Changed AUGraph frame buffer size to match the AU render size (improves performance by about 10 times)

Comment in AudioSample.cpp where we can hook in an alternate mp3 input streamer

--HG--
branch : nfb

KREngine/kraken/KRAudioManager.cpp

@@ -215,8 +215,11 @@ void KRAudioManager::renderAudio(UInt32 inNumberFrames, AudioBufferList *ioData)
     
     uint64_t end_time = mach_absolute_time();
 //    uint64_t duration = (end_time - start_time) * m_timebase_info.numer / m_timebase_info.denom; // Nanoseconds
+//    double ms = duration;
+//    ms = ms / 1000000.0;
 //    uint64_t max_duration = (uint64_t)inNumberFrames * 1000000000 / 44100;
 //    fprintf(stderr, "audio load: %5.1f%% hrtf channels: %li\n", (float)(duration * 1000 / max_duration) / 10.0f, m_mapped_sources.size());
+//    printf("ms %2.3f frames %ld audio load: %5.1f%% hrtf channels: %li\n", ms, (unsigned long) inNumberFrames, (float)(duration * 1000 / max_duration) / 10.0f, m_mapped_sources.size());
 }
 
 float *KRAudioManager::getBlockAddress(int block_offset)

KREngine/kraken/KRAudioManager.h

@@ -44,7 +44,10 @@ const int KRENGINE_AUDIO_MAX_POOL_SIZE = 32;
 const int KRENGINE_AUDIO_MAX_BUFFER_SIZE = 64*1024;
 const int KRENGINE_AUDIO_BUFFERS_PER_SOURCE = 3;
 
-const int KRENGINE_AUDIO_BLOCK_LENGTH = 128; // Length of one block to process.  Determines the latency of the audio system and sets size for FFT's used in HRTF convolution
+const int KRENGINE_AUDIO_BLOCK_LENGTH = 1024; // Length of one block to process.  Determines the latency of the audio system and sets size for FFT's used in HRTF convolution
+    // the AUGraph works in 1024 sample chunks. If we put a value of less then 1024 in here then we are making mutliple calls to our render functions without any
+    // improvement in latency and our audio render perfomance goes down significantly
+
 const int KRENGINE_AUDIO_BLOCK_LOG2N = 7; // 2 ^ KRENGINE_AUDIO_BLOCK_LOG2N = KRENGINE_AUDIO_BLOCK_LENGTH
 
 const int KRENGINE_REVERB_MAX_FFT_LOG2 = 15;

KREngine/kraken/KRAudioSample.cpp

@@ -231,6 +231,11 @@ void KRAudioSample::openFile()
 {
     //    AudioFileInitializeWithCallbacks
     if(m_fileRef == NULL) {
+        
+//        printf("Call to KRAudioSample::openFile() with extension: %s\n", m_extension.c_str());
+// The m_extension is valid (it's either wav or mp3 for the files in Circa project)
+// so we can key off the extension and use a different data handler for mp3 files if we want to
+//
 
         // Temp variables
         UInt32 propertySize;