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(),
 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         CHECK(init_movit(MOVIT_SHADER_DIR, MOVIT_DEBUG_OFF));
 152         check_error();
 153
 154         // Since we allow non-bouncing 4:2:2 YCbCrInputs, effective subpixel precision
 155         // will be halved when sampling them, and we need to compensate here.
 156         movit_texel_subpixel_precision /= 2.0;
 157
 158         resource_pool.reset(new ResourcePool);
 159         theme.reset(new Theme(global_flags.theme_filename.c_str(), resource_pool.get(), num_cards));
 160         for (unsigned i = 0; i < NUM_OUTPUTS; ++i) {
 161                 output_channel[i].parent = this;
 162         }
 163
 164         ImageFormat inout_format;
 165         inout_format.color_space = COLORSPACE_sRGB;
 166         inout_format.gamma_curve = GAMMA_sRGB;
 167
 168         // Display chain; shows the live output produced by the main chain (its RGBA version).
 169         display_chain.reset(new EffectChain(WIDTH, HEIGHT, resource_pool.get()));
 170         check_error();
 171         display_input = new FlatInput(inout_format, FORMAT_RGB, GL_UNSIGNED_BYTE, WIDTH, HEIGHT);  // FIXME: GL_UNSIGNED_BYTE is really wrong.
 172         display_chain->add_input(display_input);
 173         display_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
 174         display_chain->set_dither_bits(0);  // Don't bother.
 175         display_chain->finalize();
 176
 177         h264_encoder.reset(new H264Encoder(h264_encoder_surface, global_flags.va_display, WIDTH, HEIGHT, &httpd));
 178         h264_encoder->open_output_file(generate_local_dump_filename(/*frame=*/0).c_str());
 179
 180         // Start listening for clients only once H264Encoder has written its header, if any.
 181         httpd.start(9095);
 182
 183         // First try initializing the PCI devices, then USB, until we have the desired number of cards.
 184         unsigned num_pci_devices = 0, num_usb_devices = 0;
 185         unsigned card_index = 0;
 186
 187         IDeckLinkIterator *decklink_iterator = CreateDeckLinkIteratorInstance();
 188         if (decklink_iterator != nullptr) {
 189                 for ( ; card_index < num_cards; ++card_index) {
 190                         IDeckLink *decklink;
 191                         if (decklink_iterator->Next(&decklink) != S_OK) {
 192                                 break;
 193                         }
 194
 195                         configure_card(card_index, format, new DeckLinkCapture(decklink, card_index));
 196                         ++num_pci_devices;
 197                 }
 198                 decklink_iterator->Release();
 199                 fprintf(stderr, "Found %d DeckLink PCI card(s).\n", num_pci_devices);
 200         } else {
 201                 fprintf(stderr, "DeckLink drivers not found. Probing for USB cards only.\n");
 202         }
 203         for ( ; card_index < num_cards; ++card_index) {
 204                 configure_card(card_index, format, new BMUSBCapture(card_index - num_pci_devices));
 205                 ++num_usb_devices;
 206         }
 207
 208         if (num_usb_devices > 0) {
 209                 BMUSBCapture::start_bm_thread();
 210         }
 211
 212         for (card_index = 0; card_index < num_cards; ++card_index) {
 213                 cards[card_index].queue_length_policy.reset(card_index);
 214                 cards[card_index].capture->start_bm_capture();
 215         }
 216
 217         // Set up stuff for NV12 conversion.
 218
 219         // Cb/Cr shader.
 220         string cbcr_vert_shader =
 221                 "#version 130 \n"
 222                 " \n"
 223                 "in vec2 position; \n"
 224                 "in vec2 texcoord; \n"
 225                 "out vec2 tc0; \n"
 226                 "uniform vec2 foo_chroma_offset_0; \n"
 227                 " \n"
 228                 "void main() \n"
 229                 "{ \n"
 230                 "    // The result of glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0) is: \n"
 231                 "    // \n"
 232                 "    //   2.000  0.000  0.000 -1.000 \n"
 233                 "    //   0.000  2.000  0.000 -1.000 \n"
 234                 "    //   0.000  0.000 -2.000 -1.000 \n"
 235                 "    //   0.000  0.000  0.000  1.000 \n"
 236                 "    gl_Position = vec4(2.0 * position.x - 1.0, 2.0 * position.y - 1.0, -1.0, 1.0); \n"
 237                 "    vec2 flipped_tc = texcoord; \n"
 238                 "    tc0 = flipped_tc + foo_chroma_offset_0; \n"
 239                 "} \n";
 240         string cbcr_frag_shader =
 241                 "#version 130 \n"
 242                 "in vec2 tc0; \n"
 243                 "uniform sampler2D cbcr_tex; \n"
 244                 "out vec4 FragColor; \n"
 245                 "void main() { \n"
 246                 "    FragColor = texture(cbcr_tex, tc0); \n"
 247                 "} \n";
 248         vector<string> frag_shader_outputs;
 249         cbcr_program_num = resource_pool->compile_glsl_program(cbcr_vert_shader, cbcr_frag_shader, frag_shader_outputs);
 250
 251         float vertices[] = {
 252                 0.0f, 2.0f,
 253                 0.0f, 0.0f,
 254                 2.0f, 0.0f
 255         };
 256         cbcr_vbo = generate_vbo(2, GL_FLOAT, sizeof(vertices), vertices);
 257         cbcr_position_attribute_index = glGetAttribLocation(cbcr_program_num, "position");
 258         cbcr_texcoord_attribute_index = glGetAttribLocation(cbcr_program_num, "texcoord");
 259
 260         r128.init(2, OUTPUT_FREQUENCY);
 261         r128.integr_start();
 262
 263         locut.init(FILTER_HPF, 2);
 264
 265         // If --flat-audio is given, turn off everything that messes with the sound,
 266         // except the final makeup gain.
 267         if (global_flags.flat_audio) {
 268                 set_locut_enabled(false);
 269                 set_limiter_enabled(false);
 270                 set_compressor_enabled(false);
 271         }
 272
 273         // hlen=16 is pretty low quality, but we use quite a bit of CPU otherwise,
 274         // and there's a limit to how important the peak meter is.
 275         peak_resampler.setup(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY * 4, /*num_channels=*/2, /*hlen=*/16, /*frel=*/1.0);
 276
 277         alsa.reset(new ALSAOutput(OUTPUT_FREQUENCY, /*num_channels=*/2));
 278 }
 279
 280 Mixer::~Mixer()
 281 {
 282         resource_pool->release_glsl_program(cbcr_program_num);
 283         glDeleteBuffers(1, &cbcr_vbo);
 284         BMUSBCapture::stop_bm_thread();
 285
 286         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 287                 {
 288                         unique_lock<mutex> lock(bmusb_mutex);
 289                         cards[card_index].should_quit = true;  // Unblock thread.
 290                         cards[card_index].new_frames_changed.notify_all();
 291                 }
 292                 cards[card_index].capture->stop_dequeue_thread();
 293         }
 294
 295         h264_encoder.reset(nullptr);
 296 }
 297
 298 void Mixer::configure_card(unsigned card_index, const QSurfaceFormat &format, CaptureInterface *capture)
 299 {
 300         printf("Configuring card %d...\n", card_index);
 301
 302         CaptureCard *card = &cards[card_index];
 303         card->capture = capture;
 304         card->capture->set_frame_callback(bind(&Mixer::bm_frame, this, card_index, _1, _2, _3, _4, _5, _6, _7));
 305         card->frame_allocator.reset(new PBOFrameAllocator(8 << 20, WIDTH, HEIGHT));  // 8 MB.
 306         card->capture->set_video_frame_allocator(card->frame_allocator.get());
 307         card->surface = create_surface(format);
 308         card->capture->set_dequeue_thread_callbacks(
 309                 [card]{
 310                         eglBindAPI(EGL_OPENGL_API);
 311                         card->context = create_context(card->surface);
 312                         if (!make_current(card->context, card->surface)) {
 313                                 printf("failed to create bmusb context\n");
 314                                 exit(1);
 315                         }
 316                 },
 317                 [this]{
 318                         resource_pool->clean_context();
 319                 });
 320         card->resampling_queue.reset(new ResamplingQueue(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY, 2));
 321         card->capture->configure_card();
 322 }
 323
 324
 325 namespace {
 326
 327 int unwrap_timecode(uint16_t current_wrapped, int last)
 328 {
 329         uint16_t last_wrapped = last & 0xffff;
 330         if (current_wrapped > last_wrapped) {
 331                 return (last & ~0xffff) | current_wrapped;
 332         } else {
 333                 return 0x10000 + ((last & ~0xffff) | current_wrapped);
 334         }
 335 }
 336
 337 float find_peak(const float *samples, size_t num_samples)
 338 {
 339         float m = fabs(samples[0]);
 340         for (size_t i = 1; i < num_samples; ++i) {
 341                 m = max(m, fabs(samples[i]));
 342         }
 343         return m;
 344 }
 345
 346 void deinterleave_samples(const vector<float> &in, vector<float> *out_l, vector<float> *out_r)
 347 {
 348         size_t num_samples = in.size() / 2;
 349         out_l->resize(num_samples);
 350         out_r->resize(num_samples);
 351
 352         const float *inptr = in.data();
 353         float *lptr = &(*out_l)[0];
 354         float *rptr = &(*out_r)[0];
 355         for (size_t i = 0; i < num_samples; ++i) {
 356                 *lptr++ = *inptr++;
 357                 *rptr++ = *inptr++;
 358         }
 359 }
 360
 361 }  // namespace
 362
 363 void Mixer::bm_frame(unsigned card_index, uint16_t timecode,
 364                      FrameAllocator::Frame video_frame, size_t video_offset, VideoFormat video_format,
 365                      FrameAllocator::Frame audio_frame, size_t audio_offset, AudioFormat audio_format)
 366 {
 367         CaptureCard *card = &cards[card_index];
 368
 369         if (is_mode_scanning[card_index]) {
 370                 if (video_format.has_signal) {
 371                         // Found a stable signal, so stop scanning.
 372                         is_mode_scanning[card_index] = false;
 373                 } else {
 374                         static constexpr double switch_time_s = 0.5;  // Should be enough time for the signal to stabilize.
 375                         timespec now;
 376                         clock_gettime(CLOCK_MONOTONIC, &now);
 377                         double sec_since_last_switch = (now.tv_sec - last_mode_scan_change[card_index].tv_sec) +
 378                                 1e-9 * (now.tv_nsec - last_mode_scan_change[card_index].tv_nsec);
 379                         if (sec_since_last_switch > switch_time_s) {
 380                                 // It isn't this mode; try the next one.
 381                                 mode_scanlist_index[card_index]++;
 382                                 mode_scanlist_index[card_index] %= mode_scanlist[card_index].size();
 383                                 cards[card_index].capture->set_video_mode(mode_scanlist[card_index][mode_scanlist_index[card_index]]);
 384                                 last_mode_scan_change[card_index] = now;
 385                         }
 386                 }
 387         }
 388
 389         int64_t frame_length = int64_t(TIMEBASE * video_format.frame_rate_den) / video_format.frame_rate_nom;
 390
 391         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;
 392         if (num_samples > OUTPUT_FREQUENCY / 10) {
 393                 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",
 394                         card_index, int(audio_frame.len), int(audio_offset),
 395                         timecode, int(video_frame.len), int(video_offset), video_format.id);
 396                 if (video_frame.owner) {
 397                         video_frame.owner->release_frame(video_frame);
 398                 }
 399                 if (audio_frame.owner) {
 400                         audio_frame.owner->release_frame(audio_frame);
 401                 }
 402                 return;
 403         }
 404
 405         int64_t local_pts = card->next_local_pts;
 406         int dropped_frames = 0;
 407         if (card->last_timecode != -1) {
 408                 dropped_frames = unwrap_timecode(timecode, card->last_timecode) - card->last_timecode - 1;
 409         }
 410
 411         // Convert the audio to stereo fp32 and add it.
 412         vector<float> audio;
 413         audio.resize(num_samples * 2);
 414         switch (audio_format.bits_per_sample) {
 415         case 0:
 416                 assert(num_samples == 0);
 417                 break;
 418         case 24:
 419                 convert_fixed24_to_fp32(&audio[0], 2, audio_frame.data + audio_offset, audio_format.num_channels, num_samples);
 420                 break;
 421         case 32:
 422                 convert_fixed32_to_fp32(&audio[0], 2, audio_frame.data + audio_offset, audio_format.num_channels, num_samples);
 423                 break;
 424         default:
 425                 fprintf(stderr, "Cannot handle audio with %u bits per sample\n", audio_format.bits_per_sample);
 426                 assert(false);
 427         }
 428
 429         // Add the audio.
 430         {
 431                 unique_lock<mutex> lock(card->audio_mutex);
 432
 433                 // Number of samples per frame if we need to insert silence.
 434                 // (Could be nonintegral, but resampling will save us then.)
 435                 int silence_samples = OUTPUT_FREQUENCY * video_format.frame_rate_den / video_format.frame_rate_nom;
 436
 437                 if (dropped_frames > MAX_FPS * 2) {
 438                         fprintf(stderr, "Card %d lost more than two seconds (or time code jumping around; from 0x%04x to 0x%04x), resetting resampler\n",
 439                                 card_index, card->last_timecode, timecode);
 440                         card->resampling_queue.reset(new ResamplingQueue(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY, 2));
 441                         dropped_frames = 0;
 442                 } else if (dropped_frames > 0) {
 443                         // Insert silence as needed.
 444                         fprintf(stderr, "Card %d dropped %d frame(s) (before timecode 0x%04x), inserting silence.\n",
 445                                 card_index, dropped_frames, timecode);
 446                         vector<float> silence(silence_samples * 2, 0.0f);
 447                         for (int i = 0; i < dropped_frames; ++i) {
 448                                 card->resampling_queue->add_input_samples(local_pts / double(TIMEBASE), silence.data(), silence_samples);
 449                                 // Note that if the format changed in the meantime, we have
 450                                 // no way of detecting that; we just have to assume the frame length
 451                                 // is always the same.
 452                                 local_pts += frame_length;
 453                         }
 454                 }
 455                 if (num_samples == 0) {
 456                         audio.resize(silence_samples * 2);
 457                         num_samples = silence_samples;
 458                 }
 459                 card->resampling_queue->add_input_samples(local_pts / double(TIMEBASE), audio.data(), num_samples);
 460                 card->next_local_pts = local_pts + frame_length;
 461         }
 462
 463         card->last_timecode = timecode;
 464
 465         // Done with the audio, so release it.
 466         if (audio_frame.owner) {
 467                 audio_frame.owner->release_frame(audio_frame);
 468         }
 469
 470         size_t expected_length = video_format.width * (video_format.height + video_format.extra_lines_top + video_format.extra_lines_bottom) * 2;
 471         if (video_frame.len - video_offset == 0 ||
 472             video_frame.len - video_offset != expected_length) {
 473                 if (video_frame.len != 0) {
 474                         printf("Card %d: Dropping video frame with wrong length (%ld; expected %ld)\n",
 475                                 card_index, video_frame.len - video_offset, expected_length);
 476                 }
 477                 if (video_frame.owner) {
 478                         video_frame.owner->release_frame(video_frame);
 479                 }
 480
 481                 // Still send on the information that we _had_ a frame, even though it's corrupted,
 482                 // so that pts can go up accordingly.
 483                 {
 484                         unique_lock<mutex> lock(bmusb_mutex);
 485                         CaptureCard::NewFrame new_frame;
 486                         new_frame.frame = RefCountedFrame(FrameAllocator::Frame());
 487                         new_frame.length = frame_length;
 488                         new_frame.interlaced = false;
 489                         new_frame.dropped_frames = dropped_frames;
 490                         card->new_frames.push(move(new_frame));
 491                         card->new_frames_changed.notify_all();
 492                 }
 493                 return;
 494         }
 495
 496         PBOFrameAllocator::Userdata *userdata = (PBOFrameAllocator::Userdata *)video_frame.userdata;
 497
 498         unsigned num_fields = video_format.interlaced ? 2 : 1;
 499         timespec frame_upload_start;
 500         if (video_format.interlaced) {
 501                 // Send the two fields along as separate frames; the other side will need to add
 502                 // a deinterlacer to actually get this right.
 503                 assert(video_format.height % 2 == 0);
 504                 video_format.height /= 2;
 505                 assert(frame_length % 2 == 0);
 506                 frame_length /= 2;
 507                 num_fields = 2;
 508                 clock_gettime(CLOCK_MONOTONIC, &frame_upload_start);
 509         }
 510         userdata->last_interlaced = video_format.interlaced;
 511         userdata->last_has_signal = video_format.has_signal;
 512         userdata->last_frame_rate_nom = video_format.frame_rate_nom;
 513         userdata->last_frame_rate_den = video_format.frame_rate_den;
 514         RefCountedFrame frame(video_frame);
 515
 516         // Upload the textures.
 517         size_t cbcr_width = video_format.width / 2;
 518         size_t cbcr_offset = video_offset / 2;
 519         size_t y_offset = video_frame.size / 2 + video_offset / 2;
 520
 521         for (unsigned field = 0; field < num_fields; ++field) {
 522                 unsigned field_start_line = (field == 1) ? video_format.second_field_start : video_format.extra_lines_top + field * (video_format.height + 22);
 523
 524                 if (userdata->tex_y[field] == 0 ||
 525                     userdata->tex_cbcr[field] == 0 ||
 526                     video_format.width != userdata->last_width[field] ||
 527                     video_format.height != userdata->last_height[field]) {
 528                         // We changed resolution since last use of this texture, so we need to create
 529                         // a new object. Note that this each card has its own PBOFrameAllocator,
 530                         // we don't need to worry about these flip-flopping between resolutions.
 531                         glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr[field]);
 532                         check_error();
 533                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RG8, cbcr_width, video_format.height, 0, GL_RG, GL_UNSIGNED_BYTE, nullptr);
 534                         check_error();
 535                         glBindTexture(GL_TEXTURE_2D, userdata->tex_y[field]);
 536                         check_error();
 537                         glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, video_format.width, video_format.height, 0, GL_RED, GL_UNSIGNED_BYTE, nullptr);
 538                         check_error();
 539                         userdata->last_width[field] = video_format.width;
 540                         userdata->last_height[field] = video_format.height;
 541                 }
 542
 543                 GLuint pbo = userdata->pbo;
 544                 check_error();
 545                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER, pbo);
 546                 check_error();
 547
 548                 size_t field_y_start = y_offset + video_format.width * field_start_line;
 549                 size_t field_cbcr_start = cbcr_offset + cbcr_width * field_start_line * sizeof(uint16_t);
 550
 551                 if (global_flags.flush_pbos) {
 552                         glFlushMappedBufferRange(GL_PIXEL_UNPACK_BUFFER, field_y_start, video_format.width * video_format.height);
 553                         check_error();
 554                         glFlushMappedBufferRange(GL_PIXEL_UNPACK_BUFFER, field_cbcr_start, cbcr_width * video_format.height * sizeof(uint16_t));
 555                         check_error();
 556                 }
 557
 558                 glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr[field]);
 559                 check_error();
 560                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, cbcr_width, video_format.height, GL_RG, GL_UNSIGNED_BYTE, BUFFER_OFFSET(field_cbcr_start));
 561                 check_error();
 562                 glBindTexture(GL_TEXTURE_2D, userdata->tex_y[field]);
 563                 check_error();
 564                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, video_format.width, video_format.height, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET(field_y_start));
 565                 check_error();
 566                 glBindTexture(GL_TEXTURE_2D, 0);
 567                 check_error();
 568                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
 569                 check_error();
 570                 RefCountedGLsync fence(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
 571                 check_error();
 572                 assert(fence.get() != nullptr);
 573                 glFlush();  // Make sure the main thread doesn't have to wait until we push out enough frames to make a new command buffer.
 574                 check_error();
 575
 576                 if (field == 1) {
 577                         // Don't upload the second field as fast as we can; wait until
 578                         // the field time has approximately passed. (Otherwise, we could
 579                         // get timing jitter against the other sources, and possibly also
 580                         // against the video display, although the latter is not as critical.)
 581                         // This requires our system clock to be reasonably close to the
 582                         // video clock, but that's not an unreasonable assumption.
 583                         timespec second_field_start;
 584                         second_field_start.tv_nsec = frame_upload_start.tv_nsec +
 585                                 frame_length * 1000000000 / TIMEBASE;
 586                         second_field_start.tv_sec = frame_upload_start.tv_sec +
 587                                 second_field_start.tv_nsec / 1000000000;
 588                         second_field_start.tv_nsec %= 1000000000;
 589
 590                         while (clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME,
 591                                                &second_field_start, nullptr) == -1 &&
 592                                errno == EINTR) ;
 593                 }
 594
 595                 {
 596                         unique_lock<mutex> lock(bmusb_mutex);
 597                         CaptureCard::NewFrame new_frame;
 598                         new_frame.frame = frame;
 599                         new_frame.length = frame_length;
 600                         new_frame.field = field;
 601                         new_frame.interlaced = video_format.interlaced;
 602                         new_frame.ready_fence = fence;
 603                         new_frame.dropped_frames = dropped_frames;
 604                         card->new_frames.push(move(new_frame));
 605                         card->new_frames_changed.notify_all();
 606                 }
 607         }
 608 }
 609
 610 void Mixer::thread_func()
 611 {
 612         eglBindAPI(EGL_OPENGL_API);
 613         QOpenGLContext *context = create_context(mixer_surface);
 614         if (!make_current(context, mixer_surface)) {
 615                 printf("oops\n");
 616                 exit(1);
 617         }
 618
 619         struct timespec start, now;
 620         clock_gettime(CLOCK_MONOTONIC, &start);
 621
 622         int frame = 0;
 623         int stats_dropped_frames = 0;
 624
 625         while (!should_quit) {
 626                 CaptureCard::NewFrame new_frames[MAX_CARDS];
 627                 bool has_new_frame[MAX_CARDS] = { false };
 628                 int num_samples[MAX_CARDS] = { 0 };
 629
 630                 // TODO: Add a timeout.
 631                 unsigned master_card_index = theme->map_signal(master_clock_channel);
 632                 assert(master_card_index < num_cards);
 633
 634                 get_one_frame_from_each_card(master_card_index, new_frames, has_new_frame, num_samples);
 635                 schedule_audio_resampling_tasks(new_frames[master_card_index].dropped_frames, num_samples[master_card_index], new_frames[master_card_index].length);
 636                 stats_dropped_frames += new_frames[master_card_index].dropped_frames;
 637                 send_audio_level_callback();
 638
 639                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 640                         if (card_index == master_card_index || !has_new_frame[card_index]) {
 641                                 continue;
 642                         }
 643                         if (new_frames[card_index].frame->len == 0) {
 644                                 ++new_frames[card_index].dropped_frames;
 645                         }
 646                         if (new_frames[card_index].dropped_frames > 0) {
 647                                 printf("Card %u dropped %d frames before this\n",
 648                                         card_index, int(new_frames[card_index].dropped_frames));
 649                         }
 650                 }
 651
 652                 // If the first card is reporting a corrupted or otherwise dropped frame,
 653                 // just increase the pts (skipping over this frame) and don't try to compute anything new.
 654                 if (new_frames[master_card_index].frame->len == 0) {
 655                         ++stats_dropped_frames;
 656                         pts_int += new_frames[master_card_index].length;
 657                         continue;
 658                 }
 659
 660                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 661                         if (!has_new_frame[card_index] || new_frames[card_index].frame->len == 0)
 662                                 continue;
 663
 664                         CaptureCard::NewFrame *new_frame = &new_frames[card_index];
 665                         assert(new_frame->frame != nullptr);
 666                         insert_new_frame(new_frame->frame, new_frame->field, new_frame->interlaced, card_index, &input_state);
 667                         check_error();
 668
 669                         // The new texture might still be uploaded,
 670                         // tell the GPU to wait until it's there.
 671                         if (new_frame->ready_fence) {
 672                                 glWaitSync(new_frame->ready_fence.get(), /*flags=*/0, GL_TIMEOUT_IGNORED);
 673                                 check_error();
 674                                 new_frame->ready_fence.reset();
 675                                 check_error();
 676                         }
 677                 }
 678
 679                 render_one_frame();
 680                 ++frame;
 681                 pts_int += new_frames[master_card_index].length;
 682
 683                 clock_gettime(CLOCK_MONOTONIC, &now);
 684                 double elapsed = now.tv_sec - start.tv_sec +
 685                         1e-9 * (now.tv_nsec - start.tv_nsec);
 686                 if (frame % 100 == 0) {
 687                         printf("%d frames (%d dropped) in %.3f seconds = %.1f fps (%.1f ms/frame)\n",
 688                                 frame, stats_dropped_frames, elapsed, frame / elapsed,
 689                                 1e3 * elapsed / frame);
 690                 //      chain->print_phase_timing();
 691                 }
 692
 693                 if (should_cut.exchange(false)) {  // Test and clear.
 694                         string filename = generate_local_dump_filename(frame);
 695                         printf("Starting new recording: %s\n", filename.c_str());
 696                         h264_encoder->close_output_file();
 697                         h264_encoder->shutdown();
 698                         h264_encoder.reset(new H264Encoder(h264_encoder_surface, global_flags.va_display, WIDTH, HEIGHT, &httpd));
 699                         h264_encoder->open_output_file(filename.c_str());
 700                 }
 701
 702 #if 0
 703                 // Reset every 100 frames, so that local variations in frame times
 704                 // (especially for the first few frames, when the shaders are
 705                 // compiled etc.) don't make it hard to measure for the entire
 706                 // remaining duration of the program.
 707                 if (frame == 10000) {
 708                         frame = 0;
 709                         start = now;
 710                 }
 711 #endif
 712                 check_error();
 713         }
 714
 715         resource_pool->clean_context();
 716 }
 717
 718 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])
 719 {
 720         // The first card is the master timer, so wait for it to have a new frame.
 721         unique_lock<mutex> lock(bmusb_mutex);
 722         cards[master_card_index].new_frames_changed.wait(lock, [this, master_card_index]{ return !cards[master_card_index].new_frames.empty(); });
 723
 724         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 725                 CaptureCard *card = &cards[card_index];
 726                 if (card->new_frames.empty()) {
 727                         assert(card_index != master_card_index);
 728                         card->queue_length_policy.update_policy(-1);
 729                         continue;
 730                 }
 731                 new_frames[card_index] = move(card->new_frames.front());
 732                 has_new_frame[card_index] = true;
 733                 card->new_frames.pop();
 734                 card->new_frames_changed.notify_all();
 735
 736                 int num_samples_times_timebase = OUTPUT_FREQUENCY * new_frames[card_index].length + card->fractional_samples;
 737                 num_samples[card_index] = num_samples_times_timebase / TIMEBASE;
 738                 card->fractional_samples = num_samples_times_timebase % TIMEBASE;
 739                 assert(num_samples[card_index] >= 0);
 740
 741                 if (card_index == master_card_index) {
 742                         // We don't use the queue length policy for the master card,
 743                         // but we will if it stops being the master. Thus, clear out
 744                         // the policy in case we switch in the future.
 745                         card->queue_length_policy.reset(card_index);
 746                 } else {
 747                         // If we have excess frames compared to the policy for this card,
 748                         // drop frames from the head.
 749                         card->queue_length_policy.update_policy(card->new_frames.size());
 750                         while (card->new_frames.size() > card->queue_length_policy.get_safe_queue_length()) {
 751                                 card->new_frames.pop();
 752                         }
 753                 }
 754         }
 755 }
 756
 757 void Mixer::schedule_audio_resampling_tasks(unsigned dropped_frames, int num_samples_per_frame, int length_per_frame)
 758 {
 759         // Resample the audio as needed, including from previously dropped frames.
 760         assert(num_cards > 0);
 761         for (unsigned frame_num = 0; frame_num < dropped_frames + 1; ++frame_num) {
 762                 {
 763                         // Signal to the audio thread to process this frame.
 764                         unique_lock<mutex> lock(audio_mutex);
 765                         audio_task_queue.push(AudioTask{pts_int, num_samples_per_frame});
 766                         audio_task_queue_changed.notify_one();
 767                 }
 768                 if (frame_num != dropped_frames) {
 769                         // For dropped frames, increase the pts. Note that if the format changed
 770                         // in the meantime, we have no way of detecting that; we just have to
 771                         // assume the frame length is always the same.
 772                         pts_int += length_per_frame;
 773                 }
 774         }
 775 }
 776
 777 void Mixer::render_one_frame()
 778 {
 779         // Get the main chain from the theme, and set its state immediately.
 780         Theme::Chain theme_main_chain = theme->get_chain(0, pts(), WIDTH, HEIGHT, input_state);
 781         EffectChain *chain = theme_main_chain.chain;
 782         theme_main_chain.setup_chain();
 783         //theme_main_chain.chain->enable_phase_timing(true);
 784
 785         GLuint y_tex, cbcr_tex;
 786         bool got_frame = h264_encoder->begin_frame(&y_tex, &cbcr_tex);
 787         assert(got_frame);
 788
 789         // Render main chain.
 790         GLuint cbcr_full_tex = resource_pool->create_2d_texture(GL_RG8, WIDTH, HEIGHT);
 791         GLuint rgba_tex = resource_pool->create_2d_texture(GL_RGB565, WIDTH, HEIGHT);  // Saves texture bandwidth, although dithering gets messed up.
 792         GLuint fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex, rgba_tex);
 793         check_error();
 794         chain->render_to_fbo(fbo, WIDTH, HEIGHT);
 795         resource_pool->release_fbo(fbo);
 796
 797         subsample_chroma(cbcr_full_tex, cbcr_tex);
 798         resource_pool->release_2d_texture(cbcr_full_tex);
 799
 800         // Set the right state for rgba_tex.
 801         glBindFramebuffer(GL_FRAMEBUFFER, 0);
 802         glBindTexture(GL_TEXTURE_2D, rgba_tex);
 803         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 804         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 805         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 806
 807         const int64_t av_delay = TIMEBASE / 10;  // Corresponds to the fixed delay in resampling_queue.h. TODO: Make less hard-coded.
 808         RefCountedGLsync fence = h264_encoder->end_frame(pts_int + av_delay, theme_main_chain.input_frames);
 809
 810         // The live frame just shows the RGBA texture we just rendered.
 811         // It owns rgba_tex now.
 812         DisplayFrame live_frame;
 813         live_frame.chain = display_chain.get();
 814         live_frame.setup_chain = [this, rgba_tex]{
 815                 display_input->set_texture_num(rgba_tex);
 816         };
 817         live_frame.ready_fence = fence;
 818         live_frame.input_frames = {};
 819         live_frame.temp_textures = { rgba_tex };
 820         output_channel[OUTPUT_LIVE].output_frame(live_frame);
 821
 822         // Set up preview and any additional channels.
 823         for (int i = 1; i < theme->get_num_channels() + 2; ++i) {
 824                 DisplayFrame display_frame;
 825                 Theme::Chain chain = theme->get_chain(i, pts(), WIDTH, HEIGHT, input_state);  // FIXME: dimensions
 826                 display_frame.chain = chain.chain;
 827                 display_frame.setup_chain = chain.setup_chain;
 828                 display_frame.ready_fence = fence;
 829                 display_frame.input_frames = chain.input_frames;
 830                 display_frame.temp_textures = {};
 831                 output_channel[i].output_frame(display_frame);
 832         }
 833 }
 834
 835 void Mixer::send_audio_level_callback()
 836 {
 837         if (audio_level_callback == nullptr) {
 838                 return;
 839         }
 840
 841         unique_lock<mutex> lock(compressor_mutex);
 842         double loudness_s = r128.loudness_S();
 843         double loudness_i = r128.integrated();
 844         double loudness_range_low = r128.range_min();
 845         double loudness_range_high = r128.range_max();
 846
 847         audio_level_callback(loudness_s, 20.0 * log10(peak),
 848                 loudness_i, loudness_range_low, loudness_range_high,
 849                 gain_staging_db, 20.0 * log10(final_makeup_gain),
 850                 correlation.get_correlation());
 851 }
 852
 853 void Mixer::audio_thread_func()
 854 {
 855         while (!should_quit) {
 856                 AudioTask task;
 857
 858                 {
 859                         unique_lock<mutex> lock(audio_mutex);
 860                         audio_task_queue_changed.wait(lock, [this]{ return !audio_task_queue.empty(); });
 861                         task = audio_task_queue.front();
 862                         audio_task_queue.pop();
 863                 }
 864
 865                 process_audio_one_frame(task.pts_int, task.num_samples);
 866         }
 867 }
 868
 869 void Mixer::process_audio_one_frame(int64_t frame_pts_int, int num_samples)
 870 {
 871         vector<float> samples_card;
 872         vector<float> samples_out;
 873
 874         // TODO: Allow mixing audio from several sources.
 875         unsigned selected_audio_card = theme->map_signal(audio_source_channel);
 876         assert(selected_audio_card < num_cards);
 877
 878         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 879                 samples_card.resize(num_samples * 2);
 880                 {
 881                         unique_lock<mutex> lock(cards[card_index].audio_mutex);
 882                         if (!cards[card_index].resampling_queue->get_output_samples(double(frame_pts_int) / TIMEBASE, &samples_card[0], num_samples)) {
 883                                 printf("Card %d reported previous underrun.\n", card_index);
 884                         }
 885                 }
 886                 if (card_index == selected_audio_card) {
 887                         samples_out = move(samples_card);
 888                 }
 889         }
 890
 891         // Cut away everything under 120 Hz (or whatever the cutoff is);
 892         // we don't need it for voice, and it will reduce headroom
 893         // and confuse the compressor. (In particular, any hums at 50 or 60 Hz
 894         // should be dampened.)
 895         if (locut_enabled) {
 896                 locut.render(samples_out.data(), samples_out.size() / 2, locut_cutoff_hz * 2.0 * M_PI / OUTPUT_FREQUENCY, 0.5f);
 897         }
 898
 899         // Apply a level compressor to get the general level right.
 900         // Basically, if it's over about -40 dBFS, we squeeze it down to that level
 901         // (or more precisely, near it, since we don't use infinite ratio),
 902         // then apply a makeup gain to get it to -14 dBFS. -14 dBFS is, of course,
 903         // entirely arbitrary, but from practical tests with speech, it seems to
 904         // put ut around -23 LUFS, so it's a reasonable starting point for later use.
 905         {
 906                 unique_lock<mutex> lock(compressor_mutex);
 907                 if (level_compressor_enabled) {
 908                         float threshold = 0.01f;   // -40 dBFS.
 909                         float ratio = 20.0f;
 910                         float attack_time = 0.5f;
 911                         float release_time = 20.0f;
 912                         float makeup_gain = pow(10.0f, (ref_level_dbfs - (-40.0f)) / 20.0f);  // +26 dB.
 913                         level_compressor.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
 914                         gain_staging_db = 20.0 * log10(level_compressor.get_attenuation() * makeup_gain);
 915                 } else {
 916                         // Just apply the gain we already had.
 917                         float g = pow(10.0f, gain_staging_db / 20.0f);
 918                         for (size_t i = 0; i < samples_out.size(); ++i) {
 919                                 samples_out[i] *= g;
 920                         }
 921                 }
 922         }
 923
 924 #if 0
 925         printf("level=%f (%+5.2f dBFS) attenuation=%f (%+5.2f dB) end_result=%+5.2f dB\n",
 926                 level_compressor.get_level(), 20.0 * log10(level_compressor.get_level()),
 927                 level_compressor.get_attenuation(), 20.0 * log10(level_compressor.get_attenuation()),
 928                 20.0 * log10(level_compressor.get_level() * level_compressor.get_attenuation() * makeup_gain));
 929 #endif
 930
 931 //      float limiter_att, compressor_att;
 932
 933         // The real compressor.
 934         if (compressor_enabled) {
 935                 float threshold = pow(10.0f, compressor_threshold_dbfs / 20.0f);
 936                 float ratio = 20.0f;
 937                 float attack_time = 0.005f;
 938                 float release_time = 0.040f;
 939                 float makeup_gain = 2.0f;  // +6 dB.
 940                 compressor.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
 941 //              compressor_att = compressor.get_attenuation();
 942         }
 943
 944         // Finally a limiter at -4 dB (so, -10 dBFS) to take out the worst peaks only.
 945         // Note that since ratio is not infinite, we could go slightly higher than this.
 946         if (limiter_enabled) {
 947                 float threshold = pow(10.0f, limiter_threshold_dbfs / 20.0f);
 948                 float ratio = 30.0f;
 949                 float attack_time = 0.0f;  // Instant.
 950                 float release_time = 0.020f;
 951                 float makeup_gain = 1.0f;  // 0 dB.
 952                 limiter.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
 953 //              limiter_att = limiter.get_attenuation();
 954         }
 955
 956 //      printf("limiter=%+5.1f  compressor=%+5.1f\n", 20.0*log10(limiter_att), 20.0*log10(compressor_att));
 957
 958         // Upsample 4x to find interpolated peak.
 959         peak_resampler.inp_data = samples_out.data();
 960         peak_resampler.inp_count = samples_out.size() / 2;
 961
 962         vector<float> interpolated_samples_out;
 963         interpolated_samples_out.resize(samples_out.size());
 964         while (peak_resampler.inp_count > 0) {  // About four iterations.
 965                 peak_resampler.out_data = &interpolated_samples_out[0];
 966                 peak_resampler.out_count = interpolated_samples_out.size() / 2;
 967                 peak_resampler.process();
 968                 size_t out_stereo_samples = interpolated_samples_out.size() / 2 - peak_resampler.out_count;
 969                 peak = max<float>(peak, find_peak(interpolated_samples_out.data(), out_stereo_samples * 2));
 970                 peak_resampler.out_data = nullptr;
 971         }
 972
 973         // At this point, we are most likely close to +0 LU, but all of our
 974         // measurements have been on raw sample values, not R128 values.
 975         // So we have a final makeup gain to get us to +0 LU; the gain
 976         // adjustments required should be relatively small, and also, the
 977         // offset shouldn't change much (only if the type of audio changes
 978         // significantly). Thus, we shoot for updating this value basically
 979         // “whenever we process buffers”, since the R128 calculation isn't exactly
 980         // something we get out per-sample.
 981         //
 982         // Note that there's a feedback loop here, so we choose a very slow filter
 983         // (half-time of 100 seconds).
 984         double target_loudness_factor, alpha;
 985         {
 986                 unique_lock<mutex> lock(compressor_mutex);
 987                 double loudness_lu = r128.loudness_M() - ref_level_lufs;
 988                 double current_makeup_lu = 20.0f * log10(final_makeup_gain);
 989                 target_loudness_factor = pow(10.0f, -loudness_lu / 20.0f);
 990
 991                 // If we're outside +/- 5 LU uncorrected, we don't count it as
 992                 // a normal signal (probably silence) and don't change the
 993                 // correction factor; just apply what we already have.
 994                 if (fabs(loudness_lu - current_makeup_lu) >= 5.0 || !final_makeup_gain_auto) {
 995                         alpha = 0.0;
 996                 } else {
 997                         // Formula adapted from
 998                         // https://en.wikipedia.org/wiki/Low-pass_filter#Simple_infinite_impulse_response_filter.
 999                         const double half_time_s = 100.0;
1000                         const double fc_mul_2pi_delta_t = 1.0 / (half_time_s * OUTPUT_FREQUENCY);
1001                         alpha = fc_mul_2pi_delta_t / (fc_mul_2pi_delta_t + 1.0);
1002                 }
1003
1004                 double m = final_makeup_gain;
1005                 for (size_t i = 0; i < samples_out.size(); i += 2) {
1006                         samples_out[i + 0] *= m;
1007                         samples_out[i + 1] *= m;
1008                         m += (target_loudness_factor - m) * alpha;
1009                 }
1010                 final_makeup_gain = m;
1011         }
1012
1013         // Find R128 levels and L/R correlation.
1014         vector<float> left, right;
1015         deinterleave_samples(samples_out, &left, &right);
1016         float *ptrs[] = { left.data(), right.data() };
1017         {
1018                 unique_lock<mutex> lock(compressor_mutex);
1019                 r128.process(left.size(), ptrs);
1020                 correlation.process_samples(samples_out);
1021         }
1022
1023         // Send the samples to the sound card.
1024         if (alsa) {
1025                 alsa->write(samples_out);
1026         }
1027
1028         // And finally add them to the output.
1029         h264_encoder->add_audio(frame_pts_int, move(samples_out));
1030 }
1031
1032 void Mixer::subsample_chroma(GLuint src_tex, GLuint dst_tex)
1033 {
1034         GLuint vao;
1035         glGenVertexArrays(1, &vao);
1036         check_error();
1037
1038         glBindVertexArray(vao);
1039         check_error();
1040
1041         // Extract Cb/Cr.
1042         GLuint fbo = resource_pool->create_fbo(dst_tex);
1043         glBindFramebuffer(GL_FRAMEBUFFER, fbo);
1044         glViewport(0, 0, WIDTH/2, HEIGHT/2);
1045         check_error();
1046
1047         glUseProgram(cbcr_program_num);
1048         check_error();
1049
1050         glActiveTexture(GL_TEXTURE0);
1051         check_error();
1052         glBindTexture(GL_TEXTURE_2D, src_tex);
1053         check_error();
1054         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1055         check_error();
1056         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
1057         check_error();
1058         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
1059         check_error();
1060
1061         float chroma_offset_0[] = { -0.5f / WIDTH, 0.0f };
1062         set_uniform_vec2(cbcr_program_num, "foo", "chroma_offset_0", chroma_offset_0);
1063
1064         glBindBuffer(GL_ARRAY_BUFFER, cbcr_vbo);
1065         check_error();
1066
1067         for (GLint attr_index : { cbcr_position_attribute_index, cbcr_texcoord_attribute_index }) {
1068                 glEnableVertexAttribArray(attr_index);
1069                 check_error();
1070                 glVertexAttribPointer(attr_index, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
1071                 check_error();
1072         }
1073
1074         glDrawArrays(GL_TRIANGLES, 0, 3);
1075         check_error();
1076
1077         for (GLint attr_index : { cbcr_position_attribute_index, cbcr_texcoord_attribute_index }) {
1078                 glDisableVertexAttribArray(attr_index);
1079                 check_error();
1080         }
1081
1082         glUseProgram(0);
1083         check_error();
1084         glBindFramebuffer(GL_FRAMEBUFFER, 0);
1085         check_error();
1086
1087         resource_pool->release_fbo(fbo);
1088         glDeleteVertexArrays(1, &vao);
1089 }
1090
1091 void Mixer::release_display_frame(DisplayFrame *frame)
1092 {
1093         for (GLuint texnum : frame->temp_textures) {
1094                 resource_pool->release_2d_texture(texnum);
1095         }
1096         frame->temp_textures.clear();
1097         frame->ready_fence.reset();
1098         frame->input_frames.clear();
1099 }
1100
1101 void Mixer::start()
1102 {
1103         mixer_thread = thread(&Mixer::thread_func, this);
1104         audio_thread = thread(&Mixer::audio_thread_func, this);
1105 }
1106
1107 void Mixer::quit()
1108 {
1109         should_quit = true;
1110         mixer_thread.join();
1111         audio_thread.join();
1112 }
1113
1114 void Mixer::transition_clicked(int transition_num)
1115 {
1116         theme->transition_clicked(transition_num, pts());
1117 }
1118
1119 void Mixer::channel_clicked(int preview_num)
1120 {
1121         theme->channel_clicked(preview_num);
1122 }
1123
1124 void Mixer::reset_meters()
1125 {
1126         peak_resampler.reset();
1127         peak = 0.0f;
1128         r128.reset();
1129         r128.integr_start();
1130         correlation.reset();
1131 }
1132
1133 void Mixer::start_mode_scanning(unsigned card_index)
1134 {
1135         assert(card_index < num_cards);
1136         if (is_mode_scanning[card_index]) {
1137                 return;
1138         }
1139         is_mode_scanning[card_index] = true;
1140         mode_scanlist[card_index].clear();
1141         for (const auto &mode : cards[card_index].capture->get_available_video_modes()) {
1142                 mode_scanlist[card_index].push_back(mode.first);
1143         }
1144         assert(!mode_scanlist[card_index].empty());
1145         mode_scanlist_index[card_index] = 0;
1146         cards[card_index].capture->set_video_mode(mode_scanlist[card_index][0]);
1147         clock_gettime(CLOCK_MONOTONIC, &last_mode_scan_change[card_index]);
1148 }
1149
1150 Mixer::OutputChannel::~OutputChannel()
1151 {
1152         if (has_current_frame) {
1153                 parent->release_display_frame(&current_frame);
1154         }
1155         if (has_ready_frame) {
1156                 parent->release_display_frame(&ready_frame);
1157         }
1158 }
1159
1160 void Mixer::OutputChannel::output_frame(DisplayFrame frame)
1161 {
1162         // Store this frame for display. Remove the ready frame if any
1163         // (it was seemingly never used).
1164         {
1165                 unique_lock<mutex> lock(frame_mutex);
1166                 if (has_ready_frame) {
1167                         parent->release_display_frame(&ready_frame);
1168                 }
1169                 ready_frame = frame;
1170                 has_ready_frame = true;
1171         }
1172
1173         if (has_new_frame_ready_callback) {
1174                 new_frame_ready_callback();
1175         }
1176 }
1177
1178 bool Mixer::OutputChannel::get_display_frame(DisplayFrame *frame)
1179 {
1180         unique_lock<mutex> lock(frame_mutex);
1181         if (!has_current_frame && !has_ready_frame) {
1182                 return false;
1183         }
1184
1185         if (has_current_frame && has_ready_frame) {
1186                 // We have a new ready frame. Toss the current one.
1187                 parent->release_display_frame(&current_frame);
1188                 has_current_frame = false;
1189         }
1190         if (has_ready_frame) {
1191                 assert(!has_current_frame);
1192                 current_frame = ready_frame;
1193                 ready_frame.ready_fence.reset();  // Drop the refcount.
1194                 ready_frame.input_frames.clear();  // Drop the refcounts.
1195                 has_current_frame = true;
1196                 has_ready_frame = false;
1197         }
1198
1199         *frame = current_frame;
1200         return true;
1201 }
1202
1203 void Mixer::OutputChannel::set_frame_ready_callback(Mixer::new_frame_ready_callback_t callback)
1204 {
1205         new_frame_ready_callback = callback;
1206         has_new_frame_ready_callback = true;
1207 }