#39 Disable zero-delay convolution and use offset in the IRs instead.

Author: Archie3d

Source/aeolus/engine.cpp

@@ -216,12 +216,19 @@ void EngineGlobal::loadIRs()
 {
     _irs.clear();
 
+    // This corresponds to the zero-delay segment of the
+    // convolver (see dsp/convolver.cpp) that we remove from
+    // the beginning of the IRs and use non-zero delay instead
+    // for better performance.
+    constexpr size_t startOffset = 4096;
+
     _irs.push_back({
         "York Guildhall Council Chamber",
         BinaryData::york_council_chamber_wav,
         BinaryData::york_council_chamber_wavSize,
         0.25f,
-        true,
+        false,
+        startOffset,
         {}
     });
 
@@ -230,7 +237,8 @@ void EngineGlobal::loadIRs()
         BinaryData::st_laurentius_molenbeek_wav,
         BinaryData::st_laurentius_molenbeek_wavSize,
         0.8f,
-        true,
+        false,
+        startOffset,
         {}
     });
 
@@ -239,7 +247,8 @@ void EngineGlobal::loadIRs()
         BinaryData::st_andrews_church_wav,
         BinaryData::st_andrews_church_wavSize,
         1.0f,
-        true,
+        false,
+        startOffset,
         {}
     });
 
@@ -248,7 +257,8 @@ void EngineGlobal::loadIRs()
         BinaryData::st_georges_far_wav,
         BinaryData::st_georges_far_wavSize,
         1.0f,
-        true,
+        false,
+        startOffset,
         {}
     });
 
@@ -257,7 +267,8 @@ void EngineGlobal::loadIRs()
         BinaryData::lady_chapel_stalbans_wav,
         BinaryData::lady_chapel_stalbans_wavSize,
         1.0f,
-        true,
+        false,
+        startOffset,
         {}
     });
 
@@ -266,7 +277,8 @@ void EngineGlobal::loadIRs()
         BinaryData::_1st_baptist_nashville_balcony_wav,
         BinaryData::_1st_baptist_nashville_balcony_wavSize,
         1.0f,
-        true,
+        false,
+        startOffset,
         {}
     });
 
@@ -276,6 +288,7 @@ void EngineGlobal::loadIRs()
         BinaryData::elveden_hall_suffolk_england_wavSize,
         0.1f,
         false,
+        0,
         {}
     });
 
@@ -284,7 +297,8 @@ void EngineGlobal::loadIRs()
         BinaryData::r1_nuclear_reactor_hall_wav,
         BinaryData::r1_nuclear_reactor_hall_wavSize,
         0.4f,
-        true,
+        false,
+        startOffset,
         {}
     });
 
@@ -293,7 +307,8 @@ void EngineGlobal::loadIRs()
         BinaryData::york_uni_sportscentre_wav,
         BinaryData::york_uni_sportscentre_wavSize,
         0.4f,
-        true,
+        false,
+        startOffset,
         {}
     });
 
@@ -302,7 +317,8 @@ void EngineGlobal::loadIRs()
         BinaryData::york_minster_wav,
         BinaryData::york_minster_wavSize,
         0.3f,
-        true,
+        false,
+        startOffset,
         {}
     });
 
@@ -316,7 +332,7 @@ void EngineGlobal::loadIRs()
         std::unique_ptr<InputStream> stream = std::make_unique<MemoryInputStream>(ir.data, ir.size, false);
         std::unique_ptr<AudioFormatReader> reader{manager.createReaderFor(std::move(stream))};
         ir.waveform.setSize(reader->numChannels, (int)reader->lengthInSamples);
-        reader->read(&ir.waveform, 0, ir.waveform.getNumSamples(), 0, true, true);
+        reader->read(&ir.waveform, 0, ir.waveform.getNumSamples(), (juce::int64)ir.startOffset, true, true);
 
         ir.waveform.applyGain(ir.gain);
 

Source/aeolus/engine.h

@@ -72,6 +72,7 @@ class EngineGlobal : public juce::DeletedAtShutdown
 
         float gain;
         bool zeroDelay;
+        size_t startOffset; // Sample offset from the beginning of the IR waveform
 
         juce::AudioBuffer<float> waveform;
     };