Python script to convert generic REW eq files to pipewire native filters.

pyrewpw.py

#!/usr/bin/env python
import json
from pprint import pp
import argparse
import re

parser = argparse.ArgumentParser(
    description="Convert REW Generic EQ file to Pipewire configuration file."
)

parser.add_argument("input", help="Generic EQ .txt file from REW.")
args = parser.parse_args()

with open(args.input, "r") as f:
    data = [l.rstrip("\n") for l in f.readlines()]

def get_val(word,mlist):
    try:
        return mlist[mlist.index(word)+1]
    except ValueError:
        return False

eq_nodes = []
fildic = {'LS':'bq_lowshelf','HS':'bq_highshelf','PK':'bq_peaking','LSQ':'bq_lowshelf','HSQ':'bq_highshelf','LPQ':'bq_lowpass','HPQ':'bq_highpass'}
i = 0

# generate node graphs                                                                                                                                                                                    
for line in data:                                                                                                                                                                                         
    e = list(filter(None,re.split(" ", line)))                                                                                                                                                            
    if ("Filter" in line) and ("ON" in line):                                                                                                                                                             
        i = i + 1                                                                                                                                                                                         
        fc = get_val("Fc",e)                                                                                                                                                                              
        gain = get_val("Gain",e)                                                                                                                                                                          
        ft = get_val("ON",e)                                                                                                                                                                              
        q = get_val("Q",e)                                                                                                                                                                                
        node_dic = {'type':'builtin','name':'eq_band_'+str(i),'label':fildic[ft]}                                                                                                                         
        eq_control = {'Freq':int(fc)}                                                                                                                                                                     
        eq_control['Q'] = float(q)                                                                                                                                                                        
        eq_control['Gain'] = float(gain)                                                                                                                                                                  
        node_dic['control'] = eq_control                                                                                                                                                                  
        eq_nodes.append(node_dic)                                                                                                                                                                         
                                                                                                                                                                                                          
    elif ("Preamp:" in line):                                                                                                                                                                             
        preamp = float(get_val("Preamp:",e))                                                                                                                                                              
        node_dic = {'type':'builtin','name':'pre_gain','label':'bq_highshelf'}                                                                                                                            
        eq_control = {'Freq':0,'Q':1.0,'Gain':preamp}                                                                                                                                                     
        node_dic['control'] = eq_control                                                                                                                                                                  
        eq_nodes.append(node_dic)                                                                                                                                                                         
                                                                                                                                                                                                          
# generate node links                                                                                                                                                                                     
node_links = []                                                                                                                                                                                           
i=0                                                                                                                                                                                                       
while i < len(eq_nodes)-1:
    d = {}
    d['output'] = eq_nodes[i]['name']+':Out'
    d['input'] = eq_nodes[i+1]['name']+':In'
    node_links.append(d)
    i = i +1

# 
filter_graph = {'nodes':eq_nodes,'links':node_links}

args = {
        'node.description': 'EqualizerSink',
        'media.name': 'EqualizerSink',
        'filter.graph':filter_graph,
        'audio.channles': 2,
        'audio.position':['FL','FR'],
        'capture.props':{'node.name':'effect_input.EQ','media.class':'Audio/Sink'},
        'playback.props':{'node.name':'effect_output.EQ','node.passive':False}
        }

context_modules = [{'name':'libpipewire-module-filter-chain','args':args}]

pw_conf = {'context.modules':context_modules}
print(json.dumps(pw_conf,indent=2))