Server processing for channel levels

src/channel.h

@@ -168,6 +168,9 @@ public:
 
     bool ChannelLevelsRequired() const                { return bChannelLevelsRequired; }
 
+    double GetPrevLevel() const              { return dPrevLevel; }
+    void   SetPrevLevel ( const double nPL ) { dPrevLevel = nPL; }
+
 protected:
     bool ProtocolIsEnabled();
 
@@ -180,6 +183,8 @@ protected:
         iNetwFrameSizeFact    = FRAME_SIZE_FACTOR_PREFERRED;
         iNetwFrameSize        = CELT_MINIMUM_NUM_BYTES;
         iNumAudioChannels     = 1; // mono
+
+        dPrevLevel            = 0.0;
     }
 
     // connection parameters
@@ -220,6 +225,7 @@ protected:
     QMutex            MutexConvBuf;
 
     bool              bChannelLevelsRequired;
+    double            dPrevLevel;
 
 public slots:
     void OnSendProtMessage ( CVector<uint8_t> vecMessage );

src/global.h

@@ -199,6 +199,9 @@ LED bar:      lbr
 // list
 #define PING_UPDATE_TIME_SERVER_LIST_MS 2000 // ms
 
+// defines the interval between Channel Level updates from the server
+#define CHANNEL_LEVEL_UPDATE_INTERVAL   100  // number of frames
+
 // time-out until a registered server is deleted from the server list if no
 // new registering was made in minutes
 #define SERVLIST_TIME_OUT_MINUTES       60 // minutes

src/protocol.cpp

@@ -2039,6 +2039,11 @@ bool CProtocol::EvaluateCLChannelLevelListMes  ( const CHostAddress&     InetAdd
                                           // may have one too many entries, last being 0xF
     int       iVecLen  = iDataLen * 2; // one ushort per channel
 
+    if ( iVecLen > MAX_NUM_CHANNELS )
+    {
+        return true; // return error code
+    }
+
     CVector<uint16_t> vecLevelList ( iVecLen );
 
     for (int i = 0, j = 0; i < iDataLen; i++, j += 2 )

src/server.cpp

@@ -335,6 +335,8 @@ CServer::CServer ( const int          iNewMaxNumChan,
     // allocate worst case memory for the coded data
     vecbyCodedData.Init ( MAX_SIZE_BYTES_NETW_BUF );
 
+    // allocate worst case memory for the channel levels
+    vecChannelLevels.Init     ( iMaxNumChannels );
 
     // enable history graph (if requested)
     if ( !strHistoryFileName.isEmpty() )
@@ -864,6 +866,7 @@ JitterMeas.Measure();
     // some inits
     int  iNumClients               = 0; // init connected client counter
     bool bChannelIsNowDisconnected = false;
+    bool bSendChannelLevels        = false;
 
     // Make put and get calls thread safe. Do not forget to unlock mutex
     // afterwards!
@@ -1007,6 +1010,29 @@ JitterMeas.Measure();
     // one client is connected.
     if ( iNumClients > 0 )
     {
+
+        // Low frequency updates
+        if ( iFrameCount > CHANNEL_LEVEL_UPDATE_INTERVAL )
+        {
+            iFrameCount = 0;
+
+            // Calculate channel levels if any client has requested them
+            for ( int i = 0; i < iNumClients; i++ )
+            {
+                if ( vecChannels[ vecChanIDsCurConChan[i] ].ChannelLevelsRequired() )
+                {
+                    bSendChannelLevels = true;
+
+                    CreateLevelsForAllConChannels ( iNumClients,
+                                                    vecNumAudioChannels,
+                                                    vecvecsData,
+                                                    vecChannelLevels );
+                    break;
+                }
+            }
+        }
+        iFrameCount++;
+
         for ( int i = 0; i < iNumClients; i++ )
         {
             // get actual ID of current channel
@@ -1095,6 +1121,12 @@ opus_custom_encoder_ctl ( CurOpusEncoder,
 
             // update socket buffer size
             vecChannels[iCurChanID].UpdateSocketBufferSize();
+
+            // send channel levels
+            if ( bSendChannelLevels && vecChannels[iCurChanID].ChannelLevelsRequired() )
+            {
+                ConnLessProtocol.CreateCLChannelLevelListMes ( vecChannels[iCurChanID].GetAddress(), vecChannelLevels, iNumClients );
+            }
         }
     }
     else
@@ -1574,3 +1606,69 @@ void CServer::customEvent ( QEvent* pEvent )
         }
     }
 }
+
+/// @brief Compute frame peak level for each client
+void CServer::CreateLevelsForAllConChannels ( const int                        iNumClients,
+                                              const CVector<int>&              vecNumAudioChannels,
+                                              const CVector<CVector<int16_t> > vecvecsData,
+                                              CVector<uint16_t>&               vecLevelsOut )
+{
+    int i, j, k;
+
+    // init return vector with zeros since we mix all channels on that vector
+    vecLevelsOut.Reset ( 0 );
+
+    for ( j = 0; j < iNumClients; j++ )
+    {
+        // get a reference to the audio data
+        const CVector<int16_t>& vecsData = vecvecsData[j];
+
+        double dCurLevel = 0.0;
+        if ( vecNumAudioChannels[j] == 1 )
+        {
+            // mono
+            for ( i = 0; i < SYSTEM_FRAME_SIZE_SAMPLES; i += 3 )
+            {
+                dCurLevel = std::max ( dCurLevel, std::abs ( static_cast<double> ( vecsData[i] ) ) );
+            }
+        }
+        else
+        {
+            // stereo: apply stereo-to-mono attenuation
+            for ( i = 0, k = 0; i < SYSTEM_FRAME_SIZE_SAMPLES; i += 3, k += 6 )
+            {
+                double sMix = ( static_cast<double> ( vecsData[k] ) + vecsData[k + 1] ) / 2;
+                dCurLevel = std::max ( dCurLevel, std::abs ( sMix ) );
+            }
+        }
+
+        // smoothing
+        int iChId = vecChanIDsCurConChan [ j ];
+        dCurLevel = std::max ( dCurLevel, vecChannels[ iChId ].GetPrevLevel() * 0.5 );
+        vecChannels[ iChId ].SetPrevLevel ( dCurLevel );
+
+        // logarithmic measure
+        const double dNormChanLevel = dCurLevel / _MAXSHORT;
+        double dCurSigLevel;
+        if ( dNormChanLevel > 0 )
+        {
+            dCurSigLevel = 20.0 * log10 ( dNormChanLevel );
+        }
+        else
+        {
+            dCurSigLevel = -100000.0; // large negative value
+        }
+
+        // map to signal level meter
+        dCurSigLevel -= LOW_BOUND_SIG_METER;
+        dCurSigLevel *= NUM_STEPS_LED_BAR /
+            ( UPPER_BOUND_SIG_METER - LOW_BOUND_SIG_METER );
+
+        if ( dCurSigLevel < 0 )
+        {
+            dCurSigLevel = 0;
+        }
+
+        vecLevelsOut[j] = static_cast<uint16_t> ( ceil ( dCurSigLevel ) );
+    }
+}

src/server.h

@@ -28,6 +28,7 @@
 #include <QTimer>
 #include <QDateTime>
 #include <QHostAddress>
+#include <algorithm>
 #ifdef USE_OPUS_SHARED_LIB
 # include "opus/opus_custom.h"
 #else
@@ -225,6 +226,11 @@ protected:
     // if server mode is normal or double system frame size
     bool                       bUseDoubleSystemFrameSize;
 
+    void CreateLevelsForAllConChannels  ( const int                        iNumClients,
+                                          const CVector<int>&              vecNumAudioChannels,
+                                          const CVector<CVector<int16_t> > vecvecsData,
+                                          CVector<uint16_t>&               vecLevelsOut );
+
     // do not use the vector class since CChannel does not have appropriate
     // copy constructor/operator
     CChannel                   vecChannels[MAX_NUM_CHANNELS];
@@ -255,12 +261,18 @@ protected:
     CVector<int16_t>           vecsSendData;
     CVector<uint8_t>           vecbyCodedData;
 
+    // Channel levels
+    CVector<uint16_t>          vecChannelLevels;
+
     // actual working objects
     CHighPrioSocket            Socket;
 
     // logging
     CServerLogging             Logging;
 
+    // channel level update frame interval counter
+    uint16_t                   iFrameCount;
+
     // recording thread
     recorder::CJamRecorder     JamRecorder;
     bool                       bEnableRecording;