add frame rate management (#558)

Signed-off-by: Denis barbaron <denis.barbaron@orange.com>

lib/units/device/plugins/screen/stream.js

@@ -1,3 +1,7 @@
+/**
+* Copyright © 2022 contains code contributed by Orange SA, authors: Denis Barbaron - Licensed under the Apache license 2.0
+**/
+
 var util = require('util')
 
 var Promise = require('bluebird')
@@ -26,6 +30,7 @@ module.exports = syrup.serial()
   .define(function(options, adb, minicap, display, screenOptions) {
     var log = logger.createLogger('device:plugins:screen:stream')
     log.info('ScreenGrabber option set to %s', options.screenGrabber)
+    log.info('ScreenFrameRate option set to %d', options.screenFrameRate)
 
     function FrameProducer(config, grabber) {
       EventEmitter.call(this)
@@ -230,12 +235,23 @@ module.exports = syrup.serial()
 
     FrameProducer.prototype._startService = function() {
       log.info('Launching screen service %s', this.grabber)
-      return minicap.run(this.grabber, util.format(
-        '-S -Q %d -P %s'
-      , options.screenJpegQuality
-      , this.frameConfig.toString()
-      ))
-      .timeout(10000)
+      if (options.screenFrameRate <= 0.0) {
+        return minicap.run(this.grabber, util.format(
+          '-S -Q %d -P %s'
+        , options.screenJpegQuality
+        , this.frameConfig.toString()
+        ))
+        .timeout(10000)
+      }
+      else {
+        return minicap.run(this.grabber, util.format(
+          '-S -r %d -Q %d -P %s'
+        , options.screenFrameRate
+        , options.screenJpegQuality
+        , this.frameConfig.toString()
+        ))
+        .timeout(10000)
+      }
     }
 
     FrameProducer.prototype._readOutput = function(out) {