Stream external dslr/mirrorless camera as webcam on linux

camera-as-webcam.sh

#!/bin/sh

# webcam will be preview quality, not of actual camera capabilities  
# prerequisites and source: https://www.crackedthecode.co/how-to-use-your-dslr-as-a-webcam-in-linux/
# alternative: https://hanspinckaers.com/using-a-sony-alpha-camera-as-a-webcam-in-ubuntu

# IF PREREQUISITES ARE MET AND SCRIPT IS FAILING, RESTART MIGHT HELP

# restart v4l2loopback kernel module
sudo modprobe -r dslr-webcam
sudo modprobe dslr-webcam

# detect video0
v4l2-ctl --device=/dev/video0 --all

# detect connected camera
gphoto2 --auto-detect                                 

# uses gpu, for cpu see: source^
# /dev/video0 should be v4l2loopback device
gphoto2 --stdout --capture-movie | ffmpeg \
-hwaccel nvdec \
-c:v mjpeg_cuvid \
-i - \
-vcodec rawvideo \
-pix_fmt yuv420p \
-threads 0 \
-f v4l2 /dev/video0