Realtime oscilloscope in 20 lines of Python, via soundcard & OpenCV

oscilloscope.py

import numpy as np
import cv2
import soundcard as sc        # Get it from https://github.com/bastibe/SoundCard
imWidth, imHeight = 1024, 512                       # screen size
def draw_wave(screen, mono_audio, xs, title="oscilloscope", gain=5):
    screen *= 0                                     # clear the screen
    ys = imHeight/2*(1 - np.clip( gain * mono_audio[0:len(xs)], -1, 1))  # the y-values of the waveform
    pts = np.array(list(zip(xs,ys))).astype(np.int) # pair up xs & ys
    cv2.polylines(screen,[pts],False,(0,255,0))     # connect points w/ lines
    cv2.imshow(title, screen)                       # show what we've got
default_mic = sc.default_microphone()
screen = np.zeros((imHeight,imWidth,3), dtype=np.uint8) # 3=color channels
xs = np.arange(imWidth).astype(np.int)                  # x values of pixels
while (1):                               # keep looping until someone stops this
    with default_mic.recorder(samplerate=44100) as mic:
        audio_data = mic.record(numframes=1024)  # get some audio from the mic
    draw_wave(screen, audio_data[:,0], xs)             # draw left channel
    key = cv2.waitKey(1) & 0xFF                        # keyboard input
    if ord('q') == key:                                # quit key
        break

The minus sign in the "1 - np.clip..." on line 7 is because in computer graphics, "up" is negative.

Note: Works on Mac, but soundcard lib yields a failed assertion on Linux / pulse audio: bastibe/SoundCard#29

I have a longer version with more controls for scaling, triggering adjustment, etc, but not in "20 lines" ;-)

Can I ask you your version, maybe if you can set a trigger level and having the trigger point ceneter, i mean, with a given pre-trigger?

@CrinSoft@ROmania-2023 - Python3: osc10l.py - DefaultMicrophone Oscilloscope in less than 10 lines of simple & clear Python code

@CrinSoft@ROmania-2023 - Python3: osc10l.py -#RO: OsciloscopeMicrofonImplicit in mai putin de 10 linii de cod Python simplu si clar

1 import sounddevice as sd # import SoundDevice lib (install lib with cmd: pip install sounddevice) #RO: importa librarie
2 import matplotlib.pyplot as plt # import PyPlot lib #RO: importa librarie
3 while True: # Ctrl+C in start window to stop this script! #RO: Apasa Ctrl+C in fer. de start sa opresti scriptul!
4 rec = sd.rec(int(44100*0.01),44100,1) # collect data from def_mic #RO: colectare date de la microfonul implicit
5 plt.plot(rec) # plot data #RO: deseneaza grafic datele
6 plt.axis('off') # clear graphic axes #RO: sterge axele graficului
7 plt.pause(0.01) # wait 0.01 sec before clear plot #RO: asteapta 0.01 sec inainte sa stergi graficul
8 plt.clf() # clear plot #RO: sterge graficul

if default mic is disabled, this script will run into error! #RO: daca microfonul nu e disponibil scriptul va da eroare!

@CrinSoft@ROmania-2023 - Python3: osc10l.py - DefaultMicrophone Oscilloscope in less than 10 lines of simple & clear Python code