Mercurial > hg > beaglert
view projects/audio_in_FFT/render.cpp @ 12:a6beeba3a648
Initial support for higher matrix sample rates by reducing the number of channels. Input not tested yet, and not all examples updated to new format.
author | andrewm |
---|---|
date | Thu, 22 Jan 2015 19:00:22 +0000 |
parents | 09f03ac40fcc |
children | 06f93bef7dd2 |
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/* * 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; float gFFTScaleFactor = 0; int gNumChannels; 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; // 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; gFFTScaleFactor = 1.0f / (float)gFFTSize; gNumChannels = numChannels; 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(int numMatrixFrames, int numAudioFrames, float *audioIn, float *audioOut, uint16_t *matrixIn, uint16_t *matrixOut) { for(int n = 0; n < numAudioFrames; n++) { timeDomainIn[gReadPointer].r = (ne10_float32_t) ((audioIn[n*gNumChannels] + audioIn[n*gNumChannels+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(int channel = 0; channel < gNumChannels; channel++) audioOut[n * gNumChannels + channel] = (float) timeDomainOut[gWritePointer].r * gFFTScaleFactor; gWritePointer++; } } // 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(timeDomainIn); NE10_FREE(timeDomainOut); NE10_FREE(frequencyDomain); NE10_FREE(cfg); }