[FFmpeg-user] Decklink capture options

[Moritz Barsnick]

On Thu, Jul 07, 2016 at 13:31:59 +0200, Adrien Remillieux wrote:
> But as soon as I try to add the "-audio_input" or "-video_input"
> option somewhere it doesn't work

"It doesn't work" should kindly be amended with the actual error
message. ffmpeg outputs a lot of useful information, and we usually ask
you to provide the full, uncut console output. Especially for people
like me who don't have decklink and therefore can't reproduce with
their own incarnations of ffmpeg.

> I compiled ffmpeg 3.1.1 with decklink (Blackmagic video capture card)
> support and I'd like to set the option to choose the audio and video input.
> I read the official docs https://www.ffmpeg.org/ffmpeg-devices.html#decklink
> but I can't get the options video_input and audio_input to work. Every time
> ffmpeg throw an error saying that it doesn't recognize the option and I
> tried to put them wherever it made sense.

If you're compiling on your own anyway, why didn't you compile git
master? That's what the docs deployed on ffmpeg.org refer to (which
they unfortunately don't explicitly say, I think). *Your* official -
the ones valid for your particular version - are in your source
package, or in your installation under $prefixshare/doc/ffmpeg/.

What I'm trying to hint at: Those options where added to git master
after the release of ffmpeg 3.1 (and not backported to 3.1.1), and will
therefore likely not be in an ffmpeg release before 3.2. Checking your
local docs will confirm that.

You need to build from git master is the summary of my answer. ;)

Moritz