Frame Rate collapse when pairing audio and video... hardware issue?

StanleyTwoBrix

New Member
I'm trying to set up web streaming for a friend's DIY music venue/music store (Main Drag Music, in Brooklyn, if you know it). The perfect storm of COVID, gentrification, and Amazon have been pretty brutal, so I have been volunteering a lot of my time (I'm retired).

I have no experience in this exactly, but I worked for 20 years doing visual effects (I was a compositor) so I have a pretty deep knowledge of things sort of, but not quite, related to this. Kind of.

I haven't had a problem using my Zoom Q8 as an audio and video source (not that I have noticed, anyway!).

The video appears to work fine when I use my friend's Canon T3i (much better lens/zoom) but if I try and use either the audio from the zoom or the built in mic on my laptop, the frame rate drops down to 5-10 FPS (just guessing).

I have tried routing the audio from the Canon (as I could feed the external mic in from a mixer) to see if the frame rate would go back to normal, but it seems that the T3i can not stream audio.

I'm using the Canon T3i not because I want to, but because my friend can't afford a new camera yet.

questions:

1) It seems like OBS is constantly scaling the input video. Is there a way to display a pixel-for-pixel, and free up resource from the transform, or is this being handled in VRAM (or whatever - I'm old enough to remember SGI's Geometry Engine and have been retired for a while, so I'm def not current) and not dropping my frame rate.

Somehow I suspect that the slow frame rate has something to do with trying to keep audio sync. Is there a way to optimize this?

2) Is my laptop too slow? Here are the specs:

Model Name: MacBook Pro
Model Identifier: MacBookPro11,5
Processor Name: Quad-Core Intel Core i7
Processor Speed: 2.8 GHz
Number of Processors: 1
Total Number of Cores: 4
L2 Cache (per Core): 256 KB
L3 Cache: 6 MB
Hyper-Threading Technology: Enabled
Memory: 16 GB
System Firmware Version: 430.140.3.0.0
OS Loader Version: 540.120.3~22

3) Should I just be looking at a better camera and/or laptop (neither of which he can afford - COVID has been really rough on , one that streams audio and video? It would need to work well in low light/high contrast (dark room, flashing lights) and have a decent zoom - which is why we were trying to repurpose this old DSLR.

While the Zoom works fine streaming-wise, the lens is WAY too wide and the performance is not great in low light.

Any help would be greatly appreciated.
 

StanleyTwoBrix

New Member
One solution found - there was a mismatch in the frame rate, as I had the Canon on 24p but OBS seems to want to get at least 30fps.

I'd prefer to run at 24 for better low light exposure, but it seems like throwing in 3/2 pulldown was slowing things (as does scaling up the image to get rid of the black box surrounding it.
 
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