Add Feature V4L2 Control

* This feature allows you to setup v4l2-ctl parameters before stream starts.
* Modified webcamd accordingly.
* Modified libs/configparser.sh.
* Changed functions get_param configured_cams and check_section

Signed-off-by: Stephan Wendel <me@stephanwe.de>

libs/configparser.sh

@@ -18,15 +18,13 @@ set -e
 # call get_param section param
 # spits out raw value
 function get_param {
-    local cfg
-    local section
-    local param
+    local cfg section param
     cfg="${WEBCAMD_CFG}"
     section="${1}"
     param="${2}"
     crudini --get "${cfg}" "${section}" "${param}" | \
-    sed 's/\#.*//;s/[[:space:]]*$//'
-} 2> /dev/null
+    sed 's/\#.*//;s/[[:space:]]*$//' || echo ""
+}
 
 # Check for existing file
 # Exit with error if not exist
@@ -39,11 +37,13 @@ function check_cfg {
 
 ## Spits out all [cam <nameornumber>] configured sections
 function configured_cams {
-    local cam_count cfg
+    local cams cfg
     cfg="${WEBCAMD_CFG}"
-    cams="$(crudini --existing=file --get "${cfg}" | \
-    sed '/webcamd/d;s/cam//')"
-    echo "${cams}"
+    for i in $(crudini --existing=file --get "${cfg}" | \
+    sed '/webcamd/d;s/cam//'); do
+        cams+=("${i}")
+    done
+    echo "${cams[@]}"
 }
 
 # Checks [cam <nameornumber>] if all needed configuration sections are present
@@ -53,7 +53,7 @@ function check_section {
     section="cam ${1}"
     # Ignore missing custom flags
     param="$(crudini --existing=param --get "${WEBCAMD_CFG}" "${section}" \
-    2> /dev/null | sed '/custom_flags/d')"
+    2> /dev/null | sed '/custom_flags/d;/v4l2ctl/d')"
     must_exist="streamer port device resolution max_fps"
     missing="$(echo "${param}" "${must_exist}" | \
     tr ' ' '\n' | sort | uniq -u)"

libs/v4l2_control.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-#### Init Stream library
+#### v4l2 control library
 
 #### webcamd - A webcam Service for multiple Cams and Stream Services.
 ####
@@ -10,7 +10,49 @@
 ####
 #### This File is distributed under GPLv3
 ####
+#### Description: Configure Cam with v4l2-ctl options
+#### ex.: v4l2-ctl -c brightness=100
 
 # Exit upon Errors
 set -e
 
+function v4l2_control {
+    log_msg "V4L2 Control:"
+
+    function main {
+        local device v4l2ctl valueless opt_avail
+        for cam in $(configured_cams); do
+            # get device from cam section
+            device="$(get_param "cam ${cam}" device)"
+            # get v4l2ctl parameters
+            v4l2ctl="$(get_param "cam ${cam}" v4l2ctl)"
+
+            # if not empty do
+            if [ -n "${v4l2ctl}" ]; then
+                # Write configured options to Log
+                log_msg "Device: [cam $cam]"
+                log_msg "Options: ${v4l2ctl}"
+                # Split options to array
+                IFS=',' read -a opt < <(echo "${v4l2ctl}"); unset IFS
+                # loop through options
+                for param in "${opt[@]}"; do
+                    # parameter available for device
+                    # needs || true to prevent script to exit
+                    valueless="$(echo "${param}" | cut -d "=" -f1)"
+                    opt_avail="$(v4l2-ctl -d ${device} -L | \
+                    grep -c ${valueless} || true)"
+                    if [ "$opt_avail" -eq "0" ]; then
+                        log_msg "Parameter '${param}' not available for '${device}'. Skipped."
+                    else
+                        v4l2-ctl -d "${device}" -c "${param}" 2> /dev/null
+                    fi
+                done
+            else
+                log_msg "No parameters set for [cam ${cam}]. Skipped."
+            fi
+        done
+    }
+
+    ### MAIN
+    main
+}

webcamd

@@ -29,7 +29,7 @@ source "${BASE_CN_PATH}/libs/logging.sh"
 source "${BASE_CN_PATH}/libs/messages.sh"
 source "${BASE_CN_PATH}/libs/watchdog.sh"
 source "${BASE_CN_PATH}/libs/init_stream.sh"
-# source "${BASE_CN_PATH}/libs/v4l2_control.sh"
+source "${BASE_CN_PATH}/libs/v4l2_control.sh"
 
 function run_ustreamer {
     local cam_section ustreamer_bin device port resolution fps custom
@@ -138,6 +138,7 @@ done
 develop
 init_log_entry
 initial_check
+v4l2_control
 construct_streamer
 
 ## Loop and Watchdog