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 <movit/resource_pool.h>
  14 #include <movit/init.h>
  15 #include <movit/util.h>
  16
  17 #include "defs.h"
  18 #include "post_to_main_thread.h"
  19
  20 using namespace movit;
  21 using namespace std;
  22
  23 string filename_for_frame(unsigned stream_idx, int64_t pts);
  24
  25 struct JPEGID {
  26         unsigned stream_idx;
  27         int64_t pts;
  28 };
  29 bool operator< (const JPEGID &a, const JPEGID &b) {
  30         return make_pair(a.stream_idx, a.pts) < make_pair(b.stream_idx, b.pts);
  31 }
  32
  33 struct LRUFrame {
  34         shared_ptr<Frame> frame;
  35         size_t last_used;
  36 };
  37
  38 mutex cache_mu;
  39 map<JPEGID, LRUFrame> cache;  // Under cache_mu.
  40 condition_variable any_pending_decodes;
  41 deque<pair<JPEGID, JPEGFrameView *>> pending_decodes;  // Under cache_mu.
  42 atomic<size_t> event_counter{0};
  43 extern QGLWidget *global_share_widget;
  44
  45 // TODO: Decode using VA-API if available.
  46 shared_ptr<Frame> decode_jpeg(const string &filename)
  47 {
  48         shared_ptr<Frame> frame(new Frame);
  49
  50         jpeg_decompress_struct dinfo;
  51         jpeg_error_mgr jerr;
  52         dinfo.err = jpeg_std_error(&jerr);
  53         jpeg_create_decompress(&dinfo);
  54
  55         FILE *fp = fopen(filename.c_str(), "rb");
  56         if (fp == nullptr) {
  57                 perror(filename.c_str());
  58                 exit(1);
  59         }
  60         jpeg_stdio_src(&dinfo, fp);
  61
  62         jpeg_read_header(&dinfo, true);
  63
  64         if (dinfo.num_components != 3) {
  65                 fprintf(stderr, "Not a color JPEG. (%d components, Y=%dx%d, Cb=%dx%d, Cr=%dx%d)\n",
  66                         dinfo.num_components,
  67                         dinfo.comp_info[0].h_samp_factor, dinfo.comp_info[0].v_samp_factor,
  68                         dinfo.comp_info[1].h_samp_factor, dinfo.comp_info[1].v_samp_factor,
  69                         dinfo.comp_info[2].h_samp_factor, dinfo.comp_info[2].v_samp_factor);
  70                 exit(1);
  71         }
  72         if (dinfo.comp_info[0].h_samp_factor != dinfo.max_h_samp_factor ||
  73             dinfo.comp_info[0].v_samp_factor != dinfo.max_v_samp_factor ||  // Y' must not be subsampled.
  74             dinfo.comp_info[1].h_samp_factor != dinfo.comp_info[2].h_samp_factor ||
  75             dinfo.comp_info[1].v_samp_factor != dinfo.comp_info[2].v_samp_factor ||  // Cb and Cr must be identically subsampled.
  76             (dinfo.max_h_samp_factor % dinfo.comp_info[1].h_samp_factor) != 0 ||
  77             (dinfo.max_v_samp_factor % dinfo.comp_info[1].v_samp_factor) != 0) {  // No 2:3 subsampling or other weirdness.
  78                 fprintf(stderr, "Unsupported subsampling scheme. (Y=%dx%d, Cb=%dx%d, Cr=%dx%d)\n",
  79                         dinfo.comp_info[0].h_samp_factor, dinfo.comp_info[0].v_samp_factor,
  80                         dinfo.comp_info[1].h_samp_factor, dinfo.comp_info[1].v_samp_factor,
  81                         dinfo.comp_info[2].h_samp_factor, dinfo.comp_info[2].v_samp_factor);
  82                 exit(1);
  83         }
  84         dinfo.raw_data_out = true;
  85
  86         jpeg_start_decompress(&dinfo);
  87
  88         frame->width = dinfo.output_width;
  89         frame->height = dinfo.output_height;
  90         frame->chroma_subsampling_x = dinfo.max_h_samp_factor / dinfo.comp_info[1].h_samp_factor;
  91         frame->chroma_subsampling_y = dinfo.max_v_samp_factor / dinfo.comp_info[1].v_samp_factor;
  92
  93         unsigned h_mcu_size = DCTSIZE * dinfo.max_h_samp_factor;
  94         unsigned v_mcu_size = DCTSIZE * dinfo.max_v_samp_factor;
  95         unsigned mcu_width_blocks = (dinfo.output_width + h_mcu_size - 1) / h_mcu_size;
  96         unsigned mcu_height_blocks = (dinfo.output_height + v_mcu_size - 1) / v_mcu_size;
  97
  98         unsigned luma_width_blocks = mcu_width_blocks * dinfo.comp_info[0].h_samp_factor;
  99         unsigned chroma_width_blocks = mcu_width_blocks * dinfo.comp_info[1].h_samp_factor;
 100         unsigned luma_height_blocks = mcu_height_blocks * dinfo.comp_info[0].v_samp_factor;
 101         unsigned chroma_height_blocks = mcu_height_blocks * dinfo.comp_info[1].v_samp_factor;
 102
 103         // TODO: Decode into a PBO.
 104         frame->y.reset(new uint8_t[luma_width_blocks * luma_height_blocks * DCTSIZE2]);
 105         frame->cb.reset(new uint8_t[chroma_width_blocks * chroma_height_blocks * DCTSIZE2]);
 106         frame->cr.reset(new uint8_t[chroma_width_blocks * chroma_height_blocks * DCTSIZE2]);
 107         frame->pitch_y = luma_width_blocks * DCTSIZE;
 108         frame->pitch_chroma = chroma_width_blocks * DCTSIZE;
 109
 110         JSAMPROW yptr[v_mcu_size], cbptr[v_mcu_size], crptr[v_mcu_size];
 111         JSAMPARRAY data[3] = { yptr, cbptr, crptr };
 112         for (unsigned y = 0; y < mcu_height_blocks; ++y) {
 113                 // NOTE: The last elements of cbptr/crptr will be unused for vertically subsampled chroma.
 114                 for (unsigned yy = 0; yy < v_mcu_size; ++yy) {
 115                         yptr[yy] = frame->y.get() + (y * DCTSIZE * dinfo.max_v_samp_factor + yy) * frame->pitch_y;
 116                         cbptr[yy] = frame->cb.get() + (y * DCTSIZE * dinfo.comp_info[1].v_samp_factor + yy) * frame->pitch_chroma;
 117                         crptr[yy] = frame->cr.get() + (y * DCTSIZE * dinfo.comp_info[1].v_samp_factor + yy) * frame->pitch_chroma;
 118                 }
 119
 120                 jpeg_read_raw_data(&dinfo, data, v_mcu_size);
 121         }
 122
 123         (void) jpeg_finish_decompress(&dinfo);
 124         jpeg_destroy_decompress(&dinfo);
 125         fclose(fp);
 126
 127         return frame;
 128 }
 129
 130 void prune_cache()
 131 {
 132         // Assumes cache_mu is held.
 133         vector<size_t> lru_timestamps;
 134         for (const auto &key_and_value : cache) {
 135                 lru_timestamps.push_back(key_and_value.second.last_used);
 136         }
 137
 138         size_t cutoff_point = CACHE_SIZE / 10;  // Prune away the 10% oldest ones.
 139         nth_element(lru_timestamps.begin(), lru_timestamps.begin() + cutoff_point, lru_timestamps.end());
 140         size_t must_be_used_after = lru_timestamps[cutoff_point];
 141         for (auto it = cache.begin(); it != cache.end(); ) {
 142                 if (it->second.last_used < must_be_used_after) {
 143                         it = cache.erase(it);
 144                 } else {
 145                         ++it;
 146                 }
 147         }
 148 }
 149
 150 void jpeg_decoder_thread()
 151 {
 152         size_t num_decoded = 0, num_dropped = 0;
 153
 154         pthread_setname_np(pthread_self(), "JPEGDecoder");
 155         for ( ;; ) {
 156                 JPEGID id;
 157                 JPEGFrameView *dest;
 158                 shared_ptr<Frame> frame;
 159                 {
 160                         unique_lock<mutex> lock(cache_mu);
 161                         any_pending_decodes.wait(lock, [] {
 162                                 return !pending_decodes.empty();
 163                         });
 164                         id = pending_decodes.front().first;
 165                         dest = pending_decodes.front().second;
 166                         pending_decodes.pop_front();
 167
 168                         auto it = cache.find(id);
 169                         if (it != cache.end()) {
 170                                 frame = it->second.frame;
 171                                 it->second.last_used = event_counter++;
 172                         }
 173                 }
 174
 175                 if (frame == nullptr) {
 176                         // Not found in the cache, so we need to do a decode or drop the request.
 177                         // Prune the queue if there are too many pending for this destination.
 178                         // TODO: Could we get starvation here?
 179                         size_t num_pending = 0;
 180                         for (const pair<JPEGID, JPEGFrameView *> &decode : pending_decodes) {
 181                                 if (decode.second == dest) {
 182                                         ++num_pending;
 183                                 }
 184                         }
 185                         if (num_pending > 3) {
 186                                 ++num_dropped;
 187                                 continue;
 188                         }
 189
 190                         frame = decode_jpeg(filename_for_frame(id.stream_idx, id.pts));
 191
 192                         unique_lock<mutex> lock(cache_mu);
 193                         cache[id] = LRUFrame{ frame, event_counter++ };
 194
 195                         if (cache.size() > CACHE_SIZE) {
 196                                 prune_cache();
 197                         }
 198                         ++num_decoded;
 199                         if (num_decoded % 1000 == 0) {
 200                                 fprintf(stderr, "Decoded %zu images, dropped %zu (%.2f%% dropped)\n",
 201                                         num_decoded, num_dropped, (100.0 * num_dropped) / (num_decoded + num_dropped));
 202                         }
 203                 }
 204
 205                 dest->setDecodedFrame(frame);
 206         }
 207 }
 208
 209 JPEGFrameView::JPEGFrameView(QWidget *parent)
 210         : QGLWidget(parent, global_share_widget) {
 211 }
 212
 213 void JPEGFrameView::update_frame()
 214 {
 215         unique_lock<mutex> lock(cache_mu);
 216         pending_decodes.emplace_back(JPEGID{ stream_idx, pts }, this);
 217         any_pending_decodes.notify_all();
 218 }
 219
 220 ResourcePool *resource_pool = nullptr;
 221
 222 void JPEGFrameView::initializeGL()
 223 {
 224         glDisable(GL_BLEND);
 225         glDisable(GL_DEPTH_TEST);
 226         glDepthMask(GL_FALSE);
 227         check_error();
 228
 229         static once_flag once;
 230         call_once(once, [] {
 231                 CHECK(init_movit(MOVIT_SHADER_DIR, MOVIT_DEBUG_OFF));
 232                 resource_pool = new ResourcePool;
 233
 234                 std::thread(&jpeg_decoder_thread).detach();
 235         });
 236
 237         chain.reset(new EffectChain(1280, 720, resource_pool));
 238         ImageFormat image_format;
 239         image_format.color_space = COLORSPACE_sRGB;
 240         image_format.gamma_curve = GAMMA_sRGB;
 241         ycbcr_format.luma_coefficients = YCBCR_REC_709;
 242         ycbcr_format.full_range = false;
 243         ycbcr_format.num_levels = 256;
 244         ycbcr_format.chroma_subsampling_x = 2;
 245         ycbcr_format.chroma_subsampling_y = 1;
 246         ycbcr_format.cb_x_position = 0.0f;  // H.264 -- _not_ JPEG, even though our input is MJPEG-encoded
 247         ycbcr_format.cb_y_position = 0.5f;  // Irrelevant.
 248         ycbcr_format.cr_x_position = 0.0f;
 249         ycbcr_format.cr_y_position = 0.5f;
 250         ycbcr_input = (movit::YCbCrInput *)chain->add_input(new YCbCrInput(image_format, ycbcr_format, 1280, 720));
 251
 252         ImageFormat inout_format;
 253         inout_format.color_space = COLORSPACE_sRGB;
 254         inout_format.gamma_curve = GAMMA_sRGB;
 255
 256         check_error();
 257         chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
 258         check_error();
 259         chain->set_dither_bits(8);
 260         check_error();
 261         chain->finalize();
 262         check_error();
 263 }
 264
 265 void JPEGFrameView::resizeGL(int width, int height)
 266 {
 267         check_error();
 268         glViewport(0, 0, width, height);
 269         check_error();
 270 }
 271
 272 void JPEGFrameView::paintGL()
 273 {
 274         if (current_frame == nullptr) {
 275                 glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
 276                 glClear(GL_COLOR_BUFFER_BIT);
 277                 return;
 278         }
 279
 280         check_error();
 281         chain->render_to_screen();
 282 }
 283
 284 void JPEGFrameView::setDecodedFrame(std::shared_ptr<Frame> frame)
 285 {
 286         post_to_main_thread([this, frame] {
 287                 current_frame = frame;
 288                 ycbcr_format.chroma_subsampling_x = frame->chroma_subsampling_x;
 289                 ycbcr_format.chroma_subsampling_y = frame->chroma_subsampling_y;
 290                 ycbcr_input->change_ycbcr_format(ycbcr_format);
 291                 ycbcr_input->set_width(frame->width);
 292                 ycbcr_input->set_height(frame->height);
 293                 ycbcr_input->set_pixel_data(0, frame->y.get());
 294                 ycbcr_input->set_pixel_data(1, frame->cb.get());
 295                 ycbcr_input->set_pixel_data(2, frame->cr.get());
 296                 ycbcr_input->set_pitch(0, frame->pitch_y);
 297                 ycbcr_input->set_pitch(1, frame->pitch_chroma);
 298                 ycbcr_input->set_pitch(2, frame->pitch_chroma);
 299                 update();
 300         });
 301 }