[FFmpeg-user] DeckLink Duo 2 duplex_mode doesn't work

[Rik Roukens]

Hi All,

I'm using a DeckLink Duo 2 card which supports 4 individual in or outputs,
but by default is set to Full duplex mode (input from sdi 1 is output on
sdi 3, input from sdi 2 is output on sdi 4).

I'm running Ubuntu Server 18.04 with the following ffmpeg build:

ffmpeg version 4.1.4 Copyright (c) 2000-2019 the FFmpeg developers

  built with gcc 7 (Ubuntu 7.4.0-1ubuntu1~18.04.1)

  configuration:

--prefix=/home/ladmin/ffmpeg_build

--pkg-config-flags=--static

--extra-cflags='-I/home/ladmin/ffmpeg_build/include
-I/home/ladmin/ffmpeg_sources/BMD_SDK/include'

--extra-ldflags=-L/home/ladmin/ffmpeg_build/lib

--extra-libs='-lpthread -lm'

--bindir=/home/ladmin/bin

--enable-gpl

--enable-libass

--enable-libfdk-aac

--enable-libfreetype

--enable-libmp3lame

--enable-libopus

--enable-libvorbis

--enable-libvpx

--enable-libx264

--enable-libx265

--enable-nonfree

--enable-decklink

I can do recordings on DeckLink Duo (1) and DeckLink Duo (2) without any
problems.
However, when I try to run the following recording command on DeckLink Duo
(3) or (4), it doesn't work:

ffmpeg -format_code Hp25 -f Decklink -i 'DeckLink Duo (3)' -duplex_mode
half -c:v libx264 -preset ultrafast -map 0 -segment_time 20s -f segment
/media/primary/rolrec-cam2/output%03d.mp4

ffmpeg version 4.1.4 Copyright (c) 2000-2019 the FFmpeg developers

  built with gcc 7 (Ubuntu 7.4.0-1ubuntu1~18.04.1)

  configuration: --prefix=/home/ladmin/ffmpeg_build
--pkg-config-flags=--static
--extra-cflags='-I/home/ladmin/ffmpeg_build/include
-I/home/ladmin/ffmpeg_sources/BMD_SDK/include'
--extra-ldflags=-L/home/ladmin/ffmpeg_build/lib --extra-libs='-lpthread
-lm' --bindir=/home/ladmin/bin --enable-gpl --enable-libass
--enable-libfdk-aac --enable-libfreetype --enable-libmp3lame
--enable-libopus --enable-libvorbis --enable-libvpx --enable-libx264
--enable-libx265 --enable-nonfree --enable-decklink

  libavutil      56. 22.100 / 56. 22.100

  libavcodec     58. 35.100 / 58. 35.100

  libavformat    58. 20.100 / 58. 20.100

  libavdevice    58.  5.100 / 58.  5.100

  libavfilter     7. 40.101 /  7. 40.101

  libswscale      5.  3.100 /  5.  3.100

  libswresample   3.  3.100 /  3.  3.100

  libpostproc    55.  3.100 / 55.  3.100

[decklink @ 0x55ff0e2022c0] Found Decklink mode 1920 x 1080 with rate 25.00

[decklink @ 0x55ff0e2022c0] Cannot enable video input

DeckLink Duo (3): Input/output error

I do not understand what I'm doing wrong, according to the manual
<https://www.ffmpeg.org/ffmpeg-devices.html#decklink> you are supposed to
add -duplex_mode half to the command to set the card into half duplex mode
for the specified output.
I've also tried running it with -duplex_mode half -video_input sdi however
that doesn't seem to do it either.

I have been able to set the card to half duplex in the past using windows,
however, i don't want to use windows :)

Does anyone have any idea of what might be going wrong?

Thanks

Rik