dotfiles/.config/polybar/scripts/modules/cava.py

#!/usr/bin/python3
import sys
import time
import struct
import os.path
import subprocess
import configparser
from collections import defaultdict

##################################################
# Config

# Decide if the output should go to STDOUT or a fifo buffer
PRINT_TO_STDOUT = False

# Display no output if all bars are at level 0
HIDE_WHEN_EMPTY = True

# Separator Character between bars
# Examples: https://www.compart.com/en/unicode/category/Zs
SEPARATOR = ''

CONFIG_PATH = os.path.join(os.sep, "tmp","cava_polybar.config")
RAW_PIPE_OUT = os.path.join(os.sep, "tmp","cava_polybar_output.fifo")

# Data from the cava config
RAW_PIPE_IN = os.path.join(os.sep, "tmp","cava_polybar_input.fifo")
OUTPUT_FILE = os.path.join(os.sep, "tmp","cava_polybar.out")
BARS_NUMBER = 8
OUTPUT_BIT_FORMAT = "8bit"

# Values range from 0 to 100
# Distribute 9 states over this value range
#  ▁▂▃▄▅▆▇█

bar_factor = 100 / 10
bar_characters = dict([
    (0, '▁'),
    (bar_factor * 1, '▁'),
    (bar_factor * 2, '▂'),
    (bar_factor * 3, '▃'),
    (bar_factor * 4, '▄'),
    (bar_factor * 5, '▅'),
    (bar_factor * 6, '▆'),
    (bar_factor * 7, '▇'),
    (bar_factor * 8, '█')
])


##################################################
# Code begins here

bytetype, bytesize, bytenorm = ("H", 2, 65535) if (OUTPUT_BIT_FORMAT == "16bit") else ("B", 1, 255)

def output(value, fifo):
    if (PRINT_TO_STDOUT):
        print(value, end="")
    else:
        fifo.write(value)


def valToBar(value):    
    for bar_threshold in bar_characters:
        if(value < bar_threshold):
            return bar_characters[bar_threshold]

    return bar_characters[bar_factor * 8]

def test():
    print("")

    print("Bar Characters:")
    for bar_threshold in bar_characters:
        print('{:02.2f}: {}'.format(bar_threshold,bar_characters[bar_threshold]))

    print("")

    print("Value Test:")
    for i in range(101):
        print('{:03d}: {}'.format(i,valToBar(i)))

def createCavaConfig():
    # Exit if file is already there
    #if (os.path.isfile(CONFIG_PATH)):
    #    return

    config = configparser.ConfigParser()

    config.add_section('general')
    config.set('general', 'bars', str(BARS_NUMBER))
    #config.set('general', 'overshoot', str(0))

    config.add_section('output')
    config.set('output', 'method', 'raw')
    #config.set('output', 'channels', 'mono')
    #config.set('output', 'mono_option', 'average')
    config.set('output', 'raw_target', RAW_PIPE_IN)
    config.set('output', 'bit_format', OUTPUT_BIT_FORMAT)

    #config.add_section('smoothing')
    #config.set('smoothing', 'integral', '0')

    with open(CONFIG_PATH, 'w') as configfile:
        config.write(configfile)

def run():
    createCavaConfig()  
    process = subprocess.Popen(["cava", "-p", CONFIG_PATH])

    exit_code = 0

    fifo_out = None
    if (not PRINT_TO_STDOUT):
        if os.path.exists(RAW_PIPE_OUT):
            os.remove(RAW_PIPE_OUT)
        os.mkfifo(RAW_PIPE_OUT) 
        print("Output can be found in " + RAW_PIPE_OUT)
        fifo_out = open(RAW_PIPE_OUT, "w")
    fifo_in = open(RAW_PIPE_IN, "rb")


    try:
        convert(fifo_in, fifo_out)
    except KeyboardInterrupt:
        exit_code = 1
    finally:
        if (not PRINT_TO_STDOUT):
            fifo_out.close()
            os.remove(RAW_PIPE_OUT)

        fifo_in.close()
        sys.exit(exit_code)

def convert(fifo_in, fifo_out):
    chunk = bytesize * BARS_NUMBER
    fmt = bytetype * BARS_NUMBER

    emptyOutputs = 0
    tstring = ""

    while True:
        rawData = fifo_in.read(chunk)
        if len(rawData) < chunk:
            break

        empty = True
        tstring = ""

        for i in struct.unpack(fmt, rawData):

            value = int(i / bytenorm * 100)

            tstring += valToBar(value) + SEPARATOR

            if (value != 0):
                empty = False

        if (empty and HIDE_WHEN_EMPTY):
            emptyOutputs += 1
            if (emptyOutputs > 5):
                output("        " + '\n', fifo_out)
        else:
            emptyOutputs = 0
            output(tstring + '\n', fifo_out)


if __name__ == "__main__":
    for arg in sys.argv:
        if (arg == "h" or arg == "help"):
            print("")
            print("cava polybar parse script")
            print("Converts cava raw values into characters and outputs to STDOUT or a fifo buffer")
            print("")
            print("Adjust thresholds, characters and config directly in the script")
            print("If the config file at 'CONFIG_PATH' (/tmp/cava_polybar.config) is messed up, simply delet it")
            print("")
            print("Arguments:")
            print("<none>  ... Execute normally")
            print("t, test ... Run test mode (stdout only)")
            print("h, help ... Show this help message and exit (stdout only)")
            print("")
            sys.exit() 

        if (arg == "t" or arg == "test"):
            test()
            sys.exit() 

    run()