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

[jd1008]

On 09/17/2016 04:10 PM, Moritz Barsnick wrote:
> 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
I will try the option.
But as you could see from the 1st 100 lines, it was a private
build by one of the ffmpeg developers.

I have tried official release of 3.x with similar failures.

What's about webm thatis causing so much trouble?
Is it a non-standard organization of the contents?