git.sesse.net Git - nageru/blob - mixer.cpp

   1 #define WIDTH 1280
   2 #define HEIGHT 720
   3 #define EXTRAHEIGHT 30
   4
   5 #undef Success
   6
   7 #include "mixer.h"
   8
   9 #include <assert.h>
  10 #include <epoxy/egl.h>
  11 #include <init.h>
  12 #include <movit/effect_chain.h>
  13 #include <movit/effect_util.h>
  14 #include <movit/flat_input.h>
  15 #include <movit/image_format.h>
  16 #include <movit/resource_pool.h>
  17 #include <stdint.h>
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <sys/time.h>
  21 #include <time.h>
  22 #include <util.h>
  23 #include <algorithm>
  24 #include <cmath>
  25 #include <condition_variable>
  26 #include <cstddef>
  27 #include <memory>
  28 #include <mutex>
  29 #include <string>
  30 #include <thread>
  31 #include <utility>
  32 #include <vector>
  33
  34 #include "bmusb/bmusb.h"
  35 #include "context.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         for (size_t i = 0; i < num_samples; ++i) {
  54                 for (size_t j = 0; j < out_channels; ++j) {
  55                         uint32_t s1 = *src++;
  56                         uint32_t s2 = *src++;
  57                         uint32_t s3 = *src++;
  58                         uint32_t s = s1 | (s1 << 8) | (s2 << 16) | (s3 << 24);
  59                         dst[i * out_channels + j] = int(s) * (1.0f / 4294967296.0f);
  60                 }
  61                 src += 3 * (in_channels - out_channels);
  62         }
  63 }
  64
  65 }  // namespace
  66
  67 Mixer::Mixer(const QSurfaceFormat &format, unsigned num_cards)
  68         : httpd("test.ts", WIDTH, HEIGHT),
  69           num_cards(num_cards),
  70           mixer_surface(create_surface(format)),
  71           h264_encoder_surface(create_surface(format)),
  72           compressor(48000.0f)
  73 {
  74         httpd.start(9095);
  75
  76         CHECK(init_movit(MOVIT_SHADER_DIR, MOVIT_DEBUG_OFF));
  77         check_error();
  78
  79         // Since we allow non-bouncing 4:2:2 YCbCrInputs, effective subpixel precision
  80         // will be halved when sampling them, and we need to compensate here.
  81         movit_texel_subpixel_precision /= 2.0;
  82
  83         resource_pool.reset(new ResourcePool);
  84         theme.reset(new Theme("theme.lua", resource_pool.get(), num_cards));
  85         for (unsigned i = 0; i < NUM_OUTPUTS; ++i) {
  86                 output_channel[i].parent = this;
  87         }
  88
  89         ImageFormat inout_format;
  90         inout_format.color_space = COLORSPACE_sRGB;
  91         inout_format.gamma_curve = GAMMA_sRGB;
  92
  93         // Display chain; shows the live output produced by the main chain (its RGBA version).
  94         display_chain.reset(new EffectChain(WIDTH, HEIGHT, resource_pool.get()));
  95         check_error();
  96         display_input = new FlatInput(inout_format, FORMAT_RGB, GL_UNSIGNED_BYTE, WIDTH, HEIGHT);  // FIXME: GL_UNSIGNED_BYTE is really wrong.
  97         display_chain->add_input(display_input);
  98         display_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
  99         display_chain->set_dither_bits(0);  // Don't bother.
 100         display_chain->finalize();
 101
 102         h264_encoder.reset(new H264Encoder(h264_encoder_surface, WIDTH, HEIGHT, &httpd));
 103
 104         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 105                 printf("Configuring card %d...\n", card_index);
 106                 CaptureCard *card = &cards[card_index];
 107                 card->usb = new BMUSBCapture(card_index);
 108                 card->usb->set_frame_callback(bind(&Mixer::bm_frame, this, card_index, _1, _2, _3, _4, _5, _6, _7));
 109                 card->frame_allocator.reset(new PBOFrameAllocator(WIDTH * (HEIGHT+EXTRAHEIGHT) * 2 + 44, WIDTH, HEIGHT));
 110                 card->usb->set_video_frame_allocator(card->frame_allocator.get());
 111                 card->surface = create_surface(format);
 112                 card->usb->set_dequeue_thread_callbacks(
 113                         [card]{
 114                                 eglBindAPI(EGL_OPENGL_API);
 115                                 card->context = create_context(card->surface);
 116                                 if (!make_current(card->context, card->surface)) {
 117                                         printf("failed to create bmusb context\n");
 118                                         exit(1);
 119                                 }
 120                         },
 121                         [this]{
 122                                 resource_pool->clean_context();
 123                         });
 124                 card->resampler.reset(new Resampler(48000.0, 48000.0, 2));
 125                 card->usb->configure_card();
 126         }
 127
 128         BMUSBCapture::start_bm_thread();
 129
 130         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 131                 cards[card_index].usb->start_bm_capture();
 132         }
 133
 134         //chain->enable_phase_timing(true);
 135
 136         // Set up stuff for NV12 conversion.
 137
 138         // Cb/Cr shader.
 139         string cbcr_vert_shader = read_file("vs-cbcr.130.vert");
 140         string cbcr_frag_shader =
 141                 "#version 130 \n"
 142                 "in vec2 tc0; \n"
 143                 "uniform sampler2D cbcr_tex; \n"
 144                 "void main() { \n"
 145                 "    gl_FragColor = texture2D(cbcr_tex, tc0); \n"
 146                 "} \n";
 147         cbcr_program_num = resource_pool->compile_glsl_program(cbcr_vert_shader, cbcr_frag_shader);
 148
 149         r128.init(2, 48000);
 150         r128.integr_start();
 151 }
 152
 153 Mixer::~Mixer()
 154 {
 155         resource_pool->release_glsl_program(cbcr_program_num);
 156         BMUSBCapture::stop_bm_thread();
 157
 158         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 159                 {
 160                         unique_lock<mutex> lock(bmusb_mutex);
 161                         cards[card_index].should_quit = true;  // Unblock thread.
 162                         cards[card_index].new_data_ready_changed.notify_all();
 163                 }
 164                 cards[card_index].usb->stop_dequeue_thread();
 165         }
 166 }
 167
 168 namespace {
 169
 170 int unwrap_timecode(uint16_t current_wrapped, int last)
 171 {
 172         uint16_t last_wrapped = last & 0xffff;
 173         if (current_wrapped > last_wrapped) {
 174                 return (last & ~0xffff) | current_wrapped;
 175         } else {
 176                 return 0x10000 + ((last & ~0xffff) | current_wrapped);
 177         }
 178 }
 179
 180 float find_peak(const vector<float> &samples)
 181 {
 182         float m = fabs(samples[0]);
 183         for (size_t i = 1; i < samples.size(); ++i) {
 184                 m = std::max(m, fabs(samples[i]));
 185         }
 186         return m;
 187 }
 188
 189 void deinterleave_samples(const vector<float> &in, vector<float> *out_l, vector<float> *out_r)
 190 {
 191         size_t num_samples = in.size() / 2;
 192         out_l->resize(num_samples);
 193         out_r->resize(num_samples);
 194
 195         const float *inptr = in.data();
 196         float *lptr = &(*out_l)[0];
 197         float *rptr = &(*out_r)[0];
 198         for (size_t i = 0; i < num_samples; ++i) {
 199                 *lptr++ = *inptr++;
 200                 *rptr++ = *inptr++;
 201         }
 202 }
 203
 204 }  // namespace
 205
 206 void Mixer::bm_frame(unsigned card_index, uint16_t timecode,
 207                      FrameAllocator::Frame video_frame, size_t video_offset, uint16_t video_format,
 208                      FrameAllocator::Frame audio_frame, size_t audio_offset, uint16_t audio_format)
 209 {
 210         CaptureCard *card = &cards[card_index];
 211
 212         if (audio_frame.len - audio_offset > 30000) {
 213                 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",
 214                         card_index, int(audio_frame.len), int(audio_offset),
 215                         timecode, int(video_frame.len), int(video_offset), video_format);
 216                 if (video_frame.owner) {
 217                         video_frame.owner->release_frame(video_frame);
 218                 }
 219                 if (audio_frame.owner) {
 220                         audio_frame.owner->release_frame(audio_frame);
 221                 }
 222                 return;
 223         }
 224
 225         int unwrapped_timecode = timecode;
 226         int dropped_frames = 0;
 227         if (card->last_timecode != -1) {
 228                 unwrapped_timecode = unwrap_timecode(unwrapped_timecode, card->last_timecode);
 229                 dropped_frames = unwrapped_timecode - card->last_timecode - 1;
 230         }
 231         card->last_timecode = unwrapped_timecode;
 232
 233         // Convert the audio to stereo fp32 and add it.
 234         size_t num_samples = (audio_frame.len >= audio_offset) ? (audio_frame.len - audio_offset) / 8 / 3 : 0;
 235         vector<float> audio;
 236         audio.resize(num_samples * 2);
 237         convert_fixed24_to_fp32(&audio[0], 2, audio_frame.data + audio_offset, 8, num_samples);
 238
 239         // Add the audio.
 240         {
 241                 unique_lock<mutex> lock(card->audio_mutex);
 242
 243                 int unwrapped_timecode = timecode;
 244                 if (dropped_frames > 60 * 2) {
 245                         fprintf(stderr, "Card %d lost more than two seconds (or time code jumping around), resetting resampler\n",
 246                                 card_index);
 247                         card->resampler.reset(new Resampler(48000.0, 48000.0, 2));
 248                 } else if (dropped_frames > 0) {
 249                         // Insert silence as needed.
 250                         fprintf(stderr, "Card %d dropped %d frame(s) (before timecode 0x%04x), inserting silence.\n",
 251                                 card_index, dropped_frames, timecode);
 252                         vector<float> silence;
 253                         silence.resize((48000 / 60) * 2);
 254                         for (int i = 0; i < dropped_frames; ++i) {
 255                                 card->resampler->add_input_samples((unwrapped_timecode - dropped_frames + i) / 60.0, silence.data(), (48000 / 60));
 256                         }
 257                 }
 258                 card->resampler->add_input_samples(unwrapped_timecode / 60.0, audio.data(), num_samples);
 259         }
 260
 261         // Done with the audio, so release it.
 262         if (audio_frame.owner) {
 263                 audio_frame.owner->release_frame(audio_frame);
 264         }
 265
 266         {
 267                 // Wait until the previous frame was consumed.
 268                 unique_lock<mutex> lock(bmusb_mutex);
 269                 card->new_data_ready_changed.wait(lock, [card]{ return !card->new_data_ready || card->should_quit; });
 270                 if (card->should_quit) return;
 271         }
 272
 273         if (video_frame.len - video_offset != WIDTH * (HEIGHT+EXTRAHEIGHT) * 2) {
 274                 if (video_frame.len != 0) {
 275                         printf("Card %d: Dropping video frame with wrong length (%ld)\n",
 276                                 card_index, video_frame.len - video_offset);
 277                 }
 278                 if (video_frame.owner) {
 279                         video_frame.owner->release_frame(video_frame);
 280                 }
 281
 282                 // Still send on the information that we _had_ a frame, even though it's corrupted,
 283                 // so that pts can go up accordingly.
 284                 {
 285                         unique_lock<mutex> lock(bmusb_mutex);
 286                         card->new_data_ready = true;
 287                         card->new_frame = RefCountedFrame(FrameAllocator::Frame());
 288                         card->new_data_ready_fence = nullptr;
 289                         card->dropped_frames = dropped_frames;
 290                         card->new_data_ready_changed.notify_all();
 291                 }
 292                 return;
 293         }
 294
 295         const PBOFrameAllocator::Userdata *userdata = (const PBOFrameAllocator::Userdata *)video_frame.userdata;
 296         GLuint pbo = userdata->pbo;
 297         check_error();
 298         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
 299         check_error();
 300         glFlushMappedBufferRange(GL_PIXEL_UNPACK_BUFFER, 0, video_frame.size);
 301         check_error();
 302         //glMemoryBarrier(GL_CLIENT_MAPPED_BUFFER_BARRIER_BIT);
 303         //check_error();
 304
 305         // Upload the textures.
 306         glBindTexture(GL_TEXTURE_2D, userdata->tex_y);
 307         check_error();
 308         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, WIDTH, HEIGHT, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET((WIDTH * (HEIGHT+EXTRAHEIGHT) * 2 + 44) / 2 + WIDTH * 25 + 22));
 309         check_error();
 310         glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr);
 311         check_error();
 312         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, WIDTH/2, HEIGHT, GL_RG, GL_UNSIGNED_BYTE, BUFFER_OFFSET(WIDTH * 25 + 22));
 313         check_error();
 314         glBindTexture(GL_TEXTURE_2D, 0);
 315         check_error();
 316         GLsync fence = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
 317         check_error();
 318         assert(fence != nullptr);
 319
 320         {
 321                 unique_lock<mutex> lock(bmusb_mutex);
 322                 card->new_data_ready = true;
 323                 card->new_frame = RefCountedFrame(video_frame);
 324                 card->new_data_ready_fence = fence;
 325                 card->dropped_frames = dropped_frames;
 326                 card->new_data_ready_changed.notify_all();
 327         }
 328 }
 329
 330 void Mixer::thread_func()
 331 {
 332         eglBindAPI(EGL_OPENGL_API);
 333         QOpenGLContext *context = create_context(mixer_surface);
 334         if (!make_current(context, mixer_surface)) {
 335                 printf("oops\n");
 336                 exit(1);
 337         }
 338
 339         struct timespec start, now;
 340         clock_gettime(CLOCK_MONOTONIC, &start);
 341
 342         int frame = 0;
 343         int dropped_frames = 0;
 344
 345         while (!should_quit) {
 346                 CaptureCard card_copy[MAX_CARDS];
 347
 348                 {
 349                         unique_lock<mutex> lock(bmusb_mutex);
 350
 351                         // The first card is the master timer, so wait for it to have a new frame.
 352                         // TODO: Make configurable, and with a timeout.
 353                         cards[0].new_data_ready_changed.wait(lock, [this]{ return cards[0].new_data_ready; });
 354
 355                         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 356                                 CaptureCard *card = &cards[card_index];
 357                                 card_copy[card_index].usb = card->usb;
 358                                 card_copy[card_index].new_data_ready = card->new_data_ready;
 359                                 card_copy[card_index].new_frame = card->new_frame;
 360                                 card_copy[card_index].new_data_ready_fence = card->new_data_ready_fence;
 361                                 card_copy[card_index].dropped_frames = card->dropped_frames;
 362                                 card->new_data_ready = false;
 363                                 card->new_data_ready_changed.notify_all();
 364                         }
 365                 }
 366
 367                 // Resample the audio as needed, including from previously dropped frames.
 368                 for (unsigned frame_num = 0; frame_num < card_copy[0].dropped_frames + 1; ++frame_num) {
 369                         process_audio_one_frame();
 370                         if (frame_num != card_copy[0].dropped_frames) {
 371                                 // For dropped frames, increase the pts.
 372                                 ++dropped_frames;
 373                                 pts_int += TIMEBASE / 60;
 374                         }
 375                 }
 376
 377                 if (audio_level_callback != nullptr) {
 378                         double loudness_s = r128.loudness_S();
 379                         double loudness_i = r128.integrated();
 380                         double loudness_range_low = r128.range_min();
 381                         double loudness_range_high = r128.range_max();
 382
 383                         audio_level_callback(loudness_s, 20.0 * log10(peak),
 384                                              loudness_i, loudness_range_low, loudness_range_high);
 385                 }
 386
 387                 for (unsigned card_index = 1; card_index < num_cards; ++card_index) {
 388                         if (card_copy[card_index].new_data_ready && card_copy[card_index].new_frame->len == 0) {
 389                                 ++card_copy[card_index].dropped_frames;
 390                         }
 391                         if (card_copy[card_index].dropped_frames > 0) {
 392                                 printf("Card %u dropped %d frames before this\n",
 393                                         card_index, int(card_copy[card_index].dropped_frames));
 394                         }
 395                 }
 396
 397                 // If the first card is reporting a corrupted or otherwise dropped frame,
 398                 // just increase the pts (skipping over this frame) and don't try to compute anything new.
 399                 if (card_copy[0].new_frame->len == 0) {
 400                         ++dropped_frames;
 401                         pts_int += TIMEBASE / 60;
 402                         continue;
 403                 }
 404
 405                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 406                         CaptureCard *card = &card_copy[card_index];
 407                         if (!card->new_data_ready || card->new_frame->len == 0)
 408                                 continue;
 409
 410                         assert(card->new_frame != nullptr);
 411                         bmusb_current_rendering_frame[card_index] = card->new_frame;
 412                         check_error();
 413
 414                         // The new texture might still be uploaded,
 415                         // tell the GPU to wait until it's there.
 416                         if (card->new_data_ready_fence) {
 417                                 glWaitSync(card->new_data_ready_fence, /*flags=*/0, GL_TIMEOUT_IGNORED);
 418                                 check_error();
 419                                 glDeleteSync(card->new_data_ready_fence);
 420                                 check_error();
 421                         }
 422                         const PBOFrameAllocator::Userdata *userdata = (const PBOFrameAllocator::Userdata *)card->new_frame->userdata;
 423                         theme->set_input_textures(card_index, userdata->tex_y, userdata->tex_cbcr);
 424                 }
 425
 426                 // Get the main chain from the theme, and set its state immediately.
 427                 pair<EffectChain *, function<void()>> theme_main_chain = theme->get_chain(0, pts(), WIDTH, HEIGHT);
 428                 EffectChain *chain = theme_main_chain.first;
 429                 theme_main_chain.second();
 430
 431                 GLuint y_tex, cbcr_tex;
 432                 bool got_frame = h264_encoder->begin_frame(&y_tex, &cbcr_tex);
 433                 assert(got_frame);
 434
 435                 // Render main chain.
 436                 GLuint cbcr_full_tex = resource_pool->create_2d_texture(GL_RG8, WIDTH, HEIGHT);
 437                 GLuint rgba_tex = resource_pool->create_2d_texture(GL_RGB565, WIDTH, HEIGHT);  // Saves texture bandwidth, although dithering gets messed up.
 438                 GLuint fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex, rgba_tex);
 439                 check_error();
 440                 chain->render_to_fbo(fbo, WIDTH, HEIGHT);
 441                 resource_pool->release_fbo(fbo);
 442
 443                 subsample_chroma(cbcr_full_tex, cbcr_tex);
 444                 resource_pool->release_2d_texture(cbcr_full_tex);
 445
 446                 // Set the right state for rgba_tex.
 447                 glBindFramebuffer(GL_FRAMEBUFFER, 0);
 448                 glBindTexture(GL_TEXTURE_2D, rgba_tex);
 449                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 450                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 451                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 452
 453                 RefCountedGLsync fence(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
 454                 check_error();
 455
 456                 // Make sure the H.264 gets a reference to all the
 457                 // input frames needed, so that they are not released back
 458                 // until the rendering is done.
 459                 vector<RefCountedFrame> input_frames;
 460                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 461                         input_frames.push_back(bmusb_current_rendering_frame[card_index]);
 462                 }
 463                 const int64_t av_delay = TIMEBASE / 10;  // Corresponds to the fixed delay in resampler.h. TODO: Make less hard-coded.
 464                 h264_encoder->end_frame(fence, pts_int + av_delay, input_frames);
 465                 ++frame;
 466                 pts_int += TIMEBASE / 60;
 467
 468                 // The live frame just shows the RGBA texture we just rendered.
 469                 // It owns rgba_tex now.
 470                 DisplayFrame live_frame;
 471                 live_frame.chain = display_chain.get();
 472                 live_frame.setup_chain = [this, rgba_tex]{
 473                         display_input->set_texture_num(rgba_tex);
 474                 };
 475                 live_frame.ready_fence = fence;
 476                 live_frame.input_frames = {};
 477                 live_frame.temp_textures = { rgba_tex };
 478                 output_channel[OUTPUT_LIVE].output_frame(live_frame);
 479
 480                 // Set up preview and any additional channels.
 481                 for (int i = 1; i < theme->get_num_channels() + 2; ++i) {
 482                         DisplayFrame display_frame;
 483                         pair<EffectChain *, function<void()>> chain = theme->get_chain(i, pts(), WIDTH, HEIGHT);  // FIXME: dimensions
 484                         display_frame.chain = chain.first;
 485                         display_frame.setup_chain = chain.second;
 486                         display_frame.ready_fence = fence;
 487
 488                         // FIXME: possible to do better?
 489                         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 490                                 display_frame.input_frames.push_back(bmusb_current_rendering_frame[card_index]);
 491                         }
 492                         display_frame.temp_textures = {};
 493                         output_channel[i].output_frame(display_frame);
 494                 }
 495
 496                 clock_gettime(CLOCK_MONOTONIC, &now);
 497                 double elapsed = now.tv_sec - start.tv_sec +
 498                         1e-9 * (now.tv_nsec - start.tv_nsec);
 499                 if (frame % 100 == 0) {
 500                         printf("%d frames (%d dropped) in %.3f seconds = %.1f fps (%.1f ms/frame)\n",
 501                                 frame, dropped_frames, elapsed, frame / elapsed,
 502                                 1e3 * elapsed / frame);
 503                 //      chain->print_phase_timing();
 504                 }
 505
 506 #if 0
 507                 // Reset every 100 frames, so that local variations in frame times
 508                 // (especially for the first few frames, when the shaders are
 509                 // compiled etc.) don't make it hard to measure for the entire
 510                 // remaining duration of the program.
 511                 if (frame == 10000) {
 512                         frame = 0;
 513                         start = now;
 514                 }
 515 #endif
 516                 check_error();
 517         }
 518
 519         resource_pool->clean_context();
 520 }
 521
 522 void Mixer::process_audio_one_frame()
 523 {
 524         vector<float> samples_card;
 525         vector<float> samples_out;
 526         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
 527                 samples_card.resize((48000 / 60) * 2);
 528                 {
 529                         unique_lock<mutex> lock(cards[card_index].audio_mutex);
 530                         if (!cards[card_index].resampler->get_output_samples(pts(), &samples_card[0], 48000 / 60)) {
 531                                 printf("Card %d reported previous underrun.\n", card_index);
 532                         }
 533                 }
 534                 // TODO: Allow using audio from the other card(s) as well.
 535                 if (card_index == 0) {
 536                         samples_out = move(samples_card);
 537                 }
 538         }
 539
 540         // Apply a level compressor to get the general level right.
 541         // Basically, if it's over about -40 dBFS, we squeeze it down to that level
 542         // (or more precisely, near it, since we don't use infinite ratio),
 543         // then apply a makeup gain to get it to -12 dBFS. -12 dBFS is, of course,
 544         // entirely arbitrary, but from practical tests with speech, it seems to
 545         // put ut around -23 LUFS, so it's a reasonable starting point for later use.
 546         //
 547         // TODO: Hook this up to a UI, so we can see the effects, and/or turn it off
 548         // to control the gain manually instead. For now, there's only the #if-ed out
 549         // code below.
 550         //
 551         // TODO: Add the actual compressors/limiters (for taking care of transients)
 552         // later in the chain.
 553         float threshold = 0.01f;   // -40 dBFS.
 554         float ratio = 20.0f;
 555         float attack_time = 0.1f;
 556         float release_time = 10.0f;
 557         float makeup_gain = pow(10.0f, 28.0f / 20.0f);  // +28 dB takes us to -12 dBFS.
 558         compressor.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
 559
 560 #if 0
 561         printf("level=%f (%+5.2f dBFS) attenuation=%f (%+5.2f dB) end_result=%+5.2f dB\n",
 562                 compressor.get_level(), 20.0 * log10(compressor.get_level()),
 563                 compressor.get_attenuation(), 20.0 * log10(compressor.get_attenuation()),
 564                 20.0 * log10(compressor.get_level() * compressor.get_attenuation() * makeup_gain));
 565 #endif
 566
 567         // Find peak and R128 levels.
 568         peak = std::max(peak, find_peak(samples_out));
 569         vector<float> left, right;
 570         deinterleave_samples(samples_out, &left, &right);
 571         float *ptrs[] = { left.data(), right.data() };
 572         r128.process(left.size(), ptrs);
 573
 574         // Actually add the samples to the output.
 575         h264_encoder->add_audio(pts_int, move(samples_out));
 576 }
 577
 578 void Mixer::subsample_chroma(GLuint src_tex, GLuint dst_tex)
 579 {
 580         GLuint vao;
 581         glGenVertexArrays(1, &vao);
 582         check_error();
 583
 584         float vertices[] = {
 585                 0.0f, 2.0f,
 586                 0.0f, 0.0f,
 587                 2.0f, 0.0f
 588         };
 589
 590         glBindVertexArray(vao);
 591         check_error();
 592
 593         // Extract Cb/Cr.
 594         GLuint fbo = resource_pool->create_fbo(dst_tex);
 595         glBindFramebuffer(GL_FRAMEBUFFER, fbo);
 596         glViewport(0, 0, WIDTH/2, HEIGHT/2);
 597         check_error();
 598
 599         glUseProgram(cbcr_program_num);
 600         check_error();
 601
 602         glActiveTexture(GL_TEXTURE0);
 603         check_error();
 604         glBindTexture(GL_TEXTURE_2D, src_tex);
 605         check_error();
 606         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 607         check_error();
 608         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 609         check_error();
 610         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 611         check_error();
 612
 613         float chroma_offset_0[] = { -0.5f / WIDTH, 0.0f };
 614         set_uniform_vec2(cbcr_program_num, "foo", "chroma_offset_0", chroma_offset_0);
 615
 616         GLuint position_vbo = fill_vertex_attribute(cbcr_program_num, "position", 2, GL_FLOAT, sizeof(vertices), vertices);
 617         GLuint texcoord_vbo = fill_vertex_attribute(cbcr_program_num, "texcoord", 2, GL_FLOAT, sizeof(vertices), vertices);  // Same as vertices.
 618
 619         glDrawArrays(GL_TRIANGLES, 0, 3);
 620         check_error();
 621
 622         cleanup_vertex_attribute(cbcr_program_num, "position", position_vbo);
 623         cleanup_vertex_attribute(cbcr_program_num, "texcoord", texcoord_vbo);
 624
 625         glUseProgram(0);
 626         check_error();
 627
 628         resource_pool->release_fbo(fbo);
 629         glDeleteVertexArrays(1, &vao);
 630 }
 631
 632 void Mixer::release_display_frame(DisplayFrame *frame)
 633 {
 634         for (GLuint texnum : frame->temp_textures) {
 635                 resource_pool->release_2d_texture(texnum);
 636         }
 637         frame->temp_textures.clear();
 638         frame->ready_fence.reset();
 639         frame->input_frames.clear();
 640 }
 641
 642 void Mixer::start()
 643 {
 644         mixer_thread = thread(&Mixer::thread_func, this);
 645 }
 646
 647 void Mixer::quit()
 648 {
 649         should_quit = true;
 650         mixer_thread.join();
 651 }
 652
 653 void Mixer::transition_clicked(int transition_num)
 654 {
 655         theme->transition_clicked(transition_num, pts());
 656 }
 657
 658 void Mixer::channel_clicked(int preview_num)
 659 {
 660         theme->channel_clicked(preview_num);
 661 }
 662
 663 Mixer::OutputChannel::~OutputChannel()
 664 {
 665         if (has_current_frame) {
 666                 parent->release_display_frame(&current_frame);
 667         }
 668         if (has_ready_frame) {
 669                 parent->release_display_frame(&ready_frame);
 670         }
 671 }
 672
 673 void Mixer::OutputChannel::output_frame(DisplayFrame frame)
 674 {
 675         // Store this frame for display. Remove the ready frame if any
 676         // (it was seemingly never used).
 677         {
 678                 unique_lock<mutex> lock(frame_mutex);
 679                 if (has_ready_frame) {
 680                         parent->release_display_frame(&ready_frame);
 681                 }
 682                 ready_frame = frame;
 683                 has_ready_frame = true;
 684         }
 685
 686         if (has_new_frame_ready_callback) {
 687                 new_frame_ready_callback();
 688         }
 689 }
 690
 691 bool Mixer::OutputChannel::get_display_frame(DisplayFrame *frame)
 692 {
 693         unique_lock<mutex> lock(frame_mutex);
 694         if (!has_current_frame && !has_ready_frame) {
 695                 return false;
 696         }
 697
 698         if (has_current_frame && has_ready_frame) {
 699                 // We have a new ready frame. Toss the current one.
 700                 parent->release_display_frame(&current_frame);
 701                 has_current_frame = false;
 702         }
 703         if (has_ready_frame) {
 704                 assert(!has_current_frame);
 705                 current_frame = ready_frame;
 706                 ready_frame.ready_fence.reset();  // Drop the refcount.
 707                 ready_frame.input_frames.clear();  // Drop the refcounts.
 708                 has_current_frame = true;
 709                 has_ready_frame = false;
 710         }
 711
 712         *frame = current_frame;
 713         return true;
 714 }
 715
 716 void Mixer::OutputChannel::set_frame_ready_callback(Mixer::new_frame_ready_callback_t callback)
 717 {
 718         new_frame_ready_callback = callback;
 719         has_new_frame_ready_callback = true;
 720 }