[FFmpeg-user] Causes of color bars?

Moritz Barsnick barsnick at gmx.net
Wed Jul 15 01:14:52 EEST 2020

On Tue, Jul 14, 2020 at 15:50:55 -0600, Simon Roberts wrote:
> On Tue, Jul 14, 2020 at 1:29 AM Carl Zwanzig <cpz at tuunq.com> wrote:
> > Decklink boards are _very_ touchy about formats and parameters. Try setting
> > at least the resolution and frame rate on the input and see if that helps.
> >
> > I don't guarantee these, but it's a start:
> > -f decklink -pix_fmt uyvy422 -s 720x486 -r 30000/1001 "DeckLink SDI 4K"

I'm certain there's an "-i" missing before "DeckLink SDI 4K".

> - it says there's no such option as -r, but if I change it to
> -framerate, that part is happy in ffplay, but still doesn't work in ffmpeg
> - ffplay it says -s and -pix_fmt are deprecated and should be
> -video_size and -pixel_format respectively. However, those options are not offered at all in ffmpeg

This indicates that your version of ffmpeg is not in line with your
version of ffplay. Are you sure you are calling the correct executable,
and not an older binary in your PATH?

> - but the kicker is that after those reports both ffplay and ffmpeg
> say "option pixel_format not found" and crash out.

If you show us the exact command line and its *complete* console
output, we can help you with this (even those of us who don't know
Decklink and its quirks).

> Are these options specific to individual "-f" types? That is, is there
> a chance that I need something specific (or worse, not offered by)
> decklink?

At this point, probably not.


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