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

   1 #include "jpeg_frame_view.h"
   2
   3 #include <jpeglib.h>
   4 #include <stdint.h>
   5
   6 #include <atomic>
   7 #include <condition_variable>
   8 #include <deque>
   9 #include <mutex>
  10 #include <thread>
  11 #include <utility>
  12
  13 #include <QMouseEvent>
  14
  15 #include <movit/resource_pool.h>
  16 #include <movit/init.h>
  17 #include <movit/util.h>
  18
  19 #include "defs.h"
  20 #include "post_to_main_thread.h"
  21 #include "video_stream.h"
  22
  23 using namespace movit;
  24 using namespace std;
  25
  26 bool operator< (const JPEGID &a, const JPEGID &b) {
  27         return make_pair(a.stream_idx, a.pts) < make_pair(b.stream_idx, b.pts);
  28 }
  29
  30 struct LRUFrame {
  31         shared_ptr<Frame> frame;
  32         size_t last_used;
  33 };
  34
  35 mutex cache_mu;
  36 map<JPEGID, LRUFrame> cache;  // Under cache_mu.
  37 condition_variable any_pending_decodes;
  38 deque<pair<JPEGID, JPEGFrameView *>> pending_decodes;  // Under cache_mu.
  39 atomic<size_t> event_counter{0};
  40 extern QGLWidget *global_share_widget;
  41
  42 // TODO: Decode using VA-API if available.
  43 shared_ptr<Frame> decode_jpeg(const string &filename)
  44 {
  45         shared_ptr<Frame> frame(new Frame);
  46
  47         jpeg_decompress_struct dinfo;
  48         jpeg_error_mgr jerr;
  49         dinfo.err = jpeg_std_error(&jerr);
  50         jpeg_create_decompress(&dinfo);
  51
  52         FILE *fp = fopen(filename.c_str(), "rb");
  53         if (fp == nullptr) {
  54                 perror(filename.c_str());
  55                 exit(1);
  56         }
  57         jpeg_stdio_src(&dinfo, fp);
  58
  59         jpeg_read_header(&dinfo, true);
  60
  61         if (dinfo.num_components != 3) {
  62                 fprintf(stderr, "Not a color JPEG. (%d components, Y=%dx%d, Cb=%dx%d, Cr=%dx%d)\n",
  63                         dinfo.num_components,
  64                         dinfo.comp_info[0].h_samp_factor, dinfo.comp_info[0].v_samp_factor,
  65                         dinfo.comp_info[1].h_samp_factor, dinfo.comp_info[1].v_samp_factor,
  66                         dinfo.comp_info[2].h_samp_factor, dinfo.comp_info[2].v_samp_factor);
  67                 exit(1);
  68         }
  69         if (dinfo.comp_info[0].h_samp_factor != dinfo.max_h_samp_factor ||
  70             dinfo.comp_info[0].v_samp_factor != dinfo.max_v_samp_factor ||  // Y' must not be subsampled.
  71             dinfo.comp_info[1].h_samp_factor != dinfo.comp_info[2].h_samp_factor ||
  72             dinfo.comp_info[1].v_samp_factor != dinfo.comp_info[2].v_samp_factor ||  // Cb and Cr must be identically subsampled.
  73             (dinfo.max_h_samp_factor % dinfo.comp_info[1].h_samp_factor) != 0 ||
  74             (dinfo.max_v_samp_factor % dinfo.comp_info[1].v_samp_factor) != 0) {  // No 2:3 subsampling or other weirdness.
  75                 fprintf(stderr, "Unsupported subsampling scheme. (Y=%dx%d, Cb=%dx%d, Cr=%dx%d)\n",
  76                         dinfo.comp_info[0].h_samp_factor, dinfo.comp_info[0].v_samp_factor,
  77                         dinfo.comp_info[1].h_samp_factor, dinfo.comp_info[1].v_samp_factor,
  78                         dinfo.comp_info[2].h_samp_factor, dinfo.comp_info[2].v_samp_factor);
  79                 exit(1);
  80         }
  81         dinfo.raw_data_out = true;
  82
  83         jpeg_start_decompress(&dinfo);
  84
  85         frame->width = dinfo.output_width;
  86         frame->height = dinfo.output_height;
  87         frame->chroma_subsampling_x = dinfo.max_h_samp_factor / dinfo.comp_info[1].h_samp_factor;
  88         frame->chroma_subsampling_y = dinfo.max_v_samp_factor / dinfo.comp_info[1].v_samp_factor;
  89
  90         unsigned h_mcu_size = DCTSIZE * dinfo.max_h_samp_factor;
  91         unsigned v_mcu_size = DCTSIZE * dinfo.max_v_samp_factor;
  92         unsigned mcu_width_blocks = (dinfo.output_width + h_mcu_size - 1) / h_mcu_size;
  93         unsigned mcu_height_blocks = (dinfo.output_height + v_mcu_size - 1) / v_mcu_size;
  94
  95         unsigned luma_width_blocks = mcu_width_blocks * dinfo.comp_info[0].h_samp_factor;
  96         unsigned chroma_width_blocks = mcu_width_blocks * dinfo.comp_info[1].h_samp_factor;
  97         unsigned luma_height_blocks = mcu_height_blocks * dinfo.comp_info[0].v_samp_factor;
  98         unsigned chroma_height_blocks = mcu_height_blocks * dinfo.comp_info[1].v_samp_factor;
  99
 100         // TODO: Decode into a PBO.
 101         frame->y.reset(new uint8_t[luma_width_blocks * luma_height_blocks * DCTSIZE2]);
 102         frame->cb.reset(new uint8_t[chroma_width_blocks * chroma_height_blocks * DCTSIZE2]);
 103         frame->cr.reset(new uint8_t[chroma_width_blocks * chroma_height_blocks * DCTSIZE2]);
 104         frame->pitch_y = luma_width_blocks * DCTSIZE;
 105         frame->pitch_chroma = chroma_width_blocks * DCTSIZE;
 106
 107         JSAMPROW yptr[v_mcu_size], cbptr[v_mcu_size], crptr[v_mcu_size];
 108         JSAMPARRAY data[3] = { yptr, cbptr, crptr };
 109         for (unsigned y = 0; y < mcu_height_blocks; ++y) {
 110                 // NOTE: The last elements of cbptr/crptr will be unused for vertically subsampled chroma.
 111                 for (unsigned yy = 0; yy < v_mcu_size; ++yy) {
 112                         yptr[yy] = frame->y.get() + (y * DCTSIZE * dinfo.max_v_samp_factor + yy) * frame->pitch_y;
 113                         cbptr[yy] = frame->cb.get() + (y * DCTSIZE * dinfo.comp_info[1].v_samp_factor + yy) * frame->pitch_chroma;
 114                         crptr[yy] = frame->cr.get() + (y * DCTSIZE * dinfo.comp_info[1].v_samp_factor + yy) * frame->pitch_chroma;
 115                 }
 116
 117                 jpeg_read_raw_data(&dinfo, data, v_mcu_size);
 118         }
 119
 120         (void) jpeg_finish_decompress(&dinfo);
 121         jpeg_destroy_decompress(&dinfo);
 122         fclose(fp);
 123
 124         return frame;
 125 }
 126
 127 void prune_cache()
 128 {
 129         // Assumes cache_mu is held.
 130         vector<size_t> lru_timestamps;
 131         for (const auto &key_and_value : cache) {
 132                 lru_timestamps.push_back(key_and_value.second.last_used);
 133         }
 134
 135         size_t cutoff_point = CACHE_SIZE / 10;  // Prune away the 10% oldest ones.
 136         nth_element(lru_timestamps.begin(), lru_timestamps.begin() + cutoff_point, lru_timestamps.end());
 137         size_t must_be_used_after = lru_timestamps[cutoff_point];
 138         for (auto it = cache.begin(); it != cache.end(); ) {
 139                 if (it->second.last_used < must_be_used_after) {
 140                         it = cache.erase(it);
 141                 } else {
 142                         ++it;
 143                 }
 144         }
 145 }
 146
 147 shared_ptr<Frame> decode_jpeg_with_cache(JPEGID id, CacheMissBehavior cache_miss_behavior, bool *did_decode)
 148 {
 149         *did_decode = false;
 150         {
 151                 unique_lock<mutex> lock(cache_mu);
 152                 auto it = cache.find(id);
 153                 if (it != cache.end()) {
 154                         it->second.last_used = event_counter++;
 155                         return it->second.frame;
 156                 }
 157         }
 158
 159         if (cache_miss_behavior == RETURN_NULLPTR_IF_NOT_IN_CACHE) {
 160                 return nullptr;
 161         }
 162
 163         *did_decode = true;
 164         shared_ptr<Frame> frame = decode_jpeg(filename_for_frame(id.stream_idx, id.pts));
 165
 166         unique_lock<mutex> lock(cache_mu);
 167         cache[id] = LRUFrame{ frame, event_counter++ };
 168
 169         if (cache.size() > CACHE_SIZE) {
 170                 prune_cache();
 171         }
 172         return frame;
 173 }
 174
 175 void jpeg_decoder_thread()
 176 {
 177         size_t num_decoded = 0, num_dropped = 0;
 178
 179         pthread_setname_np(pthread_self(), "JPEGDecoder");
 180         for ( ;; ) {
 181                 JPEGID id;
 182                 JPEGFrameView *dest;
 183                 CacheMissBehavior cache_miss_behavior = DECODE_IF_NOT_IN_CACHE;
 184                 {
 185                         unique_lock<mutex> lock(cache_mu);  // TODO: Perhaps under another lock?
 186                         any_pending_decodes.wait(lock, [] {
 187                                 return !pending_decodes.empty();
 188                         });
 189                         id = pending_decodes.front().first;
 190                         dest = pending_decodes.front().second;
 191                         pending_decodes.pop_front();
 192
 193                         size_t num_pending = 0;
 194                         for (const pair<JPEGID, JPEGFrameView *> &decode : pending_decodes) {
 195                                 if (decode.second == dest) {
 196                                         ++num_pending;
 197                                 }
 198                         }
 199                         if (num_pending > 3) {
 200                                 cache_miss_behavior = RETURN_NULLPTR_IF_NOT_IN_CACHE;
 201                         }
 202                 }
 203
 204                 bool found_in_cache;
 205                 shared_ptr<Frame> frame = decode_jpeg_with_cache(id, cache_miss_behavior, &found_in_cache);
 206
 207                 if (frame == nullptr) {
 208                         assert(cache_miss_behavior == RETURN_NULLPTR_IF_NOT_IN_CACHE);
 209                         ++num_dropped;
 210                         continue;
 211                 }
 212
 213                 if (!found_in_cache) {
 214                         ++num_decoded;
 215                         if (num_decoded % 1000 == 0) {
 216                                 fprintf(stderr, "Decoded %zu images, dropped %zu (%.2f%% dropped)\n",
 217                                         num_decoded, num_dropped, (100.0 * num_dropped) / (num_decoded + num_dropped));
 218                         }
 219                 }
 220
 221                 dest->setDecodedFrame(frame);
 222         }
 223 }
 224
 225 JPEGFrameView::JPEGFrameView(QWidget *parent)
 226         : QGLWidget(parent, global_share_widget) {
 227 }
 228
 229 void JPEGFrameView::update_frame()
 230 {
 231         unique_lock<mutex> lock(cache_mu);
 232         pending_decodes.emplace_back(JPEGID{ stream_idx, pts }, this);
 233         any_pending_decodes.notify_all();
 234 }
 235
 236 ResourcePool *resource_pool = nullptr;
 237
 238 void JPEGFrameView::initializeGL()
 239 {
 240         glDisable(GL_BLEND);
 241         glDisable(GL_DEPTH_TEST);
 242         check_error();
 243
 244         static once_flag once;
 245         call_once(once, [] {
 246                 resource_pool = new ResourcePool;
 247                 std::thread(&jpeg_decoder_thread).detach();
 248         });
 249
 250         chain.reset(new EffectChain(1280, 720, resource_pool));
 251         ImageFormat image_format;
 252         image_format.color_space = COLORSPACE_sRGB;
 253         image_format.gamma_curve = GAMMA_sRGB;
 254         ycbcr_format.luma_coefficients = YCBCR_REC_709;
 255         ycbcr_format.full_range = false;
 256         ycbcr_format.num_levels = 256;
 257         ycbcr_format.chroma_subsampling_x = 2;
 258         ycbcr_format.chroma_subsampling_y = 1;
 259         ycbcr_format.cb_x_position = 0.0f;  // H.264 -- _not_ JPEG, even though our input is MJPEG-encoded
 260         ycbcr_format.cb_y_position = 0.5f;  // Irrelevant.
 261         ycbcr_format.cr_x_position = 0.0f;
 262         ycbcr_format.cr_y_position = 0.5f;
 263         ycbcr_input = (movit::YCbCrInput *)chain->add_input(new YCbCrInput(image_format, ycbcr_format, 1280, 720));
 264
 265         ImageFormat inout_format;
 266         inout_format.color_space = COLORSPACE_sRGB;
 267         inout_format.gamma_curve = GAMMA_sRGB;
 268
 269         check_error();
 270         chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
 271         check_error();
 272         chain->set_dither_bits(8);
 273         check_error();
 274         chain->finalize();
 275         check_error();
 276 }
 277
 278 void JPEGFrameView::resizeGL(int width, int height)
 279 {
 280         check_error();
 281         glViewport(0, 0, width, height);
 282         check_error();
 283 }
 284
 285 void JPEGFrameView::paintGL()
 286 {
 287         if (current_frame == nullptr) {
 288                 glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
 289                 glClear(GL_COLOR_BUFFER_BIT);
 290                 return;
 291         }
 292
 293         check_error();
 294         chain->render_to_screen();
 295 }
 296
 297 void JPEGFrameView::setDecodedFrame(std::shared_ptr<Frame> frame)
 298 {
 299         post_to_main_thread([this, frame] {
 300                 current_frame = frame;
 301                 ycbcr_format.chroma_subsampling_x = frame->chroma_subsampling_x;
 302                 ycbcr_format.chroma_subsampling_y = frame->chroma_subsampling_y;
 303                 ycbcr_input->change_ycbcr_format(ycbcr_format);
 304                 ycbcr_input->set_width(frame->width);
 305                 ycbcr_input->set_height(frame->height);
 306                 ycbcr_input->set_pixel_data(0, frame->y.get());
 307                 ycbcr_input->set_pixel_data(1, frame->cb.get());
 308                 ycbcr_input->set_pixel_data(2, frame->cr.get());
 309                 ycbcr_input->set_pitch(0, frame->pitch_y);
 310                 ycbcr_input->set_pitch(1, frame->pitch_chroma);
 311                 ycbcr_input->set_pitch(2, frame->pitch_chroma);
 312                 update();
 313         });
 314 }
 315
 316 void JPEGFrameView::mousePressEvent(QMouseEvent *event)
 317 {
 318         if (event->type() == QEvent::MouseButtonPress && event->button() == Qt::LeftButton) {
 319                 emit clicked();
 320         }
 321 }