fix v4l2

reStream.sh

@@ -3,12 +3,12 @@
 # default values for arguments
 remarkable="${REMARKABLE_IP:-10.11.99.1}" # remarkable IP address
 #remarkable="${REMARKABLE_IP:-10.143.0.112}" # remarkable IP address
-landscape=true        # rotate 90 degrees to the right
-output_path=-         # display output through ffplay
-format=-              # automatic output format
-webcam=false          # not to a webcam
-hflip=false           # horizontal flip webcam
-window_title=reStream # stream window title is reStream
+landscape=true          # rotate 90 degrees to the right
+output_path=/dev/video5 # display output through ffplay
+format=-                # automatic output format
+webcam=true             # not to a webcam
+hflip=false             # horizontal flip webcam
+window_title=reStream   # stream window title is reStream
 
 ssh_cmd() {
     echo "[SSH]" "$@" >&2
@@ -49,17 +49,26 @@ video_filters="colorlevels=rimin=0:rimax=29/255:gimin=0:gimax=29/255:bimin=0:bim
 # rotate 90 degrees if landscape=true
 $landscape && video_filters="$video_filters,transpose=1"
 
-# Scale and add padding if we are targeting a webcam because a lot of services
-# expect a size of exactly 1280x720 (tested in Firefox, MS Teams, and Skype for
-# for business). Send a PR if you can get a higher resolution working.
 if $webcam; then
     video_filters="$video_filters,format=pix_fmts=yuv420p"
-    video_filters="$video_filters,scale=-1:720"
-    video_filters="$video_filters,pad=1280:0:-1:0:#eeeeee"
+    format="v4l2"
+
+    # check if there is a modprobed v4l2 loopback device
+    # use the first cam as default if there is no output_path already
+    cam_path=$(v4l2-ctl --list-devices |
+        sed -n '/^[^\s]\+platform:v4l2loopback/{n;s/\s*//g;p;q}')
+
+    # fail if there is no such device
+    if [ -e "$cam_path" ]; then
+        if [ "$output_path" = "-" ]; then
+            output_path="$cam_path"
+        fi
+    else
+        echo "Could not find a video loopback device, did you"
+        echo "sudo modprobe v4l2loopback"
+        exit 1
+    fi
 
-    # Some applications, eg Zoom and Discord, mirror by default the webcam video
-    # Restore the correct orientation
-    $hflip && video_filters="$video_filters,hflip"
 fi
 
 # set each frame presentation time to the time it is received