from __future__ import print_function from __future__ import division import time import numpy as np from scipy.ndimage.filters import gaussian_filter1d import config import microphone import dsp import led _time_prev = time.time() * 1000.0 """The previous time that the frames_per_second() function was called""" _fps = dsp.ExpFilter(val=config.FPS, alpha_decay=0.002, alpha_rise=0.002) """The low-pass filter used to estimate frames-per-second""" def frames_per_second(): """Return the estimated frames per second Returns the current estimate for frames-per-second (FPS). FPS is estimated by measured the amount of time that has elapsed since this function was previously called. The FPS estimate is low-pass filtered to reduce noise. This function is intended to be called one time for every iteration of the program's main loop. Returns ------- fps : float Estimated frames-per-second. This value is low-pass filtered to reduce noise. """ global _time_prev, _fps time_now = time.time() * 1000.0 dt = time_now - _time_prev _time_prev = time_now if dt == 0.0: return _fps.value return _fps.update(1000.0 / dt) def interpolate(y, new_length): """Intelligently resizes the array by linearly interpolating the values Parameters ---------- y : np.array Array that should be resized new_length : int The length of the new interpolated array Returns ------- z : np.array New array with length of new_length that contains the interpolated values of y. """ if len(y) == new_length: return y x_old = np.linspace(0, 1, len(y)) x_new = np.linspace(0, 1, new_length) z = np.interp(x_new, x_old, y) return z r_filt = dsp.ExpFilter(np.tile(0.01, config.N_PIXELS // 2), alpha_decay=0.2, alpha_rise=0.99) g_filt = dsp.ExpFilter(np.tile(0.01, config.N_PIXELS // 2), alpha_decay=0.05, alpha_rise=0.3) b_filt = dsp.ExpFilter(np.tile(0.01, config.N_PIXELS // 2), alpha_decay=0.1, alpha_rise=0.5) common_mode = dsp.ExpFilter(np.tile(0.01, config.N_PIXELS // 2), alpha_decay=0.99, alpha_rise=0.01) p_filt = dsp.ExpFilter(np.tile(1, (3, config.N_PIXELS // 2)), alpha_decay=0.1, alpha_rise=0.99) p = np.tile(1.0, (3, config.N_PIXELS // 2)) gain = dsp.ExpFilter(np.tile(0.01, config.N_FFT_BINS), alpha_decay=0.001, alpha_rise=0.99) def visualize_scroll(y): """Effect that originates in the center and scrolls outwards""" global p y = np.copy(y)**2.0 gain.update(y) y /= gain.value y *= 255.0 r = int(max(y[:len(y) // 3])) g = int(max(y[len(y) // 3: 2 * len(y) // 3])) b = int(max(y[2 * len(y) // 3:])) # Scrolling effect window p = np.roll(p, 1, axis=1) p *= 0.98 p = gaussian_filter1d(p, sigma=0.2) # Create new color originating at the center p[0, 0] = r p[1, 0] = g p[2, 0] = b # Update the LED strip return np.concatenate((p[:, ::-1], p), axis=1) def visualize_energy(y): """Effect that expands from the center with increasing sound energy""" global p y = np.copy(y) gain.update(y) y /= gain.value # Scale by the width of the LED strip y *= float((config.N_PIXELS // 2) - 1) # Map color channels according to energy in the different freq bands scale = 0.9 r = int(np.mean(y[:len(y) // 3]**scale)) g = int(np.mean(y[len(y) // 3: 2 * len(y) // 3]**scale)) b = int(np.mean(y[2 * len(y) // 3:]**scale)) # Assign color to different frequency regions p[0, :r] = 255.0 p[0, r:] = 0.0 p[1, :g] = 255.0 p[1, g:] = 0.0 p[2, :b] = 255.0 p[2, b:] = 0.0 p_filt.update(p) p = np.round(p_filt.value) # Apply substantial blur to smooth the edges p[0, :] = gaussian_filter1d(p[0, :], sigma=4.0) p[1, :] = gaussian_filter1d(p[1, :], sigma=4.0) p[2, :] = gaussian_filter1d(p[2, :], sigma=4.0) # Set the new pixel value return np.concatenate((p[:, ::-1], p), axis=1) _prev_spectrum = np.tile(0.01, config.N_PIXELS // 2) def visualize_spectrum(y): """Effect that maps the Mel filterbank frequencies onto the LED strip""" global _prev_spectrum y = np.copy(interpolate(y, config.N_PIXELS // 2)) common_mode.update(gaussian_filter1d(y, sigma=2.0)) diff = y - _prev_spectrum _prev_spectrum = np.copy(y) r = gaussian_filter1d(y, sigma=0.5) - common_mode.value # g = gaussian_filter1d(y, sigma=0.5) - common_mode.value b = gaussian_filter1d(y, sigma=0.0) - common_mode.value # Update temporal filters r = r_filt.update(r) # g = g_filt.update(g) g = np.abs(diff) b = b_filt.update(b) # Mirror the color channels for symmetric output pixel_r = np.concatenate((r[::-1], r)) pixel_g = np.concatenate((g[::-1], g)) pixel_b = np.concatenate((b[::-1], b)) output = np.array([pixel_r, pixel_g, pixel_b]) * 255.0 return output fft_plot_filter = dsp.ExpFilter(np.tile(1e-1, config.N_FFT_BINS), alpha_decay=0.5, alpha_rise=0.99) mel_gain = dsp.ExpFilter(np.tile(1e-1, config.N_FFT_BINS), alpha_decay=0.01, alpha_rise=0.99) mel_smoothing = dsp.ExpFilter(np.tile(1e-1, config.N_FFT_BINS), alpha_decay=0.5, alpha_rise=0.99) volume = dsp.ExpFilter(config.MIN_VOLUME_THRESHOLD, alpha_decay=0.02, alpha_rise=0.02) # Keeps track of the number of buffer overflows # Lots of buffer overflows could mean that FPS is set too high buffer_overflows = 1 def microphone_update(stream): global y_roll, prev_rms, prev_exp # Retrieve and normalize the new audio samples try: y = np.fromstring(stream.read(samples_per_frame), dtype=np.int16) except IOError: y = y_roll[config.N_ROLLING_HISTORY - 1, :] global buffer_overflows print('Buffer overflows: {0}'.format(buffer_overflows)) buffer_overflows += 1 # Normalize samples between 0 and 1 y = y / 2.0**15 # Construct a rolling window of audio samples y_roll = np.roll(y_roll, -1, axis=0) y_roll[-1, :] = np.copy(y) y_data = np.concatenate(y_roll, axis=0) volume.update(np.nanmean(y_data ** 2)) if volume.value < config.MIN_VOLUME_THRESHOLD: print('No audio input. Volume below threshold. Volume:', volume.value) led.pixels = np.tile(0, (3, config.N_PIXELS)) led.update() else: # Transform audio input into the frequency domain XS, YS = dsp.fft(y_data, window=np.hamming) # Remove half of the FFT data because of symmetry YS = YS[:len(YS) // 2] XS = XS[:len(XS) // 2] # Construct a Mel filterbank from the FFT data mel = np.atleast_2d(np.abs(YS)).T * dsp.mel_y.T # Scale data to values more suitable for visualization mel = np.mean(mel, axis=0) mel = mel**2.0 # Gain normalization mel_gain.update(np.max(gaussian_filter1d(mel, sigma=1.0))) mel = mel / mel_gain.value mel = mel_smoothing.update(mel) # Map filterbank output onto LED strip output = visualization_effect(mel) led.pixels = output led.update() if config.USE_GUI: # Plot filterbank output x = np.linspace(config.MIN_FREQUENCY, config.MAX_FREQUENCY, len(mel)) mel_curve.setData(x=x, y=fft_plot_filter.update(mel)) # Plot the color channels r_curve.setData(y=led.pixels[0]) g_curve.setData(y=led.pixels[1]) b_curve.setData(y=led.pixels[2]) if config.USE_GUI: app.processEvents() if config.DISPLAY_FPS: print('FPS {:.0f} / {:.0f}'.format(frames_per_second(), config.FPS)) # Number of audio samples to read every time frame samples_per_frame = int(config.MIC_RATE / config.FPS) # Array containing the rolling audio sample window y_roll = np.random.rand(config.N_ROLLING_HISTORY, samples_per_frame) / 1e16 visualization_effect = visualize_spectrum """Visualization effect to display on the LED strip""" if __name__ == '__main__': if config.USE_GUI: import pyqtgraph as pg from pyqtgraph.Qt import QtGui, QtCore # Create GUI window app = QtGui.QApplication([]) view = pg.GraphicsView() layout = pg.GraphicsLayout(border=(100,100,100)) view.setCentralItem(layout) view.show() view.setWindowTitle('Visualization') view.resize(800,600) # Mel filterbank plot fft_plot = layout.addPlot(title='Filterbank Output', colspan=3) fft_plot.setRange(yRange=[-0.1, 1.2]) fft_plot.disableAutoRange(axis=pg.ViewBox.YAxis) x_data = np.array(range(1, config.N_FFT_BINS + 1)) mel_curve = pg.PlotCurveItem() mel_curve.setData(x=x_data, y=x_data*0) fft_plot.addItem(mel_curve) # Visualization plot layout.nextRow() led_plot = layout.addPlot(title='Visualization Output', colspan=3) led_plot.setRange(yRange=[-5, 260]) led_plot.disableAutoRange(axis=pg.ViewBox.YAxis) # Pen for each of the color channel curves r_pen = pg.mkPen((255, 30, 30, 200), width=4) g_pen = pg.mkPen((30, 255, 30, 200), width=4) b_pen = pg.mkPen((30, 30, 255, 200), width=4) # Color channel curves r_curve = pg.PlotCurveItem(pen=r_pen) g_curve = pg.PlotCurveItem(pen=g_pen) b_curve = pg.PlotCurveItem(pen=b_pen) # Define x data x_data = np.array(range(1, config.N_PIXELS + 1)) r_curve.setData(x=x_data, y=x_data*0) g_curve.setData(x=x_data, y=x_data*0) b_curve.setData(x=x_data, y=x_data*0) # Add curves to plot led_plot.addItem(r_curve) led_plot.addItem(g_curve) led_plot.addItem(b_curve) # Frequency range label freq_label = pg.LabelItem('') # Frequency slider def freq_slider_change(tick): minf = freq_slider.tickValue(0)**2.0 * (config.MIC_RATE / 2.0) maxf = freq_slider.tickValue(1)**2.0 * (config.MIC_RATE / 2.0) t = 'Frequency range: {:.0f} - {:.0f} Hz'.format(minf, maxf) freq_label.setText(t) config.MIN_FREQUENCY = minf config.MAX_FREQUENCY = maxf dsp.create_mel_bank() freq_slider = pg.TickSliderItem(orientation='bottom', allowAdd=False) freq_slider.addTick((config.MIN_FREQUENCY / (config.MIC_RATE / 2.0))**0.5) freq_slider.addTick((config.MAX_FREQUENCY / (config.MIC_RATE / 2.0))**0.5) freq_slider.tickMoveFinished = freq_slider_change freq_label.setText('Frequency range: {} - {} Hz'.format( config.MIN_FREQUENCY, config.MAX_FREQUENCY)) # Effect selection active_color = '#16dbeb' inactive_color = '#FFFFFF' def energy_click(x): global visualization_effect visualization_effect = visualize_energy energy_label.setText('Energy', color=active_color) scroll_label.setText('Scroll', color=inactive_color) spectrum_label.setText('Spectrum', color=inactive_color) def scroll_click(x): global visualization_effect visualization_effect = visualize_scroll energy_label.setText('Energy', color=inactive_color) scroll_label.setText('Scroll', color=active_color) spectrum_label.setText('Spectrum', color=inactive_color) def spectrum_click(x): global visualization_effect visualization_effect = visualize_spectrum energy_label.setText('Energy', color=inactive_color) scroll_label.setText('Scroll', color=inactive_color) spectrum_label.setText('Spectrum', color=active_color) # Create effect "buttons" (labels with click event) energy_label = pg.LabelItem('Energy') scroll_label = pg.LabelItem('Scroll') spectrum_label = pg.LabelItem('Spectrum') energy_label.mousePressEvent = energy_click scroll_label.mousePressEvent = scroll_click spectrum_label.mousePressEvent = spectrum_click energy_click(0) # Layout layout.nextRow() layout.addItem(freq_label, colspan=3) layout.nextRow() layout.addItem(freq_slider, colspan=3) layout.nextRow() layout.addItem(energy_label) layout.addItem(scroll_label) layout.addItem(spectrum_label) # Initialize LEDs led.update() # Start listening to live audio stream microphone.start_stream(microphone_update)