More work on numpy audio integration

examples/numpy_audio.py

@@ -0,0 +1,80 @@
+import numpy as np
+
+from juce_init import START_JUCE_COMPONENT
+import popsicle as juce
+
+
+class AudioCallback(juce.AudioIODeviceCallback):
+    gain = 1.0
+    time = 0.0
+    device = None
+
+    def audioDeviceAboutToStart(self, device: juce.AudioIODevice):
+        print("starting", device, "at", device.getCurrentSampleRate())
+        self.device = device
+        self.buffer = np.zeros(self.device.getCurrentBufferSizeSamples())
+
+    def audioDeviceIOCallbackWithContext(self, inputs, numInputChannels, outputs, numOutputChannels, numSamples, context):
+        start = self.time
+        end = start + 2.0 * numSamples
+
+        self.buffer[:] = (
+            (np.random.random(numSamples) * 2.0 - 1 * 0.025) + np.sin(np.deg2rad(np.linspace(start, end, numSamples)))
+        ) * self.gain * 0.005
+
+        self.time = end % 360.0
+
+        for output in outputs:
+            nout = np.array(output, copy=False)
+            nout[:] = self.buffer
+
+    def audioDeviceError(self, errorMessage: str):
+        print("error", errorMessage)
+
+    def audioDeviceStopped(self):
+        print("stopping")
+
+
+class MainContentComponent(juce.Component):
+    manager = juce.AudioDeviceManager()
+    audio_callback = AudioCallback()
+
+    def __init__(self):
+        juce.Component.__init__(self)
+
+        width = 600
+        height = 400
+
+        self.manager.addAudioCallback(self.audio_callback)
+        result = self.manager.initialiseWithDefaultDevices(0, 2)
+        if result:
+            print(result)
+
+        self.button = juce.TextButton("Silence!")
+        self.addAndMakeVisible(self.button)
+        self.button.onStateChange = lambda: self.onButtonStateChange()
+
+        self.setSize(int(width), int(height))
+        self.setOpaque(True)
+
+    def visibilityChanged(self):
+        if not self.isVisible() and self.manager:
+            self.manager.removeAudioCallback(self.audio_callback)
+            self.manager.closeAudioDevice()
+
+    def onButtonStateChange(self):
+        if self.button.getState() == juce.Button.ButtonState.buttonDown:
+            self.audio_callback.gain = 0.25
+        else:
+            self.audio_callback.gain = 1.0
+
+    def paint(self, g: juce.Graphics):
+        g.fillAll(juce.Colours.black)
+
+    def resized(self):
+        bounds = self.getLocalBounds()
+        self.button.setBounds(bounds.reduced(100))
+
+
+if __name__ == "__main__":
+    START_JUCE_COMPONENT(MainContentComponent, name="Audio Device Example")

modules/juce_python/bindings/ScriptJuceAudioDevicesBindings.cpp

@@ -51,14 +51,7 @@ void registerJuceAudioDevicesBindings (pybind11::module_& m)
         })
         .def_buffer ([](PyChannelData<const float>& v) -> py::buffer_info
         {
-            return py::buffer_info(
-                const_cast<void*> (static_cast<const void*> (v.data())),
-                sizeof (float),
-                py::format_descriptor<float>::format(),
-                1,
-                { static_cast<ssize_t> (1), static_cast<ssize_t> (v.size()) },
-                { static_cast<ssize_t> (sizeof(float) * v.size()), static_cast<ssize_t> (sizeof(float)) }
-            );
+            return py::buffer_info (v.data(), static_cast<ssize_t> (v.size()), true);
         })
     ;
 
@@ -81,14 +74,7 @@ void registerJuceAudioDevicesBindings (pybind11::module_& m)
         })
         .def_buffer ([](PyChannelData<float>& v) -> py::buffer_info
         {
-            return py::buffer_info(
-                static_cast<void*> (v.data()),
-                sizeof (float),
-                py::format_descriptor<float>::format(),
-                1,
-                { static_cast<ssize_t> (1), static_cast<ssize_t> (v.size()) },
-                { static_cast<ssize_t> (sizeof(float) * v.size()), static_cast<ssize_t> (sizeof(float)) }
-            );
+            return py::buffer_info (v.data(), static_cast<ssize_t> (v.size()), false);
         })
     ;