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

   1 #define WIDTH 1280
   2 #define HEIGHT 720
   3
   4 #undef Success
   5
   6 #include "mixer.h"
   7
   8 #include <assert.h>
   9 #include <effect.h>
  10 #include <effect_chain.h>
  11 #include <effect_util.h>
  12 #include <epoxy/egl.h>
  13 #include <features.h>
  14 #include <image_format.h>
  15 #include <init.h>
  16 #include <overlay_effect.h>
  17 #include <padding_effect.h>
  18 #include <resample_effect.h>
  19 #include <resource_pool.h>
  20 #include <saturation_effect.h>
  21 #include <stdint.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <sys/time.h>
  25 #include <time.h>
  26 #include <util.h>
  27 #include <white_balance_effect.h>
  28 #include <ycbcr.h>
  29 #include <ycbcr_input.h>
  30 #include <cmath>
  31 #include <condition_variable>
  32 #include <cstddef>
  33 #include <memory>
  34 #include <mutex>
  35 #include <string>
  36 #include <thread>
  37 #include <vector>
  38
  39 #include "bmusb.h"
  40 #include "context.h"
  41 #include "h264encode.h"
  42 #include "pbo_frame_allocator.h"
  43 #include "ref_counted_gl_sync.h"
  44
  45 class QOpenGLContext;
  46
  47 using namespace movit;
  48 using namespace std;
  49 using namespace std::placeholders;
  50
  51 Mixer *global_mixer = nullptr;
  52
  53 Mixer::Mixer(QSurface *surface1, QSurface *surface2, QSurface *surface3, QSurface *surface4)
  54         : surface1(surface1), surface2(surface2), surface3(surface3), surface4(surface4)
  55 {
  56         CHECK(init_movit(MOVIT_SHADER_DIR, MOVIT_DEBUG_OFF));
  57         check_error();
  58
  59         chain.reset(new EffectChain(WIDTH, HEIGHT));
  60         check_error();
  61
  62         ImageFormat inout_format;
  63         inout_format.color_space = COLORSPACE_sRGB;
  64         inout_format.gamma_curve = GAMMA_sRGB;
  65
  66         YCbCrFormat ycbcr_format;
  67         ycbcr_format.chroma_subsampling_x = 2;
  68         ycbcr_format.chroma_subsampling_y = 1;
  69         ycbcr_format.cb_x_position = 0.0;
  70         ycbcr_format.cr_x_position = 0.0;
  71         ycbcr_format.cb_y_position = 0.5;
  72         ycbcr_format.cr_y_position = 0.5;
  73         ycbcr_format.luma_coefficients = YCBCR_REC_601;
  74         ycbcr_format.full_range = false;
  75
  76         input[0] = new YCbCrInput(inout_format, ycbcr_format, WIDTH, HEIGHT, YCBCR_INPUT_SPLIT_Y_AND_CBCR);
  77         chain->add_input(input[0]);
  78         input[1] = new YCbCrInput(inout_format, ycbcr_format, WIDTH, HEIGHT, YCBCR_INPUT_SPLIT_Y_AND_CBCR);
  79         chain->add_input(input[1]);
  80         resample_effect = chain->add_effect(new ResampleEffect(), input[0]);
  81         padding_effect = chain->add_effect(new IntegralPaddingEffect());
  82         float border_color[] = { 0.0f, 0.0f, 0.0f, 1.0f };
  83         CHECK(padding_effect->set_vec4("border_color", border_color));
  84
  85         resample2_effect = chain->add_effect(new ResampleEffect(), input[1]);
  86         Effect *saturation_effect = chain->add_effect(new SaturationEffect());
  87         CHECK(saturation_effect->set_float("saturation", 0.3f));
  88         Effect *wb_effect = chain->add_effect(new WhiteBalanceEffect());
  89         CHECK(wb_effect->set_float("output_color_temperature", 3500.0));
  90         padding2_effect = chain->add_effect(new IntegralPaddingEffect());
  91
  92         chain->add_effect(new OverlayEffect(), padding_effect, padding2_effect);
  93
  94         ycbcr_format.chroma_subsampling_x = 1;
  95
  96         chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
  97         chain->add_ycbcr_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED, ycbcr_format, YCBCR_OUTPUT_SPLIT_Y_AND_CBCR);
  98         chain->set_dither_bits(8);
  99         chain->set_output_origin(OUTPUT_ORIGIN_TOP_LEFT);
 100         chain->finalize();
 101
 102         h264_encoder.reset(new H264Encoder(surface2, WIDTH, HEIGHT, "test.mp4"));
 103
 104         printf("Configuring first card...\n");
 105         cards[0].usb = new BMUSBCapture(0x1edb, 0xbd3b);  // 0xbd4f
 106         //cards[0].usb = new BMUSBCapture(0x1edb, 0xbd4f);
 107         cards[0].usb->set_frame_callback(std::bind(&Mixer::bm_frame, this, 0, _1, _2, _3, _4, _5, _6, _7));
 108         pbo_allocator1.reset(new PBOFrameAllocator(1280 * 750 * 2 + 44));
 109         cards[0].usb->set_video_frame_allocator(pbo_allocator1.get());
 110         cards[0].usb->configure_card();
 111
 112         pbo_allocator2.reset(new PBOFrameAllocator(1280 * 750 * 2 + 44));
 113         if (NUM_CARDS == 2) {
 114                 printf("Configuring second card...\n");
 115                 cards[1].usb = new BMUSBCapture(0x1edb, 0xbd4f);
 116                 cards[1].usb->set_frame_callback(std::bind(&Mixer::bm_frame, this, 1, _1, _2, _3, _4, _5, _6, _7));
 117                 cards[1].usb->set_video_frame_allocator(pbo_allocator2.get());
 118                 cards[1].usb->configure_card();
 119         }
 120
 121         BMUSBCapture::start_bm_thread();
 122
 123         for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
 124                 cards[card_index].usb->start_bm_capture();
 125         }
 126
 127         for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
 128                 bmusb_current_rendering_frame[card_index] =
 129                         cards[card_index].usb->get_video_frame_allocator()->alloc_frame();
 130                 GLint input_tex_pbo = (GLint)(intptr_t)bmusb_current_rendering_frame[card_index].userdata;
 131                 input[card_index]->set_pixel_data(0, nullptr, input_tex_pbo);
 132                 input[card_index]->set_pixel_data(1, nullptr, input_tex_pbo);
 133         }
 134
 135         //chain->enable_phase_timing(true);
 136
 137         // Set up stuff for NV12 conversion.
 138         resource_pool = chain->get_resource_pool();
 139
 140         // Cb/Cr shader.
 141         string cbcr_vert_shader = read_file("vs-cbcr.130.vert");
 142         string cbcr_frag_shader =
 143                 "#version 130 \n"
 144                 "in vec2 tc0; \n"
 145                 "uniform sampler2D cbcr_tex; \n"
 146                 "void main() { \n"
 147                 "    gl_FragColor = texture2D(cbcr_tex, tc0); \n"
 148                 "} \n";
 149         cbcr_program_num = resource_pool->compile_glsl_program(cbcr_vert_shader, cbcr_frag_shader);
 150 }
 151
 152 Mixer::~Mixer()
 153 {
 154         resource_pool->release_glsl_program(cbcr_program_num);
 155         BMUSBCapture::stop_bm_thread();
 156 }
 157
 158 void Mixer::bm_frame(int card_index, uint16_t timecode,
 159                      FrameAllocator::Frame video_frame, size_t video_offset, uint16_t video_format,
 160                      FrameAllocator::Frame audio_frame, size_t audio_offset, uint16_t audio_format)
 161 {
 162         CaptureCard *card = &cards[card_index];
 163         if (!card->thread_initialized) {
 164                 printf("initializing context for bmusb thread %d\n", card_index);
 165                 eglBindAPI(EGL_OPENGL_API);
 166                 card->context = create_context();
 167                 if (!make_current(card->context, card->surface)) {
 168                         printf("failed to create bmusb context\n");
 169                         exit(1);
 170                 }
 171                 card->thread_initialized = true;
 172         }
 173
 174         if (video_frame.len - video_offset != 1280 * 750 * 2) {
 175                 printf("dropping frame with wrong length (%ld)\n", video_frame.len - video_offset);
 176                 FILE *fp = fopen("frame.raw", "wb");
 177                 fwrite(video_frame.data, video_frame.len, 1, fp);
 178                 fclose(fp);
 179                 //exit(1);
 180                 card->usb->get_video_frame_allocator()->release_frame(video_frame);
 181                 card->usb->get_audio_frame_allocator()->release_frame(audio_frame);
 182                 return;
 183         }
 184         {
 185                 // Wait until the previous frame was consumed.
 186                 std::unique_lock<std::mutex> lock(bmusb_mutex);
 187                 card->new_data_ready_changed.wait(lock, [card]{ return !card->new_data_ready; });
 188         }
 189         GLuint pbo = (GLint)(intptr_t)video_frame.userdata;
 190         check_error();
 191         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
 192         check_error();
 193         glFlushMappedBufferRange(GL_PIXEL_UNPACK_BUFFER, 0, video_frame.size);
 194         check_error();
 195         //glMemoryBarrier(GL_CLIENT_MAPPED_BUFFER_BARRIER_BIT);
 196         //check_error();
 197         GLsync fence = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
 198         check_error();
 199         assert(fence != nullptr);
 200         {
 201                 std::unique_lock<std::mutex> lock(bmusb_mutex);
 202                 card->new_data_ready = true;
 203                 card->new_frame = video_frame;
 204                 card->new_data_ready_fence = fence;
 205                 card->new_data_ready_changed.notify_all();
 206         }
 207
 208         // Video frame will be released later.
 209         card->usb->get_audio_frame_allocator()->release_frame(audio_frame);
 210 }
 211
 212 void Mixer::place_rectangle(Effect *resample_effect, Effect *padding_effect, float x0, float y0, float x1, float y1)
 213 {
 214         float srcx0 = 0.0f;
 215         float srcx1 = 1.0f;
 216         float srcy0 = 0.0f;
 217         float srcy1 = 1.0f;
 218
 219         // Cull.
 220         if (x0 > 1280.0 || x1 < 0.0 || y0 > 720.0 || y1 < 0.0) {
 221                 CHECK(resample_effect->set_int("width", 1));
 222                 CHECK(resample_effect->set_int("height", 1));
 223                 CHECK(resample_effect->set_float("zoom_x", 1280.0));
 224                 CHECK(resample_effect->set_float("zoom_y", 720.0));
 225                 CHECK(padding_effect->set_int("left", 2000));
 226                 CHECK(padding_effect->set_int("top", 2000));
 227                 return;
 228         }
 229
 230         // Clip. (TODO: Clip on upper/left sides, too.)
 231         if (x1 > 1280.0) {
 232                 srcx1 = (1280.0 - x0) / (x1 - x0);
 233                 x1 = 1280.0;
 234         }
 235         if (y1 > 720.0) {
 236                 srcy1 = (720.0 - y0) / (y1 - y0);
 237                 y1 = 720.0;
 238         }
 239
 240         float x_subpixel_offset = x0 - floor(x0);
 241         float y_subpixel_offset = y0 - floor(y0);
 242
 243         // Resampling must be to an integral number of pixels. Round up,
 244         // and then add an extra pixel so we have some leeway for the border.
 245         int width = int(ceil(x1 - x0)) + 1;
 246         int height = int(ceil(y1 - y0)) + 1;
 247         CHECK(resample_effect->set_int("width", width));
 248         CHECK(resample_effect->set_int("height", height));
 249
 250         // Correct the discrepancy with zoom. (This will leave a small
 251         // excess edge of pixels and subpixels, which we'll correct for soon.)
 252         float zoom_x = (x1 - x0) / (width * (srcx1 - srcx0));
 253         float zoom_y = (y1 - y0) / (height * (srcy1 - srcy0));
 254         CHECK(resample_effect->set_float("zoom_x", zoom_x));
 255         CHECK(resample_effect->set_float("zoom_y", zoom_y));
 256         CHECK(resample_effect->set_float("zoom_center_x", 0.0f));
 257         CHECK(resample_effect->set_float("zoom_center_y", 0.0f));
 258
 259         // Padding must also be to a whole-pixel offset.
 260         CHECK(padding_effect->set_int("left", floor(x0)));
 261         CHECK(padding_effect->set_int("top", floor(y0)));
 262
 263         // Correct _that_ discrepancy by subpixel offset in the resampling.
 264         CHECK(resample_effect->set_float("left", -x_subpixel_offset / zoom_x));
 265         CHECK(resample_effect->set_float("top", -y_subpixel_offset / zoom_y));
 266
 267         // Finally, adjust the border so it is exactly where we want it.
 268         CHECK(padding_effect->set_float("border_offset_left", x_subpixel_offset));
 269         CHECK(padding_effect->set_float("border_offset_right", x1 - (floor(x0) + width)));
 270         CHECK(padding_effect->set_float("border_offset_top", y_subpixel_offset));
 271         CHECK(padding_effect->set_float("border_offset_bottom", y1 - (floor(y0) + height)));
 272 }
 273
 274 void Mixer::thread_func()
 275 {
 276         cards[0].surface = surface3;
 277 #if NUM_CARDS == 2
 278         cards[1].surface = surface4;
 279 #endif
 280
 281         eglBindAPI(EGL_OPENGL_API);
 282         QOpenGLContext *context = create_context();
 283         if (!make_current(context, surface1)) {
 284                 printf("oops\n");
 285                 exit(1);
 286         }
 287
 288         struct timespec start, now;
 289         clock_gettime(CLOCK_MONOTONIC, &start);
 290
 291         GLuint vao;
 292         glGenVertexArrays(1, &vao);
 293         check_error();
 294
 295         while (!should_quit) {
 296                 ++frame;
 297
 298                 //int width0 = lrintf(848 * (1.0 + 0.2 * sin(frame * 0.02)));
 299                 int width0 = 848;
 300                 int height0 = lrintf(width0 * 9.0 / 16.0);
 301
 302                 //float top0 = 96 + 48 * sin(frame * 0.005);
 303                 //float left0 = 96 + 48 * cos(frame * 0.006);
 304                 float top0 = 48;
 305                 float left0 = 16;
 306                 float bottom0 = top0 + height0;
 307                 float right0 = left0 + width0;
 308
 309                 int width1 = 384;
 310                 int height1 = 216;
 311
 312                 float bottom1 = 720 - 48;
 313                 float right1 = 1280 - 16;
 314                 float top1 = bottom1 - height1;
 315                 float left1 = right1 - width1;
 316
 317                 if (current_source == SOURCE_INPUT1) {
 318                         top0 = 0.0;
 319                         bottom0 = HEIGHT;
 320                         left0 = 0.0;
 321                         right0 = WIDTH;
 322
 323                         top1 = HEIGHT + 10;
 324                         bottom1 = HEIGHT + 20;
 325                         left1 = WIDTH + 10;
 326                         right1 = WIDTH + 20;
 327                 } else if (current_source == SOURCE_INPUT2) {
 328                         top1 = 0.0;
 329                         bottom1 = HEIGHT;
 330                         left1 = 0.0;
 331                         right1 = WIDTH;
 332
 333                         top0 = HEIGHT + 10;
 334                         bottom0 = HEIGHT + 20;
 335                         left0 = WIDTH + 10;
 336                         right0 = WIDTH + 20;
 337                 } else {
 338                         float t = 0.5 + 0.5 * cos(frame * 0.006);
 339                         float scale0 = 1.0 + t * (1280.0 / 848.0 - 1.0);
 340                         float tx0 = 0.0 + t * (-16.0 * scale0);
 341                         float ty0 = 0.0 + t * (-48.0 * scale0);
 342
 343                         top0 = top0 * scale0 + ty0;
 344                         bottom0 = bottom0 * scale0 + ty0;
 345                         left0 = left0 * scale0 + tx0;
 346                         right0 = right0 * scale0 + tx0;
 347
 348                         top1 = top1 * scale0 + ty0;
 349                         bottom1 = bottom1 * scale0 + ty0;
 350                         left1 = left1 * scale0 + tx0;
 351                         right1 = right1 * scale0 + tx0;
 352                 }
 353
 354                 place_rectangle(resample_effect, padding_effect, left0, top0, right0, bottom0);
 355                 place_rectangle(resample2_effect, padding2_effect, left1, top1, right1, bottom1);
 356
 357                 CaptureCard card_copy[NUM_CARDS];
 358
 359                 {
 360                         std::unique_lock<std::mutex> lock(bmusb_mutex);
 361
 362                         // The first card is the master timer, so wait for it to have a new frame.
 363                         // TODO: Make configurable, and with a timeout.
 364                         cards[0].new_data_ready_changed.wait(lock, [this]{ return cards[0].new_data_ready; });
 365
 366                         for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
 367                                 CaptureCard *card = &cards[card_index];
 368                                 card_copy[card_index].usb = card->usb;
 369                                 card_copy[card_index].new_data_ready = card->new_data_ready;
 370                                 card_copy[card_index].new_frame = card->new_frame;
 371                                 card_copy[card_index].new_data_ready_fence = card->new_data_ready_fence;
 372                                 card->new_data_ready = false;
 373                                 card->new_data_ready_changed.notify_all();
 374                         }
 375                 }
 376
 377                 vector<FrameAllocator::Frame> input_frames_to_release;
 378
 379                 for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
 380                         CaptureCard *card = &card_copy[card_index];
 381                         if (!card->new_data_ready)
 382                                 continue;
 383
 384                         // Now we're done with the previous frame, so we can definitely
 385                         // release it when this is done rendering. (Actually, we could do
 386                         // it one frame earlier, but before we have a new one, there's no
 387                         // knowing when the current one is released.)
 388                         input_frames_to_release.push_back(bmusb_current_rendering_frame[card_index]);
 389                         bmusb_current_rendering_frame[card_index] = card->new_frame;
 390                         check_error();
 391
 392                         // The new texture might still be uploaded,
 393                         // tell the GPU to wait until it's there.
 394                         if (card->new_data_ready_fence)
 395                                 glWaitSync(card->new_data_ready_fence, /*flags=*/0, GL_TIMEOUT_IGNORED);
 396                         check_error();
 397                         glDeleteSync(card->new_data_ready_fence);
 398                         check_error();
 399                         GLint input_tex_pbo = (GLint)(intptr_t)card->new_frame.userdata;
 400                         input[card_index]->set_pixel_data(0, (unsigned char *)BUFFER_OFFSET((1280 * 750 * 2 + 44) / 2 + 1280 * 25 + 22), input_tex_pbo);
 401                         input[card_index]->set_pixel_data(1, (unsigned char *)BUFFER_OFFSET(1280 * 25 + 22), input_tex_pbo);
 402
 403                         if (NUM_CARDS == 1) {
 404                                 // Set to the other one, too.
 405                                 input[1]->set_pixel_data(0, (unsigned char *)BUFFER_OFFSET((1280 * 750 * 2 + 44) / 2 + 1280 * 25 + 22), input_tex_pbo);
 406                                 input[1]->set_pixel_data(1, (unsigned char *)BUFFER_OFFSET(1280 * 25 + 22), input_tex_pbo);
 407                         }
 408                 }
 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                 GLuint chroma_tex = resource_pool->create_2d_texture(GL_RG8, WIDTH, HEIGHT);
 415
 416                 // Render chain.
 417                 GLuint rgba_tex = resource_pool->create_2d_texture(GL_RGBA8, WIDTH, HEIGHT);
 418                 GLuint ycbcr_fbo = resource_pool->create_fbo(y_tex, chroma_tex, rgba_tex);
 419                 chain->render_to_fbo(ycbcr_fbo, WIDTH, HEIGHT);
 420                 resource_pool->release_fbo(ycbcr_fbo);
 421
 422                 // Set up for extraction.
 423                 float vertices[] = {
 424                         0.0f, 2.0f,
 425                         0.0f, 0.0f,
 426                         2.0f, 0.0f
 427                 };
 428
 429                 glBindVertexArray(vao);
 430                 check_error();
 431
 432                 // Extract Cb/Cr.
 433                 GLuint cbcr_fbo = resource_pool->create_fbo(cbcr_tex);
 434                 glBindFramebuffer(GL_FRAMEBUFFER, cbcr_fbo);
 435                 glViewport(0, 0, WIDTH/2, HEIGHT/2);
 436                 check_error();
 437
 438                 glUseProgram(cbcr_program_num);
 439                 check_error();
 440
 441                 glActiveTexture(GL_TEXTURE0);
 442                 check_error();
 443                 glBindTexture(GL_TEXTURE_2D, chroma_tex);
 444                 check_error();
 445                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 446                 check_error();
 447                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 448                 check_error();
 449                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 450                 check_error();
 451
 452                 float chroma_offset_0[] = { -0.5f / WIDTH, 0.0f };
 453                 set_uniform_vec2(cbcr_program_num, "foo", "chroma_offset_0", chroma_offset_0);
 454
 455                 GLuint position_vbo = fill_vertex_attribute(cbcr_program_num, "position", 2, GL_FLOAT, sizeof(vertices), vertices);
 456                 GLuint texcoord_vbo = fill_vertex_attribute(cbcr_program_num, "texcoord", 2, GL_FLOAT, sizeof(vertices), vertices);  // Same as vertices.
 457
 458                 glDrawArrays(GL_TRIANGLES, 0, 3);
 459                 check_error();
 460
 461                 RefCountedGLsync fence(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
 462                 check_error();
 463
 464                 cleanup_vertex_attribute(cbcr_program_num, "position", position_vbo);
 465                 cleanup_vertex_attribute(cbcr_program_num, "texcoord", texcoord_vbo);
 466
 467                 glUseProgram(0);
 468                 check_error();
 469
 470                 resource_pool->release_fbo(cbcr_fbo);
 471                 resource_pool->release_2d_texture(chroma_tex);
 472
 473                 h264_encoder->end_frame(fence, input_frames_to_release);
 474
 475                 // Store this frame for display. Remove the ready frame if any
 476                 // (it was seemingly never used).
 477                 {
 478                         std::unique_lock<std::mutex> lock(display_frame_mutex);
 479                         if (has_ready_display_frame) {
 480                                 resource_pool->release_2d_texture(ready_display_frame.texnum);
 481                                 ready_display_frame.ready_fence.reset();
 482                         }
 483                         ready_display_frame.texnum = rgba_tex;
 484                         ready_display_frame.ready_fence = fence;
 485                         has_ready_display_frame = true;
 486                 }
 487
 488                 if (has_new_frame_ready_callback) {
 489                         new_frame_ready_callback();
 490                 }
 491
 492                 clock_gettime(CLOCK_MONOTONIC, &now);
 493                 double elapsed = now.tv_sec - start.tv_sec +
 494                         1e-9 * (now.tv_nsec - start.tv_nsec);
 495                 if (frame % 100 == 0) {
 496                         printf("%d frames in %.3f seconds = %.1f fps (%.1f ms/frame)\n",
 497                                 frame, elapsed, frame / elapsed,
 498                                 1e3 * elapsed / frame);
 499                 //      chain->print_phase_timing();
 500                 }
 501
 502                 // Reset every 100 frames, so that local variations in frame times
 503                 // (especially for the first few frames, when the shaders are
 504                 // compiled etc.) don't make it hard to measure for the entire
 505                 // remaining duration of the program.
 506                 if (frame == 10000) {
 507                         frame = 0;
 508                         start = now;
 509                 }
 510                 check_error();
 511         }
 512         glDeleteVertexArrays(1, &vao);
 513 }
 514
 515 bool Mixer::get_display_frame(DisplayFrame *frame)
 516 {
 517         std::unique_lock<std::mutex> lock(display_frame_mutex);
 518         if (!has_current_display_frame && !has_ready_display_frame) {
 519                 return false;
 520         }
 521
 522         if (has_current_display_frame && has_ready_display_frame) {
 523                 // We have a new ready frame. Toss the current one.
 524                 resource_pool->release_2d_texture(current_display_frame.texnum);
 525                 current_display_frame.ready_fence.reset();
 526                 has_current_display_frame = false;
 527         }
 528         if (has_ready_display_frame) {
 529                 assert(!has_current_display_frame);
 530                 current_display_frame = ready_display_frame;
 531                 ready_display_frame.ready_fence.reset();  // Drop the refcount.
 532                 has_current_display_frame = true;
 533                 has_ready_display_frame = false;
 534         }
 535
 536         *frame = current_display_frame;
 537         return true;
 538 }
 539
 540 void Mixer::set_frame_ready_fallback(new_frame_ready_callback_t callback)
 541 {
 542         new_frame_ready_callback = callback;
 543         has_new_frame_ready_callback = true;
 544 }
 545
 546 void Mixer::start()
 547 {
 548         mixer_thread = std::thread(&Mixer::thread_func, this);
 549 }
 550
 551 void Mixer::quit()
 552 {
 553         should_quit = true;
 554         mixer_thread.join();
 555 }
 556
 557 void Mixer::cut(Source source)
 558 {
 559         current_source = source;
 560 }