Example Programs¶
Play a Sound File¶
#!/usr/bin/env python3
"""Load an audio file and play its contents.
PySoundFile (https://github.com/bastibe/PySoundFile/) has to be installed!
"""
import argparse
import logging
def int_or_str(text):
"""Helper function for argument parsing."""
try:
return int(text)
except ValueError:
return text
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument("filename", help="audio file to be played back")
parser.add_argument('-d', '--device', type=int_or_str,
help='output device (numeric ID or substring)')
args = parser.parse_args()
try:
import sounddevice as sd
import soundfile as sf
data, fs = sf.read(args.filename, dtype='float32')
sd.play(data, fs, device=args.device, blocking=True)
status = sd.get_status()
if status:
logging.warning(str(status))
except KeyboardInterrupt:
parser.exit('\nInterrupted by user')
except Exception as e:
parser.exit(type(e).__name__ + ': ' + str(e))
Input to Output Pass-Through¶
#!/usr/bin/env python3
"""Pass input directly to output.
See https://www.assembla.com/spaces/portaudio/subversion/source/HEAD/portaudio/trunk/test/patest_wire.c
"""
import argparse
import logging
def int_or_str(text):
"""Helper function for argument parsing."""
try:
return int(text)
except ValueError:
return text
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument("-i", "--input-device", type=int_or_str,
help="input device ID or substring")
parser.add_argument("-o", "--output-device", type=int_or_str,
help="output device ID or substring")
parser.add_argument("-c", "--channels", type=int, default=2,
help="number of channels")
parser.add_argument("-t", "--dtype", help="audio data type")
parser.add_argument("-s", "--samplerate", type=float, help="sampling rate")
parser.add_argument("-b", "--blocksize", type=int, help="block size")
parser.add_argument("-l", "--latency", type=float, help="latency in seconds")
args = parser.parse_args()
try:
import sounddevice as sd
cumulated_status = sd.CallbackFlags()
def callback(indata, outdata, frames, time, status):
global cumulated_status
cumulated_status |= status
outdata[:] = indata
with sd.Stream(device=(args.input_device, args.output_device),
samplerate=args.samplerate, blocksize=args.blocksize,
dtype=args.dtype, latency=args.latency,
channels=args.channels, callback=callback):
print("#" * 80)
print("press Return to quit")
print("#" * 80)
input()
if cumulated_status:
logging.warning(str(cumulated_status))
except KeyboardInterrupt:
parser.exit('\nInterrupted by user')
except Exception as e:
parser.exit(type(e).__name__ + ': ' + str(e))
Plot Microphone Signal(s) in Real-Time¶
#!/usr/bin/env python3
"""Plot the live microphone signal(s) with matplotlib."""
import argparse
from queue import Queue, Empty
def int_or_str(text):
"""Helper function for argument parsing."""
try:
return int(text)
except ValueError:
return text
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument(
'-l', '--list-devices', action='store_true',
help='show list of audio devices and exit')
parser.add_argument(
'-d', '--device', type=int_or_str,
help='input device (numeric ID or substring)')
parser.add_argument(
'-w', '--window', type=float, default=200, metavar='DURATION',
help='visible time slot (default: %(default)s ms)')
parser.add_argument(
'-i', '--interval', type=float, default=30,
help='minimum time between plot updates (default: %(default)s ms)')
parser.add_argument(
'-b', '--blocksize', type=int, help='block size (in samples)')
parser.add_argument(
'-r', '--samplerate', type=float, help='sampling rate of audio device')
parser.add_argument(
'-n', '--downsample', type=int, default=10, metavar='N',
help='display every Nth sample (default: %(default)s)')
parser.add_argument(
'channels', type=int, default=[1], nargs='*', metavar='CHANNEL',
help='input channels to plot (default: the first)')
args = parser.parse_args()
if any(c < 1 for c in args.channels):
parser.error('argument CHANNEL: must be >= 1')
mapping = [c - 1 for c in args.channels] # Channel numbers start with 1
queue = Queue()
def audio_callback(indata, frames, time, status):
"""This is called (from a separate thread) for each audio block."""
if status:
print(status, flush=True)
# Fancy indexing with mapping creates a (necessary!) copy:
queue.put(indata[::args.downsample, mapping])
def update_plot(frame):
"""This is called by matplotlib for each plot update.
Typically, audio callbacks happen more frequently than plot updates,
therefore the queue tends to contain multiple blocks of audio data.
"""
global plotdata
block = True # The first read from the queue is blocking ...
while True:
try:
data = queue.get(block=block)
except Empty:
break
shift = len(data)
plotdata = np.roll(plotdata, -shift, axis=0)
plotdata[-shift:, :] = data
block = False # ... all further reads are non-blocking
for column, line in enumerate(lines):
line.set_ydata(plotdata[:, column])
return lines
try:
from matplotlib.animation import FuncAnimation
import matplotlib.pyplot as plt
import numpy as np
import sounddevice as sd
if args.list_devices:
print(sd.query_devices())
parser.exit()
if args.samplerate is None:
device_info = sd.query_devices(args.device, 'input')
args.samplerate = device_info['default_samplerate']
length = int(args.window * args.samplerate / (1000 * args.downsample))
plotdata = np.zeros((length, len(args.channels)))
fig, ax = plt.subplots()
lines = ax.plot(plotdata)
if len(args.channels) > 1:
ax.legend(['channel {}'.format(c) for c in args.channels],
loc='lower left', ncol=len(args.channels))
ax.axis((0, len(plotdata), -1, 1))
ax.set_yticks([0])
ax.yaxis.grid(True)
ax.tick_params(bottom='off', top='off', labelbottom='off',
right='off', left='off', labelleft='off')
fig.tight_layout(pad=0)
stream = sd.InputStream(
device=args.device, channels=max(args.channels),
samplerate=args.samplerate, callback=audio_callback)
ani = FuncAnimation(fig, update_plot, interval=args.interval, blit=True)
with stream:
plt.show()
except Exception as e:
parser.exit(type(e).__name__ + ': ' + str(e))
Real-Time Text-Mode Spectrogram¶
#!/usr/bin/env python3
"""Show a text-mode spectrogram using live microphone data."""
import argparse
import logging
import math
import numpy as np
import shutil
usage_line = ' press <enter> to quit, +<enter> or -<enter> to change scaling '
def int_or_str(text):
"""Helper function for argument parsing."""
try:
return int(text)
except ValueError:
return text
try:
columns, _ = shutil.get_terminal_size()
except AttributeError:
columns = 80
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument('-l', '--list-devices', action='store_true',
help='list audio devices and exit')
parser.add_argument('-b', '--block-duration', type=float,
metavar='DURATION', default=50,
help='block size (default %(default)s milliseconds)')
parser.add_argument('-c', '--columns', type=int, default=columns,
help='width of spectrogram')
parser.add_argument('-d', '--device', type=int_or_str,
help='input device (numeric ID or substring)')
parser.add_argument('-g', '--gain', type=float, default=10,
help='initial gain factor (default %(default)s)')
parser.add_argument('-r', '--range', type=float, nargs=2,
metavar=('LOW', 'HIGH'), default=[100, 2000],
help='frequency range (default %(default)s Hz)')
args = parser.parse_args()
low, high = args.range
if high <= low:
parser.error('HIGH must be greater than LOW')
# Create a nice output gradient using ANSI escape sequences.
# Stolen from https://gist.github.com/maurisvh/df919538bcef391bc89f
colors = 30, 34, 35, 91, 93, 97
chars = ' :%#\t#%:'
gradient = []
for bg, fg in zip(colors, colors[1:]):
for char in chars:
if char == '\t':
bg, fg = fg, bg
else:
gradient.append('\x1b[{};{}m{}'.format(fg, bg + 10, char))
try:
import sounddevice as sd
if args.list_devices:
print(sd.query_devices())
parser.exit()
samplerate = sd.query_devices(args.device, 'input')['default_samplerate']
delta_f = (high - low) / (args.columns - 1)
fftsize = math.ceil(samplerate / delta_f)
low_bin = math.floor(low / delta_f)
cumulated_status = sd.CallbackFlags()
def callback(indata, frames, time, status):
global cumulated_status
cumulated_status |= status
if any(indata):
magnitude = np.abs(np.fft.rfft(indata[:, 0], n=fftsize))
magnitude *= args.gain / fftsize
line = (gradient[int(np.clip(x, 0, 1) * (len(gradient) - 1))]
for x in magnitude[low_bin:low_bin + args.columns])
print(*line, sep='', end='\x1b[0m\n', flush=True)
else:
print('no input', flush=True)
with sd.InputStream(device=args.device, channels=1, callback=callback,
blocksize=int(samplerate * args.block_duration / 1000),
samplerate=samplerate):
while True:
response = input()
if response in ('', 'q', 'Q'):
break
for ch in response:
if ch == '+':
args.gain *= 2
elif ch == '-':
args.gain /= 2
else:
print('\x1b[31;40m', usage_line.center(args.columns, '#'),
'\x1b[0m', sep='', flush=True)
break
if cumulated_status:
logging.warning(str(cumulated_status))
except KeyboardInterrupt:
parser.exit('Interrupted by user')
except Exception as e:
parser.exit(type(e).__name__ + ': ' + str(e))
Recording with Arbitrary Duration¶
#!/usr/bin/env python3
"""Create a recording with arbitrary duration.
PySoundFile (https://github.com/bastibe/PySoundFile/) has to be installed!
WARNING: This works only in Python 3.x!
"""
import argparse
import tempfile
from queue import Queue
def int_or_str(text):
"""Helper function for argument parsing."""
try:
return int(text)
except ValueError:
return text
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument(
'-l', '--list-devices', action='store_true',
help='show list of audio devices and exit')
parser.add_argument(
'-d', '--device', type=int_or_str,
help='input device (numeric ID or substring)')
parser.add_argument(
'-r', '--samplerate', type=int, help='sampling rate')
parser.add_argument(
'-c', '--channels', type=int, default=1, help='number of input channels')
parser.add_argument(
'filename', nargs='?', metavar='FILENAME',
help='audio file to store recording to')
parser.add_argument(
'-t', '--subtype', type=str, help='sound file subtype (e.g. "PCM_24")')
args = parser.parse_args()
try:
import sounddevice as sd
import soundfile as sf
if args.list_devices:
print(sd.query_devices())
parser.exit()
if args.samplerate is None:
device_info = sd.query_devices(args.device, 'input')
# soundfile expects an int, sounddevice provides a float:
args.samplerate = int(device_info['default_samplerate'])
if args.filename is None:
args.filename = tempfile.mktemp(prefix='rec_unlimited_',
suffix='.wav', dir='')
queue = Queue()
def callback(indata, frames, time, status):
"""This is called (from a separate thread) for each audio block."""
if status:
print(status, flush=True)
queue.put(indata.copy())
# Make sure the file is opened before recording anything:
with sf.SoundFile(args.filename, mode='x', samplerate=args.samplerate,
channels=args.channels, subtype=args.subtype) as file:
with sd.InputStream(samplerate=args.samplerate, device=args.device,
channels=args.channels, callback=callback):
print("#" * 80)
print("press Ctrl+C to stop the recording")
print("#" * 80)
while True:
file.write(queue.get())
except KeyboardInterrupt:
parser.exit('\nRecording finished: ' + repr(args.filename))
except Exception as e:
parser.exit(type(e).__name__ + ': ' + str(e))