Fixes/updates for Camilla VC dynamic range option

[cdsp/php]
- Change function name from getMappedDbVol() to calcMappedDbVol() to avoid confusion with same named function in mpd.php
- Change 0 factor from 0.0000001 to 0.000001

[mpd.php]
- Fix format width for '-120dB;
- Refactor var name to camelCase
- Reference calcMappedDbVol()

www/inc/cdsp.php

@@ -553,7 +553,7 @@ function backup() {
     function restore($values) {
     }
 
-    static function getMappedDbVol($volume, $dynamic_range) {
+    static function calcMappedDbVol($volume, $dynamic_range) {
         $x = $volume/100.0;
         $y = pow(10, $dynamic_range/20);
         $a = 1/$y;
@@ -563,11 +563,10 @@ static function getMappedDbVol($volume, $dynamic_range) {
             $y = $x*10*$a*exp(0.1*$b);
         }
         if( $y == 0) {
-            $y = 0.0000001;
+            $y = 0.000001;
         }
         return 20* log10($y);
     }
-
 }
 
 // TODO: Change these to cdsp-> member functions

www/inc/mpd.php

@@ -737,16 +737,15 @@ function getMappedDbVol() {
 	phpSession('open_ro');
 
 	if (isMPD2CamillaDSPVolSyncEnabled() && doesCamillaDSPCfgHaveVolFilter()) {
-		// implement the same curve as with mpd2camilladsp
-
-		// Use SQL value instead of session
+		// For CamillaDSP volume
 		$result = sqlRead('cfg_system', sqlConnect(), 'volknob');
+
 		//TODO: create setting for it
-		$dynamic_range = 60;
+		$dynamicRange = 60;
 
-		$mappedDbVol = CamillaDsp::getMappedDbVol($result[0]['value'], $dynamic_range) ;
+		$mappedDbVol = CamillaDsp::calcMappedDbVol($result[0]['value'], $dynamicRange) ;
 		$mappedDbVol = round($mappedDbVol, 1);
-		$mappedDbVol = ($mappedDbVol > -10 ? number_format($mappedDbVol, 1) : substr($mappedDbVol, 0, 3)) . 'dB';
+		$mappedDbVol = ($mappedDbVol > -10 ? number_format($mappedDbVol, 1) : substr($mappedDbVol, 0, 4)) . 'dB';
 	} else {
 		// For MPD volume
 		$result = sysCmd('amixer -c ' . $_SESSION['cardnum'] . ' sget "' . $_SESSION['amixname'] . '" | ' .