From 4e13b625ca7dae1a970bdbf1aa747a232023efc7 Mon Sep 17 00:00:00 2001
From: "Charles J. Cliffe" <cj@cubicproductions.com>
Date: Sun, 1 Mar 2015 10:30:02 -0500
Subject: [PATCH] Fix for mixer clipping bug that's causing audio to crackle

---
 src/audio/AudioThread.cpp       | 23 ++++++++++++++++-------
 src/demod/DemodulatorThread.cpp |  4 ++--
 2 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/src/audio/AudioThread.cpp b/src/audio/AudioThread.cpp
index 4bf6ee2..dab66f3 100644
--- a/src/audio/AudioThread.cpp
+++ b/src/audio/AudioThread.cpp
@@ -40,7 +40,7 @@ void AudioThread::removeThread(AudioThread *other) {
 }
 
 void AudioThread::deviceCleanup() {
-    std::map<int,AudioThread *>::iterator i;
+    std::map<int, AudioThread *>::iterator i;
 
     for (i = deviceController.begin(); i != deviceController.end(); i++) {
         i->second->terminate();
@@ -105,7 +105,7 @@ static int audioCallback(void *outputBuffer, void *inputBuffer, unsigned int nBu
             continue;
         }
 
-        peak += srcmix->currentInput->peak * srcmix->gain;
+        float mixPeak = srcmix->currentInput->peak * srcmix->gain;
 
         if (srcmix->currentInput->channels == 1) {
             for (int i = 0; i < nBufferFrames; i++) {
@@ -122,6 +122,10 @@ static int audioCallback(void *outputBuffer, void *inputBuffer, unsigned int nBu
                         continue;
                     }
                     srcmix->audioQueuePtr = 0;
+                    float srcPeak = srcmix->currentInput->peak * srcmix->gain;
+                    if (mixPeak < srcPeak) {
+                        mixPeak = srcPeak;
+                    }
                 }
                 if (srcmix->currentInput && srcmix->currentInput->data.size()) {
                     float v = srcmix->currentInput->data[srcmix->audioQueuePtr] * srcmix->gain;
@@ -145,6 +149,10 @@ static int audioCallback(void *outputBuffer, void *inputBuffer, unsigned int nBu
                         continue;
                     }
                     srcmix->audioQueuePtr = 0;
+                    float srcPeak = srcmix->currentInput->peak * srcmix->gain;
+                    if (mixPeak < srcPeak) {
+                        mixPeak = srcPeak;
+                    }
                 }
                 if (srcmix->currentInput && srcmix->currentInput->data.size()) {
                     out[i] = out[i] + srcmix->currentInput->data[srcmix->audioQueuePtr] * srcmix->gain;
@@ -153,13 +161,14 @@ static int audioCallback(void *outputBuffer, void *inputBuffer, unsigned int nBu
             }
         }
 
-        if (peak > 1.0) {
-            for (int i = 0 ; i < nBufferFrames * 2; i ++) {
-                out[i] /= peak;
-            }
-        }
+        peak += mixPeak;
     }
 
+    if (peak > 1.0) {
+        for (int i = 0; i < nBufferFrames * 2; i++) {
+            out[i] /= peak;
+        }
+    }
     return 0;
 }
 
diff --git a/src/demod/DemodulatorThread.cpp b/src/demod/DemodulatorThread.cpp
index bd5a521..169137f 100644
--- a/src/demod/DemodulatorThread.cpp
+++ b/src/demod/DemodulatorThread.cpp
@@ -191,8 +191,8 @@ void DemodulatorThread::threadMain() {
                 break;
             }
 
-            amOutputCeilMA = amOutputCeilMA + (amOutputCeil - amOutputCeilMA) * 0.05;
-            amOutputCeilMAA = amOutputCeilMAA + (amOutputCeilMA - amOutputCeilMAA) * 0.05;
+            amOutputCeilMA = amOutputCeilMA + (amOutputCeil - amOutputCeilMA) * 0.025;
+            amOutputCeilMAA = amOutputCeilMAA + (amOutputCeilMA - amOutputCeilMAA) * 0.025;
 
             amOutputCeil = 0;