Start of persistence work: Keep existing frames that are at frames/ at startup.

diff --git a/main.cpp b/main.cpp
index 9bb666a317984e29deaecfea227377086a8987fc..42b1867dfb82e061d98ab1d12f62c0ba035e510a 100644 (file)
--- a/main.cpp
+++ b/main.cpp
@@ -1,6 +1,8 @@
 #include <assert.h>
+#include <dirent.h>
 #include <stdio.h>
 #include <stdint.h>
+#include <sys/types.h>
 
 #include <chrono>
 #include <condition_variable>
@@ -37,6 +39,8 @@ using namespace std::chrono;
 
 std::mutex RefCountedGLsync::fence_lock;
 
+int64_t start_pts = -1;
+
 // TODO: Replace by some sort of GUI control, I guess.
 int64_t current_pts = 0;
 
@@ -51,6 +55,7 @@ mutex frame_mu;
 vector<int64_t> frames[MAX_STREAMS];
 HTTPD *global_httpd;
 
+void load_existing_frames();
 int record_thread_func();
 
 int main(int argc, char **argv)
@@ -96,6 +101,7 @@ int main(int argc, char **argv)
        MainWindow mainWindow;
        mainWindow.show();
 
+       load_existing_frames();
        thread(record_thread_func).detach();
 
        init_jpeg_vaapi();
@@ -103,6 +109,49 @@ int main(int argc, char **argv)
        return app.exec();
 }
 
+void load_existing_frames()
+{
+       DIR *dir = opendir("frames/");
+       if (dir == nullptr) {
+               perror("frames/");
+               start_pts = 0;
+               return;
+       }
+
+       for ( ;; ) {
+               errno = 0;
+               dirent *de = readdir(dir);
+               if (de == nullptr) {
+                       if (errno != 0) {
+                               perror("readdir");
+                               exit(1);
+                       }
+                       break;
+               }
+
+               int stream_idx;
+               int64_t pts;
+               if (sscanf(de->d_name, "cam%d-pts%ld.jpeg", &stream_idx, &pts) == 2 &&
+                   stream_idx >= 0 && stream_idx < MAX_STREAMS) {
+                       frames[stream_idx].push_back(pts);
+                       start_pts = max(start_pts, pts);
+               }
+       }
+
+       closedir(dir);
+
+       if (start_pts == -1) {
+               start_pts = 0;
+       } else {
+               // Add a gap of one second from the old frames to the new ones.
+               start_pts += TIMEBASE;
+       }
+
+       for (int stream_idx = 0; stream_idx < MAX_STREAMS; ++stream_idx) {
+               sort(frames[stream_idx].begin(), frames[stream_idx].end());
+       }
+}
+
 int record_thread_func()
 {
        auto format_ctx = avformat_open_input_unique("multiangle.mp4", nullptr, nullptr);
@@ -112,6 +161,7 @@ int record_thread_func()
        }
 
        int64_t last_pts = -1;
+       int64_t pts_offset;
 
        for ( ;; ) {
                AVPacket pkt;
@@ -125,13 +175,18 @@ int record_thread_func()
                }
 
                // Convert pts to our own timebase.
-               // TODO: Figure out offsets, too.
                AVRational stream_timebase = format_ctx->streams[pkt.stream_index]->time_base;
-               pkt.pts = av_rescale_q(pkt.pts, stream_timebase, AVRational{ 1, TIMEBASE });
+               int64_t pts = av_rescale_q(pkt.pts, stream_timebase, AVRational{ 1, TIMEBASE });
+
+               // Translate offset into our stream.
+               if (last_pts == -1) {
+                       pts_offset = start_pts - pts;
+               }
+               pts = std::max(pts + pts_offset, start_pts);
 
                //fprintf(stderr, "Got a frame from camera %d, pts = %ld, size = %d\n",
-               //      pkt.stream_index, pkt.pts, pkt.size);
-               string filename = filename_for_frame(pkt.stream_index, pkt.pts);
+               //      pkt.stream_index, pts, pkt.size);
+               string filename = filename_for_frame(pkt.stream_index, pts);
                FILE *fp = fopen(filename.c_str(), "wb");
                if (fp == nullptr) {
                        perror(filename.c_str());
@@ -140,27 +195,27 @@ int record_thread_func()
                fwrite(pkt.data, pkt.size, 1, fp);
                fclose(fp);
 
-               post_to_main_thread([pkt] {
+               post_to_main_thread([pkt, pts] {
                        if (pkt.stream_index == 0) {
-                               global_mainwindow->ui->input1_display->setFrame(pkt.stream_index, pkt.pts, /*interpolated=*/false);
+                               global_mainwindow->ui->input1_display->setFrame(pkt.stream_index, pts, /*interpolated=*/false);
                        } else if (pkt.stream_index == 1) {
-                               global_mainwindow->ui->input2_display->setFrame(pkt.stream_index, pkt.pts, /*interpolated=*/false);
+                               global_mainwindow->ui->input2_display->setFrame(pkt.stream_index, pts, /*interpolated=*/false);
                        } else if (pkt.stream_index == 2) {
-                               global_mainwindow->ui->input3_display->setFrame(pkt.stream_index, pkt.pts, /*interpolated=*/false);
+                               global_mainwindow->ui->input3_display->setFrame(pkt.stream_index, pts, /*interpolated=*/false);
                        } else if (pkt.stream_index == 3) {
-                               global_mainwindow->ui->input4_display->setFrame(pkt.stream_index, pkt.pts, /*interpolated=*/false);
+                               global_mainwindow->ui->input4_display->setFrame(pkt.stream_index, pts, /*interpolated=*/false);
                        }
                });
 
                assert(pkt.stream_index < MAX_STREAMS);
-               frames[pkt.stream_index].push_back(pkt.pts);
+               frames[pkt.stream_index].push_back(pts);
 
                // Hack. Remove when we're dealing with live streams.
                if (last_pts != -1) {
-                       this_thread::sleep_for(microseconds((pkt.pts - last_pts) * 1000000 / TIMEBASE));
+                       this_thread::sleep_for(microseconds((pts - last_pts) * 1000000 / TIMEBASE));
                }
-               last_pts = pkt.pts;
-               current_pts = pkt.pts;
+               last_pts = pts;
+               current_pts = pts;
        }
 
        return 0;