webcam formats and computer resource usage

[danklim]

Hi, I have a Logitech Brio webcam camera that doesn't output at the format that I want to use and am trying to figure out how to use it in the most resource efficient way, can you please help?

I output video from Resolume at 1920x1080 into OBS, where the the 'base (canvas) resolution' is also 1920x1080 and the 'output (scaled) resolution' is also 1920x1080 and OBS streams it out to the internet at 30 frames per second. In Resolume, I have the composition settings for frame rate set to "auto"

With my other cameras, I can use the format of 1920x1080 @30fps and it works perfectly, but for some reason the Logitech Brio only allows me to use a format of 1920x1080 @60 fps (or use an enitrely different resolution at 30fps). Screenshot is below of all of the format options that the camera provides. I want to conserve computing resources as much as possible and am happy with 1920x1080 @30fps, but am wondering if selecting this option for 60fps might use double the computing resources because the frame rate is double even though everything else is at 30fps.

Would selecting 60fps cause the computer and Resolume to use twice as much resources as using 1920x1080 @30 fps? If so, is there any way around this that would allow me to conserve those computing resources and still use a 1920x1080 resolution? Or is the only option to just select a different resolution or use a different webcam?

Also, another question about formats and computing resource usage- If I select a very large resolution, like 4096x2160, but still keep it on the same canvas with is 1920x1080 (and either A] keep the scale parameter at 100% and just have the frame zoomed into just a portion of the entire webcam feed or B] use the scale parameter to make the webcam feed smaller so that the full image fits in the 1920x1080 canvas), then would that still take up much more computing resources than simply streaming the webcam at a format of 1920x1080?

Thanks,
Dan

[Zoltán]

Twice the frames would mean twice the bandwidth from the webcam, but if Resolume is running in Auto, it can go up to the refresh rate of your slowest display.

If you set your composition to 30FPS, Resolume will go up to 30, and should also request the frames from your webcam only 30 frames a second.

[mangtronix]

I'm having a similar issue with the Logitech Streamcam. The Streamcam seems to support 1080p60 using Mjpeg and 1080p30 using Mjpeg, Yuy2, and NV12.

Avenue only shows the 60p capture modes. I want to use 1080p30 with Yuy2 or NV12 since they are lower latency.

In OBS if you choose 1080p60 only Mjpeg codec is shown

In OBS if you choose 1080p30 then the other codecs are available

I'm guessing that Avenue requests the list of modes from the camera, and only gets the modes for Mjpeg.

I found a workaround (which also shows that it should be possible to select and use the 1080p30 modes in Avenue). While Avenue is running you can go into OBS and change the framerate. You can also change the framerate (or even resolution) using the Logi Capture software.

Would be great to be able to select from all the available framerate/codec combinations inside Resolume! On my MBP 13" the latency difference is around 200ms (400ms for 1080p60 Mjpeg and 200ms for 1080p30 NV12).

[Zoltán]

We're already in contact about this via mail, right?