[FFmpeg-trac] #1604(undetermined:new): Rtmp streaming fps continually drops

FFmpeg trac at avcodec.org
Tue Jan 6 01:51:31 CET 2015

#1604: Rtmp streaming fps continually drops
             Reporter:  Pyriel0      |                    Owner:
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:
              Version:  git-master   |  undetermined
             Keywords:  rtmp         |               Resolution:
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  0

Comment (by ctetrick):


 I'm running on a i7-2600 3.4GHz, 6GB ram, Windows 7.  I don't think ram or
 cpu is an issue in this.

 I am using a modified windows build based on ffmpeg-git-85f2c01 source.
 My test command line is

 -re -y -loglevel verbose -probesize 4096 -i "D:\Media\Clips\Studio Ghibli
 25.mp4" -flags +global_header -c:v copy -c:a copy -f flv "rtmp://live-
 prg.twitch.tv/app/ playpath=live_<mystreamid>"

 The video clip is h264/aac 720p 2.5mbps.  This effectively eliminates the
 The main factor seems to be the ping time.
 Since I'm in Texas, the above url is far away and has an average ping of
 If I stream to live-dfw.twitch.tv/app/ (Server is in Dallas TX), the ping
 time is 9ms, and works without modification.

 Your test may indicate that this is a windows specific socket's problem,
 but so far I haven't been able to confirm this.

 If anything it may be that Linux handles things differently. The main
 thing seems to be that many small sends with a large RTT stalls on
 Windows, but not Linux.

Ticket URL: <https://trac.ffmpeg.org/ticket/1604#comment:26>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker

More information about the FFmpeg-trac mailing list