Comment 0 for bug 1837480

Please upgrade to latest stable release 4.1.4:
https://ffmpeg.org/download.html#release_4.1

"4.1.4 was released on 2019-07-08. It is the latest stable FFmpeg release from the 4.1 release branch, which was cut from master on 2018-11-02."

One of the changes is the addition of the 'tpad' filter (https://ffmpeg.org/ffmpeg-filters.html#tpad) which alles temporal padding of streams.