[FFmpeg-user] Question about using Webm/Matroska container in audio transconding

[Moritz Barsnick]

On Wed, Dec 12, 2018 at 08:30:27 +0100, Ivan Zderadicka wrote:

> ivan at ivan-ThinkPad-T460:~/tmp$ ffprobe test1.webm
[...]
> Input #0, matroska,webm, from 'test1.webm':
>   Metadata:
>     title           : 10.kapitola
>     encoder         : Lavf56.40.101
>   Duration: N/A, start: 0.007000, bitrate: N/A
>     Stream #0:0: Audio: opus, 48000 Hz, stereo, fltp (default)

I get:
$ ffmpeg -i test_time.webm
[...]
Input #0, matroska,webm, from 'test_time.webm':
  Metadata:
    ENCODER         : Lavf58.23.102
  Duration: 00:00:05.00, start: -0.007000, bitrate: 27 kb/s
    Stream #0:0: Audio: opus, 48000 Hz, mono, fltp (default)
    Metadata:
      ENCODER         : Lavc58.41.101 libopus

My suggestion:

> ffmpeg version 2.8.15-0ubuntu0.16.04.1 Copyright (c) 2000-2018 the FFmpeg developers
>   built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.10) 20160609

Your version of ffmpeg is ancient. Your issue may have long been
solved. Please get hold of a recent version of ffmpeg. If you can't
find a Ubunuto repository which provides latest builds, grab a binary
from here:

https://johnvansickle.com/ffmpeg/

(Preferred: Left column, git builds - not the releases.)

I have no idea whether the file creation or the interpretation of the
created file is different in recent ffmpeg (I assume the former), but
it just works with webm.

Moritz