[FFmpeg-user] ffmpeg and webm format and mkv format

[Moritz Barsnick]

On Sat, Sep 17, 2016 at 11:59:48 -0600, jd1008 wrote:
> So, which "release" or "private build" should I use in order to properly
> transcode WEBM to MP4 ?
> Is WEBM a container arrangement? If so, why should it be a problem
> for ffmpeg to just extract the content?

Your ffmpeg is behaving as if some keyboard interaction or other stuff
on stdin is disturbing it. Please try the option "-nostdin", whether
that surpresses it.
  
This happens with every build of ffmpeg you have tried?

Moritz