diff examples/audio_in_FFT/render.cpp @ 300:dbeed520b014 prerelease

Renamed projects to examples

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/audio_in_FFT/render.cpp	Fri May 27 13:58:20 2016 +0100
@@ -0,0 +1,92 @@
+/*
+ * render.cpp
+ *
+ *  Created on: Oct 24, 2014
+ *      Author: parallels
+ */
+
+
+#include <BeagleRT.h>
+#include <rtdk.h>
+#include <NE10.h>					// neon library
+#include <cmath>
+
+int gFFTSize;
+float gFFTScaleFactor = 0;
+
+int gReadPointer = 0;
+int gWritePointer = 0;
+
+// FFT vars
+ne10_fft_cpx_float32_t* timeDomainIn;
+ne10_fft_cpx_float32_t* timeDomainOut;
+ne10_fft_cpx_float32_t* frequencyDomain;
+ne10_fft_cfg_float32_t cfg;
+
+// setup() is called once before the audio rendering starts.
+// Use it to perform any initialisation and allocation which is dependent
+// on the period size or sample rate.
+//
+// userData holds an opaque pointer to a data structure that was passed
+// in from the call to initAudio().
+//
+// Return true on success; returning false halts the program.
+
+bool setup(BeagleRTContext *context, void *userData)
+{
+	// Retrieve a parameter passed in from the initAudio() call
+	gFFTSize = *(int *)userData;
+	gFFTScaleFactor = 1.0f / (float)gFFTSize;
+
+	timeDomainIn = (ne10_fft_cpx_float32_t*) NE10_MALLOC (gFFTSize * sizeof (ne10_fft_cpx_float32_t));
+	timeDomainOut = (ne10_fft_cpx_float32_t*) NE10_MALLOC (gFFTSize * sizeof (ne10_fft_cpx_float32_t));
+	frequencyDomain = (ne10_fft_cpx_float32_t*) NE10_MALLOC (gFFTSize * sizeof (ne10_fft_cpx_float32_t));
+	cfg = ne10_fft_alloc_c2c_float32 (gFFTSize);
+
+	memset(timeDomainOut, 0, gFFTSize * sizeof (ne10_fft_cpx_float32_t));
+
+	return true;
+}
+
+// render() is called regularly at the highest priority by the audio engine.
+// Input and output are given from the audio hardware and the other
+// ADCs and DACs (if available). If only audio is available, numMatrixFrames
+// will be 0.
+
+void render(BeagleRTContext *context, void *userData)
+{
+	for(unsigned int n = 0; n < context->audioFrames; n++) {
+		timeDomainIn[gReadPointer].r = (ne10_float32_t) ((context->audioIn[n*context->audioChannels] +
+															context->audioIn[n*context->audioChannels+1]) * 0.5);
+		timeDomainIn[gReadPointer].i = 0;
+
+		if(++gReadPointer >= gFFTSize)
+		{
+			//FFT
+			ne10_fft_c2c_1d_float32_neon (frequencyDomain, timeDomainIn, cfg->twiddles, cfg->factors, gFFTSize, 0);
+
+			//Do frequency domain stuff
+
+			//IFFT
+			ne10_fft_c2c_1d_float32_neon (timeDomainOut, frequencyDomain, cfg->twiddles, cfg->factors, gFFTSize, 1);
+
+			gReadPointer = 0;
+			gWritePointer = 0;
+		}
+
+		for(unsigned int channel = 0; channel < context->audioChannels; channel++)
+			context->audioOut[n * context->audioChannels + channel] = (float) timeDomainOut[gWritePointer].r * gFFTScaleFactor;
+		gWritePointer++;
+	}
+}
+
+// cleanup() is called once at the end, after the audio has stopped.
+// Release any resources that were allocated in setup().
+
+void cleanup(BeagleRTContext *context, void *userData)
+{
+	NE10_FREE(timeDomainIn);
+	NE10_FREE(timeDomainOut);
+	NE10_FREE(frequencyDomain);
+	NE10_FREE(cfg);
+}