[FFmpeg-user] live transcoding flv files

Andrey Utkin andrey.krieger.utkin at gmail.com
Fri Mar 2 21:25:26 CET 2012

2012/3/1 Steve Roskowski <rosko at thirdiris.com>:
> 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
> forever.
> 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.

ffmpeg utility does not render anything at all. It just transcodes.
And it will process a file or a stream as it reads it (on the fly),
exactly as you need.
So you must have confused something, or missed to tell to us sth, like
how do you playback it.

Andrey Utkin

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