#!/usr/bin/env python
"""
This plot displays the audio spectrum from the microphone.
Based on updating_plot.py
"""
# Major library imports
import pyaudio
from numpy import zeros, linspace, short, fromstring, hstack, transpose
from scipy import fft
# Enthought library imports
from enthought.chaco.default_colormaps import jet
from enthought.enable.api import Window, Component, ComponentEditor
from enthought.traits.api import HasTraits, Instance
from enthought.traits.ui.api import Item, Group, View, Handler
from enthought.enable.example_support import DemoFrame, demo_main
from enthought.pyface.timer.api import Timer
# Chaco imports
from enthought.chaco.api import Plot, ArrayPlotData, HPlotContainer
NUM_SAMPLES = 1024
SAMPLING_RATE = 11025
SPECTROGRAM_LENGTH = 100
#============================================================================
# Create the Chaco plot.
#============================================================================
def _create_plot_component(obj):
# Setup the spectrum plot
frequencies = linspace(0.0, float(SAMPLING_RATE)/2, num=NUM_SAMPLES/2)
obj.spectrum_data = ArrayPlotData(frequency=frequencies)
empty_amplitude = zeros(NUM_SAMPLES/2)
obj.spectrum_data.set_data('amplitude', empty_amplitude)
obj.spectrum_plot = Plot(obj.spectrum_data)
obj.spectrum_plot.plot(("frequency", "amplitude"), name="Spectrum",
color="red")
obj.spectrum_plot.padding = 50
obj.spectrum_plot.title = "Spectrum"
spec_range = obj.spectrum_plot.plots.values()[0][0].value_mapper.range
spec_range.low = 0.0
spec_range.high = 5.0
obj.spectrum_plot.index_axis.title = 'Frequency (hz)'
obj.spectrum_plot.value_axis.title = 'Amplitude'
# Time Series plot
times = linspace(0.0, float(NUM_SAMPLES)/SAMPLING_RATE, num=NUM_SAMPLES)
obj.time_data = ArrayPlotData(time=times)
empty_amplitude = zeros(NUM_SAMPLES)
obj.time_data.set_data('amplitude', empty_amplitude)
obj.time_plot = Plot(obj.time_data)
obj.time_plot.plot(("time", "amplitude"), name="Time", color="blue")
obj.time_plot.padding = 50
obj.time_plot.title = "Time"
obj.time_plot.index_axis.title = 'Time (seconds)'
obj.time_plot.value_axis.title = 'Amplitude'
time_range = obj.time_plot.plots.values()[0][0].value_mapper.range
time_range.low = -0.2
time_range.high = 0.2
# Spectrogram plot
spectrogram_data = zeros(( NUM_SAMPLES/2, SPECTROGRAM_LENGTH))
obj.spectrogram_plotdata = ArrayPlotData()
obj.spectrogram_plotdata.set_data('imagedata', spectrogram_data)
spectrogram_plot = Plot(obj.spectrogram_plotdata)
max_time = float(SPECTROGRAM_LENGTH * NUM_SAMPLES) / SAMPLING_RATE
max_freq = float(SAMPLING_RATE / 2)
spectrogram_plot.img_plot('imagedata',
name='Spectrogram',
xbounds=(0, max_time),
ybounds=(0, max_freq),
colormap=jet,
)
range_obj = spectrogram_plot.plots['Spectrogram'][0].value_mapper.range
range_obj.high = 5
range_obj.low = 0.0
spectrogram_plot.title = 'Spectrogram'
obj.spectrogram_plot = spectrogram_plot
container = HPlotContainer()
container.add(obj.spectrum_plot)
container.add(obj.time_plot)
container.add(spectrogram_plot)
return container
_stream = None
def get_audio_data():
global _stream
if _stream is None:
pa = pyaudio.PyAudio()
_stream = pa.open(format=pyaudio.paInt16, channels=1, rate=SAMPLING_RATE,
input=True, frames_per_buffer=NUM_SAMPLES)
audio_data = fromstring(_stream.read(NUM_SAMPLES), dtype=short)
normalized_data = audio_data / 32768.0
return (abs(fft(normalized_data))[:NUM_SAMPLES/2], normalized_data)
# HasTraits class that supplies the callable for the timer event.
class TimerController(HasTraits):
def onTimer(self, *args):
spectrum, time = get_audio_data()
self.spectrum_data.set_data('amplitude', spectrum)
self.time_data.set_data('amplitude', time)
spectrogram_data = self.spectrogram_plotdata.get_data('imagedata')
spectrogram_data = hstack((spectrogram_data[:,1:],
transpose([spectrum])))
self.spectrogram_plotdata.set_data('imagedata', spectrogram_data)
self.spectrum_plot.request_redraw()
return
#============================================================================
# Attributes to use for the plot view.
size = (900,500)
title = "Audio Spectrum"
#============================================================================
# Demo class that is used by the demo.py application.
#============================================================================
class DemoHandler(Handler):
def closed(self, info, is_ok):
""" Handles a dialog-based user interface being closed by the user.
Overridden here to stop the timer once the window is destroyed.
"""
info.object.timer.Stop()
return
class Demo(HasTraits):
plot = Instance(Component)
controller = Instance(TimerController, ())
timer = Instance(Timer)
traits_view = View(
Group(
Item('plot', editor=ComponentEditor(size=size),
show_label=False),
orientation = "vertical"),
resizable=True, title=title,
width=size[0], height=size[1],
handler=DemoHandler
)
def __init__(self, **traits):
super(Demo, self).__init__(**traits)
self.plot = _create_plot_component(self.controller)
def edit_traits(self, *args, **kws):
# Start up the timer! We should do this only when the demo actually
# starts and not when the demo object is created.
self.timer = Timer(20, self.controller.onTimer)
return super(Demo, self).edit_traits(*args, **kws)
def configure_traits(self, *args, **kws):
# Start up the timer! We should do this only when the demo actually
# starts and not when the demo object is created.
self.timer = Timer(20, self.controller.onTimer)
return super(Demo, self).configure_traits(*args, **kws)
popup = Demo()
#============================================================================
# Stand-alone frame to display the plot.
#============================================================================
from enthought.etsconfig.api import ETSConfig
if ETSConfig.toolkit == "wx":
import wx
class PlotFrame(DemoFrame):
def _create_window(self):
self.controller = TimerController()
container = _create_plot_component(self.controller)
# Bind the exit event to the onClose function which will force the
# example to close. The PyAudio package causes problems that normally
# prevent the user from closing the example using the 'X' button.
# NOTE: I believe it is sufficient to just stop the timer-Vibha.
self.Bind(wx.EVT_CLOSE, self.onClose)
# Set the timer to generate events to us
timerId = wx.NewId()
self.timer = wx.Timer(self, timerId)
self.Bind(wx.EVT_TIMER, self.controller.onTimer, id=timerId)
self.timer.Start(20.0, wx.TIMER_CONTINUOUS)
# Return a window containing our plots
return Window(self, -1, component=container)
def onClose(self, event):
#sys.exit()
self.timer.Stop()
event.Skip()
elif ETSConfig.toolkit == "qt4":
from enthought.qt import QtGui, QtCore
class PlotFrame(DemoFrame):
def _create_window(self):
self.controller = TimerController()
container = _create_plot_component(self.controller)
# start a continuous timer
self.timer = QtCore.QTimer()
self.timer.timeout.connect(self.controller.onTimer)
self.timer.start(20)
return Window(self, -1, component=container)
def closeEvent(self, event):
# stop the timer
if getattr(self, "timer", None):
self.timer.stop()
return super(PlotFrame, self).closeEvent(event)
if __name__ == "__main__":
try:
demo_main(PlotFrame, size=size, title=title)
finally:
if _stream is not None:
_stream.close()
