From 09a2404fc383c14f08df0dc19d6bc5db4ce15fca Mon Sep 17 00:00:00 2001
From: Mathias Koehler <mail@mathias.im>
Date: Sat, 29 Apr 2023 19:27:05 +0200
Subject: [PATCH] Check if v4l2 device has video inputs

---
 stream.sh | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/stream.sh b/stream.sh
index a2d930a..1a928f1 100755
--- a/stream.sh
+++ b/stream.sh
@@ -5,6 +5,11 @@ if ! command -v inotifywait >/dev/null 2>&1; then
   exit 1
 fi
 
+if ! command -v v4l2-ctl >/dev/null 2>&1; then
+  echo "Please install v4l-utils"
+  exit 1
+fi
+
 declare -A STREAMS
 
 failed() {
@@ -28,13 +33,21 @@ streaming() {
   ) || failed "$1"
 }
 
-check_initial_devices() {
-  for file in /dev/video*; do
-    file="${file##*/}"
-    echo "Found $file"
+check() {
+  file=$1
+  echo "Found $file"
+
+  if v4l2-ctl -n -d "/dev/$file" | grep -q 'Input'; then
     (streaming "$file") &
     STREAMS[$file]=$!
     echo "$file PID ${STREAMS[$file]}"
+  fi
+}
+
+check_initial_devices() {
+  for file in /dev/video*; do
+    file="${file##*/}"
+    check "$file"
   done
 }
 
@@ -42,16 +55,13 @@ listen_for_new_devices() {
   inotifywait -m /dev --format "%f" -e create |
     while read -r file; do
       if [[ "$file" =~ video[0-9]+$ ]]; then
-        echo "Found $file"
 
         if ! ps -p "${STREAMS[$file]}"> /dev/null; then
           unset "STREAMS[$file]"
         fi
 
         if [[ ! -v "STREAMS[$file]" ]]; then
-          (streaming "$file") &
-          STREAMS[$file]=$!
-          echo "$file PID ${STREAMS[$file]}"
+          check "$file"
         fi
       fi
     done