17
based on http://sonnati.wordpress.com/2011/08/30/ffmpeg-–-the-swiss-army-knife-of-internet-streaming-–-part-iv/ and http://ffmpeg-users.933282.n4.nabble.com/Multiple-output-files-td2076623.html
ffmpeg -re -i rtmp://server/live/high_FMLE_stream -acodec copy -vcodec x264lib -s 640×360 -b 500k -vpre medium -vpre baseline rtmp://server/live/baseline_500k -acodec copy -vcodec x264lib -s 480×272 -b 300k -vpre medium -vpre baseline rtmp://server/live/baseline_300k -acodec copy -vcodec x264lib -s 320×200 -b 150k -vpre medium -vpre baseline rtmp://server/live/baseline_150k -acodec libfaac -vn -ab 48k rtmp://server/live/audio_only_AAC_48k
Or you could pipe the output to a "tee" and send it to "X" other processes to actually do the encoding, like
ffmpeg -i input - | tee ...
which might save cpu since it might enable more output parallelism, which is apparently otherwise unavailable
see http://ffmpeg.org/trac/ffmpeg/wiki/Creating%20multiple%20outputs and here