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Mac / Win, HW encoding - OBS, Wirecast, Vmix

Posted: Thu May 06, 2021 3:08 pm
by dbaresrc
I'm trying to sift the wheat from the chafe on a question or two.

Anyone know if OBS on Mac (Intel not M1) or Win leverages the discrete video card for encoding a stream? I've heard some people say "no" for Mac, others yes. If no, then the encoding workload is pushed to the main CPU. If you're using a Mac with OBS, how pegged is the CPU when encoding to the RTMP address or to Zoom?

Same question for Wirecast which runs on both (haven't been able to talk with anyone there to answer the question).

Vmix only runs on Windows so I assume it leverages the discrete video card but you never know . . . . .


Re: Mac / Win, HW encoding - OBS, Wirecast, Vmix

Posted: Sat May 08, 2021 12:06 am
by Mikerowaved
I'm not a Mac enthusiast, but I have quite a bit of experience with both OBS and Wirecast. According to this YouTube video (wade through the commercials), OBS version 25 fixed some of the roadblocks keeping OBS from using hardware acceleration on a Mac.

In other forums, I've learned that OBS can also now take advantage of Intel Quick Sync Video (hardware encode/decode accelerator) found in their i3-i9 processors on either a PC or Mac. This Wikipedia page shows a chart of the capabilities of each class of CPU. For the chart, "AVC" is your basic H.264 encoder and "HEVC" is the newer H.265 encoder.

Also worth noting is some Mac Pros have Xeon processors without Quick Sync Video, so YMMV depending on your particular CPU.

Hope this helps.

Re: Mac / Win, HW encoding - OBS, Wirecast, Vmix

Posted: Mon May 10, 2021 5:13 am
by Wattsuk
I'm not sure what you are aiming to achieve and can't specifically answer your question.

My dell XPS 13 which is a few years old now, with a i5-8250u cpu and integrated intel 620UHD graphics.
It will encode a 720p stream without breaking a sweat, the cooling fan runs at it's lowest speed.

It is capable of encoding 1080p but not 4k.

For the requirements of church broadcasting, 720p is more than adequate. The quality of sound is often a more important issue.

Re: Mac / Win, HW encoding - OBS, Wirecast, Vmix

Posted: Mon Jul 26, 2021 1:21 pm
by jsweeny
we use vmix - and, yes, the graphics card is used for encoding the video.