clip indicator improvements (do not show clipping too early)

src/clientdlg.h

@@ -210,7 +210,7 @@ public slots:
     void OnMuteStateHasChangedReceived ( int iChanID, bool bIsMuted )
         { MainMixerBoard->SetRemoteFaderIsMute ( iChanID, bIsMuted ); }
 
-    void OnCLChannelLevelListReceived ( CHostAddress       /* unused */,
+    void OnCLChannelLevelListReceived ( CHostAddress      /* unused */,
                                         CVector<uint16_t> vecLevelList )
         { MainMixerBoard->SetChannelLevels ( vecLevelList ); }
 

src/levelmeter.cpp

@@ -178,8 +178,12 @@ void CLevelMeter::SetValue ( const double dValue )
                 }
             }
 
-            // clip LED management
-            if ( dValue > LEV_METER_CLIP_LIMIT_RATIO * NUM_STEPS_LED_BAR)
+            // clip LED management (note that in case of clipping, i.e. full
+            // scale level, the value is above NUM_STEPS_LED_BAR since the minimum
+            // value of int16 is -32768 but we normalize with 32767 -> therefore
+            // we really only show the clipping indicator, if actually the largest
+            // value of int16 is used)
+            if ( dValue > NUM_STEPS_LED_BAR )
             {
                 vecpLEDs[NUM_STEPS_LED_BAR]->SetColor ( cLED::RL_RED );
                 TimerClip.start();

src/levelmeter.h

@@ -35,9 +35,8 @@
 
 
 /* Definitions ****************************************************************/
-#define LEV_METER_CLIP_LIMIT_RATIO      0.99
-#define NUM_LEDS_INCL_CLIP_LED          ( NUM_STEPS_LED_BAR + 1 )
-#define CLIP_IND_TIME_OUT_MS            20000
+#define NUM_LEDS_INCL_CLIP_LED           ( NUM_STEPS_LED_BAR + 1 )
+#define CLIP_IND_TIME_OUT_MS             20000
 
 
 /* Classes ********************************************************************/

src/server.cpp

@@ -1681,8 +1681,8 @@ bool CServer::CreateLevelsForAllConChannels ( const int                        i
             const CVector<int16_t>& vecsData = vecvecsData[j];
 
             // Speed optimization:
-            // - we only make use of the positive values and ignore the negative ones
-            //   -> we do not need to call the fabs() function
+            // - we only make use of the negative values and ignore the positive ones (since
+            //   int16 has range {-32768, 32767}) -> we do not need to call the fabs() function
             // - we only evaluate every third sample
             int16_t sMax = 0;
 
@@ -1691,7 +1691,7 @@ bool CServer::CreateLevelsForAllConChannels ( const int                        i
                 // mono
                 for ( i = 0; i < iServerFrameSizeSamples; i += 3 )
                 {
-                    sMax = std::max ( sMax, vecsData[i] );
+                    sMax = std::min ( sMax, vecsData[i] );
                 }
             }
             else
@@ -1700,14 +1700,14 @@ bool CServer::CreateLevelsForAllConChannels ( const int                        i
                 for ( i = 0, k = 0; i < iServerFrameSizeSamples; i += 3, k += 6 ) // 2 * 3 = 6 -> stereo
                 {
                     // left/right channels separately
-                    sMax = std::max ( sMax, vecsData[k] );
-                    sMax = std::max ( sMax, vecsData[k + 1] );
+                    sMax = std::min ( sMax, vecsData[k] );
+                    sMax = std::min ( sMax, vecsData[k + 1] );
                 }
             }
 
             // smoothing
             const int    iChId     = vecChanIDsCurConChan[j];
-            const double dCurLevel = std::max ( static_cast<double> ( sMax ), vecChannels[iChId].GetPrevLevel() * 0.5 );
+            const double dCurLevel = std::max ( -static_cast<double> ( sMax ), vecChannels[iChId].GetPrevLevel() * 0.5 );
             vecChannels[iChId].SetPrevLevel ( dCurLevel );
 
             // logarithmic measure

src/util.cpp

@@ -36,8 +36,8 @@ void CStereoSignalLevelMeter::Update ( const CVector<short>& vecsAudio )
     // Get maximum of current block
     //
     // Speed optimization:
-    // - we only make use of the positive values and ignore the negative ones
-    //   -> we do not need to call the fabs() function
+    // - we only make use of the negative values and ignore the positive ones (since
+    //   int16 has range {-32768, 32767}) -> we do not need to call the fabs() function
     // - we only evaluate every third sample
     //
     // With these speed optimizations we might loose some information in
@@ -50,18 +50,18 @@ void CStereoSignalLevelMeter::Update ( const CVector<short>& vecsAudio )
     for ( int i = 0; i < iStereoVecSize; i += 6 ) // 2 * 3 = 6 -> stereo
     {
         // left channel
-        sMaxL = std::max ( sMaxL, vecsAudio[i] );
+        sMaxL = std::min ( sMaxL, vecsAudio[i] );
 
         // right channel
-        sMaxR = std::max ( sMaxR, vecsAudio[i + 1] );
+        sMaxR = std::min ( sMaxR, vecsAudio[i + 1] );
     }
 
-    dCurLevelL = UpdateCurLevel ( dCurLevelL, sMaxL );
-    dCurLevelR = UpdateCurLevel ( dCurLevelR, sMaxR );
+    dCurLevelL = UpdateCurLevel ( dCurLevelL, -sMaxL );
+    dCurLevelR = UpdateCurLevel ( dCurLevelR, -sMaxR );
 }
 
-double CStereoSignalLevelMeter::UpdateCurLevel ( double       dCurLevel,
-                                                 const short& sMax )
+double CStereoSignalLevelMeter::UpdateCurLevel ( double dCurLevel,
+                                                 double dMax )
 {
     // decrease max with time
     if ( dCurLevel >= METER_FLY_BACK )
@@ -77,9 +77,9 @@ double CStereoSignalLevelMeter::UpdateCurLevel ( double       dCurLevel,
     }
 
     // update current level -> only use maximum
-    if ( static_cast<double> ( sMax ) > dCurLevel )
+    if ( dMax > dCurLevel )
     {
-        return static_cast<double> ( sMax );
+        return dMax;
     }
     else
     {

src/util.h

@@ -726,8 +726,8 @@ public:
     }
 
 protected:
-    double UpdateCurLevel ( double       dCurLevel,
-                            const short& sMax );
+    double UpdateCurLevel ( double dCurLevel,
+                            double dMax );
 
     double dCurLevelL;
     double dCurLevelR;