#!/usr/bin/env python3

"""Show a text-mode spectrogram using live microphone data."""

import argparse

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(0)

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)

def callback(indata, frames, time, status):

if status:

text = ' ' + str(status) + ' '

print('\x1b[34;40m', text.center(args.columns, '#'),

'\x1b[0m', sep='')

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')

else:

print('no input')

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='')

break

except KeyboardInterrupt:

parser.exit('Interrupted by user')

except Exception as e:

parser.exit(type(e).__name__ + ': ' + str(e))