FFMPEG Output to DeckLink Duo 2 - windows

Question

Im trying to use FFMPEG to stream out to my Decklink duo 2 but im unable to do so.
Heres the command that im trying:
ffmpeg -f decklink -i "DeckLink Duo (1)#5"
-pix_fmt uyvy422 -r 25000/1000 "DeckLink Duo (3)"
I tried just sending color bars as an output but it still doesnt work
Command:
ffmpeg -f lavfi -i color=color=red -t 10000 "DeckLink Duo (3)"
Both Result:
ffmpeg version N-82794-g3ab1311 Copyright (c) 2000-2016 the FFmpeg developers
built with gcc 5.4.0 (GCC)
configuration: --enable-gpl --enable-version3 --disable-w32threads
--enable-dxva2 --enable-libmfx --enable-nvenc
--enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r
--enable-gnutls --enable-iconv --enable-libass
--enable-libbluray --enable-libbs2b --enable-libcaca
--enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc
--enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb
--enable-libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg
--enable-libopus --enable-librtmp --enable-libschroedinger
--enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora
--enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc
--enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp
--enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg
--enable-lzma --enable-decklink --enable-zlib
libavutil 55. 42.100 / 55. 42.100
libavcodec 57. 67.100 / 57. 67.100
libavformat 57. 58.102 / 57. 58.102
libavdevice 57. 2.100 / 57. 2.100
libavfilter 6. 68.100 / 6. 68.100
libswscale 4. 3.101 / 4. 3.101
libswresample 2. 4.100 / 2. 4.100
libpostproc 54. 2.100 / 54. 2.100
Input #0, lavfi, from 'color=color=red':
Duration: N/A, start: 0.000000, bitrate: N/A
Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 320x240 [SAR 1:1 DAR 4:3], 25 tbr, 25 tbn, 25 tbc
[NULL # 00000000025745a0] Unable to find a suitable output format for 'DeckLink Duo (3)'
DeckLink Duo (3): Invalid argument
Any Suggestions or help to solve this is much appreciated.

Answer 1

As the documentation says "DeckLink is very picky about the formats it supports. Pixel format is always uyvy422, framerate, field order and video size must be determined for your device with -list_formats 1. Audio sample rate is always 48 kHz.", see https://www.ffmpeg.org/ffmpeg-devices.html#decklink-1. So you need to add the resolution and make sure it is supported.

Answer 2

For the Duo 2 or Quad 2, You need to confirm in Desktop Video utility that you have assigned an SDI port to the channel, otherwise it may be in key/fill mode. This can be found in the third tab called "Connectors". If you can't select one (happens on device (2) or (4) if 1 or 3 are set to key/fill mode, you go back to 1 or 3 and change them to use a single connector.
That was the cause of my I/O error trying to use chanel (3).