Delaying audio & video for live subtitles

[Hitcom]

At the end of the month I will do a live stream which has live subtitles.

I need to send the video to a live subtitle service. They will do the subtitles and send them back through NDI. This already works. What I need is a way to send them the video in real time (no delay, so they can do the subtitles) and then add those subtitles to a 5 second delayed video (and audio) and stream that out to Youtube. How would I go about making this happen?

 

[Lawrence_SoCal]

do they send you just the sub-titles, or the video with sub-titles?
if they are sending you back the video with sub-titles, why not send that to YouTube instead of yourself?

 

[Hitcom]

do they send you just the sub-titles, or the video with sub-titles?
if they are sending you back the video with sub-titles, why not send that to YouTube instead of yourself?

They are only sending me the subtitles through NDI from their location. I paste the subtitles on the video myself on the 5 second delayed video.

 

[Tomasz Góral]

How i see:
You need to instances OBS and nginx-rtmp, on first OBS select Stream Delay e.g. 5 sec, send to local nginx, on second OBS get stream from local nginx and add NDI on screen.
If on first OBS need send stream via rtmp, use multi rtmp plugin (send without delay).

 

[Lawrence_SoCal]

Be aware that a solution where you send video out, get sub-titles only via NDI, then re-send video with sub-titles back out means 2X rendering/encoding load, and 2X outbound bandwidth

 

[Hitcom]

Thanks to everybody for chipping in! I can figure it out with the advice given. :)