comparison projects/audio_in_FFT/render.cpp @ 4:f34c63568523

_new FFT example [still noisy]

+/*
+ * render.cpp
+ *
+ *  Created on: Oct 24, 2014
+ *      Author: parallels
+ */
+
+
+#include "../../include/render.h"
+#include <rtdk.h>
+#include <NE10.h>					// neon library
+#include <cmath>
+
+int gFftSize;
+int gNumChannels;
+
+int gReadPointer = 0;
+int gWritePointer = 0;
+
+// FFT vars
+ne10_fft_cpx_float32_t* timeDomain;
+ne10_fft_cpx_float32_t* frequencyDomain;
+ne10_fft_cfg_float32_t cfg;
+
+// initialise_render() 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 initialise_render(int numChannels, int numMatrixFramesPerPeriod,
+					   int numAudioFramesPerPeriod, float matrixSampleRate,
+					   float audioSampleRate, void *userData)
+{
+	// Retrieve a parameter passed in from the initAudio() call
+	gFftSize = *(int *)userData;
+	gNumChannels = numChannels;
+
+	//memset(outSamples, gFftSize, 0.0); // set all to 0
+
+	timeDomain = (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);
+
+	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(int numMatrixFrames, int numAudioFrames, float *audioIn, float *audioOut,
+			uint16_t *matrixIn, uint16_t *matrixOut)
+{
+	for(int n = 0; n < numAudioFrames; n++) {
+		timeDomain[gReadPointer].r = (ne10_float32_t) ((audioIn[n*gNumChannels] + audioIn[n*gNumChannels+1])/2);
+		timeDomain[gReadPointer].i = 0;
+		gReadPointer++;
+	}
+
+	if(gReadPointer>=gFftSize)
+	{
+		//FFT
+		ne10_fft_c2c_1d_float32_neon (frequencyDomain, timeDomain, cfg->twiddles, cfg->factors, gFftSize, 0);
+
+		//Do frequency domain stuff
+
+		//IFFT
+		ne10_fft_c2c_1d_float32_neon (timeDomain, frequencyDomain, cfg->twiddles, cfg->factors, gFftSize, 1);
+
+		gReadPointer = 0;
+		gWritePointer = 0;
+	}
+
+	for(int n = 0; n < numAudioFrames; n++) {
+		for(int channel = 0; channel < gNumChannels; channel++)
+			audioOut[n * gNumChannels + channel] = (float) timeDomain[gWritePointer++].r/gFftSize;
+	}
+}
+
+// cleanup_render() is called once at the end, after the audio has stopped.
+// Release any resources that were allocated in initialise_render().
+
+void cleanup_render()
+{
+	NE10_FREE(timeDomain);
+	NE10_FREE(frequencyDomain);
+	NE10_FREE(cfg);
+}