In AudioMonitor2 convertBuffer(), some changes were made to improve performance on older, slower Macs, especially when resampling to a higher rate (NOAA weather radio, for example). The audio should now play more smoothly with fewer skips and dropped packets. Overall CPU usage for the main app and all NSTasks looks reasonably good now.

Author: dsward2

AudioMonitor/AudioMonitor/AudioMonitor2.cpp

@@ -207,13 +207,6 @@ void * runInputBufferOnThread(void * ptr)
 
                             fprintf(stderr, "AudioMonitor2 runInputBufferOnThread - produce bytes failed, bytesAvailableCount = %d\n", bytesAvailableCount);
                         }
-                        else
-                        {
-                            if (audioConverterThreadID == 0)
-                            {
-                                //createAudioConverterThread();
-                            }
-                        }
                     }
 
                     free(rtlsdrBuffer);
@@ -468,7 +461,8 @@ void convertBuffer(void * inputBufferPtr, unsigned int dataLength)
                 void * convertedDataPtr = audioConverterOutputBufferList.mBuffers[0].mData;
 
                 int32_t space;
-                void *ptr = TPCircularBufferHead(&audioConverterCircularBuffer, &space);  // for fprintf to stderr below
+                void * headPtr = TPCircularBufferHead(&audioConverterCircularBuffer, &space);  // for fprintf to stderr below
+                int64_t bufferFilledSize = (int64_t)headPtr - (int64_t)inputBufferPtr;
 
                 fwrite(convertedDataPtr, 1, convertedDataLength, stdout);    // write resampled audio to stdout, can be piped to sox, etc.
 
@@ -477,24 +471,29 @@ void convertBuffer(void * inputBufferPtr, unsigned int dataLength)
                 if (produceBytesResult == false)
                 {
                     // TODO: We are here to avoid buffer overrun, is TPCircularBufferConsume for audioConverterCircularBuffer getting missed somewhere?
-                
-                    // clear buffer and try again (not recommended practice)
-                    TPCircularBufferClear(&(audioConverterCircularBuffer));
 
+                    // clear buffer and try again (not the recommended practice)
+                    
+                    usleep(500000);
+
+                    TPCircularBufferClear(&(audioConverterCircularBuffer));
+
+                    //fprintf(stderr, "AudioMonitor2 convertBuffer TPCircularBufferClear and try again, convertedDataLength = %d, space = %d, head = %p\n", convertedDataLength, space, headPtr);
+
                     produceBytesResult = TPCircularBufferProduceBytes(&audioConverterCircularBuffer, convertedDataPtr, convertedDataLength);
 
                     if (produceBytesResult == false)
                     {
                         // If we get here, packets will be dropped
-                    
-                        fprintf(stderr, "AudioMonitor convertBuffer Produce convertedDataLength = %d, space = %d, head = %p\n", convertedDataLength, space, ptr);
-                        fprintf(stderr, "AudioMonitor convertBuffer - produce bytes failed, convertedDataLength = %d\n", convertedDataLength);
+                        
+                        fprintf(stderr, "AudioMonitor2 convertBuffer failed, drop packet, convertedDataLength = %d, space = %d, head = %p, bufferFilledSize = %lld\n", convertedDataLength, space, headPtr, bufferFilledSize);
                     }
                 }
-                
-                if (audioQueueThreadID == 0)
+                else
                 {
-                    //createAudioQueueThread();
+                    TPCircularBufferClear(&(audioConverterCircularBuffer));
+
+                    usleep(5000);
                 }
             }
 

LocalRadio/Base.lproj/MainMenu.xib

@@ -1367,7 +1367,7 @@ Gw
                     </textField>
                 </subviews>
             </view>
-            <point key="canvasLocation" x="167" y="-15"/>
+            <point key="canvasLocation" x="167" y="5"/>
         </window>
         <window title="LocalRadio" allowsToolTipsWhenApplicationIsInactive="NO" autorecalculatesKeyViewLoop="NO" restorable="NO" releasedWhenClosed="NO" showsToolbarButton="NO" animationBehavior="default" id="QvC-M9-y7g" userLabel="Main Window">
             <windowStyleMask key="styleMask" titled="YES" miniaturizable="YES"/>
@@ -2081,7 +2081,7 @@ Gw
                     </tabView>
                 </subviews>
             </view>
-            <point key="canvasLocation" x="-474" y="223.5"/>
+            <point key="canvasLocation" x="-466" y="589"/>
         </window>
         <window title="Custom Tasks" allowsToolTipsWhenApplicationIsInactive="NO" autorecalculatesKeyViewLoop="NO" oneShot="NO" releasedWhenClosed="NO" showsToolbarButton="NO" visibleAtLaunch="NO" frameAutosaveName="" animationBehavior="default" id="JXF-jt-XNF" userLabel="Custom Tasks Window">
             <windowStyleMask key="styleMask" titled="YES" closable="YES" miniaturizable="YES" resizable="YES"/>
@@ -2584,7 +2584,7 @@ Gw
                     <constraint firstAttribute="trailing" secondItem="T3O-Vc-C1s" secondAttribute="trailing" id="mT0-CP-d7p"/>
                 </constraints>
             </view>
-            <point key="canvasLocation" x="85" y="-497"/>
+            <point key="canvasLocation" x="-489" y="12"/>
         </window>
     </objects>
 </document>