This fixes a couple of issues with AudioUnits and 1 with latency

If latency was introduced by an effect, the input position could
get offset by the amount of latency, such that the same input
would be processed twice for the number of sample of latency.

There was an issue in AUs where a "latency done" flags wasn't
being reset and so the second and subsequent uses of an effect
could not latency correct.

And in research that, I found that you need to set the sample rate
on all 3 scopes (global, input, and output) instead of just the
global scope.

src/effects/audiounits/AudioUnitEffect.cpp

@@ -931,8 +931,6 @@ AudioUnitEffect::AudioUnitEffect(const wxString & path,
 
    mUnit = NULL;
    
-   mLatency = 0.0;
-   mTailTime = 0.0;
    mBlockSize = 0.0;
 
    mUIHost = NULL;
@@ -1140,37 +1138,15 @@ bool AudioUnitEffect::SetHost(EffectHostInterface *host)
 
    SetRateAndChannels();
 
-   UInt32 dataSize;
-
-   // Retrieve the latency (can be updated via an event)
-   dataSize = sizeof(mLatency);
-   mLatency = 0.0;
-   AudioUnitGetProperty(mUnit,
-                        kAudioUnitProperty_Latency,
-                        kAudioUnitScope_Global,
-                        0,
-                        &mLatency,
-                        &dataSize);  
-
-   // Retrieve the tail time
-   dataSize = sizeof(mTailTime);
-   mTailTime = 0.0;
-   AudioUnitGetProperty(mUnit,
-                        kAudioUnitProperty_TailTime,
-                        kAudioUnitScope_Global,
-                        0,
-                        &mTailTime,
-                        &dataSize);  
-
    // Retrieve the desired number of frames per slice
-   dataSize = sizeof(mBlockSize);
+   UInt32 dataSize = sizeof(mBlockSize);
    mBlockSize = 512;
    AudioUnitGetProperty(mUnit,
                         kAudioUnitProperty_MaximumFramesPerSlice,
                         kAudioUnitScope_Global,
                         0,
                         &mBlockSize,
-                        &dataSize);  
+                        &dataSize);
 
    // mHost will be null during registration
    if (mHost)
@@ -1307,10 +1283,21 @@ sampleCount AudioUnitEffect::GetBlockSize(sampleCount maxBlockSize)
 
 sampleCount AudioUnitEffect::GetLatency()
 {
+   // Retrieve the latency (can be updated via an event)
    if (mUseLatency && !mLatencyDone)
    {
       mLatencyDone = true;
-      return mLatency * mSampleRate;
+
+      Float64 latency = 0.0;
+      UInt32 dataSize = sizeof(latency);
+      AudioUnitGetProperty(mUnit,
+                           kAudioUnitProperty_Latency,
+                           kAudioUnitScope_Global,
+                           0,
+                           &latency,
+                           &dataSize);  
+
+      return (sampleCount) (latency * mSampleRate);
    }
 
    return 0;
@@ -1318,7 +1305,17 @@ sampleCount AudioUnitEffect::GetLatency()
 
 sampleCount AudioUnitEffect::GetTailSize()
 {
-   return mTailTime * mSampleRate;
+   // Retrieve the tail time
+   Float64 tailTime = 0.0;
+   UInt32 dataSize = sizeof(tailTime);
+   AudioUnitGetProperty(mUnit,
+                        kAudioUnitProperty_TailTime,
+                        kAudioUnitScope_Global,
+                        0,
+                        &tailTime,
+                        &dataSize);  
+
+   return (sampleCount) (tailTime * mSampleRate);
 }
 
 bool AudioUnitEffect::IsReady()
@@ -1374,6 +1371,8 @@ bool AudioUnitEffect::ProcessInitialize()
       return false;
    }
 
+   mLatencyDone = false;
+
    mReady = true;
 
    return true;
@@ -2320,6 +2319,30 @@ bool AudioUnitEffect::SetRateAndChannels()
       return false;
    }
 
+   auResult = AudioUnitSetProperty(mUnit,
+                                   kAudioUnitProperty_SampleRate,
+                                   kAudioUnitScope_Input,
+                                   0,
+                                   &mSampleRate,
+                                   sizeof(Float64));
+   if (auResult != 0)
+   {
+      printf("Didn't accept sample rate\n");
+      return false;
+   }
+
+   auResult = AudioUnitSetProperty(mUnit,
+                                   kAudioUnitProperty_SampleRate,
+                                   kAudioUnitScope_Output,
+                                   0,
+                                   &mSampleRate,
+                                   sizeof(Float64));
+   if (auResult != 0)
+   {
+      printf("Didn't accept sample rate\n");
+      return false;
+   }
+
    AudioStreamBasicDescription streamFormat = {0};
 
    streamFormat.mSampleRate = mSampleRate;
@@ -2481,18 +2504,8 @@ void AudioUnitEffect::EventListener(const AudioUnitEvent *inEvent,
       // We're only registered for Latency changes
       if (inEvent->mArgument.mProperty.mPropertyID == kAudioUnitProperty_Latency)
       {
-         // Retrieve the latency
-         UInt32 dataSize = sizeof(mLatency);
-         mLatency = 0.0;
-         AudioUnitGetProperty(mUnit,
-                              kAudioUnitProperty_Latency,
-                              kAudioUnitScope_Global,
-                              0,
-                              &mLatency,
-                              &dataSize);  
-
-         // And allow change to be used
-         mLatencyDone = false;
+         // Allow change to be used
+         //mLatencyDone = false;
       }
 
       return;

src/effects/audiounits/AudioUnitEffect.h

@@ -194,8 +194,6 @@ private:
    int         mAudioOuts;
    bool        mInteractive;
    bool        mLatencyDone;
-   Float64     mLatency;      // in seconds...multiply by samplerate
-   Float64     mTailTime;     // in seconds...multiply by samplerate
    UInt32      mBlockSize;
    double      mSampleRate;