[FFmpeg-user] Decklink capture options

[Adrien Remillieux]

Hi
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.

I can capture a video flux with this command:

ffmpeg -f decklink -i "Intensity Pro (1)"@5 -acodec copy -vcodec copy output.avi

But as soon as I try to add the "-audio_input" or "-video_input"
option somewhere it doesn't work

Right now I have to set the audio and video input in the
desktopvideo_gui software and light a candle before launching ffmpeg,
works most of the time. Sometimes I have no audio.

I just found this patch https://github.com/FFmpeg/FFmpeg/pull/212 and
the corresponding ticket https://trac.ffmpeg.org/ticket/4991. I can
check if it works tomorrow and if it does an example in the docs would
be great.

Examples for the video_pts and audio_pts options would also be great.
I sometimes have sync issues and it could maybe help.

I think I found the solution to my problem by writing this email. I'm
sending it because I think an improvement to the documentation could
help everyone.

Have a nice day :)

Adrien