ffmpeg: add "FFmpeg" tag to PandaSystem

panda/src/ffmpeg/config_ffmpeg.cxx

@@ -17,8 +17,8 @@
 #include "ffmpegVideoCursor.h"
 #include "ffmpegAudio.h"
 #include "ffmpegAudioCursor.h"
-
 #include "movieTypeRegistry.h"
+#include "pandaSystem.h"
 
 extern "C" {
   #include <libavcodec/avcodec.h>
@@ -129,6 +129,9 @@ init_libffmpeg() {
   FfmpegVideo::register_with_read_factory();
   FfmpegVideoCursor::register_with_read_factory();
 
+  PandaSystem *ps = PandaSystem::get_global_ptr();
+  ps->add_system("FFmpeg");
+
   // Register ffmpeg as catch-all audiovideo type.
   MovieTypeRegistry *reg = MovieTypeRegistry::get_global_ptr();
   reg->register_audio_type(&FfmpegAudio::make, "*");