[FFmpeg-user] Causes of color bars?

[Simon Roberts]

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 think this is likely to have something to do with it, but the
options as shown are rejected by both ffplay and ffmpeg, and I'm not
sure how to go about reading the docs to work out what I need to
change. There are several complaints from ffplay, some more grumpy
than others.

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

I poked around in the docs a bit, and found -pix_fmt, which seemed to
say it's deprecated in favor of "private options" in ffplay, but seems
like it should be good in ffmpeg. But... well, they're all being
rejected.

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?