Accesing DecLink COM interface from multiple processes ?

Hello - I apologize if this question is obvious, I am just getting up to speed with COM interfaces....

Background:
- I am looking into adding support for VANC close-captioning into a CasparCG based replay system, using Blackmagic DecLink cards. The access to VANC is not implemented in CasparCG, so it would have to be done from a different process.

Question:
Can multiple processes operate on the COM interface of a single channel of a DecLink card, so that one process would control video playback, another would add VANC data ? If not, can multiple processes use multiple chanels on one Declink card ( one process using one channel ) ?

Thanks for any info/pointers. Paul Cerna.

[Nicholas Gill]

Hi Pavel,

- I am looking into adding support for VANC close-captioning into a CasparCG based replay system, using Blackmagic DecLink cards. The access to VANC is not implemented in CasparCG, so it would have to be done from a different process.

I have elaborated on the questions posted below, however with the overview of the intended outcome, my suggestion would be that this is best implemented directly in the host application controlling the DeckLink device (CasparCG).

Can multiple processes operate on the COM interface of a single channel of a DecLink card, so that one process would control video playback, another would add VANC data ?

This is not possible, access to an individual DeckLink device / sub-device is possible from a single process only.

If not, can multiple processes use multiple chanels on one Declink card ( one process using one channel ) ?

Control of distinct DeckLink devices / sub-devices is possible within and across processes, however it should be noted that a solution which captured video, injected VANC, and output a modified video frame would unavoidably introduce latency into the video stream, and synchronisation of the VANC payload and video frames would have to be performed out-of-band.

Cheers,

-nick