cathoderaydude patreon

Behind the scenes: Compositing setup

🕑 Added 2025-01-31 20:37:23 +0000 UTC

Comments

Loading_M_

For capturing multiple streams at once: I'm not sure whether there is a better solution. I would guess that the biggest issue is the encoding, since there should be no reason why multiple programs couldn't pull real-time video from different USB devices at the same time. Writing to disk also wouldn't be an issue, since the combined video should have a similar bitrate as the two videos combined. However, the encoding step would likely run on the GPU, and if two instances of OBS (or other capture software) are fighting over the GPU encoding cores, you likely lose enough performance to start dropping frames or similar. (Seek time on an HDD could also be an issue, but I assume you're saving to SSDs). I suspect that a purpose built program could solve this issue, but he OBS solution has some other fringe benefits (you get automatic sync between the two streams, etc) and the development cost is way more than any additional benefits you could get from a dedicated solution. I do wonder if a multi-GPU rig could do multiple streams, as long as each is assigned to use a different GPU.

Hayden Neumeyer

Hey if you ever want a more "professional" capture setup for various things you should check out DataPath Vision line. Tech Tangents uses the VisionAV-HD for Hydro Thunder. I have one for various retro and modern PC stuff. It does almost anything up to 1080p 60.

Ben Parkhurst

Your USB rant makes me miss the days of Firewire breakouts with the realtime serial bus being able to take 2-3 non HD streams simultaneously with few issues. I think that Firewire dealt well with an asynchronous bus where even today USB tends to choke in that situation.

Cysioland

Me: oh, it looks just like the Blackmagic Camera app for Android... Me later: oh, right, Blackmagic cameras

VinDuv

My (very limited) experience with A/V told me that if you try to do something slightly different than the examples you find on the Internet, you will encounter crashes, hangs, audio/video desync, inscrutable error messages, etc. This was a while ago and I think the development of OBS improved things, but still. So I’m not surprised that you need a complex setup to do the complex things you need. In fact I’m more surprised that you found a way to make it work at all!