clean up the reverberation and panning code in the client

src/client.cpp

@@ -889,8 +889,9 @@ void CClient::Init()
                                        iNumAudioChannels );
 
     // init reverberation
-    AudioReverbL.Init ( SYSTEM_SAMPLE_RATE_HZ );
+    AudioReverb.Init ( eAudioChannelConf,
-    AudioReverbR.Init ( SYSTEM_SAMPLE_RATE_HZ );
+                       iStereoBlockSizeSam,
+                       SYSTEM_SAMPLE_RATE_HZ );
 
     // init the sound card conversion buffers
     if ( bSndCrdConversionBufferRequired )
@@ -973,118 +974,41 @@ void CClient::ProcessAudioDataIntern ( CVector<int16_t>& vecsStereoSndCrd )
     // add reverberation effect if activated
     if ( iReverbLevel != 0 )
     {
-        // calculate attenuation amplification factor
+        AudioReverb.Process ( vecsStereoSndCrd,
-        const double dRevLev = static_cast<double> ( iReverbLevel ) / AUD_REVERB_MAX / 4;
+                              bReverbOnLeftChan,
+                              static_cast<double> ( iReverbLevel ) / AUD_REVERB_MAX / 4 );
+    }
+
+    // apply pan (audio fader) and mix mono signals
+    if ( !( ( iAudioInFader == AUD_FADER_IN_MIDDLE ) && ( eAudioChannelConf == CC_STEREO ) ) )
+    {
+        // calculate pan gain in the range 0 to 1, where 0.5 is the middle position
+        const double dPan = static_cast<double> ( iAudioInFader ) / AUD_FADER_IN_MAX;
 
         if ( eAudioChannelConf == CC_STEREO )
         {
-            // for stereo always apply reverberation effect on both channels
+            // for stereo only apply pan attenuation on one channel (same as pan in the server)
-            for ( i = 0; i < iStereoBlockSizeSam; i += 2 )
+            const double dGainL = std::min ( 0.5, 1 - dPan ) * 2;
-            {
+            const double dGainR = std::min ( 0.5, dPan ) * 2;
-                // both channels (stereo)
-                AudioReverbL.ProcessSample ( vecsStereoSndCrd[i], vecsStereoSndCrd[i + 1], dRevLev );
-            }
-        }
-        else
-        {
-            // mono and mono-in/stereo out mode
-            if ( bReverbOnLeftChan )
-            {
-                for ( i = 0; i < iStereoBlockSizeSam; i += 2 )
-                {
-                    // left channel
-                    int16_t sRightDummy = 0; // has to be 0 for mono reverb
-                    AudioReverbL.ProcessSample ( vecsStereoSndCrd[i], sRightDummy, dRevLev );
-                }
-            }
-            else
-            {
-                for ( i = 1; i < iStereoBlockSizeSam; i += 2 )
-                {
-                    // right channel
-                    int16_t sRightDummy = 0; // has to be 0 for mono reverb
-                    AudioReverbR.ProcessSample ( vecsStereoSndCrd[i], sRightDummy, dRevLev );
-                }
-            }
-        }
-    }
 
-    // mix both signals depending on the fading setting, convert
-    // from double to short
-    if ( iAudioInFader == AUD_FADER_IN_MIDDLE )
-    {
-        // no action require if fader is in the middle and stereo is used
-        if ( eAudioChannelConf != CC_STEREO )
-        {
-            // mix channels together (store result in first half of the vector)
             for ( i = 0, j = 0; i < iMonoBlockSizeSam; i++, j += 2 )
             {
-                // for the sum make sure we have more bits available (cast to
+                // note that the gain is always <= 1, therefore a simple cast is
-                // int32), after the normalization by 2, the result will fit
+                // ok since we never can get an overload
-                // into the old size so that cast to int16 is safe
+                vecsStereoSndCrd[j + 1] = static_cast<int16_t> ( dGainR * vecsStereoSndCrd[j + 1] );
-                vecsStereoSndCrd[i] = static_cast<int16_t> (
+                vecsStereoSndCrd[j]     = static_cast<int16_t> ( dGainL * vecsStereoSndCrd[j] );
-                    ( static_cast<int32_t> ( vecsStereoSndCrd[j] ) + vecsStereoSndCrd[j + 1] ) / 2 );
-            }
-        }
-    }
-    else
-    {
-        if ( eAudioChannelConf == CC_STEREO )
-        {
-            // stereo
-            const double dAttFactStereo = static_cast<double> (
-                AUD_FADER_IN_MIDDLE - abs ( AUD_FADER_IN_MIDDLE - iAudioInFader ) ) / AUD_FADER_IN_MIDDLE;
-
-            if ( iAudioInFader > AUD_FADER_IN_MIDDLE )
-            {
-                for ( i = 0, j = 0; i < iMonoBlockSizeSam; i++, j += 2 )
-                {
-                    // attenuation on right channel
-                    vecsStereoSndCrd[j + 1] = Double2Short ( dAttFactStereo * vecsStereoSndCrd[j + 1] );
             }
         }
         else
         {
+            // for mono implement a cross-fade between channels and mix them
+            const double dGainL = 1 - dPan;
+            const double dGainR = dPan;
+
             for ( i = 0, j = 0; i < iMonoBlockSizeSam; i++, j += 2 )
             {
-                    // attenuation on left channel
-                    vecsStereoSndCrd[j] = Double2Short ( dAttFactStereo * vecsStereoSndCrd[j] );
-                }
-            }
-        }
-        else
-        {
-            // mono and mono-in/stereo out mode
-            // make sure that in the middle position the two channels are
-            // amplified by 1/2, if the pan is set to one channel, this
-            // channel should have an amplification of 1
-            const double dAttFactMono = static_cast<double> (
-                AUD_FADER_IN_MIDDLE - abs ( AUD_FADER_IN_MIDDLE - iAudioInFader ) ) / AUD_FADER_IN_MIDDLE / 2;
-
-            const double dAmplFactMono = 0.5 + static_cast<double> (
-                abs ( AUD_FADER_IN_MIDDLE - iAudioInFader ) ) / AUD_FADER_IN_MIDDLE / 2;
-
-            if ( iAudioInFader > AUD_FADER_IN_MIDDLE )
-            {
-                for ( i = 0, j = 0; i < iMonoBlockSizeSam; i++, j += 2 )
-                {
-                    // attenuation on right channel (store result in first half
-                    // of the vector)
                 vecsStereoSndCrd[i] = Double2Short (
-                        dAmplFactMono * vecsStereoSndCrd[j] +
+                    dGainL * vecsStereoSndCrd[j] + dGainR * vecsStereoSndCrd[j + 1] );
-                        dAttFactMono * vecsStereoSndCrd[j + 1] );
-                }
-            }
-            else
-            {
-                for ( i = 0, j = 0; i < iMonoBlockSizeSam; i++, j += 2 )
-                {
-                    // attenuation on left channel (store result in first half
-                    // of the vector)
-                    vecsStereoSndCrd[i] = Double2Short (
-                        dAmplFactMono * vecsStereoSndCrd[j + 1] +
-                        dAttFactMono * vecsStereoSndCrd[j] );
-                }
             }
         }
     }
@@ -1175,20 +1099,6 @@ void CClient::ProcessAudioDataIntern ( CVector<int16_t>& vecsStereoSndCrd )
         }
     }
 
-/*
-// TEST
-// fid=fopen('c:\\temp\test2.dat','r');x=fread(fid,'int16');fclose(fid);
-static FILE* pFileDelay = fopen("c:\\temp\\test2.dat", "wb");
-short sData[2];
-for (i = 0; i < iMonoBlockSizeSam; i++)
-{
-    sData[0] = (short) vecsStereoSndCrd[i];
-    fwrite(&sData, size_t(2), size_t(1), pFileDelay);
-}
-fflush(pFileDelay);
-*/
-
-
     // for muted stream we have to add our local data here
     if ( bMuteOutStream )
     {

src/client.h

@@ -151,8 +151,7 @@ public:
     void SetReverbOnLeftChan ( const bool bIL )
     {
         bReverbOnLeftChan = bIL;
-        AudioReverbL.Clear();
+        AudioReverb.Clear();
-        AudioReverbR.Clear();
     }
 
     void SetDoAutoSockBufSize ( const bool bValue );
@@ -354,8 +353,7 @@ protected:
     int                     iAudioInFader;
     bool                    bReverbOnLeftChan;
     int                     iReverbLevel;
-    CAudioReverb            AudioReverbL;
+    CAudioReverb            AudioReverb;
-    CAudioReverb            AudioReverbR;
 
     int                     iSndCrdPrefFrameSizeFactor;
     int                     iSndCrdFrameSizeFactor;

src/util.cpp

@@ -165,10 +165,14 @@ uint32_t CCRC::GetCRC()
     three series allpass units, followed by four parallel comb filters, and two
     decorrelation delay lines in parallel at the output.
 */
-void CAudioReverb::Init ( const int    iSampleRate,
+void CAudioReverb::Init ( const EAudChanConf eNAudioChannelConf,
+                          const int          iNStereoBlockSizeSam,
+                          const int          iSampleRate,
                           const double       rT60 )
 {
-    int delay, i;
+    // store paramters
+    eAudioChannelConf   = eNAudioChannelConf;
+    iStereoBlockSizeSam = iNStereoBlockSizeSam;
 
     // delay lengths for 44100 Hz sample rate
     int          lengths[9] = { 1116, 1356, 1422, 1617, 225, 341, 441, 211, 179 };
@@ -176,9 +180,9 @@ void CAudioReverb::Init ( const int    iSampleRate,
 
     if ( scaler != 1.0 )
     {
-        for ( i = 0; i < 9; i++ )
+        for ( int i = 0; i < 9; i++ )
         {
-            delay = static_cast<int> ( floor ( scaler * lengths[i] ) );
+            int delay = static_cast<int> ( floor ( scaler * lengths[i] ) );
 
             if ( ( delay & 1 ) == 0 )
             {
@@ -194,12 +198,12 @@ void CAudioReverb::Init ( const int    iSampleRate,
         }
     }
 
-    for ( i = 0; i < 3; i++ )
+    for ( int i = 0; i < 3; i++ )
     {
         allpassDelays[i].Init ( lengths[i + 4] );
     }
 
-    for ( i = 0; i < 4; i++ )
+    for ( int i = 0; i < 4; i++ )
     {
         combDelays[i].Init ( lengths[i] );
         combFilters[i].setPole ( 0.2 );
@@ -285,16 +289,31 @@ double CAudioReverb::COnePole::Calc ( const double dIn )
     return dLastSample;
 }
 
-void CAudioReverb::ProcessSample ( int16_t&     iInputOutputLeft,
+void CAudioReverb::Process ( CVector<int16_t>& vecsStereoInOut,
-                                   int16_t&     iInputOutputRight,
+                             const bool        bReverbOnLeftChan,
                              const double      dAttenuation )
 {
-    // compute one output sample
+    double dMixedInput, temp, temp0, temp1, temp2;
-    double temp, temp0, temp1, temp2;
 
+    for ( int i = 0; i < iStereoBlockSizeSam; i += 2 )
+    {
         // we sum up the stereo input channels (in case mono input is used, a zero
         // shall be input for the right channel)
-    const double dMixedInput = 0.5 * ( iInputOutputLeft + iInputOutputRight );
+        if ( eAudioChannelConf == CC_STEREO )
+        {
+            dMixedInput = 0.5 * ( vecsStereoInOut[i] + vecsStereoInOut[i + 1] );
+        }
+        else
+        {
+            if ( bReverbOnLeftChan )
+            {
+                dMixedInput = vecsStereoInOut[i];
+            }
+            else
+            {
+                dMixedInput = vecsStereoInOut[i + 1];
+            }
+        }
 
         temp = allpassDelays[0].Get();
         temp0 = allpassCoefficient * temp;
@@ -329,15 +348,23 @@ void CAudioReverb::ProcessSample ( int16_t&     iInputOutputLeft,
         outLeftDelay.Add  ( filtout );
         outRightDelay.Add ( filtout );
 
-    // inplace apply the attenuated reverb signal
+        // inplace apply the attenuated reverb signal (for stereo always apply
-    iInputOutputLeft  = Double2Short (
+        // reverberation effect on both channels)
-        ( 1.0 - dAttenuation ) * iInputOutputLeft +
+        if ( ( eAudioChannelConf == CC_STEREO ) || bReverbOnLeftChan )
+        {
+            vecsStereoInOut[i] = Double2Short (
+                ( 1.0 - dAttenuation ) * vecsStereoInOut[i] +
                 0.5 * dAttenuation * outLeftDelay.Get() );
+        }
 
-    iInputOutputRight = Double2Short (
+        if ( ( eAudioChannelConf == CC_STEREO ) || !bReverbOnLeftChan )
-        ( 1.0 - dAttenuation ) * iInputOutputRight +
+        {
+            vecsStereoInOut[i + 1] = Double2Short (
+                ( 1.0 - dAttenuation ) * vecsStereoInOut[i + 1] +
                 0.5 * dAttenuation * outRightDelay.Get() );
         }
+    }
+}
 
 
 /******************************************************************************\

src/util.h

@@ -1098,10 +1098,14 @@ class CAudioReverb
 public:
     CAudioReverb() {}
     
-    void Init ( const int iSampleRate, const double rT60 = 1.1 );
+    void Init ( const EAudChanConf eNAudioChannelConf,
+                const int          iNStereoBlockSizeSam,
+                const int          iSampleRate,
+                const double       rT60 = 1.1 );
+
     void Clear();
-    void ProcessSample ( int16_t&     iInputOutputLeft,
+    void Process ( CVector<int16_t>& vecsStereoInOut,
-                         int16_t&     iInputOutputRight,
+                   const bool        bReverbOnLeftChan,
                    const double      dAttenuation );
 
 protected:
@@ -1122,6 +1126,8 @@ protected:
         double dLastSample;
     };
 
+    EAudChanConf  eAudioChannelConf;
+    int           iStereoBlockSizeSam;
     CFIFO<double> allpassDelays[3];
     CFIFO<double> combDelays[4];
     COnePole      combFilters[4];