
 274         peak_resampler.setup(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY * 4, /*num_channels=*/2, /*hlen=*/16, /*frel=*/1.0);
 275
 276         alsa.reset(new ALSAOutput(OUTPUT_FREQUENCY, /*num_channels=*/2));
 277 }
 278
 279 Mixer::~Mixer()
 280 {
 281         resource_pool->release_glsl_program(cbcr_program_num);
 282         glDeleteBuffers(1, &cbcr_vbo);
 283         BMUSBCapture::stop_bm_thread();
 284
 285         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 286                 {
 287                         unique_lock<mutex> lock(bmusb_mutex);
 288                         cards[card_index].should_quit = true;  // Unblock thread.
 289                         cards[card_index].new_frames_changed.notify_all();
 290                 }
 291                 cards[card_index].capture->stop_dequeue_thread();
 292         }
 293
 294         h264_encoder.reset(nullptr);
 295 }
 296
 297 void Mixer::configure_card(unsigned card_index, const QSurfaceFormat &format, CaptureInterface *capture)
 298 {
 299         printf("Configuring card %d...\n", card_index);
 300
 301         CaptureCard *card = &cards[card_index];
 302         card->capture = capture;
 303         card->capture->set_frame_callback(bind(&Mixer::bm_frame, this, card_index, _1, _2, _3, _4, _5, _6, _7));
 304         card->frame_allocator.reset(new PBOFrameAllocator(8 << 20, WIDTH, HEIGHT));  // 8 MB.
 305         card->capture->set_video_frame_allocator(card->frame_allocator.get());
 306         card->surface = create_surface(format);
 307         card->capture->set_dequeue_thread_callbacks(
 308                 [card]{
 309                         eglBindAPI(EGL_OPENGL_API);
 310                         card->context = create_context(card->surface);
 311                         if (!make_current(card->context, card->surface)) {
 312                                 printf("failed to create bmusb context\n");
 313                                 exit(1);
 314                         }
 315                 },
 316                 [this]{
 317                         resource_pool->clean_context();
 318                 });
 319         card->resampling_queue.reset(new ResamplingQueue(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY, 2));
 320         card->capture->configure_card();
 321 }
 322
 323
 324 namespace {
 325
 326 int unwrap_timecode(uint16_t current_wrapped, int last)
 327 {
 328         uint16_t last_wrapped = last & 0xffff;
 329         if (current_wrapped > last_wrapped) {
 330                 return (last & ~0xffff) | current_wrapped;
 331         } else {
 332                 return 0x10000 + ((last & ~0xffff) | current_wrapped);
 333         }
 334 }
 335
 336 float find_peak(const float *samples, size_t num_samples)
 337 {
 338         float m = fabs(samples[0]);
 339         for (size_t i = 1; i < num_samples; ++i) {
 340                 m = max(m, fabs(samples[i]));
 341         }
 342         return m;
 343 }
 344
 345 void deinterleave_samples(const vector<float> &in, vector<float> *out_l, vector<float> *out_r)
 346 {
 347         size_t num_samples = in.size() / 2;
 348         out_l->resize(num_samples);
 349         out_r->resize(num_samples);
 350
 351         const float *inptr = in.data();
 352         float *lptr = &(*out_l)[0];
 353         float *rptr = &(*out_r)[0];
 354         for (size_t i = 0; i < num_samples; ++i) {
 355                 *lptr++ = *inptr++;
 356                 *rptr++ = *inptr++;
 357         }
 358 }
 359
 360 }  // namespace
 361
 362 void Mixer::bm_frame(unsigned card_index, uint16_t timecode,
 363                      FrameAllocator::Frame video_frame, size_t video_offset, VideoFormat video_format,
 364                      FrameAllocator::Frame audio_frame, size_t audio_offset, AudioFormat audio_format)
 365 {
 366         CaptureCard *card = &cards[card_index];
 367
 368         if (is_mode_scanning[card_index]) {
 369                 if (video_format.has_signal) {
 370                         // Found a stable signal, so stop scanning.
 371                         is_mode_scanning[card_index] = false;
 372                 } else {
 373                         static constexpr double switch_time_s = 0.5;  // Should be enough time for the signal to stabilize.
 374                         timespec now;
 375                         clock_gettime(CLOCK_MONOTONIC, &now);
 376                         double sec_since_last_switch = (now.tv_sec - last_mode_scan_change[card_index].tv_sec) +
 377                                 1e-9 * (now.tv_nsec - last_mode_scan_change[card_index].tv_nsec);
 378                         if (sec_since_last_switch > switch_time_s) {
 379                                 // It isn't this mode; try the next one.
 380                                 mode_scanlist_index[card_index]++;
 381                                 mode_scanlist_index[card_index] %= mode_scanlist[card_index].size();
 382                                 cards[card_index].capture->set_video_mode(mode_scanlist[card_index][mode_scanlist_index[card_index]]);
 383                                 last_mode_scan_change[card_index] = now;
 384                         }
 385                 }
 386         }
 387
 388         int64_t frame_length = int64_t(TIMEBASE * video_format.frame_rate_den) / video_format.frame_rate_nom;
 389
 390         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;
 391         if (num_samples > OUTPUT_FREQUENCY / 10) {
 392                 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",
 393                         card_index, int(audio_frame.len), int(audio_offset),
 394                         timecode, int(video_frame.len), int(video_offset), video_format.id);
 395                 if (video_frame.owner) {
 396                         video_frame.owner->release_frame(video_frame);
 397                 }
 398                 if (audio_frame.owner) {
 399                         audio_frame.owner->release_frame(audio_frame);
 400                 }
 401                 return;
 402         }
 403
 404         int64_t local_pts = card->next_local_pts;
 405         int dropped_frames = 0;
 406         if (card->last_timecode != -1) {
 407                 dropped_frames = unwrap_timecode(timecode, card->last_timecode) - card->last_timecode - 1;
 408         }
 409
 410         // Convert the audio to stereo fp32 and add it.
 411         vector<float> audio;
 412         audio.resize(num_samples * 2);
 413         switch (audio_format.bits_per_sample) {
 414         case 0:
 415                 assert(num_samples == 0);
 416                 break;
 417         case 24:
 418                 convert_fixed24_to_fp32(&audio[0], 2, audio_frame.data + audio_offset, audio_format.num_channels, num_samples);
 419                 break;
 420         case 32:
 421                 convert_fixed32_to_fp32(&audio[0], 2, audio_frame.data + audio_offset, audio_format.num_channels, num_samples);
 422                 break;
 423         default:
 424                 fprintf(stderr, "Cannot handle audio with %u bits per sample\n", audio_format.bits_per_sample);
 425                 assert(false);
 426         }
 427
 428         // Add the audio.
 429         {
 430                 unique_lock<mutex> lock(card->audio_mutex);
 431
 432                 // Number of samples per frame if we need to insert silence.
 433                 // (Could be nonintegral, but resampling will save us then.)
 434                 int silence_samples = OUTPUT_FREQUENCY * video_format.frame_rate_den / video_format.frame_rate_nom;
 435
 436                 if (dropped_frames > MAX_FPS * 2) {
 437                         fprintf(stderr, "Card %d lost more than two seconds (or time code jumping around; from 0x%04x to 0x%04x), resetting resampler\n",
 438                                 card_index, card->last_timecode, timecode);
 439                         card->resampling_queue.reset(new ResamplingQueue(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY, 2));
 440                         dropped_frames = 0;
 441                 } else if (dropped_frames > 0) {
 442                         // Insert silence as needed.
 443                         fprintf(stderr, "Card %d dropped %d frame(s) (before timecode 0x%04x), inserting silence.\n",
 444                                 card_index, dropped_frames, timecode);
 445                         vector<float> silence(silence_samples * 2, 0.0f);
 446                         for (int i = 0; i < dropped_frames; ++i) {
 447                                 card->resampling_queue->add_input_samples(local_pts / double(TIMEBASE), silence.data(), silence_samples);
 448                                 // Note that if the format changed in the meantime, we have
 449                                 // no way of detecting that; we just have to assume the frame length
 450                                 // is always the same.
 451                                 local_pts += frame_length;
 452                         }
 453                 }
 454                 if (num_samples == 0) {
 455                         audio.resize(silence_samples * 2);
 456                         num_samples = silence_samples;
 457                 }
 458                 card->resampling_queue->add_input_samples(local_pts / double(TIMEBASE), audio.data(), num_samples);
 459                 card->next_local_pts = local_pts + frame_length;
 460         }
 461
 462         card->last_timecode = timecode;
 463
 464         // Done with the audio, so release it.
 465         if (audio_frame.owner) {
 466                 audio_frame.owner->release_frame(audio_frame);
 467         }
 468
 469         size_t expected_length = video_format.width * (video_format.height + video_format.extra_lines_top + video_format.extra_lines_bottom) * 2;
 470         if (video_frame.len - video_offset == 0 ||
 471             video_frame.len - video_offset != expected_length) {
 472                 if (video_frame.len != 0) {
 473                         printf("Card %d: Dropping video frame with wrong length (%ld; expected %ld)\n",
 474                                 card_index, video_frame.len - video_offset, expected_length);
 475                 }
 476                 if (video_frame.owner) {
 477                         video_frame.owner->release_frame(video_frame);
 478                 }
 479
 480                 // Still send on the information that we _had_ a frame, even though it's corrupted,
 481                 // so that pts can go up accordingly.
 482                 {
 483                         unique_lock<mutex> lock(bmusb_mutex);
 484                         CaptureCard::NewFrame new_frame;
 485                         new_frame.frame = RefCountedFrame(FrameAllocator::Frame());
 486                         new_frame.length = frame_length;
 487                         new_frame.interlaced = false;
 488                         new_frame.dropped_frames = dropped_frames;
 489                         card->new_frames.push(move(new_frame));
 490                         card->new_frames_changed.notify_all();
 491                 }
 492                 return;
 493         }
 494
 495         PBOFrameAllocator::Userdata *userdata = (PBOFrameAllocator::Userdata *)video_frame.userdata;
 496
 497         unsigned num_fields = video_format.interlaced ? 2 : 1;
 498         timespec frame_upload_start;
 499         if (video_format.interlaced) {
 500                 // Send the two fields along as separate frames; the other side will need to add
 501                 // a deinterlacer to actually get this right.
 502                 assert(video_format.height % 2 == 0);
 503                 video_format.height /= 2;
 504                 assert(frame_length % 2 == 0);
 505                 frame_length /= 2;
 506                 num_fields = 2;
 507                 clock_gettime(CLOCK_MONOTONIC, &frame_upload_start);
 508         }
 509         userdata->last_interlaced = video_format.interlaced;
 510         userdata->last_has_signal = video_format.has_signal;
 511         userdata->last_frame_rate_nom = video_format.frame_rate_nom;
 512         userdata->last_frame_rate_den = video_format.frame_rate_den;
 513         RefCountedFrame frame(video_frame);
 514
 515         // Upload the textures.
 516         size_t cbcr_width = video_format.width / 2;
 517         size_t cbcr_offset = video_offset / 2;
 518         size_t y_offset = video_frame.size / 2 + video_offset / 2;
 519
 520         for (unsigned field = 0; field < num_fields; ++field) {
 521                 unsigned field_start_line = (field == 1) ? video_format.second_field_start : video_format.extra_lines_top + field * (video_format.height + 22);
 522
 523                 if (userdata->tex_y[field] == 0 ||
 524                     userdata->tex_cbcr[field] == 0 ||
 525                     video_format.width != userdata->last_width[field] ||
 526                     video_format.height != userdata->last_height[field]) {
 527                         // We changed resolution since last use of this texture, so we need to create
 528                         // a new object. Note that this each card has its own PBOFrameAllocator,
 529                         // we don't need to worry about these flip-flopping between resolutions.
 530                         glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr[field]);
 531                         check_error();
 532                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RG8, cbcr_width, video_format.height, 0, GL_RG, GL_UNSIGNED_BYTE, nullptr);
 533                         check_error();
 534                         glBindTexture(GL_TEXTURE_2D, userdata->tex_y[field]);
 535                         check_error();
 536                         glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, video_format.width, video_format.height, 0, GL_RED, GL_UNSIGNED_BYTE, nullptr);
 537                         check_error();
 538                         userdata->last_width[field] = video_format.width;
 539                         userdata->last_height[field] = video_format.height;
 540                 }
 541
 542                 GLuint pbo = userdata->pbo;
 543                 check_error();
 544                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER, pbo);
 545                 check_error();
 546                 if (global_flags.flush_pbos) {
 547                         glFlushMappedBufferRange(GL_PIXEL_UNPACK_BUFFER, 0, video_frame.size);
 548                         check_error();
 549                 }
 550
 551                 glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr[field]);
 552                 check_error();
 553                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, cbcr_width, video_format.height, GL_RG, GL_UNSIGNED_BYTE, BUFFER_OFFSET(cbcr_offset + cbcr_width * field_start_line * sizeof(uint16_t)));
 554                 check_error();
 555                 glBindTexture(GL_TEXTURE_2D, userdata->tex_y[field]);
 556                 check_error();
 557                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, video_format.width, video_format.height, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET(y_offset + video_format.width * field_start_line));
 558                 check_error();
 559                 glBindTexture(GL_TEXTURE_2D, 0);
 560                 check_error();
 561                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
 562                 check_error();
 563                 RefCountedGLsync fence(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
 564                 check_error();
 565                 assert(fence.get() != nullptr);
 566
 567                 if (field == 1) {
 568                         // Don't upload the second field as fast as we can; wait until
 569                         // the field time has approximately passed. (Otherwise, we could
 570                         // get timing jitter against the other sources, and possibly also
 571                         // against the video display, although the latter is not as critical.)
 572                         // This requires our system clock to be reasonably close to the
 573                         // video clock, but that's not an unreasonable assumption.
 574                         timespec second_field_start;
 575                         second_field_start.tv_nsec = frame_upload_start.tv_nsec +
 576                                 frame_length * 1000000000 / TIMEBASE;
 577                         second_field_start.tv_sec = frame_upload_start.tv_sec +
 578                                 second_field_start.tv_nsec / 1000000000;
 579                         second_field_start.tv_nsec %= 1000000000;
 580
 581                         while (clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME,
 582                                                &second_field_start, nullptr) == -1 &&
 583                                errno == EINTR) ;
 584                 }
 585
 586                 {
 587                         unique_lock<mutex> lock(bmusb_mutex);
 588                         CaptureCard::NewFrame new_frame;
 589                         new_frame.frame = frame;
 590                         new_frame.length = frame_length;
 591                         new_frame.field = field;
 592                         new_frame.interlaced = video_format.interlaced;
 593                         new_frame.ready_fence = fence;
 594                         new_frame.dropped_frames = dropped_frames;
 595                         card->new_frames.push(move(new_frame));
 596                         card->new_frames_changed.notify_all();
 597                 }
 598         }
 599 }
 600
 601 void Mixer::thread_func()
 602 {
 603         eglBindAPI(EGL_OPENGL_API);
 604         QOpenGLContext *context = create_context(mixer_surface);
 605         if (!make_current(context, mixer_surface)) {
 606                 printf("oops\n");
 607                 exit(1);
 608         }
 609
 610         struct timespec start, now;
 611         clock_gettime(CLOCK_MONOTONIC, &start);
 612
 613         int frame = 0;
 614         int stats_dropped_frames = 0;
 615
 616         while (!should_quit) {
 617                 CaptureCard::NewFrame new_frames[MAX_CARDS];
 618                 bool has_new_frame[MAX_CARDS] = { false };
 619                 int num_samples[MAX_CARDS] = { 0 };
 620
 621                 // TODO: Add a timeout.
 622                 unsigned master_card_index = theme->map_signal(master_clock_channel);
 623                 assert(master_card_index < num_cards);
 624
 625                 get_one_frame_from_each_card(master_card_index, new_frames, has_new_frame, num_samples);
 626                 schedule_audio_resampling_tasks(new_frames[master_card_index].dropped_frames, num_samples[master_card_index], new_frames[master_card_index].length);
 627                 stats_dropped_frames += new_frames[master_card_index].dropped_frames;
 628                 send_audio_level_callback();
 629
 630                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 631                         if (card_index == master_card_index || !has_new_frame[card_index]) {
 632                                 continue;
 633                         }
 634                         if (new_frames[card_index].frame->len == 0) {
 635                                 ++new_frames[card_index].dropped_frames;
 636                         }
 637                         if (new_frames[card_index].dropped_frames > 0) {
 638                                 printf("Card %u dropped %d frames before this\n",
 639                                         card_index, int(new_frames[card_index].dropped_frames));
 640                         }
 641                 }
 642
 643                 // If the first card is reporting a corrupted or otherwise dropped frame,
 644                 // just increase the pts (skipping over this frame) and don't try to compute anything new.
 645                 if (new_frames[master_card_index].frame->len == 0) {
 646                         ++stats_dropped_frames;
 647                         pts_int += new_frames[master_card_index].length;
 648                         continue;
 649                 }
 650
 651                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 652                         if (!has_new_frame[card_index] || new_frames[card_index].frame->len == 0)
 653                                 continue;
 654
 655                         CaptureCard::NewFrame *new_frame = &new_frames[card_index];
 656                         assert(new_frame->frame != nullptr);
 657                         insert_new_frame(new_frame->frame, new_frame->field, new_frame->interlaced, card_index, &input_state);
 658                         check_error();
 659
 660                         // The new texture might still be uploaded,
 661                         // tell the GPU to wait until it's there.
 662                         if (new_frame->ready_fence) {
 663                                 glWaitSync(new_frame->ready_fence.get(), /*flags=*/0, GL_TIMEOUT_IGNORED);
 664                                 check_error();
 665                                 new_frame->ready_fence.reset();
 666                                 check_error();
 667                         }
 668                 }
 669
 670                 render_one_frame();
 671                 ++frame;
 672                 pts_int += new_frames[master_card_index].length;
 673
 674                 clock_gettime(CLOCK_MONOTONIC, &now);
 675                 double elapsed = now.tv_sec - start.tv_sec +
 676                         1e-9 * (now.tv_nsec - start.tv_nsec);
 677                 if (frame % 100 == 0) {
 678                         printf("%d frames (%d dropped) in %.3f seconds = %.1f fps (%.1f ms/frame)\n",
 679                                 frame, stats_dropped_frames, elapsed, frame / elapsed,
 680                                 1e3 * elapsed / frame);
 681                 //      chain->print_phase_timing();
 682                 }
 683
 684                 if (should_cut.exchange(false)) {  // Test and clear.
 685                         string filename = generate_local_dump_filename(frame);
 686                         printf("Starting new recording: %s\n", filename.c_str());
 687                         h264_encoder->shutdown();
 688                         httpd.close_output_file();
 689                         httpd.open_output_file(filename.c_str());
 690                         h264_encoder.reset(new H264Encoder(h264_encoder_surface, global_flags.va_display, WIDTH, HEIGHT, &httpd));
 691                 }
 692
 693 #if 0
 694                 // Reset every 100 frames, so that local variations in frame times
 695                 // (especially for the first few frames, when the shaders are
 696                 // compiled etc.) don't make it hard to measure for the entire
 697                 // remaining duration of the program.
 698                 if (frame == 10000) {
 699                         frame = 0;
 700                         start = now;
 701                 }
 702 #endif
 703                 check_error();
 704         }
 705
 706         resource_pool->clean_context();
 707 }
 708
 709 void Mixer::get_one_frame_from_each_card(unsigned master_card_index, CaptureCard::NewFrame new_frames[MAX_CARDS], bool has_new_frame[MAX_CARDS], int num_samples[MAX_CARDS])
 710 {
 711         // The first card is the master timer, so wait for it to have a new frame.
 712         unique_lock<mutex> lock(bmusb_mutex);
 713         cards[master_card_index].new_frames_changed.wait(lock, [this, master_card_index]{ return !cards[master_card_index].new_frames.empty(); });
 714
 715         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 716                 CaptureCard *card = &cards[card_index];
 717                 if (card->new_frames.empty()) {
 718                         assert(card_index != master_card_index);
 719                         card->queue_length_policy.update_policy(-1);
 720                         continue;
 721                 }
 722                 new_frames[card_index] = move(card->new_frames.front());
 723                 has_new_frame[card_index] = true;
 724                 card->new_frames.pop();
 725                 card->new_frames_changed.notify_all();
 726
 727                 int num_samples_times_timebase = OUTPUT_FREQUENCY * new_frames[card_index].length + card->fractional_samples;
 728                 num_samples[card_index] = num_samples_times_timebase / TIMEBASE;
 729                 card->fractional_samples = num_samples_times_timebase % TIMEBASE;
 730                 assert(num_samples[card_index] >= 0);
 731
 732                 if (card_index == master_card_index) {
 733                         // We don't use the queue length policy for the master card,
 734                         // but we will if it stops being the master. Thus, clear out
 735                         // the policy in case we switch in the future.
 736                         card->queue_length_policy.reset(card_index);
 737                 } else {
 738                         // If we have excess frames compared to the policy for this card,
 739                         // drop frames from the head.
 740                         card->queue_length_policy.update_policy(card->new_frames.size());
 741                         while (card->new_frames.size() > card->queue_length_policy.get_safe_queue_length()) {
 742                                 card->new_frames.pop();
 743                         }
 744                 }
 745         }
 746 }
 747
 748 void Mixer::schedule_audio_resampling_tasks(unsigned dropped_frames, int num_samples_per_frame, int length_per_frame)
 749 {
 750         // Resample the audio as needed, including from previously dropped frames.
 751         assert(num_cards > 0);
 752         for (unsigned frame_num = 0; frame_num < dropped_frames + 1; ++frame_num) {
 753                 {
 754                         // Signal to the audio thread to process this frame.
 755                         unique_lock<mutex> lock(audio_mutex);
 756                         audio_task_queue.push(AudioTask{pts_int, num_samples_per_frame});
 757                         audio_task_queue_changed.notify_one();
 758                 }
 759                 if (frame_num != dropped_frames) {
 760                         // For dropped frames, increase the pts. Note that if the format changed
 761                         // in the meantime, we have no way of detecting that; we just have to
 762                         // assume the frame length is always the same.
 763                         pts_int += length_per_frame;
 764                 }
 765         }
 766 }
 767
 768 void Mixer::render_one_frame()
 769 {
 770         // Get the main chain from the theme, and set its state immediately.
 771         Theme::Chain theme_main_chain = theme->get_chain(0, pts(), WIDTH, HEIGHT, input_state);
 772         EffectChain *chain = theme_main_chain.chain;
 773         theme_main_chain.setup_chain();
 774         //theme_main_chain.chain->enable_phase_timing(true);
 775
 776         GLuint y_tex, cbcr_tex;
 777         bool got_frame = h264_encoder->begin_frame(&y_tex, &cbcr_tex);
 778         assert(got_frame);
 779
 780         // Render main chain.
 781         GLuint cbcr_full_tex = resource_pool->create_2d_texture(GL_RG8, WIDTH, HEIGHT);
 782         GLuint rgba_tex = resource_pool->create_2d_texture(GL_RGB565, WIDTH, HEIGHT);  // Saves texture bandwidth, although dithering gets messed up.
 783         GLuint fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex, rgba_tex);
 784         check_error();
 785         chain->render_to_fbo(fbo, WIDTH, HEIGHT);
 786         resource_pool->release_fbo(fbo);
 787
 788         subsample_chroma(cbcr_full_tex, cbcr_tex);
 789         resource_pool->release_2d_texture(cbcr_full_tex);
 790
 791         // Set the right state for rgba_tex.
 792         glBindFramebuffer(GL_FRAMEBUFFER, 0);
 793         glBindTexture(GL_TEXTURE_2D, rgba_tex);
 794         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 795         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 796         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 797
 798         const int64_t av_delay = TIMEBASE / 10;  // Corresponds to the fixed delay in resampling_queue.h. TODO: Make less hard-coded.
 799         RefCountedGLsync fence = h264_encoder->end_frame(pts_int + av_delay, theme_main_chain.input_frames);
 800
 801         // The live frame just shows the RGBA texture we just rendered.
 802         // It owns rgba_tex now.
 803         DisplayFrame live_frame;
 804         live_frame.chain = display_chain.get();
 805         live_frame.setup_chain = [this, rgba_tex]{
 806                 display_input->set_texture_num(rgba_tex);
 807         };
 808         live_frame.ready_fence = fence;
 809         live_frame.input_frames = {};
 810         live_frame.temp_textures = { rgba_tex };
 811         output_channel[OUTPUT_LIVE].output_frame(live_frame);
 812
 813         // Set up preview and any additional channels.
 814         for (int i = 1; i < theme->get_num_channels() + 2; ++i) {
 815                 DisplayFrame display_frame;
 816                 Theme::Chain chain = theme->get_chain(i, pts(), WIDTH, HEIGHT, input_state);  // FIXME: dimensions
 817                 display_frame.chain = chain.chain;
 818                 display_frame.setup_chain = chain.setup_chain;
 819                 display_frame.ready_fence = fence;
 820                 display_frame.input_frames = chain.input_frames;
 821                 display_frame.temp_textures = {};
 822                 output_channel[i].output_frame(display_frame);
 823         }
 824 }
 825
 826 void Mixer::send_audio_level_callback()
 827 {
 828         if (audio_level_callback == nullptr) {
 829                 return;
 830         }
 831
 832         unique_lock<mutex> lock(compressor_mutex);
 833         double loudness_s = r128.loudness_S();
 834         double loudness_i = r128.integrated();
 835         double loudness_range_low = r128.range_min();
 836         double loudness_range_high = r128.range_max();
 837
 838         audio_level_callback(loudness_s, 20.0 * log10(peak),
 839                 loudness_i, loudness_range_low, loudness_range_high,
 840                 gain_staging_db, 20.0 * log10(final_makeup_gain),
 841                 correlation.get_correlation());
 842 }
 843
 844 void Mixer::audio_thread_func()
 845 {
 846         while (!should_quit) {
 847                 AudioTask task;
 848
 849                 {
 850                         unique_lock<mutex> lock(audio_mutex);
 851                         audio_task_queue_changed.wait(lock, [this]{ return !audio_task_queue.empty(); });
 852                         task = audio_task_queue.front();
 853                         audio_task_queue.pop();
 854                 }
 855
 856                 process_audio_one_frame(task.pts_int, task.num_samples);
 857         }
 858 }
 859
 860 void Mixer::process_audio_one_frame(int64_t frame_pts_int, int num_samples)
 861 {
 862         vector<float> samples_card;
 863         vector<float> samples_out;
 864
 865         // TODO: Allow mixing audio from several sources.
 866         unsigned selected_audio_card = theme->map_signal(audio_source_channel);
 867         assert(selected_audio_card < num_cards);
 868
 869         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 870                 samples_card.resize(num_samples * 2);
 871                 {
 872                         unique_lock<mutex> lock(cards[card_index].audio_mutex);
 873                         if (!cards[card_index].resampling_queue->get_output_samples(double(frame_pts_int) / TIMEBASE, &samples_card[0], num_samples)) {
 874                                 printf("Card %d reported previous underrun.\n", card_index);
 875                         }
 876                 }
 877                 if (card_index == selected_audio_card) {
 878                         samples_out = move(samples_card);
 879                 }
 880         }
 881
 882         // Cut away everything under 120 Hz (or whatever the cutoff is);
 883         // we don't need it for voice, and it will reduce headroom
 884         // and confuse the compressor. (In particular, any hums at 50 or 60 Hz
 885         // should be dampened.)
 886         if (locut_enabled) {
 887                 locut.render(samples_out.data(), samples_out.size() / 2, locut_cutoff_hz * 2.0 * M_PI / OUTPUT_FREQUENCY, 0.5f);
 888         }
 889
 890         // Apply a level compressor to get the general level right.
 891         // Basically, if it's over about -40 dBFS, we squeeze it down to that level
 892         // (or more precisely, near it, since we don't use infinite ratio),
 893         // then apply a makeup gain to get it to -14 dBFS. -14 dBFS is, of course,
 894         // entirely arbitrary, but from practical tests with speech, it seems to
 895         // put ut around -23 LUFS, so it's a reasonable starting point for later use.
 896         {
 897                 unique_lock<mutex> lock(compressor_mutex);
 898                 if (level_compressor_enabled) {
 899                         float threshold = 0.01f;   // -40 dBFS.
 900                         float ratio = 20.0f;
 901                         float attack_time = 0.5f;
 902                         float release_time = 20.0f;
 903                         float makeup_gain = pow(10.0f, (ref_level_dbfs - (-40.0f)) / 20.0f);  // +26 dB.
 904                         level_compressor.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
 905                         gain_staging_db = 20.0 * log10(level_compressor.get_attenuation() * makeup_gain);
 906                 } else {
 907                         // Just apply the gain we already had.
 908                         float g = pow(10.0f, gain_staging_db / 20.0f);
 909                         for (size_t i = 0; i < samples_out.size(); ++i) {
 910                                 samples_out[i] *= g;
 911                         }
 912                 }
 913         }
 914
 915 #if 0
 916         printf("level=%f (%+5.2f dBFS) attenuation=%f (%+5.2f dB) end_result=%+5.2f dB\n",
 917                 level_compressor.get_level(), 20.0 * log10(level_compressor.get_level()),
 918                 level_compressor.get_attenuation(), 20.0 * log10(level_compressor.get_attenuation()),
 919                 20.0 * log10(level_compressor.get_level() * level_compressor.get_attenuation() * makeup_gain));
 920 #endif
 921
 922 //      float limiter_att, compressor_att;
 923
 924         // The real compressor.
 925         if (compressor_enabled) {
 926                 float threshold = pow(10.0f, compressor_threshold_dbfs / 20.0f);
 927                 float ratio = 20.0f;
 928                 float attack_time = 0.005f;
 929                 float release_time = 0.040f;
 930                 float makeup_gain = 2.0f;  // +6 dB.
 931                 compressor.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
 932 //              compressor_att = compressor.get_attenuation();
 933         }
 934
 935         // Finally a limiter at -4 dB (so, -10 dBFS) to take out the worst peaks only.
 936         // Note that since ratio is not infinite, we could go slightly higher than this.
 937         if (limiter_enabled) {
 938                 float threshold = pow(10.0f, limiter_threshold_dbfs / 20.0f);
 939                 float ratio = 30.0f;
 940                 float attack_time = 0.0f;  // Instant.
 941                 float release_time = 0.020f;
 942                 float makeup_gain = 1.0f;  // 0 dB.
 943                 limiter.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
 944 //              limiter_att = limiter.get_attenuation();
 945         }
 946
 947 //      printf("limiter=%+5.1f  compressor=%+5.1f\n", 20.0*log10(limiter_att), 20.0*log10(compressor_att));
 948
 949         // Upsample 4x to find interpolated peak.
 950         peak_resampler.inp_data = samples_out.data();
 951         peak_resampler.inp_count = samples_out.size() / 2;
 952
 953         vector<float> interpolated_samples_out;
 954         interpolated_samples_out.resize(samples_out.size());
 955         while (peak_resampler.inp_count > 0) {  // About four iterations.
 956                 peak_resampler.out_data = &interpolated_samples_out[0];
 957                 peak_resampler.out_count = interpolated_samples_out.size() / 2;
 958                 peak_resampler.process();
 959                 size_t out_stereo_samples = interpolated_samples_out.size() / 2 - peak_resampler.out_count;
 960                 peak = max<float>(peak, find_peak(interpolated_samples_out.data(), out_stereo_samples * 2));
 961                 peak_resampler.out_data = nullptr;
 962         }
 963
 964         // At this point, we are most likely close to +0 LU, but all of our
 965         // measurements have been on raw sample values, not R128 values.
 966         // So we have a final makeup gain to get us to +0 LU; the gain
 967         // adjustments required should be relatively small, and also, the
 968         // offset shouldn't change much (only if the type of audio changes
 969         // significantly). Thus, we shoot for updating this value basically
 970         // “whenever we process buffers”, since the R128 calculation isn't exactly
 971         // something we get out per-sample.
 972         //
 973         // Note that there's a feedback loop here, so we choose a very slow filter
 974         // (half-time of 100 seconds).
 975         double target_loudness_factor, alpha;
 976         {
 977                 unique_lock<mutex> lock(compressor_mutex);
 978                 double loudness_lu = r128.loudness_M() - ref_level_lufs;
 979                 double current_makeup_lu = 20.0f * log10(final_makeup_gain);
 980                 target_loudness_factor = pow(10.0f, -loudness_lu / 20.0f);
 981
 982                 // If we're outside +/- 5 LU uncorrected, we don't count it as
 983                 // a normal signal (probably silence) and don't change the
 984                 // correction factor; just apply what we already have.
 985                 if (fabs(loudness_lu - current_makeup_lu) >= 5.0 || !final_makeup_gain_auto) {
 986                         alpha = 0.0;
 987                 } else {
 988                         // Formula adapted from
 989                         // https://en.wikipedia.org/wiki/Low-pass_filter#Simple_infinite_impulse_response_filter.
 990                         const double half_time_s = 100.0;
 991                         const double fc_mul_2pi_delta_t = 1.0 / (half_time_s * OUTPUT_FREQUENCY);
 992                         alpha = fc_mul_2pi_delta_t / (fc_mul_2pi_delta_t + 1.0);
 993                 }
 994
 995                 double m = final_makeup_gain;
 996                 for (size_t i = 0; i < samples_out.size(); i += 2) {
 997                         samples_out[i + 0] *= m;
 998                         samples_out[i + 1] *= m;
 999                         m += (target_loudness_factor - m) * alpha;
1000                 }
1001                 final_makeup_gain = m;
1002         }
1003
1004         // Find R128 levels and L/R correlation.
1005         vector<float> left, right;
1006         deinterleave_samples(samples_out, &left, &right);
1007         float *ptrs[] = { left.data(), right.data() };
1008         {
1009                 unique_lock<mutex> lock(compressor_mutex);
1010                 r128.process(left.size(), ptrs);
1011                 correlation.process_samples(samples_out);
1012         }
1013
1014         // Send the samples to the sound card.
1015         if (alsa) {
1016                 alsa->write(samples_out);
1017         }
1018
1019         // And finally add them to the output.
1020         h264_encoder->add_audio(frame_pts_int, move(samples_out));
1021 }
1022
1023 void Mixer::subsample_chroma(GLuint src_tex, GLuint dst_tex)
1024 {
1025         GLuint vao;
1026         glGenVertexArrays(1, &vao);
1027         check_error();
1028
1029         glBindVertexArray(vao);
1030         check_error();
1031
1032         // Extract Cb/Cr.
1033         GLuint fbo = resource_pool->create_fbo(dst_tex);
1034         glBindFramebuffer(GL_FRAMEBUFFER, fbo);
1035         glViewport(0, 0, WIDTH/2, HEIGHT/2);
1036         check_error();
1037
1038         glUseProgram(cbcr_program_num);
1039         check_error();
1040
1041         glActiveTexture(GL_TEXTURE0);
1042         check_error();
1043         glBindTexture(GL_TEXTURE_2D, src_tex);
1044         check_error();
1045         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1046         check_error();
1047         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
1048         check_error();
1049         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
1050         check_error();
1051
1052         float chroma_offset_0[] = { -0.5f / WIDTH, 0.0f };
1053         set_uniform_vec2(cbcr_program_num, "foo", "chroma_offset_0", chroma_offset_0);
1054
1055         glBindBuffer(GL_ARRAY_BUFFER, cbcr_vbo);
1056         check_error();
1057
1058         for (GLint attr_index : { cbcr_position_attribute_index, cbcr_texcoord_attribute_index }) {
1059                 glEnableVertexAttribArray(attr_index);
1060                 check_error();
1061                 glVertexAttribPointer(attr_index, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
1062                 check_error();
1063         }
1064
1065         glDrawArrays(GL_TRIANGLES, 0, 3);
1066         check_error();
1067
1068         for (GLint attr_index : { cbcr_position_attribute_index, cbcr_texcoord_attribute_index }) {
1069                 glDisableVertexAttribArray(attr_index);
1070                 check_error();
1071         }
1072
1073         glUseProgram(0);
1074         check_error();
1075         glBindFramebuffer(GL_FRAMEBUFFER, 0);
1076         check_error();
1077
1078         resource_pool->release_fbo(fbo);
1079         glDeleteVertexArrays(1, &vao);
1080 }
1081
1082 void Mixer::release_display_frame(DisplayFrame *frame)
1083 {
1084         for (GLuint texnum : frame->temp_textures) {
1085                 resource_pool->release_2d_texture(texnum);
1086         }
1087         frame->temp_textures.clear();
1088         frame->ready_fence.reset();
1089         frame->input_frames.clear();
1090 }
1091
1092 void Mixer::start()
1093 {
1094         mixer_thread = thread(&Mixer::thread_func, this);
1095         audio_thread = thread(&Mixer::audio_thread_func, this);
1096 }
1097
1098 void Mixer::quit()
1099 {
1100         should_quit = true;
1101         mixer_thread.join();
1102         audio_thread.join();
1103 }
1104
1105 void Mixer::transition_clicked(int transition_num)
1106 {
1107         theme->transition_clicked(transition_num, pts());
1108 }
1109
1110 void Mixer::channel_clicked(int preview_num)
1111 {
1112         theme->channel_clicked(preview_num);
1113 }
1114
1115 void Mixer::reset_meters()
1116 {
1117         peak_resampler.reset();
1118         peak = 0.0f;
1119         r128.reset();
1120         r128.integr_start();
1121         correlation.reset();
1122 }
1123
1124 void Mixer::start_mode_scanning(unsigned card_index)
1125 {
1126         assert(card_index < num_cards);
1127         if (is_mode_scanning[card_index]) {
1128                 return;
1129         }
1130         is_mode_scanning[card_index] = true;
1131         mode_scanlist[card_index].clear();
1132         for (const auto &mode : cards[card_index].capture->get_available_video_modes()) {
1133                 mode_scanlist[card_index].push_back(mode.first);
1134         }
1135         assert(!mode_scanlist[card_index].empty());
1136         mode_scanlist_index[card_index] = 0;
1137         cards[card_index].capture->set_video_mode(mode_scanlist[card_index][0]);
1138         clock_gettime(CLOCK_MONOTONIC, &last_mode_scan_change[card_index]);
1139 }
1140
1141 Mixer::OutputChannel::~OutputChannel()
1142 {
1143         if (has_current_frame) {
1144                 parent->release_display_frame(&current_frame);
1145         }
1146         if (has_ready_frame) {
1147                 parent->release_display_frame(&ready_frame);
1148         }
1149 }
1150
1151 void Mixer::OutputChannel::output_frame(DisplayFrame frame)
1152 {
1153         // Store this frame for display. Remove the ready frame if any
1154         // (it was seemingly never used).
1155         {
1156                 unique_lock<mutex> lock(frame_mutex);
1157                 if (has_ready_frame) {
1158                         parent->release_display_frame(&ready_frame);
1159                 }
1160                 ready_frame = frame;
1161                 has_ready_frame = true;
1162         }
1163
1164         if (has_new_frame_ready_callback) {
1165                 new_frame_ready_callback();
1166         }
1167 }
1168
1169 bool Mixer::OutputChannel::get_display_frame(DisplayFrame *frame)
1170 {
1171         unique_lock<mutex> lock(frame_mutex);
1172         if (!has_current_frame && !has_ready_frame) {
1173                 return false;
1174         }
1175
1176         if (has_current_frame && has_ready_frame) {
1177                 // We have a new ready frame. Toss the current one.
1178                 parent->release_display_frame(&current_frame);
1179                 has_current_frame = false;
1180         }
1181         if (has_ready_frame) {
1182                 assert(!has_current_frame);
1183                 current_frame = ready_frame;
1184                 ready_frame.ready_fence.reset();  // Drop the refcount.
1185                 ready_frame.input_frames.clear();  // Drop the refcounts.
1186                 has_current_frame = true;
1187                 has_ready_frame = false;
1188         }
1189
1190         *frame = current_frame;
1191         return true;
1192 }
1193
1194 void Mixer::OutputChannel::set_frame_ready_callback(Mixer::new_frame_ready_callback_t callback)
1195 {
1196         new_frame_ready_callback = callback;
1197         has_new_frame_ready_callback = true;
1198 }