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 <init.h>
   8 #include <movit/effect_chain.h>
   9 #include <movit/effect_util.h>
  10 #include <movit/flat_input.h>
  11 #include <movit/image_format.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
  30 #include "bmusb/bmusb.h"
  31 #include "context.h"
  32 #include "defs.h"
  33 #include "h264encode.h"
  34 #include "pbo_frame_allocator.h"
  35 #include "ref_counted_gl_sync.h"
  36 #include "timebase.h"
  37
  38 class QOpenGLContext;
  39
  40 using namespace movit;
  41 using namespace std;
  42 using namespace std::placeholders;
  43
  44 Mixer *global_mixer = nullptr;
  45
  46 namespace {
  47
  48 void convert_fixed24_to_fp32(float *dst, size_t out_channels, const uint8_t *src, size_t in_channels, size_t num_samples)
  49 {
  50         for (size_t i = 0; i < num_samples; ++i) {
  51                 for (size_t j = 0; j < out_channels; ++j) {
  52                         uint32_t s1 = *src++;
  53                         uint32_t s2 = *src++;
  54                         uint32_t s3 = *src++;
  55                         uint32_t s = s1 | (s1 << 8) | (s2 << 16) | (s3 << 24);
  56                         dst[i * out_channels + j] = int(s) * (1.0f / 4294967296.0f);
  57                 }
  58                 src += 3 * (in_channels - out_channels);
  59         }
  60 }
  61
  62 }  // namespace
  63
  64 Mixer::Mixer(const QSurfaceFormat &format, unsigned num_cards)
  65         : httpd(LOCAL_DUMP_FILE_NAME, WIDTH, HEIGHT),
  66           num_cards(num_cards),
  67           mixer_surface(create_surface(format)),
  68           h264_encoder_surface(create_surface(format)),
  69           level_compressor(OUTPUT_FREQUENCY),
  70           limiter(OUTPUT_FREQUENCY),
  71           compressor(OUTPUT_FREQUENCY)
  72 {
  73         httpd.start(9095);
  74
  75         CHECK(init_movit(MOVIT_SHADER_DIR, MOVIT_DEBUG_OFF));
  76         check_error();
  77
  78         // Since we allow non-bouncing 4:2:2 YCbCrInputs, effective subpixel precision
  79         // will be halved when sampling them, and we need to compensate here.
  80         movit_texel_subpixel_precision /= 2.0;
  81
  82         resource_pool.reset(new ResourcePool);
  83         theme.reset(new Theme("theme.lua", resource_pool.get(), num_cards));
  84         for (unsigned i = 0; i < NUM_OUTPUTS; ++i) {
  85                 output_channel[i].parent = this;
  86         }
  87
  88         ImageFormat inout_format;
  89         inout_format.color_space = COLORSPACE_sRGB;
  90         inout_format.gamma_curve = GAMMA_sRGB;
  91
  92         // Display chain; shows the live output produced by the main chain (its RGBA version).
  93         display_chain.reset(new EffectChain(WIDTH, HEIGHT, resource_pool.get()));
  94         check_error();
  95         display_input = new FlatInput(inout_format, FORMAT_RGB, GL_UNSIGNED_BYTE, WIDTH, HEIGHT);  // FIXME: GL_UNSIGNED_BYTE is really wrong.
  96         display_chain->add_input(display_input);
  97         display_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
  98         display_chain->set_dither_bits(0);  // Don't bother.
  99         display_chain->finalize();
 100
 101         h264_encoder.reset(new H264Encoder(h264_encoder_surface, WIDTH, HEIGHT, &httpd));
 102
 103         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 104                 printf("Configuring card %d...\n", card_index);
 105                 CaptureCard *card = &cards[card_index];
 106                 card->usb = new BMUSBCapture(card_index);
 107                 card->usb->set_frame_callback(bind(&Mixer::bm_frame, this, card_index, _1, _2, _3, _4, _5, _6, _7));
 108                 card->frame_allocator.reset(new PBOFrameAllocator(8 << 20, WIDTH, HEIGHT));  // 8 MB.
 109                 card->usb->set_video_frame_allocator(card->frame_allocator.get());
 110                 card->surface = create_surface(format);
 111                 card->usb->set_dequeue_thread_callbacks(
 112                         [card]{
 113                                 eglBindAPI(EGL_OPENGL_API);
 114                                 card->context = create_context(card->surface);
 115                                 if (!make_current(card->context, card->surface)) {
 116                                         printf("failed to create bmusb context\n");
 117                                         exit(1);
 118                                 }
 119                         },
 120                         [this]{
 121                                 resource_pool->clean_context();
 122                         });
 123                 card->resampling_queue.reset(new ResamplingQueue(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY, 2));
 124                 card->usb->configure_card();
 125         }
 126
 127         BMUSBCapture::start_bm_thread();
 128
 129         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 130                 cards[card_index].usb->start_bm_capture();
 131         }
 132
 133         //chain->enable_phase_timing(true);
 134
 135         // Set up stuff for NV12 conversion.
 136
 137         // Cb/Cr shader.
 138         string cbcr_vert_shader = read_file("vs-cbcr.130.vert");
 139         string cbcr_frag_shader =
 140                 "#version 130 \n"
 141                 "in vec2 tc0; \n"
 142                 "uniform sampler2D cbcr_tex; \n"
 143                 "void main() { \n"
 144                 "    gl_FragColor = texture2D(cbcr_tex, tc0); \n"
 145                 "} \n";
 146         cbcr_program_num = resource_pool->compile_glsl_program(cbcr_vert_shader, cbcr_frag_shader);
 147
 148         r128.init(2, OUTPUT_FREQUENCY);
 149         r128.integr_start();
 150
 151         locut.init(FILTER_HPF, 2);
 152
 153         // hlen=16 is pretty low quality, but we use quite a bit of CPU otherwise,
 154         // and there's a limit to how important the peak meter is.
 155         peak_resampler.setup(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY * 4, /*num_channels=*/2, /*hlen=*/16);
 156
 157         alsa.reset(new ALSAOutput(OUTPUT_FREQUENCY, /*num_channels=*/2));
 158 }
 159
 160 Mixer::~Mixer()
 161 {
 162         resource_pool->release_glsl_program(cbcr_program_num);
 163         BMUSBCapture::stop_bm_thread();
 164
 165         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 166                 {
 167                         unique_lock<mutex> lock(bmusb_mutex);
 168                         cards[card_index].should_quit = true;  // Unblock thread.
 169                         cards[card_index].new_data_ready_changed.notify_all();
 170                 }
 171                 cards[card_index].usb->stop_dequeue_thread();
 172         }
 173
 174         h264_encoder.reset(nullptr);
 175 }
 176
 177 namespace {
 178
 179 int unwrap_timecode(uint16_t current_wrapped, int last)
 180 {
 181         uint16_t last_wrapped = last & 0xffff;
 182         if (current_wrapped > last_wrapped) {
 183                 return (last & ~0xffff) | current_wrapped;
 184         } else {
 185                 return 0x10000 + ((last & ~0xffff) | current_wrapped);
 186         }
 187 }
 188
 189 float find_peak(const float *samples, size_t num_samples)
 190 {
 191         float m = fabs(samples[0]);
 192         for (size_t i = 1; i < num_samples; ++i) {
 193                 m = std::max(m, fabs(samples[i]));
 194         }
 195         return m;
 196 }
 197
 198 void deinterleave_samples(const vector<float> &in, vector<float> *out_l, vector<float> *out_r)
 199 {
 200         size_t num_samples = in.size() / 2;
 201         out_l->resize(num_samples);
 202         out_r->resize(num_samples);
 203
 204         const float *inptr = in.data();
 205         float *lptr = &(*out_l)[0];
 206         float *rptr = &(*out_r)[0];
 207         for (size_t i = 0; i < num_samples; ++i) {
 208                 *lptr++ = *inptr++;
 209                 *rptr++ = *inptr++;
 210         }
 211 }
 212
 213 }  // namespace
 214
 215 void Mixer::bm_frame(unsigned card_index, uint16_t timecode,
 216                      FrameAllocator::Frame video_frame, size_t video_offset, uint16_t video_format,
 217                      FrameAllocator::Frame audio_frame, size_t audio_offset, uint16_t audio_format)
 218 {
 219         CaptureCard *card = &cards[card_index];
 220
 221         unsigned width, height, second_field_start, frame_rate_nom, frame_rate_den, extra_lines_top, extra_lines_bottom;
 222         bool interlaced;
 223
 224         decode_video_format(video_format, &width, &height, &second_field_start, &extra_lines_top, &extra_lines_bottom,
 225                             &frame_rate_nom, &frame_rate_den, &interlaced);  // Ignore return value for now.
 226         int64_t frame_length = TIMEBASE * frame_rate_den / frame_rate_nom;
 227
 228         size_t num_samples = (audio_frame.len >= audio_offset) ? (audio_frame.len - audio_offset) / 8 / 3 : 0;
 229         if (num_samples > OUTPUT_FREQUENCY / 10) {
 230                 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",
 231                         card_index, int(audio_frame.len), int(audio_offset),
 232                         timecode, int(video_frame.len), int(video_offset), video_format);
 233                 if (video_frame.owner) {
 234                         video_frame.owner->release_frame(video_frame);
 235                 }
 236                 if (audio_frame.owner) {
 237                         audio_frame.owner->release_frame(audio_frame);
 238                 }
 239                 return;
 240         }
 241
 242         int64_t local_pts = card->next_local_pts;
 243         int dropped_frames = 0;
 244         if (card->last_timecode != -1) {
 245                 dropped_frames = unwrap_timecode(timecode, card->last_timecode) - card->last_timecode - 1;
 246         }
 247
 248         // Convert the audio to stereo fp32 and add it.
 249         vector<float> audio;
 250         audio.resize(num_samples * 2);
 251         convert_fixed24_to_fp32(&audio[0], 2, audio_frame.data + audio_offset, 8, num_samples);
 252
 253         // Add the audio.
 254         {
 255                 unique_lock<mutex> lock(card->audio_mutex);
 256
 257                 // Number of samples per frame if we need to insert silence.
 258                 // (Could be nonintegral, but resampling will save us then.)
 259                 int silence_samples = OUTPUT_FREQUENCY * frame_rate_den / frame_rate_nom;
 260
 261                 if (dropped_frames > MAX_FPS * 2) {
 262                         fprintf(stderr, "Card %d lost more than two seconds (or time code jumping around; from 0x%04x to 0x%04x), resetting resampler\n",
 263                                 card_index, card->last_timecode, timecode);
 264                         card->resampling_queue.reset(new ResamplingQueue(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY, 2));
 265                         dropped_frames = 0;
 266                 } else if (dropped_frames > 0) {
 267                         // Insert silence as needed.
 268                         fprintf(stderr, "Card %d dropped %d frame(s) (before timecode 0x%04x), inserting silence.\n",
 269                                 card_index, dropped_frames, timecode);
 270                         vector<float> silence;
 271                         silence.resize(silence_samples * 2);
 272                         for (int i = 0; i < dropped_frames; ++i) {
 273                                 card->resampling_queue->add_input_samples(local_pts / double(TIMEBASE), silence.data(), silence_samples);
 274                                 // Note that if the format changed in the meantime, we have
 275                                 // no way of detecting that; we just have to assume the frame length
 276                                 // is always the same.
 277                                 local_pts += frame_length;
 278                         }
 279                 }
 280                 if (num_samples == 0) {
 281                         audio.resize(silence_samples * 2);
 282                         num_samples = silence_samples;
 283                 }
 284                 card->resampling_queue->add_input_samples(local_pts / double(TIMEBASE), audio.data(), num_samples);
 285                 card->next_local_pts = local_pts + frame_length;
 286         }
 287
 288         card->last_timecode = timecode;
 289
 290         // Done with the audio, so release it.
 291         if (audio_frame.owner) {
 292                 audio_frame.owner->release_frame(audio_frame);
 293         }
 294
 295         {
 296                 // Wait until the previous frame was consumed.
 297                 unique_lock<mutex> lock(bmusb_mutex);
 298                 card->new_data_ready_changed.wait(lock, [card]{ return !card->new_data_ready || card->should_quit; });
 299                 if (card->should_quit) return;
 300         }
 301
 302         if (video_frame.len - video_offset == 0 ||
 303             video_frame.len - video_offset != size_t(width * (height + extra_lines_top + extra_lines_bottom) * 2)) {
 304                 if (video_frame.len != 0) {
 305                         printf("Card %d: Dropping video frame with wrong length (%ld)\n",
 306                                 card_index, video_frame.len - video_offset);
 307                 }
 308                 if (video_frame.owner) {
 309                         video_frame.owner->release_frame(video_frame);
 310                 }
 311
 312                 // Still send on the information that we _had_ a frame, even though it's corrupted,
 313                 // so that pts can go up accordingly.
 314                 {
 315                         unique_lock<mutex> lock(bmusb_mutex);
 316                         card->new_data_ready = true;
 317                         card->new_frame = RefCountedFrame(FrameAllocator::Frame());
 318                         card->new_frame_length = frame_length;
 319                         card->new_frame_interlaced = false;
 320                         card->new_data_ready_fence = nullptr;
 321                         card->dropped_frames = dropped_frames;
 322                         card->new_data_ready_changed.notify_all();
 323                 }
 324                 return;
 325         }
 326
 327         PBOFrameAllocator::Userdata *userdata = (PBOFrameAllocator::Userdata *)video_frame.userdata;
 328
 329         unsigned num_fields = interlaced ? 2 : 1;
 330         timespec frame_upload_start;
 331         if (interlaced) {
 332                 // NOTE: This isn't deinterlacing. This is just sending the two fields along
 333                 // as separate frames without considering anything like the half-field offset.
 334                 // We'll need to add a proper deinterlacer on the receiving side to get this right.
 335                 assert(height % 2 == 0);
 336                 height /= 2;
 337                 assert(frame_length % 2 == 0);
 338                 frame_length /= 2;
 339                 num_fields = 2;
 340                 clock_gettime(CLOCK_MONOTONIC, &frame_upload_start);
 341         }
 342         RefCountedFrame new_frame(video_frame);
 343
 344         // Upload the textures.
 345         size_t cbcr_width = width / 2;
 346         size_t cbcr_offset = video_offset / 2;
 347         size_t y_offset = video_frame.size / 2 + video_offset / 2;
 348
 349         for (unsigned field = 0; field < num_fields; ++field) {
 350                 unsigned field_start_line = (field == 1) ? second_field_start : extra_lines_top + field * (height + 22);
 351
 352                 if (userdata->tex_y[field] == 0 ||
 353                     userdata->tex_cbcr[field] == 0 ||
 354                     width != userdata->last_width[field] ||
 355                     height != userdata->last_height[field]) {
 356                         // We changed resolution since last use of this texture, so we need to create
 357                         // a new object. Note that this each card has its own PBOFrameAllocator,
 358                         // we don't need to worry about these flip-flopping between resolutions.
 359                         glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr[field]);
 360                         check_error();
 361                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RG8, cbcr_width, height, 0, GL_RG, GL_UNSIGNED_BYTE, nullptr);
 362                         check_error();
 363                         glBindTexture(GL_TEXTURE_2D, userdata->tex_y[field]);
 364                         check_error();
 365                         glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, width, height, 0, GL_RED, GL_UNSIGNED_BYTE, nullptr);
 366                         check_error();
 367                         userdata->last_width[field] = width;
 368                         userdata->last_height[field] = height;
 369                 }
 370
 371                 GLuint pbo = userdata->pbo;
 372                 check_error();
 373                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
 374                 check_error();
 375                 glFlushMappedBufferRange(GL_PIXEL_UNPACK_BUFFER, 0, video_frame.size);
 376                 check_error();
 377                 //glMemoryBarrier(GL_CLIENT_MAPPED_BUFFER_BARRIER_BIT);
 378                 //check_error();
 379
 380                 glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr[field]);
 381                 check_error();
 382                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, cbcr_width, height, GL_RG, GL_UNSIGNED_BYTE, BUFFER_OFFSET(cbcr_offset + cbcr_width * field_start_line * sizeof(uint16_t)));
 383                 check_error();
 384                 glBindTexture(GL_TEXTURE_2D, userdata->tex_y[field]);
 385                 check_error();
 386                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET(y_offset + width * field_start_line));
 387                 check_error();
 388                 glBindTexture(GL_TEXTURE_2D, 0);
 389                 check_error();
 390                 GLsync fence = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
 391                 check_error();
 392                 assert(fence != nullptr);
 393
 394                 if (field == 1) {
 395                         // Don't upload the second field as fast as we can; wait until
 396                         // the field time has approximately passed. (Otherwise, we could
 397                         // get timing jitter against the other sources, and possibly also
 398                         // against the video display, although the latter is not as critical.)
 399                         // This requires our system clock to be reasonably close to the
 400                         // video clock, but that's not an unreasonable assumption.
 401                         timespec second_field_start;
 402                         second_field_start.tv_nsec = frame_upload_start.tv_nsec +
 403                                 frame_length * 1000000000 / TIMEBASE;
 404                         second_field_start.tv_sec = frame_upload_start.tv_sec +
 405                                 second_field_start.tv_nsec / 1000000000;
 406                         second_field_start.tv_nsec %= 1000000000;
 407
 408                         while (clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME,
 409                                                &second_field_start, nullptr) == -1 &&
 410                                errno == EINTR) ;
 411                 }
 412
 413                 {
 414                         unique_lock<mutex> lock(bmusb_mutex);
 415                         card->new_data_ready = true;
 416                         card->new_frame = new_frame;
 417                         card->new_frame_length = frame_length;
 418                         card->new_frame_field = field;
 419                         card->new_frame_interlaced = interlaced;
 420                         card->new_data_ready_fence = fence;
 421                         card->dropped_frames = dropped_frames;
 422                         card->new_data_ready_changed.notify_all();
 423
 424                         if (field != num_fields - 1) {
 425                                 // Wait until the previous frame was consumed.
 426                                 card->new_data_ready_changed.wait(lock, [card]{ return !card->new_data_ready || card->should_quit; });
 427                                 if (card->should_quit) return;
 428                         }
 429                 }
 430         }
 431 }
 432
 433 void Mixer::thread_func()
 434 {
 435         eglBindAPI(EGL_OPENGL_API);
 436         QOpenGLContext *context = create_context(mixer_surface);
 437         if (!make_current(context, mixer_surface)) {
 438                 printf("oops\n");
 439                 exit(1);
 440         }
 441
 442         struct timespec start, now;
 443         clock_gettime(CLOCK_MONOTONIC, &start);
 444
 445         int frame = 0;
 446         int stats_dropped_frames = 0;
 447
 448         while (!should_quit) {
 449                 CaptureCard card_copy[MAX_CARDS];
 450                 int num_samples[MAX_CARDS];
 451
 452                 {
 453                         unique_lock<mutex> lock(bmusb_mutex);
 454
 455                         // The first card is the master timer, so wait for it to have a new frame.
 456                         // TODO: Make configurable, and with a timeout.
 457                         cards[0].new_data_ready_changed.wait(lock, [this]{ return cards[0].new_data_ready; });
 458
 459                         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 460                                 CaptureCard *card = &cards[card_index];
 461                                 card_copy[card_index].usb = card->usb;
 462                                 card_copy[card_index].new_data_ready = card->new_data_ready;
 463                                 card_copy[card_index].new_frame = card->new_frame;
 464                                 card_copy[card_index].new_frame_length = card->new_frame_length;
 465                                 card_copy[card_index].new_frame_field = card->new_frame_field;
 466                                 card_copy[card_index].new_frame_interlaced = card->new_frame_interlaced;
 467                                 card_copy[card_index].new_data_ready_fence = card->new_data_ready_fence;
 468                                 card_copy[card_index].dropped_frames = card->dropped_frames;
 469                                 card->new_data_ready = false;
 470                                 card->new_data_ready_changed.notify_all();
 471
 472                                 int num_samples_times_timebase = OUTPUT_FREQUENCY * card->new_frame_length + card->fractional_samples;
 473                                 num_samples[card_index] = num_samples_times_timebase / TIMEBASE;
 474                                 card->fractional_samples = num_samples_times_timebase % TIMEBASE;
 475                                 assert(num_samples[card_index] >= 0);
 476                         }
 477                 }
 478
 479                 // Resample the audio as needed, including from previously dropped frames.
 480                 for (unsigned frame_num = 0; frame_num < card_copy[0].dropped_frames + 1; ++frame_num) {
 481                         {
 482                                 // Signal to the audio thread to process this frame.
 483                                 unique_lock<mutex> lock(audio_mutex);
 484                                 audio_task_queue.push(AudioTask{pts_int, num_samples[0]});
 485                                 audio_task_queue_changed.notify_one();
 486                         }
 487                         if (frame_num != card_copy[0].dropped_frames) {
 488                                 // For dropped frames, increase the pts. Note that if the format changed
 489                                 // in the meantime, we have no way of detecting that; we just have to
 490                                 // assume the frame length is always the same.
 491                                 ++stats_dropped_frames;
 492                                 pts_int += card_copy[0].new_frame_length;
 493                         }
 494                 }
 495
 496                 if (audio_level_callback != nullptr) {
 497                         double loudness_s = r128.loudness_S();
 498                         double loudness_i = r128.integrated();
 499                         double loudness_range_low = r128.range_min();
 500                         double loudness_range_high = r128.range_max();
 501
 502                         audio_level_callback(loudness_s, 20.0 * log10(peak),
 503                                              loudness_i, loudness_range_low, loudness_range_high,
 504                                              last_gain_staging_db);
 505                 }
 506
 507                 for (unsigned card_index = 1; card_index < num_cards; ++card_index) {
 508                         if (card_copy[card_index].new_data_ready && card_copy[card_index].new_frame->len == 0) {
 509                                 ++card_copy[card_index].dropped_frames;
 510                         }
 511                         if (card_copy[card_index].dropped_frames > 0) {
 512                                 printf("Card %u dropped %d frames before this\n",
 513                                         card_index, int(card_copy[card_index].dropped_frames));
 514                         }
 515                 }
 516
 517                 // If the first card is reporting a corrupted or otherwise dropped frame,
 518                 // just increase the pts (skipping over this frame) and don't try to compute anything new.
 519                 if (card_copy[0].new_frame->len == 0) {
 520                         ++stats_dropped_frames;
 521                         pts_int += card_copy[0].new_frame_length;
 522                         continue;
 523                 }
 524
 525                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 526                         CaptureCard *card = &card_copy[card_index];
 527                         if (!card->new_data_ready || card->new_frame->len == 0)
 528                                 continue;
 529
 530                         assert(card->new_frame != nullptr);
 531                         if (card->new_frame_interlaced) {
 532                                 for (unsigned frame_num = FRAME_HISTORY_LENGTH; frame_num --> 1; ) {  // :-)
 533                                         buffered_frames[card_index][frame_num] = buffered_frames[card_index][frame_num - 1];
 534                                 }
 535                                 buffered_frames[card_index][0] = { card->new_frame, card->new_frame_field };
 536                         } else {
 537                                 for (unsigned frame_num = 0; frame_num < FRAME_HISTORY_LENGTH; ++frame_num) {
 538                                         buffered_frames[card_index][frame_num] = { card->new_frame, card->new_frame_field };
 539                                 }
 540                         }
 541                         check_error();
 542
 543                         // The new texture might still be uploaded,
 544                         // tell the GPU to wait until it's there.
 545                         if (card->new_data_ready_fence) {
 546                                 glWaitSync(card->new_data_ready_fence, /*flags=*/0, GL_TIMEOUT_IGNORED);
 547                                 check_error();
 548                                 glDeleteSync(card->new_data_ready_fence);
 549                                 check_error();
 550                         }
 551                 }
 552
 553                 // Get the main chain from the theme, and set its state immediately.
 554                 Theme::Chain theme_main_chain = theme->get_chain(0, pts(), WIDTH, HEIGHT);
 555                 EffectChain *chain = theme_main_chain.chain;
 556                 theme_main_chain.setup_chain();
 557
 558                 GLuint y_tex, cbcr_tex;
 559                 bool got_frame = h264_encoder->begin_frame(&y_tex, &cbcr_tex);
 560                 assert(got_frame);
 561
 562                 // Render main chain.
 563                 GLuint cbcr_full_tex = resource_pool->create_2d_texture(GL_RG8, WIDTH, HEIGHT);
 564                 GLuint rgba_tex = resource_pool->create_2d_texture(GL_RGB565, WIDTH, HEIGHT);  // Saves texture bandwidth, although dithering gets messed up.
 565                 GLuint fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex, rgba_tex);
 566                 check_error();
 567                 chain->render_to_fbo(fbo, WIDTH, HEIGHT);
 568                 resource_pool->release_fbo(fbo);
 569
 570                 subsample_chroma(cbcr_full_tex, cbcr_tex);
 571                 resource_pool->release_2d_texture(cbcr_full_tex);
 572
 573                 // Set the right state for rgba_tex.
 574                 glBindFramebuffer(GL_FRAMEBUFFER, 0);
 575                 glBindTexture(GL_TEXTURE_2D, rgba_tex);
 576                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 577                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 578                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 579
 580                 RefCountedGLsync fence(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
 581                 check_error();
 582
 583                 const int64_t av_delay = TIMEBASE / 10;  // Corresponds to the fixed delay in resampling_queue.h. TODO: Make less hard-coded.
 584                 h264_encoder->end_frame(fence, pts_int + av_delay, theme_main_chain.input_frames);
 585                 ++frame;
 586                 pts_int += card_copy[0].new_frame_length;
 587
 588                 // The live frame just shows the RGBA texture we just rendered.
 589                 // It owns rgba_tex now.
 590                 DisplayFrame live_frame;
 591                 live_frame.chain = display_chain.get();
 592                 live_frame.setup_chain = [this, rgba_tex]{
 593                         display_input->set_texture_num(rgba_tex);
 594                 };
 595                 live_frame.ready_fence = fence;
 596                 live_frame.input_frames = {};
 597                 live_frame.temp_textures = { rgba_tex };
 598                 output_channel[OUTPUT_LIVE].output_frame(live_frame);
 599
 600                 // Set up preview and any additional channels.
 601                 for (int i = 1; i < theme->get_num_channels() + 2; ++i) {
 602                         DisplayFrame display_frame;
 603                         Theme::Chain chain = theme->get_chain(i, pts(), WIDTH, HEIGHT);  // FIXME: dimensions
 604                         display_frame.chain = chain.chain;
 605                         display_frame.setup_chain = chain.setup_chain;
 606                         display_frame.ready_fence = fence;
 607                         display_frame.input_frames = chain.input_frames;
 608                         display_frame.temp_textures = {};
 609                         output_channel[i].output_frame(display_frame);
 610                 }
 611
 612                 clock_gettime(CLOCK_MONOTONIC, &now);
 613                 double elapsed = now.tv_sec - start.tv_sec +
 614                         1e-9 * (now.tv_nsec - start.tv_nsec);
 615                 if (frame % 100 == 0) {
 616                         printf("%d frames (%d dropped) in %.3f seconds = %.1f fps (%.1f ms/frame)\n",
 617                                 frame, stats_dropped_frames, elapsed, frame / elapsed,
 618                                 1e3 * elapsed / frame);
 619                 //      chain->print_phase_timing();
 620                 }
 621
 622 #if 0
 623                 // Reset every 100 frames, so that local variations in frame times
 624                 // (especially for the first few frames, when the shaders are
 625                 // compiled etc.) don't make it hard to measure for the entire
 626                 // remaining duration of the program.
 627                 if (frame == 10000) {
 628                         frame = 0;
 629                         start = now;
 630                 }
 631 #endif
 632                 check_error();
 633         }
 634
 635         resource_pool->clean_context();
 636 }
 637
 638 void Mixer::audio_thread_func()
 639 {
 640         while (!should_quit) {
 641                 AudioTask task;
 642
 643                 {
 644                         unique_lock<mutex> lock(audio_mutex);
 645                         audio_task_queue_changed.wait(lock, [this]{ return !audio_task_queue.empty(); });
 646                         task = audio_task_queue.front();
 647                         audio_task_queue.pop();
 648                 }
 649
 650                 process_audio_one_frame(task.pts_int, task.num_samples);
 651         }
 652 }
 653
 654 void Mixer::process_audio_one_frame(int64_t frame_pts_int, int num_samples)
 655 {
 656         vector<float> samples_card;
 657         vector<float> samples_out;
 658         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 659                 samples_card.resize(num_samples * 2);
 660                 {
 661                         unique_lock<mutex> lock(cards[card_index].audio_mutex);
 662                         if (!cards[card_index].resampling_queue->get_output_samples(double(frame_pts_int) / TIMEBASE, &samples_card[0], num_samples)) {
 663                                 printf("Card %d reported previous underrun.\n", card_index);
 664                         }
 665                 }
 666                 // TODO: Allow using audio from the other card(s) as well.
 667                 if (card_index == 0) {
 668                         samples_out = move(samples_card);
 669                 }
 670         }
 671
 672         // Cut away everything under 120 Hz (or whatever the cutoff is);
 673         // we don't need it for voice, and it will reduce headroom
 674         // and confuse the compressor. (In particular, any hums at 50 or 60 Hz
 675         // should be dampened.)
 676         locut.render(samples_out.data(), samples_out.size() / 2, locut_cutoff_hz * 2.0 * M_PI / OUTPUT_FREQUENCY, 0.5f);
 677
 678         // Apply a level compressor to get the general level right.
 679         // Basically, if it's over about -40 dBFS, we squeeze it down to that level
 680         // (or more precisely, near it, since we don't use infinite ratio),
 681         // then apply a makeup gain to get it to -14 dBFS. -14 dBFS is, of course,
 682         // entirely arbitrary, but from practical tests with speech, it seems to
 683         // put ut around -23 LUFS, so it's a reasonable starting point for later use.
 684         float ref_level_dbfs = -14.0f;
 685         {
 686                 float threshold = 0.01f;   // -40 dBFS.
 687                 float ratio = 20.0f;
 688                 float attack_time = 0.5f;
 689                 float release_time = 20.0f;
 690                 float makeup_gain = pow(10.0f, (ref_level_dbfs - (-40.0f)) / 20.0f);  // +26 dB.
 691                 level_compressor.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
 692                 last_gain_staging_db = 20.0 * log10(level_compressor.get_attenuation() * makeup_gain);
 693         }
 694
 695 #if 0
 696         printf("level=%f (%+5.2f dBFS) attenuation=%f (%+5.2f dB) end_result=%+5.2f dB\n",
 697                 level_compressor.get_level(), 20.0 * log10(level_compressor.get_level()),
 698                 level_compressor.get_attenuation(), 20.0 * log10(level_compressor.get_attenuation()),
 699                 20.0 * log10(level_compressor.get_level() * level_compressor.get_attenuation() * makeup_gain));
 700 #endif
 701
 702 //      float limiter_att, compressor_att;
 703
 704         // The real compressor.
 705         if (compressor_enabled) {
 706                 float threshold = pow(10.0f, compressor_threshold_dbfs / 20.0f);
 707                 float ratio = 20.0f;
 708                 float attack_time = 0.005f;
 709                 float release_time = 0.040f;
 710                 float makeup_gain = 2.0f;  // +6 dB.
 711                 compressor.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
 712 //              compressor_att = compressor.get_attenuation();
 713         }
 714
 715         // Finally a limiter at -4 dB (so, -10 dBFS) to take out the worst peaks only.
 716         // Note that since ratio is not infinite, we could go slightly higher than this.
 717         if (limiter_enabled) {
 718                 float threshold = pow(10.0f, limiter_threshold_dbfs / 20.0f);
 719                 float ratio = 30.0f;
 720                 float attack_time = 0.0f;  // Instant.
 721                 float release_time = 0.020f;
 722                 float makeup_gain = 1.0f;  // 0 dB.
 723                 limiter.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
 724 //              limiter_att = limiter.get_attenuation();
 725         }
 726
 727 //      printf("limiter=%+5.1f  compressor=%+5.1f\n", 20.0*log10(limiter_att), 20.0*log10(compressor_att));
 728
 729         // Upsample 4x to find interpolated peak.
 730         peak_resampler.inp_data = samples_out.data();
 731         peak_resampler.inp_count = samples_out.size() / 2;
 732
 733         vector<float> interpolated_samples_out;
 734         interpolated_samples_out.resize(samples_out.size());
 735         while (peak_resampler.inp_count > 0) {  // About four iterations.
 736                 peak_resampler.out_data = &interpolated_samples_out[0];
 737                 peak_resampler.out_count = interpolated_samples_out.size() / 2;
 738                 peak_resampler.process();
 739                 size_t out_stereo_samples = interpolated_samples_out.size() / 2 - peak_resampler.out_count;
 740                 peak = max<float>(peak, find_peak(interpolated_samples_out.data(), out_stereo_samples * 2));
 741         }
 742
 743         // Find R128 levels.
 744         vector<float> left, right;
 745         deinterleave_samples(samples_out, &left, &right);
 746         float *ptrs[] = { left.data(), right.data() };
 747         r128.process(left.size(), ptrs);
 748
 749         // Send the samples to the sound card.
 750         if (alsa) {
 751                 alsa->write(samples_out);
 752         }
 753
 754         // And finally add them to the output.
 755         h264_encoder->add_audio(frame_pts_int, move(samples_out));
 756 }
 757
 758 void Mixer::subsample_chroma(GLuint src_tex, GLuint dst_tex)
 759 {
 760         GLuint vao;
 761         glGenVertexArrays(1, &vao);
 762         check_error();
 763
 764         float vertices[] = {
 765                 0.0f, 2.0f,
 766                 0.0f, 0.0f,
 767                 2.0f, 0.0f
 768         };
 769
 770         glBindVertexArray(vao);
 771         check_error();
 772
 773         // Extract Cb/Cr.
 774         GLuint fbo = resource_pool->create_fbo(dst_tex);
 775         glBindFramebuffer(GL_FRAMEBUFFER, fbo);
 776         glViewport(0, 0, WIDTH/2, HEIGHT/2);
 777         check_error();
 778
 779         glUseProgram(cbcr_program_num);
 780         check_error();
 781
 782         glActiveTexture(GL_TEXTURE0);
 783         check_error();
 784         glBindTexture(GL_TEXTURE_2D, src_tex);
 785         check_error();
 786         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 787         check_error();
 788         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 789         check_error();
 790         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 791         check_error();
 792
 793         float chroma_offset_0[] = { -0.5f / WIDTH, 0.0f };
 794         set_uniform_vec2(cbcr_program_num, "foo", "chroma_offset_0", chroma_offset_0);
 795
 796         GLuint position_vbo = fill_vertex_attribute(cbcr_program_num, "position", 2, GL_FLOAT, sizeof(vertices), vertices);
 797         GLuint texcoord_vbo = fill_vertex_attribute(cbcr_program_num, "texcoord", 2, GL_FLOAT, sizeof(vertices), vertices);  // Same as vertices.
 798
 799         glDrawArrays(GL_TRIANGLES, 0, 3);
 800         check_error();
 801
 802         cleanup_vertex_attribute(cbcr_program_num, "position", position_vbo);
 803         cleanup_vertex_attribute(cbcr_program_num, "texcoord", texcoord_vbo);
 804
 805         glUseProgram(0);
 806         check_error();
 807
 808         resource_pool->release_fbo(fbo);
 809         glDeleteVertexArrays(1, &vao);
 810 }
 811
 812 void Mixer::release_display_frame(DisplayFrame *frame)
 813 {
 814         for (GLuint texnum : frame->temp_textures) {
 815                 resource_pool->release_2d_texture(texnum);
 816         }
 817         frame->temp_textures.clear();
 818         frame->ready_fence.reset();
 819         frame->input_frames.clear();
 820 }
 821
 822 void Mixer::start()
 823 {
 824         mixer_thread = thread(&Mixer::thread_func, this);
 825         audio_thread = thread(&Mixer::audio_thread_func, this);
 826 }
 827
 828 void Mixer::quit()
 829 {
 830         should_quit = true;
 831         mixer_thread.join();
 832         audio_thread.join();
 833 }
 834
 835 void Mixer::transition_clicked(int transition_num)
 836 {
 837         theme->transition_clicked(transition_num, pts());
 838 }
 839
 840 void Mixer::channel_clicked(int preview_num)
 841 {
 842         theme->channel_clicked(preview_num);
 843 }
 844
 845 void Mixer::reset_meters()
 846 {
 847         peak_resampler.reset();
 848         peak = 0.0f;
 849         r128.reset();
 850         r128.integr_start();
 851 }
 852
 853 Mixer::OutputChannel::~OutputChannel()
 854 {
 855         if (has_current_frame) {
 856                 parent->release_display_frame(&current_frame);
 857         }
 858         if (has_ready_frame) {
 859                 parent->release_display_frame(&ready_frame);
 860         }
 861 }
 862
 863 void Mixer::OutputChannel::output_frame(DisplayFrame frame)
 864 {
 865         // Store this frame for display. Remove the ready frame if any
 866         // (it was seemingly never used).
 867         {
 868                 unique_lock<mutex> lock(frame_mutex);
 869                 if (has_ready_frame) {
 870                         parent->release_display_frame(&ready_frame);
 871                 }
 872                 ready_frame = frame;
 873                 has_ready_frame = true;
 874         }
 875
 876         if (has_new_frame_ready_callback) {
 877                 new_frame_ready_callback();
 878         }
 879 }
 880
 881 bool Mixer::OutputChannel::get_display_frame(DisplayFrame *frame)
 882 {
 883         unique_lock<mutex> lock(frame_mutex);
 884         if (!has_current_frame && !has_ready_frame) {
 885                 return false;
 886         }
 887
 888         if (has_current_frame && has_ready_frame) {
 889                 // We have a new ready frame. Toss the current one.
 890                 parent->release_display_frame(&current_frame);
 891                 has_current_frame = false;
 892         }
 893         if (has_ready_frame) {
 894                 assert(!has_current_frame);
 895                 current_frame = ready_frame;
 896                 ready_frame.ready_fence.reset();  // Drop the refcount.
 897                 ready_frame.input_frames.clear();  // Drop the refcounts.
 898                 has_current_frame = true;
 899                 has_ready_frame = false;
 900         }
 901
 902         *frame = current_frame;
 903         return true;
 904 }
 905
 906 void Mixer::OutputChannel::set_frame_ready_callback(Mixer::new_frame_ready_callback_t callback)
 907 {
 908         new_frame_ready_callback = callback;
 909         has_new_frame_ready_callback = true;
 910 }