If you are going that route (I have), keep in mind that streaming from your mirrorless/DSLR HDMI port usually means h.264 live encoding, which might not work sm

If you are going that route (I have), keep in mind that streaming from your mirrorless/DSLR HDMI port usually means h.264 live encoding, which might not work smoothly with older machine, there are very few HDMI to USB capture cards that perform the encoding. Since I'm still mostly using my old Macbook (late 2014) and a Sony A7II + (Sony FE 55mm f/1.8), I soon realized that with a basic USB capture device (a UVC device that exposes an uncompressed video as webcam) I couldn't get anywhere past 360p with 24fps, and even then, CPU was skyrocketing. Next I tried to utilize an Raspberry Pi that I have to stream the video, but using VLC as well as FFMpeg and few other streaming products, all did not do well when it came to resolution, fps and latency. At the same time, I researched some existing USB capture devices, and while Elgato seems like the popular choice, non of their USB capture devices perform hardware h.264 encoding, so the bottleneck remains the host machine. The only two hardware brands that I found at the time (around a year ago) that made USB capture devices with on-board h.264 encoders were Blackmagic and Magewell. I went with the Magewell USB Capture Gen 2 which seemed to do exactly what I wanted and no more than that. I was able to find for ~$80 and it has worked perfectly since — no latency or missing frames at 1080p. It also has a very nice management console that let you tweak the (hardware) encoding (enable/disable mirror mode, crop frame and more). EDIT: another thing that I tried was to use Sony Imaging Edge Webcam — a USB driver that turn Sony cameras into UVC (webcam) device. It works pretty well but has a max resolution of 1024 x 576. Not what I was looking for but still I remember it as being equal or even better than combining a cheap HDMI to USB devices that don't do hardware encoding with OBS for virtual camera.