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