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