git.sesse.net Git - nageru/blob - futatabi/jpeg_frame_view.cpp

   1 #include "jpeg_frame_view.h"
   2
   3 #include "defs.h"
   4 #include "flags.h"
   5 #include "jpeg_destroyer.h"
   6 #include "jpeglib_error_wrapper.h"
   7 #include "pbo_pool.h"
   8 #include "shared/context.h"
   9 #include "shared/metrics.h"
  10 #include "shared/post_to_main_thread.h"
  11 #include "video_stream.h"
  12 #include "ycbcr_converter.h"
  13
  14 #include <QMouseEvent>
  15 #include <QScreen>
  16 #include <atomic>
  17 #include <chrono>
  18 #include <condition_variable>
  19 #include <deque>
  20 #include <jpeglib.h>
  21 #include <movit/init.h>
  22 #include <movit/resource_pool.h>
  23 #include <movit/util.h>
  24 #include <mutex>
  25 #include <stdint.h>
  26 #include <thread>
  27 #include <unistd.h>
  28 #include <utility>
  29
  30 // Must come after the Qt stuff.
  31 #include "vaapi_jpeg_decoder.h"
  32
  33 using namespace movit;
  34 using namespace std;
  35 using namespace std::chrono;
  36
  37 namespace {
  38
  39 // Just an arbitrary order for std::map.
  40 struct FrameOnDiskLexicalOrder {
  41         bool operator()(const FrameOnDisk &a, const FrameOnDisk &b) const
  42         {
  43                 if (a.pts != b.pts)
  44                         return a.pts < b.pts;
  45                 if (a.offset != b.offset)
  46                         return a.offset < b.offset;
  47                 if (a.filename_idx != b.filename_idx)
  48                         return a.filename_idx < b.filename_idx;
  49                 assert(a.size == b.size);
  50                 return false;
  51         }
  52 };
  53
  54 inline size_t frame_size(const Frame &frame)
  55 {
  56         size_t y_size = frame.width * frame.height;
  57         size_t cbcr_size = y_size / frame.chroma_subsampling_x / frame.chroma_subsampling_y;
  58         return y_size + cbcr_size * 2;
  59 }
  60
  61 struct LRUFrame {
  62         shared_ptr<Frame> frame;
  63         size_t last_used;
  64 };
  65
  66 // There can be multiple JPEGFrameView instances, so make all the metrics static.
  67 once_flag jpeg_metrics_inited;
  68 atomic<int64_t> metric_jpeg_cache_used_bytes{ 0 };  // Same value as cache_bytes_used.
  69 atomic<int64_t> metric_jpeg_cache_limit_bytes{ size_t(CACHE_SIZE_MB) * 1024 * 1024 };
  70 atomic<int64_t> metric_jpeg_cache_given_up_frames{ 0 };
  71 atomic<int64_t> metric_jpeg_cache_hit_frames{ 0 };
  72 atomic<int64_t> metric_jpeg_cache_miss_frames{ 0 };
  73 atomic<int64_t> metric_jpeg_software_decode_frames{ 0 };
  74 atomic<int64_t> metric_jpeg_software_fail_frames{ 0 };
  75 atomic<int64_t> metric_jpeg_vaapi_decode_frames{ 0 };
  76 atomic<int64_t> metric_jpeg_vaapi_fail_frames{ 0 };
  77 atomic<int64_t> metric_jpeg_prepared_frames{ 0 };
  78 atomic<int64_t> metric_jpeg_displayed_frames{ 0 };
  79 Summary metric_jpeg_decode_time_seconds;
  80
  81 }  // namespace
  82
  83 mutex cache_mu;
  84 map<FrameOnDisk, LRUFrame, FrameOnDiskLexicalOrder> cache;  // Under cache_mu.
  85 size_t cache_bytes_used = 0;  // Under cache_mu.
  86 atomic<size_t> event_counter{ 0 };
  87 extern QGLWidget *global_share_widget;
  88 extern atomic<bool> should_quit;
  89
  90 shared_ptr<Frame> decode_jpeg(const string &jpeg)
  91 {
  92         steady_clock::time_point start = steady_clock::now();
  93         shared_ptr<Frame> frame;
  94         if (vaapi_jpeg_decoding_usable) {
  95                 frame = decode_jpeg_vaapi(jpeg);
  96                 if (frame != nullptr) {
  97                         ++metric_jpeg_vaapi_decode_frames;
  98                         steady_clock::time_point stop = steady_clock::now();
  99                         metric_jpeg_decode_time_seconds.count_event(duration<double>(stop - start).count());
 100                         return frame;
 101                 }
 102                 fprintf(stderr, "VA-API hardware decoding failed; falling back to software.\n");
 103                 ++metric_jpeg_vaapi_fail_frames;
 104         }
 105
 106         frame.reset(new Frame);
 107
 108         jpeg_decompress_struct dinfo;
 109         JPEGWrapErrorManager error_mgr(&dinfo);
 110         if (!error_mgr.run([&dinfo] { jpeg_create_decompress(&dinfo); })) {
 111                 return get_black_frame();
 112         }
 113         JPEGDestroyer destroy_dinfo(&dinfo);
 114
 115         if (!error_mgr.run([&dinfo, &jpeg] {
 116                     jpeg_mem_src(&dinfo, reinterpret_cast<const unsigned char *>(jpeg.data()), jpeg.size());
 117                     jpeg_read_header(&dinfo, true);
 118             })) {
 119                 return get_black_frame();
 120         }
 121
 122         jpeg_save_markers(&dinfo, JPEG_APP0 + 1, 0xFFFF);
 123
 124         if (dinfo.num_components != 3) {
 125                 fprintf(stderr, "Not a color JPEG. (%d components, Y=%dx%d, Cb=%dx%d, Cr=%dx%d)\n",
 126                         dinfo.num_components,
 127                         dinfo.comp_info[0].h_samp_factor, dinfo.comp_info[0].v_samp_factor,
 128                         dinfo.comp_info[1].h_samp_factor, dinfo.comp_info[1].v_samp_factor,
 129                         dinfo.comp_info[2].h_samp_factor, dinfo.comp_info[2].v_samp_factor);
 130                 return get_black_frame();
 131         }
 132         if (dinfo.comp_info[0].h_samp_factor != dinfo.max_h_samp_factor ||
 133             dinfo.comp_info[0].v_samp_factor != dinfo.max_v_samp_factor ||  // Y' must not be subsampled.
 134             dinfo.comp_info[1].h_samp_factor != dinfo.comp_info[2].h_samp_factor ||
 135             dinfo.comp_info[1].v_samp_factor != dinfo.comp_info[2].v_samp_factor ||  // Cb and Cr must be identically subsampled.
 136             (dinfo.max_h_samp_factor % dinfo.comp_info[1].h_samp_factor) != 0 ||
 137             (dinfo.max_v_samp_factor % dinfo.comp_info[1].v_samp_factor) != 0) {  // No 2:3 subsampling or other weirdness.
 138                 fprintf(stderr, "Unsupported subsampling scheme. (Y=%dx%d, Cb=%dx%d, Cr=%dx%d)\n",
 139                         dinfo.comp_info[0].h_samp_factor, dinfo.comp_info[0].v_samp_factor,
 140                         dinfo.comp_info[1].h_samp_factor, dinfo.comp_info[1].v_samp_factor,
 141                         dinfo.comp_info[2].h_samp_factor, dinfo.comp_info[2].v_samp_factor);
 142                 abort();
 143         }
 144         dinfo.raw_data_out = true;
 145
 146         if (!error_mgr.run([&dinfo] {
 147                     jpeg_start_decompress(&dinfo);
 148             })) {
 149                 return get_black_frame();
 150         }
 151
 152         frame->width = dinfo.output_width;
 153         frame->height = dinfo.output_height;
 154         frame->chroma_subsampling_x = dinfo.max_h_samp_factor / dinfo.comp_info[1].h_samp_factor;
 155         frame->chroma_subsampling_y = dinfo.max_v_samp_factor / dinfo.comp_info[1].v_samp_factor;
 156
 157         unsigned h_mcu_size = DCTSIZE * dinfo.max_h_samp_factor;
 158         unsigned v_mcu_size = DCTSIZE * dinfo.max_v_samp_factor;
 159         unsigned mcu_width_blocks = (dinfo.output_width + h_mcu_size - 1) / h_mcu_size;
 160         unsigned mcu_height_blocks = (dinfo.output_height + v_mcu_size - 1) / v_mcu_size;
 161
 162         unsigned luma_width_blocks = mcu_width_blocks * dinfo.comp_info[0].h_samp_factor;
 163         unsigned chroma_width_blocks = mcu_width_blocks * dinfo.comp_info[1].h_samp_factor;
 164
 165         PBO pbo = global_pbo_pool->alloc_pbo();
 166         size_t cb_offset = dinfo.image_width * dinfo.image_height;
 167         size_t cr_offset = cb_offset + (dinfo.image_width / 2) * dinfo.image_height;
 168         uint8_t *y_pix = pbo.ptr;
 169         uint8_t *cb_pix = pbo.ptr + cb_offset;
 170         uint8_t *cr_pix = pbo.ptr + cr_offset;
 171         unsigned pitch_y = luma_width_blocks * DCTSIZE;
 172         unsigned pitch_chroma = chroma_width_blocks * DCTSIZE * 2;
 173
 174         if (dinfo.marker_list != nullptr &&
 175             dinfo.marker_list->marker == JPEG_APP0 + 1 &&
 176             dinfo.marker_list->data_length >= 4 &&
 177             memcmp(dinfo.marker_list->data, "Exif", 4) == 0) {
 178                 frame->exif_data.assign(reinterpret_cast<char *>(dinfo.marker_list->data),
 179                         dinfo.marker_list->data_length);
 180         }
 181
 182         if (!error_mgr.run([&dinfo, &y_pix, &cb_pix, &cr_pix, pitch_y, pitch_chroma, v_mcu_size, mcu_height_blocks] {
 183                     JSAMPROW yptr[v_mcu_size], cbptr[v_mcu_size], crptr[v_mcu_size];
 184                     JSAMPARRAY data[3] = { yptr, cbptr, crptr };
 185                     for (unsigned y = 0; y < mcu_height_blocks; ++y) {
 186                             // NOTE: The last elements of cbptr/crptr will be unused for vertically subsampled chroma.
 187                             for (unsigned yy = 0; yy < v_mcu_size; ++yy) {
 188                                     yptr[yy] = y_pix + (y * DCTSIZE * dinfo.max_v_samp_factor + yy) * pitch_y;
 189                                     cbptr[yy] = cb_pix + (y * DCTSIZE * dinfo.comp_info[1].v_samp_factor + yy) * pitch_chroma;
 190                                     crptr[yy] = cr_pix + (y * DCTSIZE * dinfo.comp_info[1].v_samp_factor + yy) * pitch_chroma;
 191                             }
 192
 193                             jpeg_read_raw_data(&dinfo, data, v_mcu_size);
 194                     }
 195
 196                     (void)jpeg_finish_decompress(&dinfo);
 197             })) {
 198                 return get_black_frame();
 199         }
 200
 201         // FIXME: what about resolutions that are not divisible by the block factor?
 202         glBindBuffer(GL_PIXEL_UNPACK_BUFFER, pbo.pbo);
 203         frame->y = create_texture_2d(frame->width, frame->height, GL_R8, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
 204         frame->cb = create_texture_2d(frame->width / 2, frame->height, GL_R8, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET(cb_offset));
 205         frame->cr = create_texture_2d(frame->width / 2, frame->height, GL_R8, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET(cr_offset));
 206         glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
 207
 208         glFlushMappedNamedBufferRange(pbo.pbo, 0, dinfo.image_width * dinfo.image_height * 2);
 209         glMemoryBarrier(GL_PIXEL_BUFFER_BARRIER_BIT);
 210         pbo.upload_done = RefCountedGLsync(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
 211         frame->uploaded_ui_thread = pbo.upload_done;
 212         frame->uploaded_interpolation = pbo.upload_done;
 213         global_pbo_pool->release_pbo(move(pbo));
 214
 215         ++metric_jpeg_software_decode_frames;
 216         steady_clock::time_point stop = steady_clock::now();
 217         metric_jpeg_decode_time_seconds.count_event(duration<double>(stop - start).count());
 218         return frame;
 219 }
 220
 221 void prune_cache()
 222 {
 223         // Assumes cache_mu is held.
 224         int64_t bytes_still_to_remove = cache_bytes_used - (size_t(CACHE_SIZE_MB) * 1024 * 1024) * 9 / 10;
 225         if (bytes_still_to_remove <= 0)
 226                 return;
 227
 228         vector<pair<size_t, size_t>> lru_timestamps_and_size;
 229         for (const auto &key_and_value : cache) {
 230                 lru_timestamps_and_size.emplace_back(
 231                         key_and_value.second.last_used,
 232                         frame_size(*key_and_value.second.frame));
 233         }
 234         sort(lru_timestamps_and_size.begin(), lru_timestamps_and_size.end());
 235
 236         // Remove the oldest ones until we are below 90% of the cache used.
 237         size_t lru_cutoff_point = 0;
 238         for (const pair<size_t, size_t> &it : lru_timestamps_and_size) {
 239                 lru_cutoff_point = it.first;
 240                 bytes_still_to_remove -= it.second;
 241                 if (bytes_still_to_remove <= 0)
 242                         break;
 243         }
 244
 245         for (auto it = cache.begin(); it != cache.end();) {
 246                 if (it->second.last_used <= lru_cutoff_point) {
 247                         cache_bytes_used -= frame_size(*it->second.frame);
 248                         metric_jpeg_cache_used_bytes = cache_bytes_used;
 249                         it = cache.erase(it);
 250                 } else {
 251                         ++it;
 252                 }
 253         }
 254 }
 255
 256 shared_ptr<Frame> decode_jpeg_with_cache(FrameOnDisk frame_spec, CacheMissBehavior cache_miss_behavior, FrameReader *frame_reader, bool *did_decode)
 257 {
 258         *did_decode = false;
 259         {
 260                 lock_guard<mutex> lock(cache_mu);
 261                 auto it = cache.find(frame_spec);
 262                 if (it != cache.end()) {
 263                         ++metric_jpeg_cache_hit_frames;
 264                         it->second.last_used = event_counter++;
 265                         return it->second.frame;
 266                 }
 267         }
 268
 269         if (cache_miss_behavior == RETURN_NULLPTR_IF_NOT_IN_CACHE) {
 270                 ++metric_jpeg_cache_given_up_frames;
 271                 return nullptr;
 272         }
 273
 274         ++metric_jpeg_cache_miss_frames;
 275
 276         *did_decode = true;
 277         shared_ptr<Frame> frame = decode_jpeg(frame_reader->read_frame(frame_spec, /*read_video=*/true, /*read_audio=*/false).video);
 278
 279         lock_guard<mutex> lock(cache_mu);
 280         cache_bytes_used += frame_size(*frame);
 281         metric_jpeg_cache_used_bytes = cache_bytes_used;
 282         cache[frame_spec] = LRUFrame{ frame, event_counter++ };
 283
 284         if (cache_bytes_used > size_t(CACHE_SIZE_MB) * 1024 * 1024) {
 285                 prune_cache();
 286         }
 287         return frame;
 288 }
 289
 290 void JPEGFrameView::jpeg_decoder_thread_func()
 291 {
 292         size_t num_decoded = 0, num_dropped = 0;
 293
 294         pthread_setname_np(pthread_self(), "JPEGDecoder");
 295         QSurface *surface = create_surface();
 296         QOpenGLContext *context = create_context(surface);
 297         bool ok = make_current(context, surface);
 298         if (!ok) {
 299                 fprintf(stderr, "Video stream couldn't get an OpenGL context\n");
 300                 abort();
 301         }
 302         while (!should_quit.load()) {
 303                 PendingDecode decode;
 304                 CacheMissBehavior cache_miss_behavior = DECODE_IF_NOT_IN_CACHE;
 305                 {
 306                         unique_lock<mutex> lock(cache_mu);  // TODO: Perhaps under another lock?
 307                         any_pending_decodes.wait(lock, [this] {
 308                                 return !pending_decodes.empty() || should_quit.load();
 309                         });
 310                         if (should_quit.load())
 311                                 break;
 312                         decode = pending_decodes.front();
 313                         pending_decodes.pop_front();
 314
 315                         if (pending_decodes.size() > 3) {
 316                                 cache_miss_behavior = RETURN_NULLPTR_IF_NOT_IN_CACHE;
 317                         }
 318                 }
 319
 320                 if (decode.frame != nullptr) {
 321                         // Already decoded, so just show it.
 322                         setDecodedFrame(decode.frame, nullptr, 1.0f);
 323                         continue;
 324                 }
 325
 326                 shared_ptr<Frame> primary_frame, secondary_frame;
 327                 bool drop = false;
 328                 for (int subframe_idx = 0; subframe_idx < 2; ++subframe_idx) {
 329                         const FrameOnDisk &frame_spec = (subframe_idx == 0 ? decode.primary : decode.secondary);
 330                         if (frame_spec.pts == -1) {
 331                                 // No secondary frame.
 332                                 continue;
 333                         }
 334
 335                         bool found_in_cache;
 336                         shared_ptr<Frame> frame = decode_jpeg_with_cache(frame_spec, cache_miss_behavior, &frame_reader, &found_in_cache);
 337
 338                         if (frame == nullptr) {
 339                                 assert(cache_miss_behavior == RETURN_NULLPTR_IF_NOT_IN_CACHE);
 340                                 drop = true;
 341                                 break;
 342                         }
 343
 344                         if (!found_in_cache) {
 345                                 ++num_decoded;
 346                                 if (num_decoded % 1000 == 0) {
 347                                         fprintf(stderr, "Decoded %zu images, dropped %zu (%.2f%% dropped)\n",
 348                                                 num_decoded, num_dropped, (100.0 * num_dropped) / (num_decoded + num_dropped));
 349                                 }
 350                         }
 351                         if (subframe_idx == 0) {
 352                                 primary_frame = std::move(frame);
 353                         } else {
 354                                 secondary_frame = std::move(frame);
 355                         }
 356                 }
 357                 if (drop) {
 358                         ++num_dropped;
 359                         continue;
 360                 }
 361
 362                 // TODO: Could we get jitter between non-interpolated and interpolated frames here?
 363                 setDecodedFrame(primary_frame, secondary_frame, decode.fade_alpha);
 364         }
 365 }
 366
 367 JPEGFrameView::~JPEGFrameView()
 368 {
 369         any_pending_decodes.notify_all();
 370         jpeg_decoder_thread.join();
 371 }
 372
 373 JPEGFrameView::JPEGFrameView(QWidget *parent)
 374         : QGLWidget(parent, global_share_widget)
 375 {
 376         call_once(jpeg_metrics_inited, [] {
 377                 global_metrics.add("jpeg_cache_used_bytes", &metric_jpeg_cache_used_bytes, Metrics::TYPE_GAUGE);
 378                 global_metrics.add("jpeg_cache_limit_bytes", &metric_jpeg_cache_limit_bytes, Metrics::TYPE_GAUGE);
 379                 global_metrics.add("jpeg_cache_frames", { { "action", "given_up" } }, &metric_jpeg_cache_given_up_frames);
 380                 global_metrics.add("jpeg_cache_frames", { { "action", "hit" } }, &metric_jpeg_cache_hit_frames);
 381                 global_metrics.add("jpeg_cache_frames", { { "action", "miss" } }, &metric_jpeg_cache_miss_frames);
 382                 global_metrics.add("jpeg_decode_frames", { { "decoder", "software" }, { "result", "decode" } }, &metric_jpeg_software_decode_frames);
 383                 global_metrics.add("jpeg_decode_frames", { { "decoder", "software" }, { "result", "fail" } }, &metric_jpeg_software_fail_frames);
 384                 global_metrics.add("jpeg_decode_frames", { { "decoder", "vaapi" }, { "result", "decode" } }, &metric_jpeg_vaapi_decode_frames);
 385                 global_metrics.add("jpeg_decode_frames", { { "decoder", "vaapi" }, { "result", "fail" } }, &metric_jpeg_vaapi_fail_frames);
 386                 global_metrics.add("jpeg_frames", { { "action", "prepared" } }, &metric_jpeg_prepared_frames);
 387                 global_metrics.add("jpeg_frames", { { "action", "displayed" } }, &metric_jpeg_displayed_frames);
 388                 vector<double> quantiles{ 0.01, 0.1, 0.25, 0.5, 0.75, 0.9, 0.99 };
 389                 metric_jpeg_decode_time_seconds.init(quantiles, 60.0);
 390                 global_metrics.add("jpeg_decode_time_seconds", &metric_jpeg_decode_time_seconds);
 391         });
 392 }
 393
 394 void JPEGFrameView::setFrame(unsigned stream_idx, FrameOnDisk frame, FrameOnDisk secondary_frame, float fade_alpha)
 395 {
 396         current_stream_idx = stream_idx;  // TODO: Does this interact with fades?
 397
 398         lock_guard<mutex> lock(cache_mu);
 399         PendingDecode decode;
 400         decode.primary = frame;
 401         decode.secondary = secondary_frame;
 402         decode.fade_alpha = fade_alpha;
 403         pending_decodes.push_back(decode);
 404         any_pending_decodes.notify_all();
 405 }
 406
 407 void JPEGFrameView::setFrame(shared_ptr<Frame> frame)
 408 {
 409         lock_guard<mutex> lock(cache_mu);
 410         PendingDecode decode;
 411         decode.frame = std::move(frame);
 412         pending_decodes.push_back(decode);
 413         any_pending_decodes.notify_all();
 414 }
 415
 416 void JPEGFrameView::initializeGL()
 417 {
 418         init_pbo_pool();
 419
 420         glDisable(GL_BLEND);
 421         glDisable(GL_DEPTH_TEST);
 422         check_error();
 423
 424         resource_pool = new ResourcePool;
 425         jpeg_decoder_thread = std::thread(&JPEGFrameView::jpeg_decoder_thread_func, this);
 426
 427         ycbcr_converter.reset(new YCbCrConverter(YCbCrConverter::OUTPUT_TO_RGBA, resource_pool));
 428
 429         ImageFormat inout_format;
 430         inout_format.color_space = COLORSPACE_sRGB;
 431         inout_format.gamma_curve = GAMMA_sRGB;
 432
 433         overlay_chain.reset(new EffectChain(overlay_base_width, overlay_base_height, resource_pool));
 434         overlay_input = (movit::FlatInput *)overlay_chain->add_input(new FlatInput(inout_format, FORMAT_GRAYSCALE, GL_UNSIGNED_BYTE, overlay_base_width, overlay_base_height));
 435
 436         overlay_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
 437         overlay_chain->finalize();
 438 }
 439
 440 void JPEGFrameView::resizeGL(int width, int height)
 441 {
 442         check_error();
 443         glViewport(0, 0, width, height);
 444         check_error();
 445
 446         // Save these, as width() and height() will lie with DPI scaling.
 447         gl_width = width;
 448         gl_height = height;
 449 }
 450
 451 void JPEGFrameView::paintGL()
 452 {
 453         glViewport(0, 0, gl_width, gl_height);
 454         if (current_frame == nullptr) {
 455                 glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
 456                 glClear(GL_COLOR_BUFFER_BIT);
 457                 return;
 458         }
 459
 460         if (!displayed_this_frame) {
 461                 ++metric_jpeg_displayed_frames;
 462                 displayed_this_frame = true;
 463         }
 464         if (current_frame->uploaded_ui_thread != nullptr) {
 465                 glWaitSync(current_frame->uploaded_ui_thread.get(), /*flags=*/0, GL_TIMEOUT_IGNORED);
 466                 current_frame->uploaded_ui_thread.reset();
 467         }
 468         if (current_secondary_frame != nullptr && current_secondary_frame->uploaded_ui_thread != nullptr) {
 469                 glWaitSync(current_secondary_frame->uploaded_ui_thread.get(), /*flags=*/0, GL_TIMEOUT_IGNORED);
 470                 current_secondary_frame->uploaded_ui_thread.reset();
 471         }
 472
 473         check_error();
 474         current_chain->render_to_screen();
 475
 476         if (overlay_image != nullptr) {
 477                 if (overlay_input_needs_refresh) {
 478                         overlay_input->set_width(overlay_width);
 479                         overlay_input->set_height(overlay_height);
 480                         overlay_input->set_pixel_data(overlay_image->bits());
 481                         overlay_input_needs_refresh = false;
 482                 }
 483                 glViewport(gl_width - overlay_width, 0, overlay_width, overlay_height);
 484                 overlay_chain->render_to_screen();
 485         }
 486 }
 487
 488 namespace {
 489
 490 }  // namespace
 491
 492 void JPEGFrameView::setDecodedFrame(shared_ptr<Frame> frame, shared_ptr<Frame> secondary_frame, float fade_alpha)
 493 {
 494         post_to_main_thread([this, frame, secondary_frame, fade_alpha] {
 495                 current_frame = frame;
 496                 current_secondary_frame = secondary_frame;
 497
 498                 if (secondary_frame != nullptr) {
 499                         current_chain = ycbcr_converter->prepare_chain_for_fade(frame, secondary_frame, fade_alpha);
 500                 } else {
 501                         current_chain = ycbcr_converter->prepare_chain_for_conversion(frame);
 502                 }
 503                 ++metric_jpeg_prepared_frames;
 504                 displayed_this_frame = false;
 505                 update();
 506         });
 507 }
 508
 509 void JPEGFrameView::mousePressEvent(QMouseEvent *event)
 510 {
 511         if (event->type() == QEvent::MouseButtonPress && event->button() == Qt::LeftButton) {
 512                 emit clicked();
 513         }
 514 }
 515
 516 void JPEGFrameView::set_overlay(const string &text)
 517 {
 518         if (text.empty()) {
 519                 overlay_image.reset();
 520                 return;
 521         }
 522
 523         // Figure out how large the texture needs to be.
 524         {
 525                 QImage img(overlay_width, overlay_height, QImage::Format_Grayscale8);
 526                 QPainter painter(&img);
 527                 QFont font = painter.font();
 528                 font.setPointSize(12);
 529                 QFontMetrics metrics(font);
 530                 overlay_base_width = lrint(metrics.boundingRect(QString::fromStdString(text)).width() + 8.0);
 531                 overlay_base_height = lrint(metrics.height());
 532         }
 533
 534         float dpr = QGuiApplication::primaryScreen()->devicePixelRatio();
 535         overlay_width = lrint(overlay_base_width * dpr);
 536         overlay_height = lrint(overlay_base_height * dpr);
 537
 538         // Work around OpenGL alignment issues.
 539         while (overlay_width % 4 != 0) ++overlay_width;
 540
 541         // Now do the actual drawing.
 542         overlay_image.reset(new QImage(overlay_width, overlay_height, QImage::Format_Grayscale8));
 543         overlay_image->setDevicePixelRatio(dpr);
 544         overlay_image->fill(0);
 545         QPainter painter(overlay_image.get());
 546
 547         painter.setPen(Qt::white);
 548         QFont font = painter.font();
 549         font.setPointSize(12);
 550         painter.setFont(font);
 551
 552         painter.drawText(QRectF(0, 0, overlay_base_width, overlay_base_height), Qt::AlignCenter, QString::fromStdString(text));
 553
 554         // Don't refresh immediately; we might not have an OpenGL context here.
 555         overlay_input_needs_refresh = true;
 556 }
 557
 558 shared_ptr<Frame> get_black_frame()
 559 {
 560         static shared_ptr<Frame> black_frame;
 561         static once_flag flag;
 562         call_once(flag, [] {
 563                 // Not really black, but whatever. :-)
 564                 uint8_t black[] = { 0, 0, 0, 255 };
 565                 RefCountedTexture black_tex = create_texture_2d(1, 1, GL_RGBA8, GL_RGBA, GL_UNSIGNED_BYTE, black);
 566
 567                 black_frame->y = black_tex;
 568                 black_frame->cb = black_tex;
 569                 black_frame->cr = move(black_tex);
 570                 black_frame->width = 1;
 571                 black_frame->height = 1;
 572                 black_frame->chroma_subsampling_x = 1;
 573                 black_frame->chroma_subsampling_y = 1;
 574         });
 575         ++metric_jpeg_software_fail_frames;
 576         return black_frame;
 577 }