[FFmpeg-user] Failed to update header with correct duration. Failed to update header with correct filesize.

[Carl Zwanzig]

On 6/17/2021 4:40 AM, Gary Pfeffer via ffmpeg-user wrote:
> ffmpeg version 4.2.4-1ubuntu0.1 Copyright (c) 2000-2020 the FFmpeg
> developers

Have you tried with the most recent ffmpeg? Older versions aren't supported 
on this list.

You can pick up last night's build from https://ffmpeg.org/download.html and 
from https://johnvansickle.com/ffmpeg/

Later,

z!