View Full Version : Blackmagic Decklink Pro vs Directshow (trying to process SDI on the fly)

Mug Funky
9th February 2008, 13:35
hi all.

i've been tinkering with a spare Decklink Pro card that was otherwise unused at work. there's 2 things i want to do with it that haven't worked so far (though i've got what i need for now).

- input from SDI, stream h.264 via VLC.

- input from SDI, process with avisynth via ffdshow, output to SDI.

the problem here is that:

- VLC crashes whenever i try to use decklink as a capture device, no matter what the settings (googling revealed a couple of things that worked for other people, but no such luck for me).

- i can't make anything connect to decklink renderer in graphedit

has anyone got experience with this kind of thing? i don't know programming, especially for directshow, and it seems this may be the only way to make the filters connect.

basically i'd like to turn a computer i don't use much into a standards-converter/noise reducer, and also be able to stream the output of my telecine to interstate clients so they can give immediate feedback rather than waiting for a tape to be sent (i've got this part working in MSN messenger as a webcam, and also in windows media encoder, but i'd rather use h.264 and an open-source solution)

yeah, that about wraps it up :)

9th February 2008, 15:49
Possibly the same restrictions apply to the decklink pro as my intensity pro (which is labelled as a decklink by directshow and uses the same SDK):

- The renderer won't accept anything outside standard definitions e.g 720x576x25/720x480x29.97/HD formats. Oddly it will accept YUY2 while the card only captures UYVY.
- You can't use the renderer at all if the input is currently being used e.g. while capturing. It will only do passthru.

Not sure about VLC, here it either crashes or gives some kind of weird stretched version of the top left corner of the stream.