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(const QSurfaceFormat &format)
  54         : mixer_surface(create_surface(format)),
  55           h264_encoder_surface(create_surface(format))
  56 {
  57         CHECK(init_movit(MOVIT_SHADER_DIR, MOVIT_DEBUG_OFF));
  58         check_error();
  59
  60         resource_pool.reset(new ResourcePool);
  61         output_channel[OUTPUT_LIVE].parent = this;
  62         output_channel[OUTPUT_PREVIEW].parent = this;
  63         output_channel[OUTPUT_INPUT0].parent = this;
  64         output_channel[OUTPUT_INPUT1].parent = this;
  65
  66         ImageFormat inout_format;
  67         inout_format.color_space = COLORSPACE_sRGB;
  68         inout_format.gamma_curve = GAMMA_sRGB;
  69
  70         YCbCrFormat input_ycbcr_format;
  71         input_ycbcr_format.chroma_subsampling_x = 2;
  72         input_ycbcr_format.chroma_subsampling_y = 1;
  73         input_ycbcr_format.cb_x_position = 0.0;
  74         input_ycbcr_format.cr_x_position = 0.0;
  75         input_ycbcr_format.cb_y_position = 0.5;
  76         input_ycbcr_format.cr_y_position = 0.5;
  77         input_ycbcr_format.luma_coefficients = YCBCR_REC_601;
  78         input_ycbcr_format.full_range = false;
  79
  80         YCbCrFormat output_ycbcr_format;
  81         output_ycbcr_format.chroma_subsampling_x = 1;
  82         output_ycbcr_format.chroma_subsampling_y = 1;
  83         output_ycbcr_format.luma_coefficients = YCBCR_REC_601;
  84         output_ycbcr_format.full_range = false;
  85
  86         // Main chain.
  87         chain.reset(new EffectChain(WIDTH, HEIGHT, resource_pool.get()));
  88         check_error();
  89         input[0] = new YCbCrInput(inout_format, input_ycbcr_format, WIDTH, HEIGHT, YCBCR_INPUT_SPLIT_Y_AND_CBCR);
  90         chain->add_input(input[0]);
  91         input[1] = new YCbCrInput(inout_format, input_ycbcr_format, WIDTH, HEIGHT, YCBCR_INPUT_SPLIT_Y_AND_CBCR);
  92         chain->add_input(input[1]);
  93         resample_effect = chain->add_effect(new ResampleEffect(), input[0]);
  94         padding_effect = chain->add_effect(new IntegralPaddingEffect());
  95         float border_color[] = { 0.0f, 0.0f, 0.0f, 1.0f };
  96         CHECK(padding_effect->set_vec4("border_color", border_color));
  97
  98         resample2_effect = chain->add_effect(new ResampleEffect(), input[1]);
  99         Effect *saturation_effect = chain->add_effect(new SaturationEffect());
 100         CHECK(saturation_effect->set_float("saturation", 0.3f));
 101         Effect *wb_effect = chain->add_effect(new WhiteBalanceEffect());
 102         CHECK(wb_effect->set_float("output_color_temperature", 3500.0));
 103         padding2_effect = chain->add_effect(new IntegralPaddingEffect());
 104
 105         chain->add_effect(new OverlayEffect(), padding_effect, padding2_effect);
 106
 107         chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
 108         chain->add_ycbcr_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED, output_ycbcr_format, YCBCR_OUTPUT_SPLIT_Y_AND_CBCR);
 109         chain->set_dither_bits(8);
 110         chain->set_output_origin(OUTPUT_ORIGIN_TOP_LEFT);
 111         chain->finalize();
 112
 113         // Display chain; shows the live output produced by the main chain (its RGBA version).
 114         display_chain.reset(new EffectChain(WIDTH, HEIGHT, resource_pool.get()));
 115         check_error();
 116         display_input = new FlatInput(inout_format, FORMAT_RGB, GL_UNSIGNED_BYTE, WIDTH, HEIGHT);  // FIXME: GL_UNSIGNED_BYTE is really wrong.
 117         display_chain->add_input(display_input);
 118         display_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
 119         display_chain->set_dither_bits(0);  // Don't bother.
 120         display_chain->finalize();
 121
 122         // Preview chains (always shows just the inputs for now).
 123         preview0_chain.reset(new EffectChain(WIDTH, HEIGHT, resource_pool.get()));
 124         check_error();
 125         preview0_input = new YCbCrInput(inout_format, input_ycbcr_format, WIDTH, HEIGHT, YCBCR_INPUT_SPLIT_Y_AND_CBCR);
 126         preview0_chain->add_input(preview0_input);
 127         preview0_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
 128         preview0_chain->set_dither_bits(0);  // Don't bother.
 129         preview0_chain->finalize();
 130
 131         preview1_chain.reset(new EffectChain(WIDTH, HEIGHT, resource_pool.get()));
 132         check_error();
 133         preview1_input = new YCbCrInput(inout_format, input_ycbcr_format, WIDTH, HEIGHT, YCBCR_INPUT_SPLIT_Y_AND_CBCR);
 134         preview1_chain->add_input(preview1_input);
 135         preview1_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
 136         preview1_chain->set_dither_bits(0);  // Don't bother.
 137         preview1_chain->finalize();
 138
 139         h264_encoder.reset(new H264Encoder(h264_encoder_surface, WIDTH, HEIGHT, "test.mp4"));
 140
 141         printf("Configuring first card...\n");
 142         cards[0].usb = new BMUSBCapture(0x1edb, 0xbd3b);  // 0xbd4f
 143         cards[0].usb->set_frame_callback(std::bind(&Mixer::bm_frame, this, 0, _1, _2, _3, _4, _5, _6, _7));
 144         cards[0].frame_allocator.reset(new PBOFrameAllocator(1280 * 750 * 2 + 44, 1280, 720));
 145         cards[0].usb->set_video_frame_allocator(cards[0].frame_allocator.get());
 146         cards[0].usb->configure_card();
 147         cards[0].surface = create_surface(format);
 148 #if NUM_CARDS == 2
 149         cards[1].surface = create_surface(format);
 150 #endif
 151
 152         if (NUM_CARDS == 2) {
 153                 printf("Configuring second card...\n");
 154                 cards[1].usb = new BMUSBCapture(0x1edb, 0xbd4f);
 155                 cards[1].usb->set_frame_callback(std::bind(&Mixer::bm_frame, this, 1, _1, _2, _3, _4, _5, _6, _7));
 156                 cards[1].frame_allocator.reset(new PBOFrameAllocator(1280 * 750 * 2 + 44, 1280, 720));
 157                 cards[1].usb->set_video_frame_allocator(cards[1].frame_allocator.get());
 158                 cards[1].usb->configure_card();
 159         }
 160
 161         BMUSBCapture::start_bm_thread();
 162
 163         for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
 164                 cards[card_index].usb->start_bm_capture();
 165                 input[card_index]->set_pixel_data(0, nullptr, 0);
 166                 input[card_index]->set_pixel_data(1, nullptr, 0);
 167         }
 168
 169         //chain->enable_phase_timing(true);
 170
 171         // Set up stuff for NV12 conversion.
 172
 173         // Cb/Cr shader.
 174         string cbcr_vert_shader = read_file("vs-cbcr.130.vert");
 175         string cbcr_frag_shader =
 176                 "#version 130 \n"
 177                 "in vec2 tc0; \n"
 178                 "uniform sampler2D cbcr_tex; \n"
 179                 "void main() { \n"
 180                 "    gl_FragColor = texture2D(cbcr_tex, tc0); \n"
 181                 "} \n";
 182         cbcr_program_num = resource_pool->compile_glsl_program(cbcr_vert_shader, cbcr_frag_shader);
 183 }
 184
 185 Mixer::~Mixer()
 186 {
 187         resource_pool->release_glsl_program(cbcr_program_num);
 188         BMUSBCapture::stop_bm_thread();
 189 }
 190
 191 void Mixer::bm_frame(int card_index, uint16_t timecode,
 192                      FrameAllocator::Frame video_frame, size_t video_offset, uint16_t video_format,
 193                      FrameAllocator::Frame audio_frame, size_t audio_offset, uint16_t audio_format)
 194 {
 195         CaptureCard *card = &cards[card_index];
 196         if (!card->thread_initialized) {
 197                 printf("initializing context for bmusb thread %d\n", card_index);
 198                 eglBindAPI(EGL_OPENGL_API);
 199                 card->context = create_context();
 200                 if (!make_current(card->context, card->surface)) {
 201                         printf("failed to create bmusb context\n");
 202                         exit(1);
 203                 }
 204                 card->thread_initialized = true;
 205         }
 206
 207         if (video_frame.len - video_offset != 1280 * 750 * 2) {
 208                 printf("dropping frame with wrong length (%ld)\n", video_frame.len - video_offset);
 209                 FILE *fp = fopen("frame.raw", "wb");
 210                 fwrite(video_frame.data, video_frame.len, 1, fp);
 211                 fclose(fp);
 212                 //exit(1);
 213                 card->usb->get_video_frame_allocator()->release_frame(video_frame);
 214                 card->usb->get_audio_frame_allocator()->release_frame(audio_frame);
 215                 return;
 216         }
 217         {
 218                 // Wait until the previous frame was consumed.
 219                 std::unique_lock<std::mutex> lock(bmusb_mutex);
 220                 card->new_data_ready_changed.wait(lock, [card]{ return !card->new_data_ready; });
 221         }
 222         const PBOFrameAllocator::Userdata *userdata = (const PBOFrameAllocator::Userdata *)video_frame.userdata;
 223         GLuint pbo = userdata->pbo;
 224         check_error();
 225         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
 226         check_error();
 227         glFlushMappedBufferRange(GL_PIXEL_UNPACK_BUFFER, 0, video_frame.size);
 228         check_error();
 229         //glMemoryBarrier(GL_CLIENT_MAPPED_BUFFER_BARRIER_BIT);
 230         //check_error();
 231
 232         // Upload the textures.
 233         glBindTexture(GL_TEXTURE_2D, userdata->tex_y);
 234         check_error();
 235         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 1280, 720, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET((1280 * 750 * 2 + 44) / 2 + 1280 * 25 + 22));
 236         check_error();
 237         glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr);
 238         check_error();
 239         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 1280/2, 720, GL_RG, GL_UNSIGNED_BYTE, BUFFER_OFFSET(1280 * 25 + 22));
 240         check_error();
 241         glBindTexture(GL_TEXTURE_2D, 0);
 242         check_error();
 243         GLsync fence = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
 244         check_error();
 245         assert(fence != nullptr);
 246         {
 247                 std::unique_lock<std::mutex> lock(bmusb_mutex);
 248                 card->new_data_ready = true;
 249                 card->new_frame = RefCountedFrame(video_frame);
 250                 card->new_data_ready_fence = fence;
 251                 card->new_data_ready_changed.notify_all();
 252         }
 253
 254         // Video frame will be released when last user of card->new_frame goes out of scope.
 255         card->usb->get_audio_frame_allocator()->release_frame(audio_frame);
 256 }
 257
 258 void Mixer::place_rectangle(Effect *resample_effect, Effect *padding_effect, float x0, float y0, float x1, float y1)
 259 {
 260         float srcx0 = 0.0f;
 261         float srcx1 = 1.0f;
 262         float srcy0 = 0.0f;
 263         float srcy1 = 1.0f;
 264
 265         // Cull.
 266         if (x0 > 1280.0 || x1 < 0.0 || y0 > 720.0 || y1 < 0.0) {
 267                 CHECK(resample_effect->set_int("width", 1));
 268                 CHECK(resample_effect->set_int("height", 1));
 269                 CHECK(resample_effect->set_float("zoom_x", 1280.0));
 270                 CHECK(resample_effect->set_float("zoom_y", 720.0));
 271                 CHECK(padding_effect->set_int("left", 2000));
 272                 CHECK(padding_effect->set_int("top", 2000));
 273                 return;
 274         }
 275
 276         // Clip. (TODO: Clip on upper/left sides, too.)
 277         if (x1 > 1280.0) {
 278                 srcx1 = (1280.0 - x0) / (x1 - x0);
 279                 x1 = 1280.0;
 280         }
 281         if (y1 > 720.0) {
 282                 srcy1 = (720.0 - y0) / (y1 - y0);
 283                 y1 = 720.0;
 284         }
 285
 286         float x_subpixel_offset = x0 - floor(x0);
 287         float y_subpixel_offset = y0 - floor(y0);
 288
 289         // Resampling must be to an integral number of pixels. Round up,
 290         // and then add an extra pixel so we have some leeway for the border.
 291         int width = int(ceil(x1 - x0)) + 1;
 292         int height = int(ceil(y1 - y0)) + 1;
 293         CHECK(resample_effect->set_int("width", width));
 294         CHECK(resample_effect->set_int("height", height));
 295
 296         // Correct the discrepancy with zoom. (This will leave a small
 297         // excess edge of pixels and subpixels, which we'll correct for soon.)
 298         float zoom_x = (x1 - x0) / (width * (srcx1 - srcx0));
 299         float zoom_y = (y1 - y0) / (height * (srcy1 - srcy0));
 300         CHECK(resample_effect->set_float("zoom_x", zoom_x));
 301         CHECK(resample_effect->set_float("zoom_y", zoom_y));
 302         CHECK(resample_effect->set_float("zoom_center_x", 0.0f));
 303         CHECK(resample_effect->set_float("zoom_center_y", 0.0f));
 304
 305         // Padding must also be to a whole-pixel offset.
 306         CHECK(padding_effect->set_int("left", floor(x0)));
 307         CHECK(padding_effect->set_int("top", floor(y0)));
 308
 309         // Correct _that_ discrepancy by subpixel offset in the resampling.
 310         CHECK(resample_effect->set_float("left", -x_subpixel_offset / zoom_x));
 311         CHECK(resample_effect->set_float("top", -y_subpixel_offset / zoom_y));
 312
 313         // Finally, adjust the border so it is exactly where we want it.
 314         CHECK(padding_effect->set_float("border_offset_left", x_subpixel_offset));
 315         CHECK(padding_effect->set_float("border_offset_right", x1 - (floor(x0) + width)));
 316         CHECK(padding_effect->set_float("border_offset_top", y_subpixel_offset));
 317         CHECK(padding_effect->set_float("border_offset_bottom", y1 - (floor(y0) + height)));
 318 }
 319
 320 void Mixer::thread_func()
 321 {
 322         eglBindAPI(EGL_OPENGL_API);
 323         QOpenGLContext *context = create_context();
 324         if (!make_current(context, mixer_surface)) {
 325                 printf("oops\n");
 326                 exit(1);
 327         }
 328
 329         struct timespec start, now;
 330         clock_gettime(CLOCK_MONOTONIC, &start);
 331
 332         while (!should_quit) {
 333                 ++frame;
 334
 335                 //int width0 = lrintf(848 * (1.0 + 0.2 * sin(frame * 0.02)));
 336                 int width0 = 848;
 337                 int height0 = lrintf(width0 * 9.0 / 16.0);
 338
 339                 //float top0 = 96 + 48 * sin(frame * 0.005);
 340                 //float left0 = 96 + 48 * cos(frame * 0.006);
 341                 float top0 = 48;
 342                 float left0 = 16;
 343                 float bottom0 = top0 + height0;
 344                 float right0 = left0 + width0;
 345
 346                 int width1 = 384;
 347                 int height1 = 216;
 348
 349                 float bottom1 = 720 - 48;
 350                 float right1 = 1280 - 16;
 351                 float top1 = bottom1 - height1;
 352                 float left1 = right1 - width1;
 353
 354                 if (current_source == SOURCE_INPUT1) {
 355                         top0 = 0.0;
 356                         bottom0 = HEIGHT;
 357                         left0 = 0.0;
 358                         right0 = WIDTH;
 359
 360                         top1 = HEIGHT + 10;
 361                         bottom1 = HEIGHT + 20;
 362                         left1 = WIDTH + 10;
 363                         right1 = WIDTH + 20;
 364                 } else if (current_source == SOURCE_INPUT2) {
 365                         top1 = 0.0;
 366                         bottom1 = HEIGHT;
 367                         left1 = 0.0;
 368                         right1 = WIDTH;
 369
 370                         top0 = HEIGHT + 10;
 371                         bottom0 = HEIGHT + 20;
 372                         left0 = WIDTH + 10;
 373                         right0 = WIDTH + 20;
 374                 } else {
 375                         float t = 0.5 + 0.5 * cos(frame * 0.006);
 376                         float scale0 = 1.0 + t * (1280.0 / 848.0 - 1.0);
 377                         float tx0 = 0.0 + t * (-16.0 * scale0);
 378                         float ty0 = 0.0 + t * (-48.0 * scale0);
 379
 380                         top0 = top0 * scale0 + ty0;
 381                         bottom0 = bottom0 * scale0 + ty0;
 382                         left0 = left0 * scale0 + tx0;
 383                         right0 = right0 * scale0 + tx0;
 384
 385                         top1 = top1 * scale0 + ty0;
 386                         bottom1 = bottom1 * scale0 + ty0;
 387                         left1 = left1 * scale0 + tx0;
 388                         right1 = right1 * scale0 + tx0;
 389                 }
 390
 391                 place_rectangle(resample_effect, padding_effect, left0, top0, right0, bottom0);
 392                 place_rectangle(resample2_effect, padding2_effect, left1, top1, right1, bottom1);
 393
 394                 CaptureCard card_copy[NUM_CARDS];
 395
 396                 {
 397                         std::unique_lock<std::mutex> lock(bmusb_mutex);
 398
 399                         // The first card is the master timer, so wait for it to have a new frame.
 400                         // TODO: Make configurable, and with a timeout.
 401                         cards[0].new_data_ready_changed.wait(lock, [this]{ return cards[0].new_data_ready; });
 402
 403                         for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
 404                                 CaptureCard *card = &cards[card_index];
 405                                 card_copy[card_index].usb = card->usb;
 406                                 card_copy[card_index].new_data_ready = card->new_data_ready;
 407                                 card_copy[card_index].new_frame = card->new_frame;
 408                                 card_copy[card_index].new_data_ready_fence = card->new_data_ready_fence;
 409                                 card->new_data_ready = false;
 410                                 card->new_data_ready_changed.notify_all();
 411                         }
 412                 }
 413
 414                 for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
 415                         CaptureCard *card = &card_copy[card_index];
 416                         if (!card->new_data_ready)
 417                                 continue;
 418
 419                         bmusb_current_rendering_frame[card_index] = card->new_frame;
 420                         check_error();
 421
 422                         // The new texture might still be uploaded,
 423                         // tell the GPU to wait until it's there.
 424                         if (card->new_data_ready_fence)
 425                                 glWaitSync(card->new_data_ready_fence, /*flags=*/0, GL_TIMEOUT_IGNORED);
 426                         check_error();
 427                         glDeleteSync(card->new_data_ready_fence);
 428                         check_error();
 429                         const PBOFrameAllocator::Userdata *userdata = (const PBOFrameAllocator::Userdata *)card->new_frame->userdata;
 430                         input[card_index]->set_texture_num(0, userdata->tex_y);
 431                         input[card_index]->set_texture_num(1, userdata->tex_cbcr);
 432
 433                         if (NUM_CARDS == 1) {
 434                                 // Set to the other one, too.
 435                                 input[1]->set_texture_num(0, userdata->tex_y);
 436                                 input[1]->set_texture_num(1, userdata->tex_cbcr);
 437                         }
 438                 }
 439
 440                 GLuint y_tex, cbcr_tex;
 441                 bool got_frame = h264_encoder->begin_frame(&y_tex, &cbcr_tex);
 442                 assert(got_frame);
 443
 444                 // Render main chain.
 445                 GLuint cbcr_full_tex = resource_pool->create_2d_texture(GL_RG8, WIDTH, HEIGHT);
 446                 GLuint rgba_tex = resource_pool->create_2d_texture(GL_RGB565, WIDTH, HEIGHT);  // Saves texture bandwidth, although dithering gets messed up.
 447                 GLuint fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex, rgba_tex);
 448                 chain->render_to_fbo(fbo, WIDTH, HEIGHT);
 449                 resource_pool->release_fbo(fbo);
 450
 451                 subsample_chroma(cbcr_full_tex, cbcr_tex);
 452                 resource_pool->release_2d_texture(cbcr_full_tex);
 453
 454                 // Set the right state for rgba_tex.
 455                 glBindFramebuffer(GL_FRAMEBUFFER, 0);
 456                 glBindTexture(GL_TEXTURE_2D, rgba_tex);
 457                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 458                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 459                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 460
 461                 RefCountedGLsync fence(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
 462                 check_error();
 463
 464                 // Make sure the H.264 gets a reference to all the
 465                 // input frames needed, so that they are not released back
 466                 // until the rendering is done.
 467                 vector<RefCountedFrame> input_frames;
 468                 for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
 469                         input_frames.push_back(bmusb_current_rendering_frame[card_index]);
 470                 }
 471                 h264_encoder->end_frame(fence, input_frames);
 472
 473                 // The live frame just shows the RGBA texture we just rendered.
 474                 // It owns rgba_tex now.
 475                 DisplayFrame live_frame;
 476                 live_frame.chain = display_chain.get();
 477                 live_frame.setup_chain = [this, rgba_tex]{
 478                         display_input->set_texture_num(rgba_tex);
 479                 };
 480                 live_frame.ready_fence = fence;
 481                 live_frame.input_frames = {};
 482                 live_frame.temp_textures = { rgba_tex };
 483                 output_channel[OUTPUT_LIVE].output_frame(live_frame);
 484
 485                 // The preview frame shows the first input. Note that the textures
 486                 // are owned by the input frame, not the display frame.
 487                 {
 488                         const PBOFrameAllocator::Userdata *input0_userdata = (const PBOFrameAllocator::Userdata *)bmusb_current_rendering_frame[0]->userdata;
 489                         GLuint input0_y_tex = input0_userdata->tex_y;
 490                         GLuint input0_cbcr_tex = input0_userdata->tex_cbcr;
 491                         DisplayFrame preview0_frame;
 492                         preview0_frame.chain = preview0_chain.get();
 493                         preview0_frame.setup_chain = [this, input0_y_tex, input0_cbcr_tex]{
 494                                 preview0_input->set_texture_num(0, input0_y_tex);
 495                                 preview0_input->set_texture_num(1, input0_cbcr_tex);
 496                         };
 497                         preview0_frame.ready_fence = fence;
 498                         preview0_frame.input_frames = { bmusb_current_rendering_frame[0] };
 499                         preview0_frame.temp_textures = {};
 500                         output_channel[OUTPUT_PREVIEW].output_frame(preview0_frame);
 501                         output_channel[OUTPUT_INPUT0].output_frame(preview0_frame);
 502                 }
 503
 504                 // Same for the other preview.
 505                 // TODO: Use a for loop. Gah.
 506                 {
 507                         const PBOFrameAllocator::Userdata *input1_userdata = (const PBOFrameAllocator::Userdata *)bmusb_current_rendering_frame[1]->userdata;
 508                         GLuint input1_y_tex = input1_userdata->tex_y;
 509                         GLuint input1_cbcr_tex = input1_userdata->tex_cbcr;
 510                         DisplayFrame preview1_frame;
 511                         preview1_frame.chain = preview1_chain.get();
 512                         preview1_frame.setup_chain = [this, input1_y_tex, input1_cbcr_tex]{
 513                                 preview1_input->set_texture_num(0, input1_y_tex);
 514                                 preview1_input->set_texture_num(1, input1_cbcr_tex);
 515                         };
 516                         preview1_frame.ready_fence = fence;
 517                         preview1_frame.input_frames = { bmusb_current_rendering_frame[1] };
 518                         preview1_frame.temp_textures = {};
 519                         output_channel[OUTPUT_INPUT1].output_frame(preview1_frame);
 520                 }
 521
 522                 clock_gettime(CLOCK_MONOTONIC, &now);
 523                 double elapsed = now.tv_sec - start.tv_sec +
 524                         1e-9 * (now.tv_nsec - start.tv_nsec);
 525                 if (frame % 100 == 0) {
 526                         printf("%d frames in %.3f seconds = %.1f fps (%.1f ms/frame)\n",
 527                                 frame, elapsed, frame / elapsed,
 528                                 1e3 * elapsed / frame);
 529                 //      chain->print_phase_timing();
 530                 }
 531
 532                 // Reset every 100 frames, so that local variations in frame times
 533                 // (especially for the first few frames, when the shaders are
 534                 // compiled etc.) don't make it hard to measure for the entire
 535                 // remaining duration of the program.
 536                 if (frame == 10000) {
 537                         frame = 0;
 538                         start = now;
 539                 }
 540                 check_error();
 541         }
 542 }
 543
 544 void Mixer::subsample_chroma(GLuint src_tex, GLuint dst_tex)
 545 {
 546         GLuint vao;
 547         glGenVertexArrays(1, &vao);
 548         check_error();
 549
 550         float vertices[] = {
 551                 0.0f, 2.0f,
 552                 0.0f, 0.0f,
 553                 2.0f, 0.0f
 554         };
 555
 556         glBindVertexArray(vao);
 557         check_error();
 558
 559         // Extract Cb/Cr.
 560         GLuint fbo = resource_pool->create_fbo(dst_tex);
 561         glBindFramebuffer(GL_FRAMEBUFFER, fbo);
 562         glViewport(0, 0, WIDTH/2, HEIGHT/2);
 563         check_error();
 564
 565         glUseProgram(cbcr_program_num);
 566         check_error();
 567
 568         glActiveTexture(GL_TEXTURE0);
 569         check_error();
 570         glBindTexture(GL_TEXTURE_2D, src_tex);
 571         check_error();
 572         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 573         check_error();
 574         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 575         check_error();
 576         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 577         check_error();
 578
 579         float chroma_offset_0[] = { -0.5f / WIDTH, 0.0f };
 580         set_uniform_vec2(cbcr_program_num, "foo", "chroma_offset_0", chroma_offset_0);
 581
 582         GLuint position_vbo = fill_vertex_attribute(cbcr_program_num, "position", 2, GL_FLOAT, sizeof(vertices), vertices);
 583         GLuint texcoord_vbo = fill_vertex_attribute(cbcr_program_num, "texcoord", 2, GL_FLOAT, sizeof(vertices), vertices);  // Same as vertices.
 584
 585         glDrawArrays(GL_TRIANGLES, 0, 3);
 586         check_error();
 587
 588         cleanup_vertex_attribute(cbcr_program_num, "position", position_vbo);
 589         cleanup_vertex_attribute(cbcr_program_num, "texcoord", texcoord_vbo);
 590
 591         glUseProgram(0);
 592         check_error();
 593
 594         resource_pool->release_fbo(fbo);
 595         glDeleteVertexArrays(1, &vao);
 596 }
 597
 598 void Mixer::release_display_frame(DisplayFrame *frame)
 599 {
 600         for (GLuint texnum : frame->temp_textures) {
 601                 resource_pool->release_2d_texture(texnum);
 602         }
 603         frame->temp_textures.clear();
 604         frame->ready_fence.reset();
 605         frame->input_frames.clear();
 606 }
 607
 608 void Mixer::start()
 609 {
 610         mixer_thread = std::thread(&Mixer::thread_func, this);
 611 }
 612
 613 void Mixer::quit()
 614 {
 615         should_quit = true;
 616         mixer_thread.join();
 617 }
 618
 619 void Mixer::cut(Source source)
 620 {
 621         current_source = source;
 622 }
 623
 624 void Mixer::OutputChannel::output_frame(DisplayFrame frame)
 625 {
 626         // Store this frame for display. Remove the ready frame if any
 627         // (it was seemingly never used).
 628         {
 629                 std::unique_lock<std::mutex> lock(frame_mutex);
 630                 if (has_ready_frame) {
 631                         parent->release_display_frame(&ready_frame);
 632                 }
 633                 ready_frame = frame;
 634                 has_ready_frame = true;
 635         }
 636
 637         if (has_new_frame_ready_callback) {
 638                 new_frame_ready_callback();
 639         }
 640 }
 641
 642 bool Mixer::OutputChannel::get_display_frame(DisplayFrame *frame)
 643 {
 644         std::unique_lock<std::mutex> lock(frame_mutex);
 645         if (!has_current_frame && !has_ready_frame) {
 646                 return false;
 647         }
 648
 649         if (has_current_frame && has_ready_frame) {
 650                 // We have a new ready frame. Toss the current one.
 651                 parent->release_display_frame(&current_frame);
 652                 has_current_frame = false;
 653         }
 654         if (has_ready_frame) {
 655                 assert(!has_current_frame);
 656                 current_frame = ready_frame;
 657                 ready_frame.ready_fence.reset();  // Drop the refcount.
 658                 ready_frame.input_frames.clear();  // Drop the refcounts.
 659                 has_current_frame = true;
 660                 has_ready_frame = false;
 661         }
 662
 663         *frame = current_frame;
 664         return true;
 665 }
 666
 667 void Mixer::OutputChannel::set_frame_ready_callback(Mixer::new_frame_ready_callback_t callback)
 668 {
 669         new_frame_ready_callback = callback;
 670         has_new_frame_ready_callback = true;
 671 }