--- /dev/null
+#include "image_input.h"
+
+#include <errno.h>
+#include <movit/flat_input.h>
+#include <movit/image_format.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+extern "C" {
+#include <libavcodec/avcodec.h>
+#include <libavformat/avformat.h>
+#include <libavutil/avutil.h>
+#include <libavutil/error.h>
+#include <libavutil/frame.h>
+#include <libavutil/imgutils.h>
+#include <libavutil/mem.h>
+#include <libavutil/pixfmt.h>
+#include <libswscale/swscale.h>
+}
+
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <cstddef>
+#include <functional>
+#include <mutex>
+#include <thread>
+#include <utility>
+#include <vector>
+
+#include "ffmpeg_raii.h"
+#include "ffmpeg_util.h"
+#include "flags.h"
+
+struct SwsContext;
+
+using namespace std;
+
+ImageInput::ImageInput(const string &filename)
+ : movit::FlatInput({movit::COLORSPACE_sRGB, movit::GAMMA_sRGB}, movit::FORMAT_RGBA_POSTMULTIPLIED_ALPHA,
+ GL_UNSIGNED_BYTE, 1280, 720), // Resolution will be overwritten.
+ filename(filename),
+ pathname(search_for_file_or_die(filename)),
+ current_image(load_image(filename, pathname))
+{
+ if (current_image == nullptr) { // Could happen even though search_for_file() returned.
+ fprintf(stderr, "Couldn't load image, exiting.\n");
+ exit(1);
+ }
+ set_width(current_image->width);
+ set_height(current_image->height);
+ set_pixel_data(current_image->pixels.get());
+}
+
+void ImageInput::set_gl_state(GLuint glsl_program_num, const string& prefix, unsigned *sampler_num)
+{
+ // See if the background thread has given us a new version of our image.
+ // Note: The old version might still be lying around in other ImageInputs
+ // (in fact, it's likely), but at least the total amount of memory used
+ // is bounded. Currently we don't even share textures between them,
+ // so there's a fair amount of OpenGL memory waste anyway (the cache
+ // is mostly there to save startup time, not RAM).
+ {
+ unique_lock<mutex> lock(all_images_lock);
+ if (all_images[pathname] != current_image) {
+ current_image = all_images[pathname];
+ set_pixel_data(current_image->pixels.get());
+ }
+ }
+ movit::FlatInput::set_gl_state(glsl_program_num, prefix, sampler_num);
+}
+
+shared_ptr<const ImageInput::Image> ImageInput::load_image(const string &filename, const string &pathname)
+{
+ unique_lock<mutex> lock(all_images_lock); // Held also during loading.
+ if (all_images.count(pathname)) {
+ return all_images[pathname];
+ }
+
+ all_images[pathname] = load_image_raw(pathname);
+ timespec first_modified = all_images[pathname]->last_modified;
+ update_threads[pathname] =
+ thread(bind(update_thread_func, filename, pathname, first_modified));
+
+ return all_images[pathname];
+}
+
+shared_ptr<const ImageInput::Image> ImageInput::load_image_raw(const string &pathname)
+{
+ // Note: Call before open, not after; otherwise, there's a race.
+ // (There is now, too, but it tips the correct way. We could use fstat()
+ // if we had the file descriptor.)
+ struct stat buf;
+ if (stat(pathname.c_str(), &buf) != 0) {
+ fprintf(stderr, "%s: Error stat-ing file\n", pathname.c_str());
+ return nullptr;
+ }
+ timespec last_modified = buf.st_mtim;
+
+ auto format_ctx = avformat_open_input_unique(pathname.c_str(), nullptr, nullptr);
+ if (format_ctx == nullptr) {
+ fprintf(stderr, "%s: Error opening file\n", pathname.c_str());
+ return nullptr;
+ }
+
+ if (avformat_find_stream_info(format_ctx.get(), nullptr) < 0) {
+ fprintf(stderr, "%s: Error finding stream info\n", pathname.c_str());
+ return nullptr;
+ }
+
+ int stream_index = find_stream_index(format_ctx.get(), AVMEDIA_TYPE_VIDEO);
+ if (stream_index == -1) {
+ fprintf(stderr, "%s: No video stream found\n", pathname.c_str());
+ return nullptr;
+ }
+
+ const AVCodecParameters *codecpar = format_ctx->streams[stream_index]->codecpar;
+ AVCodecContextWithDeleter codec_ctx = avcodec_alloc_context3_unique(nullptr);
+ if (avcodec_parameters_to_context(codec_ctx.get(), codecpar) < 0) {
+ fprintf(stderr, "%s: Cannot fill codec parameters\n", pathname.c_str());
+ return nullptr;
+ }
+ AVCodec *codec = avcodec_find_decoder(codecpar->codec_id);
+ if (codec == nullptr) {
+ fprintf(stderr, "%s: Cannot find decoder\n", pathname.c_str());
+ return nullptr;
+ }
+ if (avcodec_open2(codec_ctx.get(), codec, nullptr) < 0) {
+ fprintf(stderr, "%s: Cannot open decoder\n", pathname.c_str());
+ return nullptr;
+ }
+ unique_ptr<AVCodecContext, decltype(avcodec_close)*> codec_ctx_cleanup(
+ codec_ctx.get(), avcodec_close);
+
+ // Read packets until we have a frame or there are none left.
+ int frame_finished = 0;
+ AVFrameWithDeleter frame = av_frame_alloc_unique();
+ bool eof = false;
+ do {
+ AVPacket pkt;
+ unique_ptr<AVPacket, decltype(av_packet_unref)*> pkt_cleanup(
+ &pkt, av_packet_unref);
+ av_init_packet(&pkt);
+ pkt.data = nullptr;
+ pkt.size = 0;
+ if (av_read_frame(format_ctx.get(), &pkt) == 0) {
+ if (pkt.stream_index != stream_index) {
+ continue;
+ }
+ if (avcodec_send_packet(codec_ctx.get(), &pkt) < 0) {
+ fprintf(stderr, "%s: Cannot send packet to codec.\n", pathname.c_str());
+ return nullptr;
+ }
+ } else {
+ eof = true; // Or error, but ignore that for the time being.
+ }
+
+ int err = avcodec_receive_frame(codec_ctx.get(), frame.get());
+ if (err == 0) {
+ frame_finished = true;
+ break;
+ } else if (err != AVERROR(EAGAIN)) {
+ fprintf(stderr, "%s: Cannot receive frame from codec.\n", pathname.c_str());
+ return nullptr;
+ }
+ } while (!eof);
+
+ if (!frame_finished) {
+ fprintf(stderr, "%s: Decoder did not output frame.\n", pathname.c_str());
+ return nullptr;
+ }
+
+ uint8_t *pic_data[4] = {nullptr};
+ unique_ptr<uint8_t *, decltype(av_freep)*> pic_data_cleanup(
+ &pic_data[0], av_freep);
+ int linesizes[4];
+ if (av_image_alloc(pic_data, linesizes, frame->width, frame->height, AV_PIX_FMT_RGBA, 1) < 0) {
+ fprintf(stderr, "%s: Could not allocate picture data\n", pathname.c_str());
+ return nullptr;
+ }
+ unique_ptr<SwsContext, decltype(sws_freeContext)*> sws_ctx(
+ sws_getContext(frame->width, frame->height,
+ (AVPixelFormat)frame->format, frame->width, frame->height,
+ AV_PIX_FMT_RGBA, SWS_BICUBIC, nullptr, nullptr, nullptr),
+ sws_freeContext);
+ if (sws_ctx == nullptr) {
+ fprintf(stderr, "%s: Could not create scaler context\n", pathname.c_str());
+ return nullptr;
+ }
+ sws_scale(sws_ctx.get(), frame->data, frame->linesize, 0, frame->height, pic_data, linesizes);
+
+ size_t len = frame->width * frame->height * 4;
+ unique_ptr<uint8_t[]> image_data(new uint8_t[len]);
+ av_image_copy_to_buffer(image_data.get(), len, pic_data, linesizes, AV_PIX_FMT_RGBA, frame->width, frame->height, 1);
+
+ shared_ptr<Image> image(new Image{unsigned(frame->width), unsigned(frame->height), move(image_data), last_modified});
+ return image;
+}
+
+// Fire up a thread to update the image every second.
+// We could do inotify, but this is good enough for now.
+void ImageInput::update_thread_func(const std::string &filename, const std::string &pathname, const timespec &first_modified)
+{
+ char thread_name[16];
+ snprintf(thread_name, sizeof(thread_name), "Update_%s", filename.c_str());
+ pthread_setname_np(pthread_self(), thread_name);
+
+ timespec last_modified = first_modified;
+ struct stat buf;
+ for ( ;; ) {
+ {
+ unique_lock<mutex> lock(threads_should_quit_mu);
+ threads_should_quit_modified.wait_for(lock, chrono::seconds(1), []() { return threads_should_quit; });
+ }
+
+ if (threads_should_quit) {
+ return;
+ }
+
+ if (stat(pathname.c_str(), &buf) != 0) {
+ fprintf(stderr, "%s: Couldn't check for new version, leaving the old in place.\n", pathname.c_str());
+ continue;
+ }
+ if (buf.st_mtim.tv_sec == last_modified.tv_sec &&
+ buf.st_mtim.tv_nsec == last_modified.tv_nsec) {
+ // Not changed.
+ continue;
+ }
+ shared_ptr<const Image> image = load_image_raw(pathname);
+ if (image == nullptr) {
+ fprintf(stderr, "Couldn't load image, leaving the old in place.\n");
+ continue;
+ }
+ fprintf(stderr, "Loaded new version of %s from disk.\n", pathname.c_str());
+ unique_lock<mutex> lock(all_images_lock);
+ all_images[pathname] = image;
+ last_modified = image->last_modified;
+ }
+}
+
+void ImageInput::shutdown_updaters()
+{
+ {
+ unique_lock<mutex> lock(threads_should_quit_mu);
+ threads_should_quit = true;
+ threads_should_quit_modified.notify_all();
+ }
+ for (auto &it : update_threads) {
+ it.second.join();
+ }
+}
+
+mutex ImageInput::all_images_lock;
+map<string, shared_ptr<const ImageInput::Image>> ImageInput::all_images;
+map<string, thread> ImageInput::update_threads;
+mutex ImageInput::threads_should_quit_mu;
+bool ImageInput::threads_should_quit = false;
+condition_variable ImageInput::threads_should_quit_modified;