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.init(2, 48000);
 151         r128.integr_start();
 152 }
 153
 154 Mixer::~Mixer()
 155 {
 156         resource_pool->release_glsl_program(cbcr_program_num);
 157         BMUSBCapture::stop_bm_thread();
 158
 159         for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
 160                 {
 161                         unique_lock<mutex> lock(bmusb_mutex);
 162                         cards[card_index].should_quit = true;  // Unblock thread.
 163                         cards[card_index].new_data_ready_changed.notify_all();
 164                 }
 165                 cards[card_index].usb->stop_dequeue_thread();
 166         }
 167 }
 168
 169 namespace {
 170
 171 int unwrap_timecode(uint16_t current_wrapped, int last)
 172 {
 173         uint16_t last_wrapped = last & 0xffff;
 174         if (current_wrapped > last_wrapped) {
 175                 return (last & ~0xffff) | current_wrapped;
 176         } else {
 177                 return 0x10000 + ((last & ~0xffff) | current_wrapped);
 178         }
 179 }
 180
 181 float find_peak(const vector<float> &samples)
 182 {
 183         float m = fabs(samples[0]);
 184         for (size_t i = 1; i < samples.size(); ++i) {
 185                 m = std::max(m, fabs(samples[i]));
 186         }
 187         return m;
 188 }
 189
 190 void deinterleave_samples(const vector<float> &in, vector<float> *out_l, vector<float> *out_r)
 191 {
 192         size_t num_samples = in.size() / 2;
 193         out_l->resize(num_samples);
 194         out_r->resize(num_samples);
 195
 196         const float *inptr = in.data();
 197         float *lptr = &(*out_l)[0];
 198         float *rptr = &(*out_r)[0];
 199         for (size_t i = 0; i < num_samples; ++i) {
 200                 *lptr++ = *inptr++;
 201                 *rptr++ = *inptr++;
 202         }
 203 }
 204
 205 }  // namespace
 206
 207 void Mixer::bm_frame(int card_index, uint16_t timecode,
 208                      FrameAllocator::Frame video_frame, size_t video_offset, uint16_t video_format,
 209                      FrameAllocator::Frame audio_frame, size_t audio_offset, uint16_t audio_format)
 210 {
 211         CaptureCard *card = &cards[card_index];
 212
 213         if (audio_frame.len - audio_offset > 30000) {
 214                 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",
 215                         card_index, int(audio_frame.len), int(audio_offset),
 216                         timecode, int(video_frame.len), int(video_offset), video_format);
 217                 if (video_frame.owner) {
 218                         video_frame.owner->release_frame(video_frame);
 219                 }
 220                 if (audio_frame.owner) {
 221                         audio_frame.owner->release_frame(audio_frame);
 222                 }
 223                 return;
 224         }
 225
 226         // Convert the audio to stereo fp32 and add it.
 227         size_t num_samples = (audio_frame.len - audio_offset) / 8 / 3;
 228         vector<float> audio;
 229         audio.resize(num_samples * 2);
 230         convert_fixed24_to_fp32(&audio[0], 2, audio_frame.data + audio_offset, 8, num_samples);
 231
 232         int unwrapped_timecode = timecode;
 233         int dropped_frames = 0;
 234         if (card->last_timecode != -1) {
 235                 unwrapped_timecode = unwrap_timecode(unwrapped_timecode, card->last_timecode);
 236                 dropped_frames = unwrapped_timecode - card->last_timecode - 1;
 237         }
 238         card->last_timecode = unwrapped_timecode;
 239
 240         // Add the audio.
 241         {
 242                 unique_lock<mutex> lock(card->audio_mutex);
 243
 244                 int unwrapped_timecode = timecode;
 245                 if (dropped_frames > 60 * 2) {
 246                         fprintf(stderr, "Card %d lost more than two seconds (or time code jumping around), resetting resampler\n",
 247                                 card_index);
 248                         card->resampler.reset(new Resampler(48000.0, 48000.0, 2));
 249                 } else if (dropped_frames > 0) {
 250                         // Insert silence as needed.
 251                         fprintf(stderr, "Card %d dropped %d frame(s) (before timecode 0x%04x), inserting silence.\n",
 252                                 card_index, dropped_frames, timecode);
 253                         vector<float> silence;
 254                         silence.resize((48000 / 60) * 2);
 255                         for (int i = 0; i < dropped_frames; ++i) {
 256                                 card->resampler->add_input_samples((unwrapped_timecode - dropped_frames + i) / 60.0, silence.data(), (48000 / 60));
 257                         }
 258                 }
 259                 card->resampler->add_input_samples(unwrapped_timecode / 60.0, audio.data(), num_samples);
 260         }
 261
 262         // Done with the audio, so release it.
 263         if (audio_frame.owner) {
 264                 audio_frame.owner->release_frame(audio_frame);
 265         }
 266
 267         {
 268                 // Wait until the previous frame was consumed.
 269                 unique_lock<mutex> lock(bmusb_mutex);
 270                 card->new_data_ready_changed.wait(lock, [card]{ return !card->new_data_ready || card->should_quit; });
 271                 if (card->should_quit) return;
 272         }
 273
 274         if (video_frame.len - video_offset != WIDTH * (HEIGHT+EXTRAHEIGHT) * 2) {
 275                 if (video_frame.len != 0) {
 276                         printf("Card %d: Dropping video frame with wrong length (%ld)\n",
 277                                 card_index, video_frame.len - video_offset);
 278                 }
 279                 if (video_frame.owner) {
 280                         video_frame.owner->release_frame(video_frame);
 281                 }
 282
 283                 // Still send on the information that we _had_ a frame, even though it's corrupted,
 284                 // so that pts can go up accordingly.
 285                 {
 286                         unique_lock<mutex> lock(bmusb_mutex);
 287                         card->new_data_ready = true;
 288                         card->new_frame = RefCountedFrame(FrameAllocator::Frame());
 289                         card->new_data_ready_fence = nullptr;
 290                         card->dropped_frames = dropped_frames;
 291                         card->new_data_ready_changed.notify_all();
 292                 }
 293                 return;
 294         }
 295
 296         const PBOFrameAllocator::Userdata *userdata = (const PBOFrameAllocator::Userdata *)video_frame.userdata;
 297         GLuint pbo = userdata->pbo;
 298         check_error();
 299         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
 300         check_error();
 301         glFlushMappedBufferRange(GL_PIXEL_UNPACK_BUFFER, 0, video_frame.size);
 302         check_error();
 303         //glMemoryBarrier(GL_CLIENT_MAPPED_BUFFER_BARRIER_BIT);
 304         //check_error();
 305
 306         // Upload the textures.
 307         glBindTexture(GL_TEXTURE_2D, userdata->tex_y);
 308         check_error();
 309         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));
 310         check_error();
 311         glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr);
 312         check_error();
 313         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, WIDTH/2, HEIGHT, GL_RG, GL_UNSIGNED_BYTE, BUFFER_OFFSET(WIDTH * 25 + 22));
 314         check_error();
 315         glBindTexture(GL_TEXTURE_2D, 0);
 316         check_error();
 317         GLsync fence = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
 318         check_error();
 319         assert(fence != nullptr);
 320
 321         {
 322                 unique_lock<mutex> lock(bmusb_mutex);
 323                 card->new_data_ready = true;
 324                 card->new_frame = RefCountedFrame(video_frame);
 325                 card->new_data_ready_fence = fence;
 326                 card->dropped_frames = dropped_frames;
 327                 card->new_data_ready_changed.notify_all();
 328         }
 329 }
 330
 331 void Mixer::thread_func()
 332 {
 333         eglBindAPI(EGL_OPENGL_API);
 334         QOpenGLContext *context = create_context();
 335         if (!make_current(context, mixer_surface)) {
 336                 printf("oops\n");
 337                 exit(1);
 338         }
 339
 340         struct timespec start, now;
 341         clock_gettime(CLOCK_MONOTONIC, &start);
 342
 343         int frame = 0;
 344         int dropped_frames = 0;
 345
 346         while (!should_quit) {
 347                 CaptureCard card_copy[NUM_CARDS];
 348
 349                 {
 350                         unique_lock<mutex> lock(bmusb_mutex);
 351
 352                         // The first card is the master timer, so wait for it to have a new frame.
 353                         // TODO: Make configurable, and with a timeout.
 354                         cards[0].new_data_ready_changed.wait(lock, [this]{ return cards[0].new_data_ready; });
 355
 356                         for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
 357                                 CaptureCard *card = &cards[card_index];
 358                                 card_copy[card_index].usb = card->usb;
 359                                 card_copy[card_index].new_data_ready = card->new_data_ready;
 360                                 card_copy[card_index].new_frame = card->new_frame;
 361                                 card_copy[card_index].new_data_ready_fence = card->new_data_ready_fence;
 362                                 card_copy[card_index].new_frame_audio = move(card->new_frame_audio);
 363                                 card_copy[card_index].dropped_frames = card->dropped_frames;
 364                                 card->new_data_ready = false;
 365                                 card->new_data_ready_changed.notify_all();
 366                         }
 367                 }
 368
 369                 // Resample the audio as needed, including from previously dropped frames.
 370                 vector<float> samples_out;
 371                 // TODO: Allow using audio from the other card(s) as well.
 372                 for (unsigned frame_num = 0; frame_num < card_copy[0].dropped_frames + 1; ++frame_num) {
 373                         for (unsigned card_index = 0; card_index < NUM_CARDS; ++card_index) {
 374                                 samples_out.resize((48000 / 60) * 2);
 375                                 {
 376                                         unique_lock<mutex> lock(cards[card_index].audio_mutex);
 377                                         if (!cards[card_index].resampler->get_output_samples(pts(), &samples_out[0], 48000 / 60)) {
 378                                                 printf("Card %d reported previous underrun.\n", card_index);
 379                                         }
 380                                 }
 381                                 if (card_index == 0) {
 382                                         vector<float> left, right;
 383                                         peak = std::max(peak, find_peak(samples_out));
 384                                         deinterleave_samples(samples_out, &left, &right);
 385                                         float *ptrs[] = { left.data(), right.data() };
 386                                         r128.process(left.size(), ptrs);
 387                                         h264_encoder->add_audio(pts_int, move(samples_out));
 388                                 }
 389                         }
 390                         if (frame_num != card_copy[0].dropped_frames) {
 391                                 // For dropped frames, increase the pts.
 392                                 ++dropped_frames;
 393                                 pts_int += TIMEBASE / 60;
 394                         }
 395                 }
 396
 397                 if (audio_level_callback != nullptr) {
 398                         double loudness_s = r128.loudness_S();
 399                         double loudness_i = r128.integrated();
 400                         double loudness_range_low = r128.range_min();
 401                         double loudness_range_high = r128.range_max();
 402
 403                         audio_level_callback(loudness_s, 20.0 * log10(peak),
 404                                              loudness_i, loudness_range_low, loudness_range_high);
 405                 }
 406
 407                 // If the first card is reporting a corrupted or otherwise dropped frame,
 408                 // just increase the pts (skipping over this frame) and don't try to compute anything new.
 409                 if (card_copy[0].new_frame->len == 0) {
 410                         ++dropped_frames;
 411                         pts_int += TIMEBASE / 60;
 412                         continue;
 413                 }
 414
 415                 for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
 416                         CaptureCard *card = &card_copy[card_index];
 417                         if (!card->new_data_ready || card->new_frame->len == 0)
 418                                 continue;
 419
 420                         assert(card->new_frame != nullptr);
 421                         bmusb_current_rendering_frame[card_index] = card->new_frame;
 422                         check_error();
 423
 424                         // The new texture might still be uploaded,
 425                         // tell the GPU to wait until it's there.
 426                         if (card->new_data_ready_fence) {
 427                                 glWaitSync(card->new_data_ready_fence, /*flags=*/0, GL_TIMEOUT_IGNORED);
 428                                 check_error();
 429                                 glDeleteSync(card->new_data_ready_fence);
 430                                 check_error();
 431                         }
 432                         const PBOFrameAllocator::Userdata *userdata = (const PBOFrameAllocator::Userdata *)card->new_frame->userdata;
 433                         theme->set_input_textures(card_index, userdata->tex_y, userdata->tex_cbcr);
 434                 }
 435
 436                 // Get the main chain from the theme, and set its state immediately.
 437                 pair<EffectChain *, function<void()>> theme_main_chain = theme->get_chain(0, pts(), WIDTH, HEIGHT);
 438                 EffectChain *chain = theme_main_chain.first;
 439                 theme_main_chain.second();
 440
 441                 GLuint y_tex, cbcr_tex;
 442                 bool got_frame = h264_encoder->begin_frame(&y_tex, &cbcr_tex);
 443                 assert(got_frame);
 444
 445                 // Render main chain.
 446                 GLuint cbcr_full_tex = resource_pool->create_2d_texture(GL_RG8, WIDTH, HEIGHT);
 447                 GLuint rgba_tex = resource_pool->create_2d_texture(GL_RGB565, WIDTH, HEIGHT);  // Saves texture bandwidth, although dithering gets messed up.
 448                 GLuint fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex, rgba_tex);
 449                 check_error();
 450                 chain->render_to_fbo(fbo, WIDTH, HEIGHT);
 451                 resource_pool->release_fbo(fbo);
 452
 453                 subsample_chroma(cbcr_full_tex, cbcr_tex);
 454                 resource_pool->release_2d_texture(cbcr_full_tex);
 455
 456                 // Set the right state for rgba_tex.
 457                 glBindFramebuffer(GL_FRAMEBUFFER, 0);
 458                 glBindTexture(GL_TEXTURE_2D, rgba_tex);
 459                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 460                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 461                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 462
 463                 RefCountedGLsync fence(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
 464                 check_error();
 465
 466                 // Make sure the H.264 gets a reference to all the
 467                 // input frames needed, so that they are not released back
 468                 // until the rendering is done.
 469                 vector<RefCountedFrame> input_frames;
 470                 for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
 471                         input_frames.push_back(bmusb_current_rendering_frame[card_index]);
 472                 }
 473                 const int64_t av_delay = TIMEBASE / 10;  // Corresponds to the fixed delay in resampler.h. TODO: Make less hard-coded.
 474                 h264_encoder->end_frame(fence, pts_int + av_delay, input_frames);
 475                 ++frame;
 476                 pts_int += TIMEBASE / 60;
 477
 478                 // The live frame just shows the RGBA texture we just rendered.
 479                 // It owns rgba_tex now.
 480                 DisplayFrame live_frame;
 481                 live_frame.chain = display_chain.get();
 482                 live_frame.setup_chain = [this, rgba_tex]{
 483                         display_input->set_texture_num(rgba_tex);
 484                 };
 485                 live_frame.ready_fence = fence;
 486                 live_frame.input_frames = {};
 487                 live_frame.temp_textures = { rgba_tex };
 488                 output_channel[OUTPUT_LIVE].output_frame(live_frame);
 489
 490                 // Set up preview and any additional channels.
 491                 for (int i = 1; i < theme->get_num_channels() + 2; ++i) {
 492                         DisplayFrame display_frame;
 493                         pair<EffectChain *, function<void()>> chain = theme->get_chain(i, pts(), WIDTH, HEIGHT);  // FIXME: dimensions
 494                         display_frame.chain = chain.first;
 495                         display_frame.setup_chain = chain.second;
 496                         display_frame.ready_fence = fence;
 497                         display_frame.input_frames = { bmusb_current_rendering_frame[0], bmusb_current_rendering_frame[1] };  // FIXME: possible to do better?
 498                         display_frame.temp_textures = {};
 499                         output_channel[i].output_frame(display_frame);
 500                 }
 501
 502                 clock_gettime(CLOCK_MONOTONIC, &now);
 503                 double elapsed = now.tv_sec - start.tv_sec +
 504                         1e-9 * (now.tv_nsec - start.tv_nsec);
 505                 if (frame % 100 == 0) {
 506                         printf("%d frames (%d dropped) in %.3f seconds = %.1f fps (%.1f ms/frame)\n",
 507                                 frame, dropped_frames, elapsed, frame / elapsed,
 508                                 1e3 * elapsed / frame);
 509                 //      chain->print_phase_timing();
 510                 }
 511
 512 #if 0
 513                 // Reset every 100 frames, so that local variations in frame times
 514                 // (especially for the first few frames, when the shaders are
 515                 // compiled etc.) don't make it hard to measure for the entire
 516                 // remaining duration of the program.
 517                 if (frame == 10000) {
 518                         frame = 0;
 519                         start = now;
 520                 }
 521 #endif
 522                 check_error();
 523         }
 524
 525         resource_pool->clean_context();
 526 }
 527
 528 void Mixer::subsample_chroma(GLuint src_tex, GLuint dst_tex)
 529 {
 530         GLuint vao;
 531         glGenVertexArrays(1, &vao);
 532         check_error();
 533
 534         float vertices[] = {
 535                 0.0f, 2.0f,
 536                 0.0f, 0.0f,
 537                 2.0f, 0.0f
 538         };
 539
 540         glBindVertexArray(vao);
 541         check_error();
 542
 543         // Extract Cb/Cr.
 544         GLuint fbo = resource_pool->create_fbo(dst_tex);
 545         glBindFramebuffer(GL_FRAMEBUFFER, fbo);
 546         glViewport(0, 0, WIDTH/2, HEIGHT/2);
 547         check_error();
 548
 549         glUseProgram(cbcr_program_num);
 550         check_error();
 551
 552         glActiveTexture(GL_TEXTURE0);
 553         check_error();
 554         glBindTexture(GL_TEXTURE_2D, src_tex);
 555         check_error();
 556         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 557         check_error();
 558         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 559         check_error();
 560         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 561         check_error();
 562
 563         float chroma_offset_0[] = { -0.5f / WIDTH, 0.0f };
 564         set_uniform_vec2(cbcr_program_num, "foo", "chroma_offset_0", chroma_offset_0);
 565
 566         GLuint position_vbo = fill_vertex_attribute(cbcr_program_num, "position", 2, GL_FLOAT, sizeof(vertices), vertices);
 567         GLuint texcoord_vbo = fill_vertex_attribute(cbcr_program_num, "texcoord", 2, GL_FLOAT, sizeof(vertices), vertices);  // Same as vertices.
 568
 569         glDrawArrays(GL_TRIANGLES, 0, 3);
 570         check_error();
 571
 572         cleanup_vertex_attribute(cbcr_program_num, "position", position_vbo);
 573         cleanup_vertex_attribute(cbcr_program_num, "texcoord", texcoord_vbo);
 574
 575         glUseProgram(0);
 576         check_error();
 577
 578         resource_pool->release_fbo(fbo);
 579         glDeleteVertexArrays(1, &vao);
 580 }
 581
 582 void Mixer::release_display_frame(DisplayFrame *frame)
 583 {
 584         for (GLuint texnum : frame->temp_textures) {
 585                 resource_pool->release_2d_texture(texnum);
 586         }
 587         frame->temp_textures.clear();
 588         frame->ready_fence.reset();
 589         frame->input_frames.clear();
 590 }
 591
 592 void Mixer::start()
 593 {
 594         mixer_thread = thread(&Mixer::thread_func, this);
 595 }
 596
 597 void Mixer::quit()
 598 {
 599         should_quit = true;
 600         mixer_thread.join();
 601 }
 602
 603 void Mixer::transition_clicked(int transition_num)
 604 {
 605         theme->transition_clicked(transition_num, pts());
 606 }
 607
 608 void Mixer::channel_clicked(int preview_num)
 609 {
 610         theme->channel_clicked(preview_num);
 611 }
 612
 613 Mixer::OutputChannel::~OutputChannel()
 614 {
 615         if (has_current_frame) {
 616                 parent->release_display_frame(&current_frame);
 617         }
 618         if (has_ready_frame) {
 619                 parent->release_display_frame(&ready_frame);
 620         }
 621 }
 622
 623 void Mixer::OutputChannel::output_frame(DisplayFrame frame)
 624 {
 625         // Store this frame for display. Remove the ready frame if any
 626         // (it was seemingly never used).
 627         {
 628                 unique_lock<mutex> lock(frame_mutex);
 629                 if (has_ready_frame) {
 630                         parent->release_display_frame(&ready_frame);
 631                 }
 632                 ready_frame = frame;
 633                 has_ready_frame = true;
 634         }
 635
 636         if (has_new_frame_ready_callback) {
 637                 new_frame_ready_callback();
 638         }
 639 }
 640
 641 bool Mixer::OutputChannel::get_display_frame(DisplayFrame *frame)
 642 {
 643         unique_lock<mutex> lock(frame_mutex);
 644         if (!has_current_frame && !has_ready_frame) {
 645                 return false;
 646         }
 647
 648         if (has_current_frame && has_ready_frame) {
 649                 // We have a new ready frame. Toss the current one.
 650                 parent->release_display_frame(&current_frame);
 651                 has_current_frame = false;
 652         }
 653         if (has_ready_frame) {
 654                 assert(!has_current_frame);
 655                 current_frame = ready_frame;
 656                 ready_frame.ready_fence.reset();  // Drop the refcount.
 657                 ready_frame.input_frames.clear();  // Drop the refcounts.
 658                 has_current_frame = true;
 659                 has_ready_frame = false;
 660         }
 661
 662         *frame = current_frame;
 663         return true;
 664 }
 665
 666 void Mixer::OutputChannel::set_frame_ready_callback(Mixer::new_frame_ready_callback_t callback)
 667 {
 668         new_frame_ready_callback = callback;
 669         has_new_frame_ready_callback = true;
 670 }