def create_filter(cls, definition, fs):
'''
creates a filter from a textual representation
'''
definition = definition.lower().strip()
if definition.startswith("lp:"):
try:
(_lp, f, q) = definition.split(":")
q = float(q)
except:
(_lp, f) = definition.split(":")
q = 0.707
f = parse_frequency(f)
return Biquad.low_pass(f, q, fs)
elif definition.startswith("hp:"):
try:
(_hp, f, q) = definition.split(":")
q = float(q)
except:
(_hp, f) = definition.split(":")
q = 0.707
f = parse_frequency(f)
return Biquad.high_pass(f, q, fs)
elif definition.startswith("eq:"):
try:
(_eq, f, q, dbgain) = definition.split(":")
q = float(q)
f = parse_frequency(f)
dbgain = parse_decibel(dbgain)
return Biquad.peaking_eq(f, q, dbgain, fs)
except:
return None
elif definition.startswith("vol:"):
try:
(_vol, db) = definition.split(":")
db = parse_decibel(db)
return Biquad.volume(db)
except:
return None
elif definition.startswith("pass"):
return Biquad.pass_filter()
elif definition == "mute" or definition == "null":
return Biquad.mute()
else:
print("unknown", definition)
return None
def cmd_tonecontrol(self):
if len(self.args.parameters) > 2:
filtertype = self.args.parameters[0].lower()
frequency = parse_frequency(self.args.parameters[1])
dbgain = parse_decibel(self.args.parameters[2])
else:
print(
"parameter missing, need type frequency db, e.g. ls 200Hz 3db")
sys.exit(1)
if frequency <= 0:
print("frequency {} invalid".format(frequency))
sys.exit(1)
if filtertype not in ["ls", "hs"]:
print("filter type {} unsupported".format(type))
sys.exit(1)
filterdef = "{}:{}:{}".format(filtertype, frequency, dbgain)
tonefilter = Biquad.create_filter(filterdef,
self.dsptk.get_samplerate())
if tonefilter is None:
print("can't handle filter {}".format(filterdef))
sys.exit(1)
if filtertype[0] == "l":
low = tonefilter
high = None
else:
low = None
high = tonefilter
try:
self.dsptk.set_tonecontrol_filters(low, high)
except Exception as e:
print(e)
sys.exit(1)
def create_filter(cls, definition, fs):
'''
creates a filter from a textual representation
'''
definition = definition.lower().strip()
if definition.startswith("lp:"):
try:
(_lp, f, q) = definition.split(":")
q = float(q)
except:
(_lp, f) = definition.split(":")
q = 0.707
f = parse_frequency(f)
return Biquad.low_pass(f, q, fs)
elif definition.startswith("hp:"):
try:
(_hp, f, q) = definition.split(":")
q = float(q)
except:
(_hp, f) = definition.split(":")
q = 0.707
f = parse_frequency(f)
return Biquad.high_pass(f, q, fs)
elif definition.startswith("eq:"):
try:
(_eq, f, q, dbgain) = definition.split(":")
q = float(q)
f = parse_frequency(f)
dbgain = parse_decibel(dbgain)
return Biquad.peaking_eq(f, q, dbgain, fs)
except:
logging.error("can't parse ea filter")
return None
elif definition.startswith("vol:"):
try:
(_vol, db) = definition.split(":")
db = parse_decibel(db)
return Biquad.volume(db)
except:
logging.error("can't parse vol filter")
return None
elif definition.startswith("coeff:"):
try:
coeffs = definition.split(":")
coeffs = coeffs[1:]
numc = []
for c in coeffs:
numc.append(float(c))
if len(numc) == 5:
return Biquad(1, numc[0], numc[1], numc[2],
numc[3], numc[4],
"biquad from coefficients")
elif len(numc) == 6:
return Biquad(numc[0], numc[1], numc[2], numc[3],
numc[4], numc[5],
"biquad from coefficients")
else:
logging.error("5 or 6 biquad coefficients expected")
except Exception as e:
logging.error("can't parse biquad filter (%s)", e)
return None
elif definition.startswith("pass"):
return Biquad.pass_filter()
elif definition == "mute" or definition == "null":
return Biquad.mute()
else:
logging.error("can't parse %s filter", definition)
return None