#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <sys/stat.h>
#include <unistd.h>
extern "C" {
return origin + duration_cast<steady_clock::duration>(pts / rate);
}
+bool changed_since(const std::string &pathname, const timespec &ts)
+{
+ if (ts.tv_sec < 0) {
+ return false;
+ }
+ struct stat buf;
+ 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());
+ return false;
+ }
+ return (buf.st_mtim.tv_sec != ts.tv_sec || buf.st_mtim.tv_nsec != ts.tv_nsec);
+}
+
} // namespace
FFmpegCapture::FFmpegCapture(const string &filename, unsigned width, unsigned height)
bool FFmpegCapture::play_video(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.)
+ timespec last_modified;
+ struct stat buf;
+ if (stat(pathname.c_str(), &buf) != 0) {
+ // Probably some sort of protocol, so can't stat.
+ last_modified.tv_sec = -1;
+ } else {
+ 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());
if (av_seek_frame(format_ctx.get(), /*stream_index=*/-1, /*timestamp=*/0, /*flags=*/0) < 0) {
fprintf(stderr, "%s: Rewind failed, stopping play.\n", pathname.c_str());
}
+ // If the file has changed since last time, return to get it reloaded.
+ // Note that depending on how you move the file into place, you might
+ // end up corrupting the one you're already playing, so this path
+ // might not trigger.
+ if (changed_since(pathname, last_modified)) {
+ return true;
+ }
internal_rewind();
break;
fprintf(stderr, "%s: Rewind failed, not looping.\n", pathname.c_str());
return true;
}
+ // If the file has changed since last time, return to get it reloaded.
+ // Note that depending on how you move the file into place, you might
+ // end up corrupting the one you're already playing, so this path
+ // might not trigger.
+ if (changed_since(pathname, last_modified)) {
+ return true;
+ }
internal_rewind();
continue;
}