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

   1 #include "image_input.h"
   2
   3 #include <errno.h>
   4 #include <movit/flat_input.h>
   5 #include <movit/image_format.h>
   6 #include <stdint.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10
  11 extern "C" {
  12 #include <libavcodec/avcodec.h>
  13 #include <libavformat/avformat.h>
  14 #include <libavutil/avutil.h>
  15 #include <libavutil/error.h>
  16 #include <libavutil/frame.h>
  17 #include <libavutil/imgutils.h>
  18 #include <libavutil/mem.h>
  19 #include <libavutil/pixfmt.h>
  20 #include <libswscale/swscale.h>
  21 }
  22
  23 #include <fcntl.h>
  24 #include <sys/stat.h>
  25 #include <unistd.h>
  26 #include <cstddef>
  27 #include <functional>
  28 #include <mutex>
  29 #include <thread>
  30 #include <utility>
  31 #include <vector>
  32
  33 #include "shared/ffmpeg_raii.h"
  34 #include "ffmpeg_util.h"
  35 #include "flags.h"
  36
  37 struct SwsContext;
  38
  39 using namespace std;
  40
  41 ImageInput::ImageInput(const string &filename)
  42         : movit::FlatInput({movit::COLORSPACE_sRGB, movit::GAMMA_sRGB}, movit::FORMAT_RGBA_POSTMULTIPLIED_ALPHA,
  43                            GL_UNSIGNED_BYTE, 1280, 720),  // Resolution will be overwritten.
  44           pathname(search_for_file_or_die(filename)),
  45           current_image(load_image(filename, pathname))
  46 {
  47         if (current_image == nullptr) {  // Could happen even though search_for_file() returned.
  48                 fprintf(stderr, "Couldn't load image, exiting.\n");
  49                 abort();
  50         }
  51         set_width(current_image->width);
  52         set_height(current_image->height);
  53         set_pixel_data(current_image->pixels.get());
  54 }
  55
  56 void ImageInput::set_gl_state(GLuint glsl_program_num, const string& prefix, unsigned *sampler_num)
  57 {
  58         // See if the background thread has given us a new version of our image.
  59         // Note: The old version might still be lying around in other ImageInputs
  60         // (in fact, it's likely), but at least the total amount of memory used
  61         // is bounded. Currently we don't even share textures between them,
  62         // so there's a fair amount of OpenGL memory waste anyway (the cache
  63         // is mostly there to save startup time, not RAM).
  64         {
  65                 lock_guard<mutex> lock(all_images_lock);
  66                 if (all_images[pathname] != current_image) {
  67                         current_image = all_images[pathname];
  68                         set_pixel_data(current_image->pixels.get());
  69                 }
  70         }
  71         movit::FlatInput::set_gl_state(glsl_program_num, prefix, sampler_num);
  72 }
  73
  74 shared_ptr<const ImageInput::Image> ImageInput::load_image(const string &filename, const string &pathname)
  75 {
  76         lock_guard<mutex> lock(all_images_lock);  // Held also during loading.
  77         if (all_images.count(pathname)) {
  78                 return all_images[pathname];
  79         }
  80
  81         all_images[pathname] = load_image_raw(pathname);
  82
  83         if (!update_thread_started) {
  84                 update_thread = thread(update_thread_func);
  85                 update_thread_started = true;
  86         }
  87
  88         return all_images[pathname];
  89 }
  90
  91 shared_ptr<const ImageInput::Image> ImageInput::load_image_raw(const string &pathname)
  92 {
  93         // Note: Call before open, not after; otherwise, there's a race.
  94         // (There is now, too, but it tips the correct way. We could use fstat()
  95         // if we had the file descriptor.)
  96         struct stat buf;
  97         if (stat(pathname.c_str(), &buf) != 0) {
  98                 fprintf(stderr, "%s: Error stat-ing file\n", pathname.c_str());
  99                 return nullptr;
 100         }
 101         timespec last_modified = buf.st_mtim;
 102
 103         auto format_ctx = avformat_open_input_unique(pathname.c_str(), nullptr, nullptr);
 104         if (format_ctx == nullptr) {
 105                 fprintf(stderr, "%s: Error opening file\n", pathname.c_str());
 106                 return nullptr;
 107         }
 108
 109         if (avformat_find_stream_info(format_ctx.get(), nullptr) < 0) {
 110                 fprintf(stderr, "%s: Error finding stream info\n", pathname.c_str());
 111                 return nullptr;
 112         }
 113
 114         int stream_index = find_stream_index(format_ctx.get(), AVMEDIA_TYPE_VIDEO);
 115         if (stream_index == -1) {
 116                 fprintf(stderr, "%s: No video stream found\n", pathname.c_str());
 117                 return nullptr;
 118         }
 119
 120         const AVCodecParameters *codecpar = format_ctx->streams[stream_index]->codecpar;
 121         AVCodecContextWithDeleter codec_ctx = avcodec_alloc_context3_unique(nullptr);
 122         if (avcodec_parameters_to_context(codec_ctx.get(), codecpar) < 0) {
 123                 fprintf(stderr, "%s: Cannot fill codec parameters\n", pathname.c_str());
 124                 return nullptr;
 125         }
 126         AVCodec *codec = avcodec_find_decoder(codecpar->codec_id);
 127         if (codec == nullptr) {
 128                 fprintf(stderr, "%s: Cannot find decoder\n", pathname.c_str());
 129                 return nullptr;
 130         }
 131         if (avcodec_open2(codec_ctx.get(), codec, nullptr) < 0) {
 132                 fprintf(stderr, "%s: Cannot open decoder\n", pathname.c_str());
 133                 return nullptr;
 134         }
 135         unique_ptr<AVCodecContext, decltype(avcodec_close)*> codec_ctx_cleanup(
 136                 codec_ctx.get(), avcodec_close);
 137
 138         // Read packets until we have a frame or there are none left.
 139         int frame_finished = 0;
 140         AVFrameWithDeleter frame = av_frame_alloc_unique();
 141         bool eof = false;
 142         do {
 143                 AVPacket pkt;
 144                 unique_ptr<AVPacket, decltype(av_packet_unref)*> pkt_cleanup(
 145                         &pkt, av_packet_unref);
 146                 av_init_packet(&pkt);
 147                 pkt.data = nullptr;
 148                 pkt.size = 0;
 149                 if (av_read_frame(format_ctx.get(), &pkt) == 0) {
 150                         if (pkt.stream_index != stream_index) {
 151                                 continue;
 152                         }
 153                         if (avcodec_send_packet(codec_ctx.get(), &pkt) < 0) {
 154                                 fprintf(stderr, "%s: Cannot send packet to codec.\n", pathname.c_str());
 155                                 return nullptr;
 156                         }
 157                 } else {
 158                         eof = true;  // Or error, but ignore that for the time being.
 159                 }
 160
 161                 int err = avcodec_receive_frame(codec_ctx.get(), frame.get());
 162                 if (err == 0) {
 163                         frame_finished = true;
 164                         break;
 165                 } else if (err != AVERROR(EAGAIN)) {
 166                         fprintf(stderr, "%s: Cannot receive frame from codec.\n", pathname.c_str());
 167                         return nullptr;
 168                 }
 169         } while (!eof);
 170
 171         if (!frame_finished) {
 172                 fprintf(stderr, "%s: Decoder did not output frame.\n", pathname.c_str());
 173                 return nullptr;
 174         }
 175
 176         uint8_t *pic_data[4] = {nullptr};
 177         unique_ptr<uint8_t *, decltype(av_freep)*> pic_data_cleanup(
 178                 &pic_data[0], av_freep);
 179         int linesizes[4];
 180         if (av_image_alloc(pic_data, linesizes, frame->width, frame->height, AV_PIX_FMT_RGBA, 1) < 0) {
 181                 fprintf(stderr, "%s: Could not allocate picture data\n", pathname.c_str());
 182                 return nullptr;
 183         }
 184         unique_ptr<SwsContext, decltype(sws_freeContext)*> sws_ctx(
 185                 sws_getContext(frame->width, frame->height,
 186                         (AVPixelFormat)frame->format, frame->width, frame->height,
 187                         AV_PIX_FMT_RGBA, SWS_BICUBIC, nullptr, nullptr, nullptr),
 188                 sws_freeContext);
 189         if (sws_ctx == nullptr) {
 190                 fprintf(stderr, "%s: Could not create scaler context\n", pathname.c_str());
 191                 return nullptr;
 192         }
 193         sws_scale(sws_ctx.get(), frame->data, frame->linesize, 0, frame->height, pic_data, linesizes);
 194
 195         size_t len = frame->width * frame->height * 4;
 196         unique_ptr<uint8_t[]> image_data(new uint8_t[len]);
 197         av_image_copy_to_buffer(image_data.get(), len, pic_data, linesizes, AV_PIX_FMT_RGBA, frame->width, frame->height, 1);
 198
 199         shared_ptr<Image> image(new Image{unsigned(frame->width), unsigned(frame->height), move(image_data), last_modified});
 200         return image;
 201 }
 202
 203 // Fire up a thread to update all images every second.
 204 // We could do inotify, but this is good enough for now.
 205 void ImageInput::update_thread_func()
 206 {
 207         pthread_setname_np(pthread_self(), "Update_Images");
 208
 209         struct stat buf;
 210         for ( ;; ) {
 211                 {
 212                         unique_lock<mutex> lock(threads_should_quit_mu);
 213                         threads_should_quit_modified.wait_for(lock, chrono::seconds(1), []() { return threads_should_quit; });
 214                 }
 215                 if (threads_should_quit) {
 216                         return;
 217                 }
 218
 219                 // Go through all loaded images and see if they need to be updated.
 220                 // We do one pass first through the array with no I/O, to avoid
 221                 // blocking the renderer.
 222                 vector<pair<string, timespec>> images_to_check;
 223                 {
 224                         unique_lock<mutex> lock(all_images_lock);
 225                         for (const auto &pathname_and_image : all_images) {
 226                                 const string pathname = pathname_and_image.first;
 227                                 const timespec last_modified = pathname_and_image.second->last_modified;
 228                                 images_to_check.emplace_back(pathname, last_modified);
 229                         }
 230                 }
 231
 232                 for (const auto &pathname_and_timespec : images_to_check) {
 233                         const string pathname = pathname_and_timespec.first;
 234                         const timespec last_modified = pathname_and_timespec.second;
 235
 236                         if (stat(pathname.c_str(), &buf) != 0) {
 237                                 fprintf(stderr, "%s: Couldn't check for new version, leaving the old in place.\n", pathname.c_str());
 238                                 continue;
 239                         }
 240                         if (buf.st_mtim.tv_sec == last_modified.tv_sec &&
 241                             buf.st_mtim.tv_nsec == last_modified.tv_nsec) {
 242                                 // Not changed.
 243                                 continue;
 244                         }
 245
 246                         shared_ptr<const Image> image = load_image_raw(pathname);
 247                         if (image == nullptr) {
 248                                 fprintf(stderr, "Couldn't load image, leaving the old in place.\n");
 249                                 continue;
 250                         }
 251
 252                         unique_lock<mutex> lock(all_images_lock);
 253                         all_images[pathname] = image;
 254                 }
 255         }
 256 }
 257
 258 void ImageInput::shutdown_updaters()
 259 {
 260         {
 261                 lock_guard<mutex> lock(threads_should_quit_mu);
 262                 threads_should_quit = true;
 263                 threads_should_quit_modified.notify_all();
 264         }
 265
 266         lock_guard<mutex> lock(all_images_lock);
 267         if (update_thread_started) {
 268                 update_thread.join();
 269         }
 270 }
 271
 272 mutex ImageInput::all_images_lock;
 273 map<string, shared_ptr<const ImageInput::Image>> ImageInput::all_images;
 274 bool ImageInput::update_thread_started = false;
 275 thread ImageInput::update_thread;
 276 mutex ImageInput::threads_should_quit_mu;
 277 bool ImageInput::threads_should_quit = false;
 278 condition_variable ImageInput::threads_should_quit_modified;