[FFmpeg-user] live transcoding flv files

dE . de.techno at gmail.com
Sat Mar 3 07:22:38 CET 2012

On 03/02/12 01:52, Steve Roskowski wrote:
> 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.

If you want to stream the output, it does have to be to a file. Use a 
pipe... maybe.

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