Add "pitch" parameter to scriptable audio injector options.

Used in playSound() to pitch-shift the audio when injector is created.

libraries/audio/src/AudioInjector.cpp

@@ -463,10 +463,39 @@ AudioInjectorPointer AudioInjector::playSoundAndDelete(const QByteArray& buffer,
 
 
 AudioInjectorPointer AudioInjector::playSound(const QByteArray& buffer, const AudioInjectorOptions options) {
-    AudioInjectorPointer injector = AudioInjectorPointer::create(buffer, options);
 
-    if (!injector->inject(&AudioInjectorManager::threadInjector)) {
-        qWarning() << "AudioInjector::playSound failed to thread injector";
+    if (options.pitch == 1.0f) {
+
+        AudioInjectorPointer injector = AudioInjectorPointer::create(buffer, options);
+
+        if (!injector->inject(&AudioInjectorManager::threadInjector)) {
+            qWarning() << "AudioInjector::playSound failed to thread injector";
+        }
+        return injector;
+
+    } else {
+
+        const int standardRate = AudioConstants::SAMPLE_RATE;
+        const int resampledRate = AudioConstants::SAMPLE_RATE / glm::clamp(options.pitch, 1/16.0f, 16.0f);  // limit to 4 octaves
+        const int numChannels = options.ambisonic ? AudioConstants::AMBISONIC : 
+            (options.stereo ? AudioConstants::STEREO : AudioConstants::MONO);
+
+        AudioSRC resampler(standardRate, resampledRate, numChannels);
+
+        // create a resampled buffer that is guaranteed to be large enough
+        const int nInputFrames = buffer.size() / (numChannels * sizeof(int16_t));
+        const int maxOutputFrames = resampler.getMaxOutput(nInputFrames);
+        QByteArray resampledBuffer(maxOutputFrames * numChannels * sizeof(int16_t), '\0');
+
+        resampler.render(reinterpret_cast<const int16_t*>(buffer.data()),
+                         reinterpret_cast<int16_t*>(resampledBuffer.data()),
+                         nInputFrames);
+
+        AudioInjectorPointer injector = AudioInjectorPointer::create(resampledBuffer, options);
+
+        if (!injector->inject(&AudioInjectorManager::threadInjector)) {
+            qWarning() << "AudioInjector::playSound failed to thread pitch-shifted injector";
+        }
+        return injector;
     }
-    return injector;
 }

libraries/audio/src/AudioInjectorOptions.cpp

@@ -26,7 +26,8 @@ AudioInjectorOptions::AudioInjectorOptions() :
     ambisonic(false),
     ignorePenumbra(false),
     localOnly(false),
-    secondOffset(0.0f)
+    secondOffset(0.0f),
+    pitch(1.0f)
 {
 
 }
@@ -40,6 +41,7 @@ QScriptValue injectorOptionsToScriptValue(QScriptEngine* engine, const AudioInje
     obj.setProperty("ignorePenumbra", injectorOptions.ignorePenumbra);
     obj.setProperty("localOnly", injectorOptions.localOnly);
     obj.setProperty("secondOffset", injectorOptions.secondOffset);
+    obj.setProperty("pitch", injectorOptions.pitch);
     return obj;
 }
 
@@ -87,6 +89,12 @@ void injectorOptionsFromScriptValue(const QScriptValue& object, AudioInjectorOpt
             } else {
                 qCWarning(audio) << "Audio injector options: secondOffset is not a number";
             }
+        } else if (it.name() == "pitch") {
+            if (it.value().isNumber()) {
+                injectorOptions.pitch = it.value().toNumber();
+            } else {
+                qCWarning(audio) << "Audio injector options: pitch is not a number";
+            }
         } else {
             qCWarning(audio) << "Unknown audio injector option:" << it.name();
         }

libraries/audio/src/AudioInjectorOptions.h

@@ -29,6 +29,7 @@ public:
     bool ignorePenumbra;
     bool localOnly;
     float secondOffset;
+    float pitch;    // multiplier, where 2.0f shifts up one octave
 };
 
 Q_DECLARE_METATYPE(AudioInjectorOptions);