[FFmpeg-user] Controlling an ffmpeg stream?

Sven C. Dack sven.c.dack at sky.com
Thu Sep 8 01:01:12 EEST 2016

On 07/09/16 22:00, Roy Pardi wrote:
> Hi, I am new to the list and also to ffmpeg so this is likely to be a naive question.
> My question concerns the command line version of ffmpeg. I am developing a cross-platform app in Adobe AIR and the problem I am trying to solve is being able to seek to an arbitrary point in a video file without having to render the video with a keyframe every frame. I am able to launch ffmpeg in the background and pipe a stream of an existing video file to my client app. Here are my questions:
> 1. Am I wrong in my understanding that ffmpeg will seek to a requested time, rendering from the nearest keyframe?
> 2. Using Actionscript I can successfully launch ffmpeg with:
> 	ffmpeg -re -i  test.mp4  -c:a copy -c:v copy -f flv -
> and subscribe to the stream and display it. I am also able to seek using:
> 	ffmpeg  -ss 300 -re -i  test.mp4  -c:a copy -c:v copy -f flv -
> What I am not able to do is to communicate with or control ffmpeg through stdin once it has started streaming, either to tell it to seek or to pause the stream. I can’t tell if my code is bad or if I misunderstanding the ffmpeg command line tool. Is the tool only designed for a "set up/run/exit” usage scenario.
> I can provide more details if needed.
> Thanks,
> –Roy
Hello Roy,

have you looked at ffserver yet? See it's manpage ffserver(1):


        ffserver - ffserver video server

        ffserver [options]

        ffserver is a streaming server for both audio and video.  It supports
        several live feeds, streaming from files and time shifting on live
        feeds. You can seek to positions in the past on each live feed,
        provided you specify a big enough feed storage.

        ffserver is configured through a configuration file, which is read at
        startup. If not explicitly specified, it will read from

        ffserver receives prerecorded files or FFM streams from some ffmpeg
        instance as input, then streams them over RTP/RTSP/HTTP.


More information about the ffmpeg-user mailing list