[FFmpeg-user] Video file often not recognised

[Reindl Harald]

Am 15.06.22 um 16:25 schrieb Cecil Westerhof via ffmpeg-user:
> Lately I am doing a lot with ffmpeg again.
> But I have a strange problem.
> Sometimes I send mp4 through WhatsApp.
> Sometimes I see the thumbnail, sometimes I do not.
> Today WhatsApp thinks my mp4 is not a video.
> So I send it as an ordinary file.
> On some places it can be played fine.
> On another it plays only audio.
> And another it cannot be played.
> 
> What can be happening here?
> And could I do something about it by changing the parameters I use for
> ffmpeg?

god knows when you don't find it logical to post said parameters - 
crystal balls are out of order