title: FFmpeg/FFplay directshow and blackmagic
body: <p>I got a BlackMagic  intensity pro 4k capturing card, which is working fine with the express tool, I can see the live feed and record, but after I tried different stuff from what I found online to make ffplay/ffmpeg working, I ended up to have just a black screen.</p>
  
  <p>I have checked if all the versions of my ffmpeg files were eanable-decklinnk, I have compiled the latest one with the latest version of the api, but still I get a black screen instead of the actually feed.</p>
  
  <pre><code>ffmpeg -list_devices true -f dshow -i dummy
  ffmpeg version N-77245-g7209c94 Copyright (c) 2000-2015 the FFmpeg developers
    built with gcc 5.2.0 (Rev4, Built by MSYS2 project)
    configuration:  --enable-avisynth --enable-libbluray --enable-libcaca --enable -libass --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame
   --enable-libschroedinger --enable-libsoxr --enable-libtwolame --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libopus --enable-libtesseract --
  enable-libdcadec --enable-libbs2b --enable-libmfx --enable-libfreetype --enable-fontconfig --enable-libfribidi --enable-opengl --enable-libvpx --enable-libkvaza
  ar --enable-libwebp --enable-decklink --enable-libgme --disable-w32threads --enable-opencl --enable-libzimg --enable-openssl --disable-debug
    libavutil      55. 10.100 / 55. 10.100
    libavcodec     57. 17.100 / 57. 17.100
    libavformat    57. 20.100 / 57. 20.100
    libavdevice    57.  0.100 / 57.  0.100
    libavfilter     6. 21.100 /  6. 21.100
    libswscale      4.  0.100 /  4.  0.100
    libswresample   2.  0.101 /  2.  0.101
  [dshow @ 0000000ba36b6480] DirectShow video devices (some may be both video and audio devices)
  [dshow @ 0000000ba36b6480]  "Blackmagic WDM Capture"
  [dshow @ 0000000ba36b6480]     Alternative name "@device_pnp_\\?\decklink#avstream#5&amp;2550cef9&amp;0&amp;0000#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\decklinkcapture1"
  [dshow @ 0000000ba36b6480]  "Decklink Video Capture"
  [dshow @ 0000000ba36b6480]     Alternative name "@device_sw_{860BB310-5D01-11D0-BD3B-00A0C911CE86}\{44A8B5C7-13B6-4211-BD40-35B629D9E6DF}"
  [dshow @ 0000000ba36b6480] DirectShow audio devices
  [dshow @ 0000000ba36b6480]  "Wej?øcie liniowe (Blackmagic Audio)"
  [dshow @ 0000000ba36b6480]     Alternative name "@device_cm_{33D9A762-90C8-11D0-BD43-00A0C911CE86}\wave_{977E2DB6-B17C-4343-9018-652924C20A8C}"
  [dshow @ 0000000ba36b6480]  "Decklink Audio Capture"
  [dshow @ 0000000ba36b6480]     Alternative name "@device_sw_{33D9A762-90C8-11D0-BD43-00A0C911CE86}\{AAA22F7E-5AA0-49D9-8C8D-B52B1AA92EB7}"
  dummy: Immediate exit requested
  </code></pre>
  
  <p>The result above tells me that ffmpeg can see the card and I am able to open a communication, I have checked one post where it says you need to specific which input type is showing, otherwise it will never work, and I did that, but still no luck.</p>
  
  <p>By running the command line above, I can only see a black screen but not actually errors.</p>
  
  <p>I am running Windows 8.1 64bit.</p>
  
  <pre><code>ffplay  -pixel_format uyvy422 -framerate 25 -f dshow -i video="Decklink Video Capture"  -format x264
  ffplay version N-77245-g7209c94 Copyright (c) 2003-2015 the FFmpeg developers
    built with gcc 5.2.0 (Rev4, Built by MSYS2 project)
    configuration:  --enable-avisynth --enable-libbluray --enable-libcaca --enable-libass --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame
   --enable-libschroedinger --enable-libsoxr --enable-libtwolame --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libopus --enable-libtesseract --
  enable-libdcadec --enable-libbs2b --enable-libmfx --enable-libfreetype --enable-fontconfig --enable-libfribidi --enable-opengl --enable-libvpx --enable-libkvaza
  ar --enable-libwebp --enable-decklink --enable-libgme --disable-w32threads --enable-opencl --enable-libzimg --enable-openssl --disable-debug
    libavutil      55. 10.100 / 55. 10.100
    libavcodec     57. 17.100 / 57. 17.100
    libavformat    57. 20.100 / 57. 20.100
    libavdevice    57.  0.100 / 57.  0.100
    libavfilter     6. 21.100 /  6. 21.100
    libswscale      4.  0.100 /  4.  0.100
    libswresample   2.  0.101 /  2.  0.101
  Input #0, dshow, from 'video=Decklink Video Capture':    0B f=0/0
    Duration: N/A, start: 0.138773, bitrate: N/A
      Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422, 720x576, 25 tbr,
  10000k tbn, 25 tbc
     1.51 M-V: -0.000 fd=   0 aq=    0KB vq=    0KB sq=    0B f=0/0
  </code></pre>