+// A class dealing with stream output, both to HTTP (thus the class name)
+// and to local output files. Since we generally have very few outputs
+// (end clients are not meant to connect directly to our stream; it should be
+// transcoded by something else and then sent to a reflector), we don't need to
+// care a lot about performance. Thus, we solve this by the simplest possible
+// way, namely having one ffmpeg mux per output.
+