[FFmpeg-user] live transcoding flv files

Steve Roskowski rosko at thirdiris.com
Thu Mar 1 21:22:35 CET 2012

I have an http server which generates FLV format video "on the fly", which
allows flash to play them back in realtime - live streaming.

I would like to use ffmpeg to transcode them, specifically to lower bit
rates for mobile clients.

I cannot figure out how to get ffmpeg to do the transcoding in realtime.
 FFMPEG seems to download the entire source file before beginning to
generate output.  VLC shows the exact same behavior - video does not start
playing till the entire flv file is downloaded... which on a live stream is

is this something I am missing in the options/configuration, or is this
something specific to the flv demuxer?

typical ffmpeg command

ffmpeg -i http://myserver/live_stream1/flv -b 64k -vcodec libx264 foo.flv

works fine, but only starts rendering the output file when the live stream
is closed.

Steve Roskowski

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