dshow does not show as a valid input format for FFMPEG

Question

I have just bought a DeckLink Quad HDMI recorder to do some screen capture and I want to use FFMPEG to do the recording.

I discovered that I had to compile FFMPEG with additional flags so I could use dshow as an input source. I followed these two guides for compiling:

https://gist.github.com/afriza/879fed4ede539a5a6501e0f046f71463
https://trac.ffmpeg.org/wiki/CompilationGuide/Ubuntu

Everything seemed to work fine, but when I run

  ffmpeg -list_devices true -f dshow -i dummy

it tells me "Unknown input format: 'dshow'"

When I run the command I can see the tags "--enable-nonfree --enable-decklink"
I know the capture card is working because I can capture through OBS.

So I'm not sure why I can't use dshow

Here's the complete output of the terminal:

ffmpeg -list_devices true -f dshow -i dummy
ffmpeg version N-94264-g74d4fd0 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 7 (Ubuntu 7.4.0-1ubuntu1~18.04.1)
  configuration: --prefix=/home/capture/ffmpeg_build --pkg-config-flags=--static --extra-cflags='-I/home/capture/ffmpeg_build/include -I/home/capture/ffmpeg_sources/BMD_SDK/include' --extra-ldflags=-L/home/capture/ffmpeg_build/lib --extra-libs='-lpthread -lm' --bindir=/home/capture/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. 30.100 / 56. 30.100
  libavcodec     58. 53.101 / 58. 53.101
  libavformat    58. 28.101 / 58. 28.101
  libavdevice    58.  7.100 / 58.  7.100
  libavfilter     7. 56.101 /  7. 56.101
  libswscale      5.  4.101 /  5.  4.101
  libswresample   3.  4.100 /  3.  4.100
  libpostproc    55.  4.100 / 55.  4.100
Unknown input format: 'dshow'

Solution

dshow is the Windows DirectShow input device, so it won't be available on Linux.

Try using the decklink input device if you want to capture from the Decklink card. If you want to capture the screen an alternative is x11grab.

Comments

[Elisa Cha Cha]

dshow is the Windows DirectShow input device. Try using the decklink input device if you want to capture from the card. If you want to capture the screen an alternative is x11grab.

[HandsomeSimon]

Ah, my mistake. That works now. Thanks for the quick answer.