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mirror of https://github.com/radio95-rnt/rds95.git synced 2026-02-27 04:43:52 +01:00

add rt timeout, clean up code, add error checking for rdsencoder save, add rds eon af and remove stale values

This commit is contained in:
2025-04-05 13:48:51 +02:00
parent 5c84171497
commit 7b4706cf79
10 changed files with 159 additions and 109 deletions

View File

@@ -4,7 +4,7 @@ FFT = PLOT and True
import math
import io, os
if PLOT: import matplotlib.pyplot as plt
if FFT: import numpy as np # Import numpy for FFT
if FFT: import numpy as np
DATA_RATE = 1187.5
SIZE_RATIO = 2
@@ -16,33 +16,33 @@ if not sample_rate.is_integer(): raise ValueError("Need a even value")
# this is modified from ChristopheJacquet's pydemod
def rrcosfilter(NumSamples):
T_delta = 1/float(sample_rate)
sample_num = list(range(NumSamples))
h_rrc = [0.0] * NumSamples
SymbolPeriod = 1/(2*DATA_RATE)
T_delta = 1/float(sample_rate)
sample_num = list(range(NumSamples))
h_rrc = [0.0] * NumSamples
SymbolPeriod = 1/(2*DATA_RATE)
for x in sample_num:
t = (x-NumSamples/2)*T_delta
if t == 0.0:
h_rrc[x] = 1.0 - 1 + (4/math.pi)
elif t == SymbolPeriod/4:
h_rrc[x] = (1/math.sqrt(2))*(((1+2/math.pi)* \
(math.sin(math.pi/4))) + ((1-2/math.pi)*(math.cos(math.pi/4))))
elif t == -SymbolPeriod/4:
h_rrc[x] = (1/math.sqrt(2))*(((1+2/math.pi)* \
(math.sin(math.pi/4))) + ((1-2/math.pi)*(math.cos(math.pi/4))))
else:
h_rrc[x] = (4*(t/SymbolPeriod)*math.cos(math.pi*t*2/SymbolPeriod))/ \
(math.pi*t*(1-(4*t/SymbolPeriod)*(4*t/SymbolPeriod))/SymbolPeriod)
for x in sample_num:
t = (x-NumSamples/2)*T_delta
if t == 0.0:
h_rrc[x] = 1.0 - 1 + (4/math.pi)
elif t == SymbolPeriod/4:
h_rrc[x] = (1/math.sqrt(2))*(((1+2/math.pi)* \
(math.sin(math.pi/4))) + ((1-2/math.pi)*(math.cos(math.pi/4))))
elif t == -SymbolPeriod/4:
h_rrc[x] = (1/math.sqrt(2))*(((1+2/math.pi)* \
(math.sin(math.pi/4))) + ((1-2/math.pi)*(math.cos(math.pi/4))))
else:
h_rrc[x] = (4*(t/SymbolPeriod)*math.cos(math.pi*t*2/SymbolPeriod))/ \
(math.pi*t*(1-(4*t/SymbolPeriod)*(4*t/SymbolPeriod))/SymbolPeriod)
return h_rrc
return h_rrc
def convolve(a, b):
out = [0] * (len(a) + len(b) - 1)
for i in range(len(a)):
for j in range(len(b)):
out[i+j] += a[i] * b[j]
return out
out = [0] * (len(a) + len(b) - 1)
for i in range(len(a)):
for j in range(len(b)):
out[i+j] += a[i] * b[j]
return out
PATH = os.path.dirname(os.path.abspath(__file__))
@@ -63,61 +63,58 @@ outc.write(header)
outh.write(header)
def generate():
l = ratio // 2
l = ratio // 2
sample = [0.0] * (16*l)
sample[l] = 1
sample[2*l] = -1
sample = [0.0] * (16*l)
sample[l] = 1
sample[2*l] = -1
sf = rrcosfilter(l*16)
shapedSamples = convolve(sample, sf)
lowest = 0
lowest_idx = 0
highest = 0
highest_idx = 0
for i,j in enumerate(shapedSamples):
if j < lowest:
lowest = j
lowest_idx = i
if j > highest:
highest = j
highest_idx = i
middle = int((lowest_idx+highest_idx)/2)
sf = rrcosfilter(l*16)
shapedSamples = convolve(sample, sf)
out = shapedSamples[middle-int(ratio*SIZE_RATIO):middle+int(ratio*SIZE_RATIO)]
out = [2 * (i - min(out)) / (max(out) - min(out)) - 1 for i in out]
if max(out) > 1 or min(out) < -1: raise Exception("Clipped")
print(f"{len(out)=} {len(out)/sample_rate=} {(len(out)/sample_rate)/(1/DATA_RATE)=} {1/DATA_RATE=}")
lowest = 0
lowest_idx = 0
highest = 0
highest_idx = 0
for i,j in enumerate(shapedSamples):
if j < lowest:
lowest = j
lowest_idx = i
if j > highest:
highest = j
highest_idx = i
middle = int((lowest_idx+highest_idx)/2)
if PLOT:
# Plot the waveform
plt.plot(out, label="out")
plt.legend()
plt.grid(True)
plt.show()
out = shapedSamples[middle-int(ratio*SIZE_RATIO):middle+int(ratio*SIZE_RATIO)]
out = [2 * (i - min(out)) / (max(out) - min(out)) - 1 for i in out]
if max(out) > 1 or min(out) < -1: raise Exception("Clipped")
print(f"{len(out)=} {len(out)/sample_rate=} {(len(out)/sample_rate)/(1/DATA_RATE)=} {1/DATA_RATE=}")
if FFT:
# Compute the FFT of the waveform
N = len(out)
fft_out = np.fft.fft(out)
fft_freqs = np.fft.fftfreq(N, d=1/sample_rate)
if PLOT:
plt.plot(out, label="out")
plt.legend()
plt.grid(True)
plt.show()
# Plot the magnitude of the FFT
plt.figure(figsize=(10, 6))
plt.plot(fft_freqs[:N//2], np.abs(fft_out)[:N//2]) # Plot only the positive frequencies
plt.xlim(0,DATA_RATE*3)
plt.title("FFT of the waveform")
plt.xlabel("Frequency (Hz)")
plt.ylabel("Magnitude")
plt.grid(True)
plt.show()
if FFT:
N = len(out)
fft_out = np.fft.fft(out)
fft_freqs = np.fft.fftfreq(N, d=1/sample_rate)
outc.write(u"float waveform_biphase[{size}] = {{{values}}};\n\n".format(
values = u", ".join(map(str, out)),
size = len(out)))
plt.figure(figsize=(10, 6))
plt.plot(fft_freqs[:N//2], np.abs(fft_out)[:N//2])
plt.xlim(0,DATA_RATE*3)
plt.title("FFT of the waveform")
plt.xlabel("Frequency (Hz)")
plt.ylabel("Magnitude")
plt.grid(True)
plt.show()
outh.write(u"extern float waveform_biphase[{size}];\n".format(size=len(out)))
outc.write(u"float waveform_biphase[{size}] = {{{values}}};\n\n".format(
values = u", ".join(map(str, out)),
size = len(out)))
outh.write(u"extern float waveform_biphase[{size}];\n".format(size=len(out)))
generate()