Sound Spectrum Display using Laser Projector and OpenLASE

spectrum.py

#!/usr/bin/env python
import pyaudio
import pylase as ol
import numpy as np
import sys
import threading

chunk = 1024
#chunk = 2048
CHANNELS = 2

DISPLAY_SIZE = 128
#DISPLAY_SIZE = 256


def spectrum_linear(data):
    #d = data * np.hanning(chunk) 
    d = data * np.blackman(chunk) 
    ps = np.fft.fft(d) / chunk
    return np.abs(ps)[0:chunk/2]
def spectrum_log(data):
    d = data * np.blackman(chunk) 
    ps = np.fft.fft(d) / chunk
    ps = np.log(np.abs(ps)**2)[0:chunk/2]
    ps += 3
    ps[ps < 0] = 0
    return ps

ol.init()

import jack
jack.attach("ctrl")
jack.activate()
jack.connect("libol:out_x", "system:playback_4")
jack.connect("libol:out_y", "system:playback_3")
jack.connect("libol:out_x", "system:playback_2")
jack.connect("libol:out_y", "system:playback_1")
jack.connect("libol:out_g", "system:playback_5")

data = None
evt = threading.Event()

def capture():
    paud = pyaudio.PyAudio()
    di = paud.get_default_input_device_info()
    rate = int(di['defaultSampleRate'])
    print "Audio source: %s %dHz\n" % (di['name'],rate)
    stream = paud.open(format = pyaudio.paInt16, channels = CHANNELS, rate = rate,
                       input = True, frames_per_buffer = chunk)
    while True:
        global data
        d = stream.read(chunk)
        d = np.fromstring(d, dtype=np.int16)
        data = d - np.average(d)
        evt.set()

def draw():
    while True:
        evt.wait()
        left = data[0::2]
        right = data[1::2]
        evt.clear()
        psd_l = spectrum_log(left)[16:DISPLAY_SIZE]
        psd_r = spectrum_log(right)[16:DISPLAY_SIZE]
        ol.loadIdentity()
        ol.scale((0.08, -0.8))
        y = 1
        ystep = -2.0 / len(psd_r)
        ol.begin(ol.LINESTRIP)
        ol.vertex((0, y), ol.C_WHITE)
        for p in psd_r:
            y += ystep
            x = p
            ol.vertex((x, y), ol.C_WHITE)
        ol.vertex((0, y), ol.C_WHITE)
        ol.scale((-1, 1))
        y = 1
        ystep = -2.0 / len(psd_l)
        ol.vertex((0, y), ol.C_WHITE)
        for p in psd_l:
            y += ystep
            x = p
            ol.vertex((x, y), ol.C_WHITE)
        ol.vertex((0, y), ol.C_WHITE)
        ol.vertex((0, 1), ol.C_WHITE)
        ol.end()
        ol.renderFrame(120)

thd = threading.Thread(target=draw, name="draw", args=())
#thd = threading.Thread(target=capture, name="capture", args=())
thd.daemon = True
thd.start()
capture()
#draw()