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 "shared/metrics.h"
   8 #include "shared/post_to_main_thread.h"
   9 #include "video_stream.h"
  10 #include "ycbcr_converter.h"
  11
  12 #include <QMouseEvent>
  13 #include <QScreen>
  14 #include <atomic>
  15 #include <condition_variable>
  16 #include <deque>
  17 #include <jpeglib.h>
  18 #include <movit/init.h>
  19 #include <movit/resource_pool.h>
  20 #include <movit/util.h>
  21 #include <mutex>
  22 #include <stdint.h>
  23 #include <thread>
  24 #include <unistd.h>
  25 #include <utility>
  26
  27 // Must come after the Qt stuff.
  28 #include "vaapi_jpeg_decoder.h"
  29
  30 using namespace movit;
  31 using namespace std;
  32
  33 namespace {
  34
  35 // Just an arbitrary order for std::map.
  36 struct FrameOnDiskLexicalOrder {
  37         bool operator()(const FrameOnDisk &a, const FrameOnDisk &b) const
  38         {
  39                 if (a.pts != b.pts)
  40                         return a.pts < b.pts;
  41                 if (a.offset != b.offset)
  42                         return a.offset < b.offset;
  43                 if (a.filename_idx != b.filename_idx)
  44                         return a.filename_idx < b.filename_idx;
  45                 assert(a.size == b.size);
  46                 return false;
  47         }
  48 };
  49
  50 inline size_t frame_size(const Frame &frame)
  51 {
  52         size_t y_size = frame.width * frame.height;
  53         size_t cbcr_size = y_size / frame.chroma_subsampling_x / frame.chroma_subsampling_y;
  54         return y_size + cbcr_size * 2;
  55 }
  56
  57 struct LRUFrame {
  58         shared_ptr<Frame> frame;
  59         size_t last_used;
  60 };
  61
  62 // There can be multiple JPEGFrameView instances, so make all the metrics static.
  63 once_flag jpeg_metrics_inited;
  64 atomic<int64_t> metric_jpeg_cache_used_bytes{ 0 };  // Same value as cache_bytes_used.
  65 atomic<int64_t> metric_jpeg_cache_limit_bytes{ size_t(CACHE_SIZE_MB) * 1024 * 1024 };
  66 atomic<int64_t> metric_jpeg_cache_given_up_frames{ 0 };
  67 atomic<int64_t> metric_jpeg_cache_hit_frames{ 0 };
  68 atomic<int64_t> metric_jpeg_cache_miss_frames{ 0 };
  69 atomic<int64_t> metric_jpeg_software_decode_frames{ 0 };
  70 atomic<int64_t> metric_jpeg_software_fail_frames{ 0 };
  71 atomic<int64_t> metric_jpeg_vaapi_decode_frames{ 0 };
  72 atomic<int64_t> metric_jpeg_vaapi_fail_frames{ 0 };
  73
  74 }  // namespace
  75
  76 mutex cache_mu;
  77 map<FrameOnDisk, LRUFrame, FrameOnDiskLexicalOrder> cache;  // Under cache_mu.
  78 size_t cache_bytes_used = 0;  // Under cache_mu.
  79 atomic<size_t> event_counter{ 0 };
  80 extern QGLWidget *global_share_widget;
  81 extern atomic<bool> should_quit;
  82
  83 shared_ptr<Frame> decode_jpeg(const string &jpeg)
  84 {
  85         shared_ptr<Frame> frame;
  86         if (vaapi_jpeg_decoding_usable) {
  87                 frame = decode_jpeg_vaapi(jpeg);
  88                 if (frame != nullptr) {
  89                         ++metric_jpeg_vaapi_decode_frames;
  90                         return frame;
  91                 }
  92                 fprintf(stderr, "VA-API hardware decoding failed; falling back to software.\n");
  93                 ++metric_jpeg_vaapi_fail_frames;
  94         }
  95
  96         frame.reset(new Frame);
  97
  98         jpeg_decompress_struct dinfo;
  99         JPEGWrapErrorManager error_mgr(&dinfo);
 100         if (!error_mgr.run([&dinfo] { jpeg_create_decompress(&dinfo); })) {
 101                 return get_black_frame();
 102         }
 103         JPEGDestroyer destroy_dinfo(&dinfo);
 104
 105         if (!error_mgr.run([&dinfo, &jpeg] {
 106                     jpeg_mem_src(&dinfo, reinterpret_cast<const unsigned char *>(jpeg.data()), jpeg.size());
 107                     jpeg_read_header(&dinfo, true);
 108             })) {
 109                 return get_black_frame();
 110         }
 111
 112         jpeg_save_markers(&dinfo, JPEG_APP0 + 1, 0xFFFF);
 113
 114         if (dinfo.num_components != 3) {
 115                 fprintf(stderr, "Not a color JPEG. (%d components, Y=%dx%d, Cb=%dx%d, Cr=%dx%d)\n",
 116                         dinfo.num_components,
 117                         dinfo.comp_info[0].h_samp_factor, dinfo.comp_info[0].v_samp_factor,
 118                         dinfo.comp_info[1].h_samp_factor, dinfo.comp_info[1].v_samp_factor,
 119                         dinfo.comp_info[2].h_samp_factor, dinfo.comp_info[2].v_samp_factor);
 120                 return get_black_frame();
 121         }
 122         if (dinfo.comp_info[0].h_samp_factor != dinfo.max_h_samp_factor ||
 123             dinfo.comp_info[0].v_samp_factor != dinfo.max_v_samp_factor ||  // Y' must not be subsampled.
 124             dinfo.comp_info[1].h_samp_factor != dinfo.comp_info[2].h_samp_factor ||
 125             dinfo.comp_info[1].v_samp_factor != dinfo.comp_info[2].v_samp_factor ||  // Cb and Cr must be identically subsampled.
 126             (dinfo.max_h_samp_factor % dinfo.comp_info[1].h_samp_factor) != 0 ||
 127             (dinfo.max_v_samp_factor % dinfo.comp_info[1].v_samp_factor) != 0) {  // No 2:3 subsampling or other weirdness.
 128                 fprintf(stderr, "Unsupported subsampling scheme. (Y=%dx%d, Cb=%dx%d, Cr=%dx%d)\n",
 129                         dinfo.comp_info[0].h_samp_factor, dinfo.comp_info[0].v_samp_factor,
 130                         dinfo.comp_info[1].h_samp_factor, dinfo.comp_info[1].v_samp_factor,
 131                         dinfo.comp_info[2].h_samp_factor, dinfo.comp_info[2].v_samp_factor);
 132                 abort();
 133         }
 134         dinfo.raw_data_out = true;
 135
 136         if (!error_mgr.run([&dinfo] {
 137                     jpeg_start_decompress(&dinfo);
 138             })) {
 139                 return get_black_frame();
 140         }
 141
 142         frame->width = dinfo.output_width;
 143         frame->height = dinfo.output_height;
 144         frame->chroma_subsampling_x = dinfo.max_h_samp_factor / dinfo.comp_info[1].h_samp_factor;
 145         frame->chroma_subsampling_y = dinfo.max_v_samp_factor / dinfo.comp_info[1].v_samp_factor;
 146
 147         unsigned h_mcu_size = DCTSIZE * dinfo.max_h_samp_factor;
 148         unsigned v_mcu_size = DCTSIZE * dinfo.max_v_samp_factor;
 149         unsigned mcu_width_blocks = (dinfo.output_width + h_mcu_size - 1) / h_mcu_size;
 150         unsigned mcu_height_blocks = (dinfo.output_height + v_mcu_size - 1) / v_mcu_size;
 151
 152         unsigned luma_width_blocks = mcu_width_blocks * dinfo.comp_info[0].h_samp_factor;
 153         unsigned chroma_width_blocks = mcu_width_blocks * dinfo.comp_info[1].h_samp_factor;
 154         unsigned luma_height_blocks = mcu_height_blocks * dinfo.comp_info[0].v_samp_factor;
 155         unsigned chroma_height_blocks = mcu_height_blocks * dinfo.comp_info[1].v_samp_factor;
 156
 157         // TODO: Decode into a PBO.
 158         frame->y.reset(new uint8_t[luma_width_blocks * luma_height_blocks * DCTSIZE2]);
 159         frame->cb.reset(new uint8_t[chroma_width_blocks * chroma_height_blocks * DCTSIZE2]);
 160         frame->cr.reset(new uint8_t[chroma_width_blocks * chroma_height_blocks * DCTSIZE2]);
 161         frame->pitch_y = luma_width_blocks * DCTSIZE;
 162         frame->pitch_chroma = chroma_width_blocks * DCTSIZE;
 163
 164         if (dinfo.marker_list != nullptr &&
 165             dinfo.marker_list->marker == JPEG_APP0 + 1 &&
 166             dinfo.marker_list->data_length >= 4 &&
 167             memcmp(dinfo.marker_list->data, "Exif", 4) == 0) {
 168                 frame->exif_data.assign(reinterpret_cast<char *>(dinfo.marker_list->data),
 169                         dinfo.marker_list->data_length);
 170         }
 171
 172         if (!error_mgr.run([&dinfo, &frame, v_mcu_size, mcu_height_blocks] {
 173                     JSAMPROW yptr[v_mcu_size], cbptr[v_mcu_size], crptr[v_mcu_size];
 174                     JSAMPARRAY data[3] = { yptr, cbptr, crptr };
 175                     for (unsigned y = 0; y < mcu_height_blocks; ++y) {
 176                             // NOTE: The last elements of cbptr/crptr will be unused for vertically subsampled chroma.
 177                             for (unsigned yy = 0; yy < v_mcu_size; ++yy) {
 178                                     yptr[yy] = frame->y.get() + (y * DCTSIZE * dinfo.max_v_samp_factor + yy) * frame->pitch_y;
 179                                     cbptr[yy] = frame->cb.get() + (y * DCTSIZE * dinfo.comp_info[1].v_samp_factor + yy) * frame->pitch_chroma;
 180                                     crptr[yy] = frame->cr.get() + (y * DCTSIZE * dinfo.comp_info[1].v_samp_factor + yy) * frame->pitch_chroma;
 181                             }
 182
 183                             jpeg_read_raw_data(&dinfo, data, v_mcu_size);
 184                     }
 185
 186                     (void)jpeg_finish_decompress(&dinfo);
 187             })) {
 188                 return get_black_frame();
 189         }
 190
 191         ++metric_jpeg_software_decode_frames;
 192         return frame;
 193 }
 194
 195 void prune_cache()
 196 {
 197         // Assumes cache_mu is held.
 198         int64_t bytes_still_to_remove = cache_bytes_used - (size_t(CACHE_SIZE_MB) * 1024 * 1024) * 9 / 10;
 199         if (bytes_still_to_remove <= 0)
 200                 return;
 201
 202         vector<pair<size_t, size_t>> lru_timestamps_and_size;
 203         for (const auto &key_and_value : cache) {
 204                 lru_timestamps_and_size.emplace_back(
 205                         key_and_value.second.last_used,
 206                         frame_size(*key_and_value.second.frame));
 207         }
 208         sort(lru_timestamps_and_size.begin(), lru_timestamps_and_size.end());
 209
 210         // Remove the oldest ones until we are below 90% of the cache used.
 211         size_t lru_cutoff_point = 0;
 212         for (const pair<size_t, size_t> &it : lru_timestamps_and_size) {
 213                 lru_cutoff_point = it.first;
 214                 bytes_still_to_remove -= it.second;
 215                 if (bytes_still_to_remove <= 0)
 216                         break;
 217         }
 218
 219         for (auto it = cache.begin(); it != cache.end();) {
 220                 if (it->second.last_used <= lru_cutoff_point) {
 221                         cache_bytes_used -= frame_size(*it->second.frame);
 222                         metric_jpeg_cache_used_bytes = cache_bytes_used;
 223                         it = cache.erase(it);
 224                 } else {
 225                         ++it;
 226                 }
 227         }
 228 }
 229
 230 shared_ptr<Frame> decode_jpeg_with_cache(FrameOnDisk frame_spec, CacheMissBehavior cache_miss_behavior, FrameReader *frame_reader, bool *did_decode)
 231 {
 232         *did_decode = false;
 233         {
 234                 lock_guard<mutex> lock(cache_mu);
 235                 auto it = cache.find(frame_spec);
 236                 if (it != cache.end()) {
 237                         ++metric_jpeg_cache_hit_frames;
 238                         it->second.last_used = event_counter++;
 239                         return it->second.frame;
 240                 }
 241         }
 242
 243         if (cache_miss_behavior == RETURN_NULLPTR_IF_NOT_IN_CACHE) {
 244                 ++metric_jpeg_cache_given_up_frames;
 245                 return nullptr;
 246         }
 247
 248         ++metric_jpeg_cache_miss_frames;
 249
 250         *did_decode = true;
 251         shared_ptr<Frame> frame = decode_jpeg(frame_reader->read_frame(frame_spec, /*read_video=*/true, /*read_audio=*/false).video);
 252
 253         lock_guard<mutex> lock(cache_mu);
 254         cache_bytes_used += frame_size(*frame);
 255         metric_jpeg_cache_used_bytes = cache_bytes_used;
 256         cache[frame_spec] = LRUFrame{ frame, event_counter++ };
 257
 258         if (cache_bytes_used > size_t(CACHE_SIZE_MB) * 1024 * 1024) {
 259                 prune_cache();
 260         }
 261         return frame;
 262 }
 263
 264 void JPEGFrameView::jpeg_decoder_thread_func()
 265 {
 266         size_t num_decoded = 0, num_dropped = 0;
 267
 268         pthread_setname_np(pthread_self(), "JPEGDecoder");
 269         while (!should_quit.load()) {
 270                 PendingDecode decode;
 271                 CacheMissBehavior cache_miss_behavior = DECODE_IF_NOT_IN_CACHE;
 272                 {
 273                         unique_lock<mutex> lock(cache_mu);  // TODO: Perhaps under another lock?
 274                         any_pending_decodes.wait(lock, [this] {
 275                                 return !pending_decodes.empty() || should_quit.load();
 276                         });
 277                         if (should_quit.load())
 278                                 break;
 279                         decode = pending_decodes.front();
 280                         pending_decodes.pop_front();
 281
 282                         if (pending_decodes.size() > 3) {
 283                                 cache_miss_behavior = RETURN_NULLPTR_IF_NOT_IN_CACHE;
 284                         }
 285                 }
 286
 287                 if (decode.frame != nullptr) {
 288                         // Already decoded, so just show it.
 289                         setDecodedFrame(decode.frame, nullptr, 1.0f);
 290                         continue;
 291                 }
 292
 293                 shared_ptr<Frame> primary_frame, secondary_frame;
 294                 bool drop = false;
 295                 for (int subframe_idx = 0; subframe_idx < 2; ++subframe_idx) {
 296                         const FrameOnDisk &frame_spec = (subframe_idx == 0 ? decode.primary : decode.secondary);
 297                         if (frame_spec.pts == -1) {
 298                                 // No secondary frame.
 299                                 continue;
 300                         }
 301
 302                         bool found_in_cache;
 303                         shared_ptr<Frame> frame = decode_jpeg_with_cache(frame_spec, cache_miss_behavior, &frame_reader, &found_in_cache);
 304
 305                         if (frame == nullptr) {
 306                                 assert(cache_miss_behavior == RETURN_NULLPTR_IF_NOT_IN_CACHE);
 307                                 drop = true;
 308                                 break;
 309                         }
 310
 311                         if (!found_in_cache) {
 312                                 ++num_decoded;
 313                                 if (num_decoded % 1000 == 0) {
 314                                         fprintf(stderr, "Decoded %zu images, dropped %zu (%.2f%% dropped)\n",
 315                                                 num_decoded, num_dropped, (100.0 * num_dropped) / (num_decoded + num_dropped));
 316                                 }
 317                         }
 318                         if (subframe_idx == 0) {
 319                                 primary_frame = std::move(frame);
 320                         } else {
 321                                 secondary_frame = std::move(frame);
 322                         }
 323                 }
 324                 if (drop) {
 325                         ++num_dropped;
 326                         continue;
 327                 }
 328
 329                 // TODO: Could we get jitter between non-interpolated and interpolated frames here?
 330                 setDecodedFrame(primary_frame, secondary_frame, decode.fade_alpha);
 331         }
 332 }
 333
 334 JPEGFrameView::~JPEGFrameView()
 335 {
 336         any_pending_decodes.notify_all();
 337         jpeg_decoder_thread.join();
 338 }
 339
 340 JPEGFrameView::JPEGFrameView(QWidget *parent)
 341         : QGLWidget(parent, global_share_widget)
 342 {
 343         call_once(jpeg_metrics_inited, [] {
 344                 global_metrics.add("jpeg_cache_used_bytes", &metric_jpeg_cache_used_bytes, Metrics::TYPE_GAUGE);
 345                 global_metrics.add("jpeg_cache_limit_bytes", &metric_jpeg_cache_limit_bytes, Metrics::TYPE_GAUGE);
 346                 global_metrics.add("jpeg_cache_frames", { { "action", "given_up" } }, &metric_jpeg_cache_given_up_frames);
 347                 global_metrics.add("jpeg_cache_frames", { { "action", "hit" } }, &metric_jpeg_cache_hit_frames);
 348                 global_metrics.add("jpeg_cache_frames", { { "action", "miss" } }, &metric_jpeg_cache_miss_frames);
 349                 global_metrics.add("jpeg_decode_frames", { { "decoder", "software" }, { "result", "decode" } }, &metric_jpeg_software_decode_frames);
 350                 global_metrics.add("jpeg_decode_frames", { { "decoder", "software" }, { "result", "fail" } }, &metric_jpeg_software_fail_frames);
 351                 global_metrics.add("jpeg_decode_frames", { { "decoder", "vaapi" }, { "result", "decode" } }, &metric_jpeg_vaapi_decode_frames);
 352                 global_metrics.add("jpeg_decode_frames", { { "decoder", "vaapi" }, { "result", "fail" } }, &metric_jpeg_vaapi_fail_frames);
 353         });
 354 }
 355
 356 void JPEGFrameView::setFrame(unsigned stream_idx, FrameOnDisk frame, FrameOnDisk secondary_frame, float fade_alpha)
 357 {
 358         current_stream_idx = stream_idx;  // TODO: Does this interact with fades?
 359
 360         lock_guard<mutex> lock(cache_mu);
 361         PendingDecode decode;
 362         decode.primary = frame;
 363         decode.secondary = secondary_frame;
 364         decode.fade_alpha = fade_alpha;
 365         pending_decodes.push_back(decode);
 366         any_pending_decodes.notify_all();
 367 }
 368
 369 void JPEGFrameView::setFrame(shared_ptr<Frame> frame)
 370 {
 371         lock_guard<mutex> lock(cache_mu);
 372         PendingDecode decode;
 373         decode.frame = std::move(frame);
 374         pending_decodes.push_back(decode);
 375         any_pending_decodes.notify_all();
 376 }
 377
 378 void JPEGFrameView::initializeGL()
 379 {
 380         glDisable(GL_BLEND);
 381         glDisable(GL_DEPTH_TEST);
 382         check_error();
 383
 384         resource_pool = new ResourcePool;
 385         jpeg_decoder_thread = std::thread(&JPEGFrameView::jpeg_decoder_thread_func, this);
 386
 387         ycbcr_converter.reset(new YCbCrConverter(YCbCrConverter::OUTPUT_TO_RGBA, resource_pool));
 388
 389         ImageFormat inout_format;
 390         inout_format.color_space = COLORSPACE_sRGB;
 391         inout_format.gamma_curve = GAMMA_sRGB;
 392
 393         overlay_chain.reset(new EffectChain(overlay_base_width, overlay_base_height, resource_pool));
 394         overlay_input = (movit::FlatInput *)overlay_chain->add_input(new FlatInput(inout_format, FORMAT_GRAYSCALE, GL_UNSIGNED_BYTE, overlay_base_width, overlay_base_height));
 395
 396         overlay_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
 397         overlay_chain->finalize();
 398 }
 399
 400 void JPEGFrameView::resizeGL(int width, int height)
 401 {
 402         check_error();
 403         glViewport(0, 0, width, height);
 404         check_error();
 405
 406         // Save these, as width() and height() will lie with DPI scaling.
 407         gl_width = width;
 408         gl_height = height;
 409 }
 410
 411 void JPEGFrameView::paintGL()
 412 {
 413         glViewport(0, 0, gl_width, gl_height);
 414         if (current_frame == nullptr) {
 415                 glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
 416                 glClear(GL_COLOR_BUFFER_BIT);
 417                 return;
 418         }
 419
 420         check_error();
 421         current_chain->render_to_screen();
 422
 423         if (overlay_image != nullptr) {
 424                 if (overlay_input_needs_refresh) {
 425                         overlay_input->set_width(overlay_width);
 426                         overlay_input->set_height(overlay_height);
 427                         overlay_input->set_pixel_data(overlay_image->bits());
 428                         overlay_input_needs_refresh = false;
 429                 }
 430                 glViewport(gl_width - overlay_width, 0, overlay_width, overlay_height);
 431                 overlay_chain->render_to_screen();
 432         }
 433 }
 434
 435 namespace {
 436
 437 }  // namespace
 438
 439 void JPEGFrameView::setDecodedFrame(shared_ptr<Frame> frame, shared_ptr<Frame> secondary_frame, float fade_alpha)
 440 {
 441         post_to_main_thread([this, frame, secondary_frame, fade_alpha] {
 442                 current_frame = frame;
 443                 current_secondary_frame = secondary_frame;
 444
 445                 if (secondary_frame != nullptr) {
 446                         current_chain = ycbcr_converter->prepare_chain_for_fade(frame, secondary_frame, fade_alpha);
 447                 } else {
 448                         current_chain = ycbcr_converter->prepare_chain_for_conversion(frame);
 449                 }
 450                 update();
 451         });
 452 }
 453
 454 void JPEGFrameView::mousePressEvent(QMouseEvent *event)
 455 {
 456         if (event->type() == QEvent::MouseButtonPress && event->button() == Qt::LeftButton) {
 457                 emit clicked();
 458         }
 459 }
 460
 461 void JPEGFrameView::set_overlay(const string &text)
 462 {
 463         if (text.empty()) {
 464                 overlay_image.reset();
 465                 return;
 466         }
 467
 468         // Figure out how large the texture needs to be.
 469         {
 470                 QImage img(overlay_width, overlay_height, QImage::Format_Grayscale8);
 471                 QPainter painter(&img);
 472                 QFont font = painter.font();
 473                 font.setPointSize(12);
 474                 QFontMetrics metrics(font);
 475                 overlay_base_width = lrint(metrics.boundingRect(QString::fromStdString(text)).width() + 8.0);
 476                 overlay_base_height = lrint(metrics.height());
 477         }
 478
 479         float dpr = QGuiApplication::primaryScreen()->devicePixelRatio();
 480         overlay_width = lrint(overlay_base_width * dpr);
 481         overlay_height = lrint(overlay_base_height * dpr);
 482
 483         // Work around OpenGL alignment issues.
 484         while (overlay_width % 4 != 0) ++overlay_width;
 485
 486         // Now do the actual drawing.
 487         overlay_image.reset(new QImage(overlay_width, overlay_height, QImage::Format_Grayscale8));
 488         overlay_image->setDevicePixelRatio(dpr);
 489         overlay_image->fill(0);
 490         QPainter painter(overlay_image.get());
 491
 492         painter.setPen(Qt::white);
 493         QFont font = painter.font();
 494         font.setPointSize(12);
 495         painter.setFont(font);
 496
 497         painter.drawText(QRectF(0, 0, overlay_base_width, overlay_base_height), Qt::AlignCenter, QString::fromStdString(text));
 498
 499         // Don't refresh immediately; we might not have an OpenGL context here.
 500         overlay_input_needs_refresh = true;
 501 }
 502
 503 shared_ptr<Frame> get_black_frame()
 504 {
 505         static shared_ptr<Frame> black_frame;
 506         static once_flag flag;
 507         call_once(flag, [] {
 508                 black_frame.reset(new Frame);
 509                 black_frame->y.reset(new uint8_t[global_flags.width * global_flags.height]);
 510                 black_frame->cb.reset(new uint8_t[(global_flags.width / 2) * (global_flags.height / 2)]);
 511                 black_frame->cr.reset(new uint8_t[(global_flags.width / 2) * (global_flags.height / 2)]);
 512                 black_frame->width = global_flags.width;
 513                 black_frame->height = global_flags.height;
 514                 black_frame->chroma_subsampling_x = 2;
 515                 black_frame->chroma_subsampling_y = 2;
 516                 black_frame->pitch_y = global_flags.width;
 517                 black_frame->pitch_chroma = global_flags.width / 2;
 518         });
 519         ++metric_jpeg_software_fail_frames;
 520         return black_frame;
 521 }