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 <effect.h>
  11 #include <effect_chain.h>
  12 #include <effect_util.h>
  13 #include <epoxy/egl.h>
  14 #include <features.h>
  15 #include <image_format.h>
  16 #include <init.h>
  17 #include <overlay_effect.h>
  18 #include <padding_effect.h>
  19 #include <resample_effect.h>
  20 #include <resource_pool.h>
  21 #include <saturation_effect.h>
  22 #include <stdint.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <sys/time.h>
  26 #include <time.h>
  27 #include <util.h>
  28 #include <white_balance_effect.h>
  29 #include <ycbcr.h>
  30 #include <ycbcr_input.h>
  31 #include <cmath>
  32 #include <condition_variable>
  33 #include <cstddef>
  34 #include <memory>
  35 #include <mutex>
  36 #include <string>
  37 #include <thread>
  38 #include <vector>
  39
  40 #include "bmusb/bmusb.h"
  41 #include "context.h"
  42 #include "h264encode.h"
  43 #include "pbo_frame_allocator.h"
  44 #include "ref_counted_gl_sync.h"
  45 #include "timebase.h"
  46
  47 class QOpenGLContext;
  48
  49 using namespace movit;
  50 using namespace std;
  51 using namespace std::placeholders;
  52
  53 Mixer *global_mixer = nullptr;
  54
  55 namespace {
  56
  57 void convert_fixed24_to_fp32(float *dst, size_t out_channels, const uint8_t *src, size_t in_channels, size_t num_samples)
  58 {
  59         for (size_t i = 0; i < num_samples; ++i) {
  60                 for (size_t j = 0; j < out_channels; ++j) {
  61                         uint32_t s1 = *src++;
  62                         uint32_t s2 = *src++;
  63                         uint32_t s3 = *src++;
  64                         uint32_t s = s1 | (s1 << 8) | (s2 << 16) | (s3 << 24);
  65                         dst[i * out_channels + j] = int(s) * (1.0f / 4294967296.0f);
  66                 }
  67                 src += 3 * (in_channels - out_channels);
  68         }
  69 }
  70
  71 }  // namespace
  72
  73 Mixer::Mixer(const QSurfaceFormat &format)
  74         : httpd("test.ts", WIDTH, HEIGHT),
  75           mixer_surface(create_surface(format)),
  76           h264_encoder_surface(create_surface(format))
  77 {
  78         httpd.start(9095);
  79
  80         CHECK(init_movit(MOVIT_SHADER_DIR, MOVIT_DEBUG_OFF));
  81         check_error();
  82
  83         resource_pool.reset(new ResourcePool);
  84         theme.reset(new Theme("theme.lua", resource_pool.get()));
  85         output_channel[OUTPUT_LIVE].parent = this;
  86         output_channel[OUTPUT_PREVIEW].parent = this;
  87         output_channel[OUTPUT_INPUT0].parent = this;
  88         output_channel[OUTPUT_INPUT1].parent = this;
  89
  90         ImageFormat inout_format;
  91         inout_format.color_space = COLORSPACE_sRGB;
  92         inout_format.gamma_curve = GAMMA_sRGB;
  93
  94         // Display chain; shows the live output produced by the main chain (its RGBA version).
  95         display_chain.reset(new EffectChain(WIDTH, HEIGHT, resource_pool.get()));
  96         check_error();
  97         display_input = new FlatInput(inout_format, FORMAT_RGB, GL_UNSIGNED_BYTE, WIDTH, HEIGHT);  // FIXME: GL_UNSIGNED_BYTE is really wrong.
  98         display_chain->add_input(display_input);
  99         display_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
 100         display_chain->set_dither_bits(0);  // Don't bother.
 101         display_chain->finalize();
 102
 103         h264_encoder.reset(new H264Encoder(h264_encoder_surface, WIDTH, HEIGHT, &httpd));
 104
 105         for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
 106                 printf("Configuring card %d...\n", card_index);
 107                 CaptureCard *card = &cards[card_index];
 108                 card->usb = new BMUSBCapture(card_index);
 109                 card->usb->set_frame_callback(bind(&Mixer::bm_frame, this, card_index, _1, _2, _3, _4, _5, _6, _7));
 110                 card->frame_allocator.reset(new PBOFrameAllocator(WIDTH * (HEIGHT+EXTRAHEIGHT) * 2 + 44, WIDTH, HEIGHT));
 111                 card->usb->set_video_frame_allocator(card->frame_allocator.get());
 112                 card->surface = create_surface(format);
 113                 card->usb->set_dequeue_thread_callbacks(
 114                         [card]{
 115                                 eglBindAPI(EGL_OPENGL_API);
 116                                 card->context = create_context();
 117                                 if (!make_current(card->context, card->surface)) {
 118                                         printf("failed to create bmusb context\n");
 119                                         exit(1);
 120                                 }
 121                         },
 122                         [this]{
 123                                 resource_pool->clean_context();
 124                         });
 125                 card->resampler.reset(new Resampler(48000.0, 48000.0, 2));
 126                 card->usb->configure_card();
 127         }
 128
 129         BMUSBCapture::start_bm_thread();
 130
 131         for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
 132                 cards[card_index].usb->start_bm_capture();
 133         }
 134
 135         //chain->enable_phase_timing(true);
 136
 137         // Set up stuff for NV12 conversion.
 138
 139         // Cb/Cr shader.
 140         string cbcr_vert_shader = read_file("vs-cbcr.130.vert");
 141         string cbcr_frag_shader =
 142                 "#version 130 \n"
 143                 "in vec2 tc0; \n"
 144                 "uniform sampler2D cbcr_tex; \n"
 145                 "void main() { \n"
 146                 "    gl_FragColor = texture2D(cbcr_tex, tc0); \n"
 147                 "} \n";
 148         cbcr_program_num = resource_pool->compile_glsl_program(cbcr_vert_shader, cbcr_frag_shader);
 149
 150         r128_state = ebur128_init(2, 48000, EBUR128_MODE_SAMPLE_PEAK | EBUR128_MODE_M | EBUR128_MODE_S | EBUR128_MODE_I | EBUR128_MODE_LRA);
 151 }
 152
 153 Mixer::~Mixer()
 154 {
 155         resource_pool->release_glsl_program(cbcr_program_num);
 156         BMUSBCapture::stop_bm_thread();
 157
 158         for (int 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         ebur128_destroy(&r128_state);
 168 }
 169
 170 namespace {
 171
 172 int unwrap_timecode(uint16_t current_wrapped, int last)
 173 {
 174         uint16_t last_wrapped = last & 0xffff;
 175         if (current_wrapped > last_wrapped) {
 176                 return (last & ~0xffff) | current_wrapped;
 177         } else {
 178                 return 0x10000 + ((last & ~0xffff) | current_wrapped);
 179         }
 180 }
 181
 182 }  // namespace
 183
 184 void Mixer::bm_frame(int card_index, uint16_t timecode,
 185                      FrameAllocator::Frame video_frame, size_t video_offset, uint16_t video_format,
 186                      FrameAllocator::Frame audio_frame, size_t audio_offset, uint16_t audio_format)
 187 {
 188         CaptureCard *card = &cards[card_index];
 189
 190         if (audio_frame.len - audio_offset > 30000) {
 191                 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",
 192                         card_index, int(audio_frame.len), int(audio_offset),
 193                         timecode, int(video_frame.len), int(video_offset), video_format);
 194                 if (video_frame.owner) {
 195                         video_frame.owner->release_frame(video_frame);
 196                 }
 197                 if (audio_frame.owner) {
 198                         audio_frame.owner->release_frame(audio_frame);
 199                 }
 200                 return;
 201         }
 202
 203         // Convert the audio to stereo fp32 and add it.
 204         size_t num_samples = (audio_frame.len - audio_offset) / 8 / 3;
 205         vector<float> audio;
 206         audio.resize(num_samples * 2);
 207         convert_fixed24_to_fp32(&audio[0], 2, audio_frame.data + audio_offset, 8, num_samples);
 208
 209         int unwrapped_timecode = timecode;
 210         int dropped_frames = 0;
 211         if (card->last_timecode != -1) {
 212                 unwrapped_timecode = unwrap_timecode(unwrapped_timecode, card->last_timecode);
 213                 dropped_frames = unwrapped_timecode - card->last_timecode - 1;
 214         }
 215         card->last_timecode = unwrapped_timecode;
 216
 217         // Add the audio.
 218         {
 219                 unique_lock<mutex> lock(card->audio_mutex);
 220
 221                 int unwrapped_timecode = timecode;
 222                 if (dropped_frames > 60 * 2) {
 223                         fprintf(stderr, "Card %d lost more than two seconds (or time code jumping around), resetting resampler\n",
 224                                 card_index);
 225                         card->resampler.reset(new Resampler(48000.0, 48000.0, 2));
 226                 } else if (dropped_frames > 0) {
 227                         // Insert silence as needed.
 228                         fprintf(stderr, "Card %d dropped %d frame(s) (before timecode 0x%04x), inserting silence.\n",
 229                                 card_index, dropped_frames, timecode);
 230                         vector<float> silence;
 231                         silence.resize((48000 / 60) * 2);
 232                         for (int i = 0; i < dropped_frames; ++i) {
 233                                 card->resampler->add_input_samples((unwrapped_timecode - dropped_frames + i) / 60.0, silence.data(), (48000 / 60));
 234                         }
 235                 }
 236                 card->resampler->add_input_samples(unwrapped_timecode / 60.0, audio.data(), num_samples);
 237         }
 238
 239         // Done with the audio, so release it.
 240         if (audio_frame.owner) {
 241                 audio_frame.owner->release_frame(audio_frame);
 242         }
 243
 244         {
 245                 // Wait until the previous frame was consumed.
 246                 unique_lock<mutex> lock(bmusb_mutex);
 247                 card->new_data_ready_changed.wait(lock, [card]{ return !card->new_data_ready || card->should_quit; });
 248                 if (card->should_quit) return;
 249         }
 250
 251         if (video_frame.len - video_offset != WIDTH * (HEIGHT+EXTRAHEIGHT) * 2) {
 252                 if (video_frame.len != 0) {
 253                         printf("Card %d: Dropping video frame with wrong length (%ld)\n",
 254                                 card_index, video_frame.len - video_offset);
 255                 }
 256                 if (video_frame.owner) {
 257                         video_frame.owner->release_frame(video_frame);
 258                 }
 259
 260                 // Still send on the information that we _had_ a frame, even though it's corrupted,
 261                 // so that pts can go up accordingly.
 262                 {
 263                         unique_lock<mutex> lock(bmusb_mutex);
 264                         card->new_data_ready = true;
 265                         card->new_frame = RefCountedFrame(FrameAllocator::Frame());
 266                         card->new_data_ready_fence = nullptr;
 267                         card->dropped_frames = dropped_frames;
 268                         card->new_data_ready_changed.notify_all();
 269                 }
 270                 return;
 271         }
 272
 273         const PBOFrameAllocator::Userdata *userdata = (const PBOFrameAllocator::Userdata *)video_frame.userdata;
 274         GLuint pbo = userdata->pbo;
 275         check_error();
 276         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
 277         check_error();
 278         glFlushMappedBufferRange(GL_PIXEL_UNPACK_BUFFER, 0, video_frame.size);
 279         check_error();
 280         //glMemoryBarrier(GL_CLIENT_MAPPED_BUFFER_BARRIER_BIT);
 281         //check_error();
 282
 283         // Upload the textures.
 284         glBindTexture(GL_TEXTURE_2D, userdata->tex_y);
 285         check_error();
 286         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));
 287         check_error();
 288         glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr);
 289         check_error();
 290         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, WIDTH/2, HEIGHT, GL_RG, GL_UNSIGNED_BYTE, BUFFER_OFFSET(WIDTH * 25 + 22));
 291         check_error();
 292         glBindTexture(GL_TEXTURE_2D, 0);
 293         check_error();
 294         GLsync fence = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
 295         check_error();
 296         assert(fence != nullptr);
 297
 298         {
 299                 unique_lock<mutex> lock(bmusb_mutex);
 300                 card->new_data_ready = true;
 301                 card->new_frame = RefCountedFrame(video_frame);
 302                 card->new_data_ready_fence = fence;
 303                 card->dropped_frames = dropped_frames;
 304                 card->new_data_ready_changed.notify_all();
 305         }
 306 }
 307
 308 void Mixer::thread_func()
 309 {
 310         eglBindAPI(EGL_OPENGL_API);
 311         QOpenGLContext *context = create_context();
 312         if (!make_current(context, mixer_surface)) {
 313                 printf("oops\n");
 314                 exit(1);
 315         }
 316
 317         struct timespec start, now;
 318         clock_gettime(CLOCK_MONOTONIC, &start);
 319
 320         int frame = 0;
 321         int dropped_frames = 0;
 322
 323         while (!should_quit) {
 324                 CaptureCard card_copy[NUM_CARDS];
 325
 326                 {
 327                         unique_lock<mutex> lock(bmusb_mutex);
 328
 329                         // The first card is the master timer, so wait for it to have a new frame.
 330                         // TODO: Make configurable, and with a timeout.
 331                         cards[0].new_data_ready_changed.wait(lock, [this]{ return cards[0].new_data_ready; });
 332
 333                         for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
 334                                 CaptureCard *card = &cards[card_index];
 335                                 card_copy[card_index].usb = card->usb;
 336                                 card_copy[card_index].new_data_ready = card->new_data_ready;
 337                                 card_copy[card_index].new_frame = card->new_frame;
 338                                 card_copy[card_index].new_data_ready_fence = card->new_data_ready_fence;
 339                                 card_copy[card_index].new_frame_audio = move(card->new_frame_audio);
 340                                 card_copy[card_index].dropped_frames = card->dropped_frames;
 341                                 card->new_data_ready = false;
 342                                 card->new_data_ready_changed.notify_all();
 343                         }
 344                 }
 345
 346                 // Resample the audio as needed, including from previously dropped frames.
 347                 vector<float> samples_out;
 348                 // TODO: Allow using audio from the other card(s) as well.
 349                 for (unsigned frame_num = 0; frame_num < card_copy[0].dropped_frames + 1; ++frame_num) {
 350                         for (unsigned card_index = 0; card_index < NUM_CARDS; ++card_index) {
 351                                 samples_out.resize((48000 / 60) * 2);
 352                                 {
 353                                         unique_lock<mutex> lock(cards[card_index].audio_mutex);
 354                                         if (!cards[card_index].resampler->get_output_samples(pts(), &samples_out[0], 48000 / 60)) {
 355                                                 printf("Card %d reported previous underrun.\n", card_index);
 356                                         }
 357                                 }
 358                                 if (card_index == 0) {
 359                                         ebur128_add_frames_float(r128_state, samples_out.data(), samples_out.size() / 2);
 360                                         h264_encoder->add_audio(pts_int, move(samples_out));
 361                                 }
 362                         }
 363                         if (frame_num != card_copy[0].dropped_frames) {
 364                                 // For dropped frames, increase the pts.
 365                                 ++dropped_frames;
 366                                 pts_int += TIMEBASE / 60;
 367                         }
 368                 }
 369
 370                 if (audio_level_callback != nullptr) {
 371                         double loudness_s;
 372                         ebur128_loudness_shortterm(r128_state, &loudness_s);
 373                         audio_level_callback(loudness_s);
 374                 }
 375
 376                 // If the first card is reporting a corrupted or otherwise dropped frame,
 377                 // just increase the pts (skipping over this frame) and don't try to compute anything new.
 378                 if (card_copy[0].new_frame->len == 0) {
 379                         ++dropped_frames;
 380                         pts_int += TIMEBASE / 60;
 381                         continue;
 382                 }
 383
 384                 for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
 385                         CaptureCard *card = &card_copy[card_index];
 386                         if (!card->new_data_ready || card->new_frame->len == 0)
 387                                 continue;
 388
 389                         assert(card->new_frame != nullptr);
 390                         bmusb_current_rendering_frame[card_index] = card->new_frame;
 391                         check_error();
 392
 393                         // The new texture might still be uploaded,
 394                         // tell the GPU to wait until it's there.
 395                         if (card->new_data_ready_fence) {
 396                                 glWaitSync(card->new_data_ready_fence, /*flags=*/0, GL_TIMEOUT_IGNORED);
 397                                 check_error();
 398                                 glDeleteSync(card->new_data_ready_fence);
 399                                 check_error();
 400                         }
 401                         const PBOFrameAllocator::Userdata *userdata = (const PBOFrameAllocator::Userdata *)card->new_frame->userdata;
 402                         theme->set_input_textures(card_index, userdata->tex_y, userdata->tex_cbcr);
 403                 }
 404
 405                 // Get the main chain from the theme, and set its state immediately.
 406                 pair<EffectChain *, function<void()>> theme_main_chain = theme->get_chain(0, pts(), WIDTH, HEIGHT);
 407                 EffectChain *chain = theme_main_chain.first;
 408                 theme_main_chain.second();
 409
 410                 GLuint y_tex, cbcr_tex;
 411                 bool got_frame = h264_encoder->begin_frame(&y_tex, &cbcr_tex);
 412                 assert(got_frame);
 413
 414                 // Render main chain.
 415                 GLuint cbcr_full_tex = resource_pool->create_2d_texture(GL_RG8, WIDTH, HEIGHT);
 416                 GLuint rgba_tex = resource_pool->create_2d_texture(GL_RGB565, WIDTH, HEIGHT);  // Saves texture bandwidth, although dithering gets messed up.
 417                 GLuint fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex, rgba_tex);
 418                 chain->render_to_fbo(fbo, WIDTH, HEIGHT);
 419                 resource_pool->release_fbo(fbo);
 420
 421                 subsample_chroma(cbcr_full_tex, cbcr_tex);
 422                 resource_pool->release_2d_texture(cbcr_full_tex);
 423
 424                 // Set the right state for rgba_tex.
 425                 glBindFramebuffer(GL_FRAMEBUFFER, 0);
 426                 glBindTexture(GL_TEXTURE_2D, rgba_tex);
 427                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 428                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 429                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 430
 431                 RefCountedGLsync fence(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
 432                 check_error();
 433
 434                 // Make sure the H.264 gets a reference to all the
 435                 // input frames needed, so that they are not released back
 436                 // until the rendering is done.
 437                 vector<RefCountedFrame> input_frames;
 438                 for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
 439                         input_frames.push_back(bmusb_current_rendering_frame[card_index]);
 440                 }
 441                 const int64_t av_delay = TIMEBASE / 10;  // Corresponds to the fixed delay in resampler.h. TODO: Make less hard-coded.
 442                 h264_encoder->end_frame(fence, pts_int + av_delay, input_frames);
 443                 ++frame;
 444                 pts_int += TIMEBASE / 60;
 445
 446                 // The live frame just shows the RGBA texture we just rendered.
 447                 // It owns rgba_tex now.
 448                 DisplayFrame live_frame;
 449                 live_frame.chain = display_chain.get();
 450                 live_frame.setup_chain = [this, rgba_tex]{
 451                         display_input->set_texture_num(rgba_tex);
 452                 };
 453                 live_frame.ready_fence = fence;
 454                 live_frame.input_frames = {};
 455                 live_frame.temp_textures = { rgba_tex };
 456                 output_channel[OUTPUT_LIVE].output_frame(live_frame);
 457
 458                 // Set up preview and any additional channels.
 459                 for (int i = 1; i < theme->get_num_channels() + 2; ++i) {
 460                         DisplayFrame display_frame;
 461                         pair<EffectChain *, function<void()>> chain = theme->get_chain(i, pts(), WIDTH, HEIGHT);  // FIXME: dimensions
 462                         display_frame.chain = chain.first;
 463                         display_frame.setup_chain = chain.second;
 464                         display_frame.ready_fence = fence;
 465                         display_frame.input_frames = { bmusb_current_rendering_frame[0], bmusb_current_rendering_frame[1] };  // FIXME: possible to do better?
 466                         display_frame.temp_textures = {};
 467                         output_channel[i].output_frame(display_frame);
 468                 }
 469
 470                 clock_gettime(CLOCK_MONOTONIC, &now);
 471                 double elapsed = now.tv_sec - start.tv_sec +
 472                         1e-9 * (now.tv_nsec - start.tv_nsec);
 473                 if (frame % 100 == 0) {
 474                         printf("%d frames (%d dropped) in %.3f seconds = %.1f fps (%.1f ms/frame)\n",
 475                                 frame, dropped_frames, elapsed, frame / elapsed,
 476                                 1e3 * elapsed / frame);
 477                 //      chain->print_phase_timing();
 478                 }
 479
 480 #if 0
 481                 // Reset every 100 frames, so that local variations in frame times
 482                 // (especially for the first few frames, when the shaders are
 483                 // compiled etc.) don't make it hard to measure for the entire
 484                 // remaining duration of the program.
 485                 if (frame == 10000) {
 486                         frame = 0;
 487                         start = now;
 488                 }
 489 #endif
 490                 check_error();
 491         }
 492
 493         resource_pool->clean_context();
 494 }
 495
 496 void Mixer::subsample_chroma(GLuint src_tex, GLuint dst_tex)
 497 {
 498         GLuint vao;
 499         glGenVertexArrays(1, &vao);
 500         check_error();
 501
 502         float vertices[] = {
 503                 0.0f, 2.0f,
 504                 0.0f, 0.0f,
 505                 2.0f, 0.0f
 506         };
 507
 508         glBindVertexArray(vao);
 509         check_error();
 510
 511         // Extract Cb/Cr.
 512         GLuint fbo = resource_pool->create_fbo(dst_tex);
 513         glBindFramebuffer(GL_FRAMEBUFFER, fbo);
 514         glViewport(0, 0, WIDTH/2, HEIGHT/2);
 515         check_error();
 516
 517         glUseProgram(cbcr_program_num);
 518         check_error();
 519
 520         glActiveTexture(GL_TEXTURE0);
 521         check_error();
 522         glBindTexture(GL_TEXTURE_2D, src_tex);
 523         check_error();
 524         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 525         check_error();
 526         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 527         check_error();
 528         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 529         check_error();
 530
 531         float chroma_offset_0[] = { -0.5f / WIDTH, 0.0f };
 532         set_uniform_vec2(cbcr_program_num, "foo", "chroma_offset_0", chroma_offset_0);
 533
 534         GLuint position_vbo = fill_vertex_attribute(cbcr_program_num, "position", 2, GL_FLOAT, sizeof(vertices), vertices);
 535         GLuint texcoord_vbo = fill_vertex_attribute(cbcr_program_num, "texcoord", 2, GL_FLOAT, sizeof(vertices), vertices);  // Same as vertices.
 536
 537         glDrawArrays(GL_TRIANGLES, 0, 3);
 538         check_error();
 539
 540         cleanup_vertex_attribute(cbcr_program_num, "position", position_vbo);
 541         cleanup_vertex_attribute(cbcr_program_num, "texcoord", texcoord_vbo);
 542
 543         glUseProgram(0);
 544         check_error();
 545
 546         resource_pool->release_fbo(fbo);
 547         glDeleteVertexArrays(1, &vao);
 548 }
 549
 550 void Mixer::release_display_frame(DisplayFrame *frame)
 551 {
 552         for (GLuint texnum : frame->temp_textures) {
 553                 resource_pool->release_2d_texture(texnum);
 554         }
 555         frame->temp_textures.clear();
 556         frame->ready_fence.reset();
 557         frame->input_frames.clear();
 558 }
 559
 560 void Mixer::start()
 561 {
 562         mixer_thread = thread(&Mixer::thread_func, this);
 563 }
 564
 565 void Mixer::quit()
 566 {
 567         should_quit = true;
 568         mixer_thread.join();
 569 }
 570
 571 void Mixer::transition_clicked(int transition_num)
 572 {
 573         theme->transition_clicked(transition_num, pts());
 574 }
 575
 576 void Mixer::channel_clicked(int preview_num)
 577 {
 578         theme->channel_clicked(preview_num);
 579 }
 580
 581 Mixer::OutputChannel::~OutputChannel()
 582 {
 583         if (has_current_frame) {
 584                 parent->release_display_frame(&current_frame);
 585         }
 586         if (has_ready_frame) {
 587                 parent->release_display_frame(&ready_frame);
 588         }
 589 }
 590
 591 void Mixer::OutputChannel::output_frame(DisplayFrame frame)
 592 {
 593         // Store this frame for display. Remove the ready frame if any
 594         // (it was seemingly never used).
 595         {
 596                 unique_lock<mutex> lock(frame_mutex);
 597                 if (has_ready_frame) {
 598                         parent->release_display_frame(&ready_frame);
 599                 }
 600                 ready_frame = frame;
 601                 has_ready_frame = true;
 602         }
 603
 604         if (has_new_frame_ready_callback) {
 605                 new_frame_ready_callback();
 606         }
 607 }
 608
 609 bool Mixer::OutputChannel::get_display_frame(DisplayFrame *frame)
 610 {
 611         unique_lock<mutex> lock(frame_mutex);
 612         if (!has_current_frame && !has_ready_frame) {
 613                 return false;
 614         }
 615
 616         if (has_current_frame && has_ready_frame) {
 617                 // We have a new ready frame. Toss the current one.
 618                 parent->release_display_frame(&current_frame);
 619                 has_current_frame = false;
 620         }
 621         if (has_ready_frame) {
 622                 assert(!has_current_frame);
 623                 current_frame = ready_frame;
 624                 ready_frame.ready_fence.reset();  // Drop the refcount.
 625                 ready_frame.input_frames.clear();  // Drop the refcounts.
 626                 has_current_frame = true;
 627                 has_ready_frame = false;
 628         }
 629
 630         *frame = current_frame;
 631         return true;
 632 }
 633
 634 void Mixer::OutputChannel::set_frame_ready_callback(Mixer::new_frame_ready_callback_t callback)
 635 {
 636         new_frame_ready_callback = callback;
 637         has_new_frame_ready_callback = true;
 638 }