feat: looping virtual camera

bin/virtcam

@@ -0,0 +1,41 @@
+#!/bin/sh
+
+# Looping virtual webcam
+
+set -e
+
+killall -9 ffmpeg || true
+
+sleep 2
+
+# unload virtual
+sudo modprobe v4l2loopback -r -f
+
+# create 2 virtual webcam
+sudo modprobe v4l2loopback video_nr=21,22 card_label=virtcam1,virtcam2 exclusive_caps=1
+
+# pipe actual webcam to virtcams
+actualwebcam() {
+    if [ -n "$FAKER_PID" ]; then
+        kill -s INT "$FAKER_PID"
+        FAKER_PID=
+    fi
+    ffmpeg -f v4l2 -i /dev/video0 -codec copy -f v4l2 /dev/video21 -f v4l2 /dev/video22 >/dev/null 2>&1 </dev/null &
+    echo $!
+}
+
+while true; do
+    PID=$(actualwebcam)
+    echo piping actual webcam, press ENTER to start recording
+    read C
+    echo recording, press [q] to replay
+    ffmpeg -y -i /dev/video22 ~/Video/seq.mp4 >/dev/null 2>&1
+    echo recording stopped
+    ffmpeg -y -i ~/Video/seq.mp4 -vf reverse ~/Video/reversed.mp4 >/dev/null 2>&1
+    echo reversed clip created
+    ffmpeg -y -i ~/Video/seq.mp4 -i ~/Video/reversed.mp4 -filter_complex "[0:v] [1:v] concat=n=2:v=1 [v]" -map "[v]" loop.mp4 >/dev/null 2>&1
+    echo looping clip created
+    kill -s INT $PID
+    echo webcam stopped, enter looping mode, press [q] to resume webcam
+    ffmpeg -re -stream_loop -1 -i ~/Video/loop.mp4 -f v4l2 -vcodec rawvideo -pix_fmt yuyv422 -framerate 30 /dev/video21 >/dev/null 2>&1
+done