Directshow, passing a stream to a program like ffmpeg

Question

I am new to DirectShow. I have an ASI/SDI Dectek device, DTU-225, and a relative sdk: http://www.dektec.com/products/USB2/DTU-225/index.asp . In this sdk there is a Directshow filter. I need to pass the output generated by this filter to ffmpeg, mencoder o vlc for further proccessing in real-time (no intermediate files to be created). How can I do this? For the SDI interface the filter's output pin specifics are:

Type1

• Majortype: MEDIATYPE_Video
• Subtype: MEDIASUBTYPE_UYVY
• Formattype: FORMAT_VIDEOINFO2

Type2

• MEDIATYPE_Video
• MEDIASUBTYPE_UYVY
• FORMAT_VideoInfo

I think it is more confortable to use DirectShow because the next step will be: do the same thing not in SDI mode but in DVB-ASI mode, mpeg2-transport stream; so i have to parse the stream and extract different PID. I think DirectShow will help me in this process. Maybe. Thank you.

Answer 1

Windows vlc will capture from a DirectShow filter. See the link below. Works fine on my Windows system capturing from the built in webcam and microphone. From the open capture device dialog you can select 'show more options' to see the options which you can use on the vlc command line to open that capture device and stream/transcode etc.

http://www.videolan.org/doc/play-howto/en/ch03.html

Basic DirectShow input options on my system look like the following:

:dshow-vdev=USB Video Device :dshow-adev=Microphone (Realtek High Definition) :dshow-caching=200

I don't have much knowledge of vlc and I haven't managed to get this working from the command line. There are some worrying reports of not being able to use DirectShow devices with spaces in the name from the command line but there may be workarounds.

http://trac.videolan.org/vlc/ticket/1654

If you're prepared to do some DirectShow programming or use Windows Media Player instead there is an infinite variety of video processing options available in DirectShow. See the Wikipedia page on DirectShow to get an overview.

Another option would be to write a plugin for vlc, ffmpeg or mencode that talks directly to DirectShow to get data from the filter for your device though it's not nearly as simple as using vlc's DirectShow input.

Answer 2

Just use ffdshow, this is ffmpeg in a form of DirectShow filter.

Answer 3

ffmpeg can accept "dshow" input

ffmpeg/ffplay can also accept avisynth input, avisynth can accept graphedit files as input, you can add your filters into a graphedit file and play that. This is the only way to capture "non source" filters.