+@item -max_muxing_queue_size @var{packets} (@emph{output,per-stream})
+When transcoding audio and/or video streams, ffmpeg will not begin writing into
+the output until it has one packet for each such stream. While waiting for that
+to happen, packets for other streams are buffered. This option sets the size of
+this buffer, in packets, for the matching output stream.
+
+The default value of this option should be high enough for most uses, so only
+touch this option if you are sure that you need it.
+