[FFmpeg-user] 608/ 708 Closed Captions output with ffmpeg and Decklink

[Devin Heitmueller]

On Mon, Jan 3, 2022 at 3:00 PM Matt C <asperi at hotmail.com> wrote:

> Have tried these lines, they all play fine out the SDI but no captions show:

I haven't tried your actual files, but there are two likely issues here:

1.  Your ffmpeg build needs to be compiled to make use of the
libklvanc library.  That is necessary to produce the SDI VANC data
that makes up the CEA-708 captions.

https://github.com/stoth68000/libklvanc

2.  You must use the v210 codec.  If you use "-pix_fmt uyvy422" that
puts the decklink output into 8-bit mode, which won't work with 10-bit
VANC (as required for CEA-708).

Regards,

Devin

-- 
Devin Heitmueller, Senior Software Engineer
LTN Global Communications
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