fileradio.py

@@ -6,7 +6,7 @@ import os
 
 
 class FileRadio(Streamer):
-    REST_PATH = "sample"
+    REST_PATH = 'sample'
 
     def __init__(self, path):
         super().__init__()
@@ -17,26 +17,22 @@ class FileRadio(Streamer):
     def _stream_thread(self):
         self.playback = subprocess.Popen(
             [
-                "/usr/bin/ffmpeg",
-                "-re",          # http://trac.ffmpeg.org/wiki/StreamingGuide#The-reflag
-                "-stream_loop", # Loop the stream -
-                "-1",           # ...indefinitely
-                "-i",
-                self.path,
-                "-c",
-                "copy",
-                "-f",
-                "rtsp",
-                self.stream_address("localhost"),
+                '/usr/bin/ffmpeg',
+                '-re',                      # http://trac.ffmpeg.org/wiki/StreamingGuide#The-reflag
+                '-stream_loop', '-1',       # Loop the stream indefinitely
+                '-i', self.path,
+                '-c', 'copy',
+                '-f', 'rtsp',
+                self.stream_address('localhost')
             ],
             stdin=subprocess.PIPE,
             stdout=subprocess.DEVNULL,
-            stderr=subprocess.DEVNULL,
+            stderr=subprocess.DEVNULL
         )
 
         while self.run:
             if not is_alive(self.playback):
-                print("Playback failed, aborting stream.", file=sys.stderr)
+                print('Playback failed, aborting stream.', file=sys.stderr)
                 break
             time.sleep(0.1)
 
@@ -47,8 +43,9 @@ class FileRadio(Streamer):
         self.playback = None
 
 
-if __name__ == "__main__":
-    fr = FileRadio("./data/sampleaudio/taunt.mp3")
+
+if __name__ == '__main__':
+    fr = FileRadio('./data/sampleaudio/taunt.mp3')
     fr.start_stream()
 
     while True:

filters.py

@@ -10,159 +10,156 @@
 import numpy, math, sys, time
 from numpy import fft
 
-
 def impulse(mask):
-    """Convert frequency domain mask to time-domain"""
-    # Negative side, a mirror of positive side
-    negatives = mask[1:-1]
-    negatives.reverse()
-    mask = mask + negatives
-    fft_length = len(mask)
+	''' Convert frequency domain mask to time-domain '''
+	# Negative side, a mirror of positive side
+	negatives = mask[1:-1]
+	negatives.reverse()
+	mask = mask + negatives
+	fft_length = len(mask)
 
-    # Convert FFT filter mask to FIR coefficients
-    impulse_response = fft.ifft(mask).real.tolist()
+	# Convert FFT filter mask to FIR coefficients
+	impulse_response = fft.ifft(mask).real.tolist()
 
-    # swap left and right sides
-    left = impulse_response[: fft_length // 2]
-    right = impulse_response[fft_length // 2 :]
-    impulse_response = right + left
+	# swap left and right sides
+	left = impulse_response[:fft_length // 2]
+	right = impulse_response[fft_length // 2:]
+	impulse_response = right + left
 
-    return impulse_response
+	return impulse_response
 
 
 def lo_mask(sample_rate, tap_count, freq, dboct):
-    """Create a freq domain mask for a lowpass filter"""
-    order = dboct / 6
-    max_freq = sample_rate / 2.0
-    f2s = max_freq / (tap_count / 2.0)
-    # Convert freq to filter step unit
-    freq /= f2s
-    l = tap_count // 2
-    mask = []
-    for f in range(0, l + 1):
-        H = 1.0 / (1 + (f / freq) ** (2 * order)) ** 0.5
-        mask.append(H)
-    return mask
+	''' Create a freq domain mask for a lowpass filter '''
+	order = dboct / 6
+	max_freq = sample_rate / 2.0
+	f2s = max_freq / (tap_count / 2.0)
+	# Convert freq to filter step unit
+	freq /= f2s
+	l = tap_count // 2
+	mask = []
+	for f in range(0, l+1):
+		H = 1.0 / ( 1 + (f / freq) ** (2 * order) ) ** 0.5
+		mask.append(H)
+	return mask
 
 
 def hi_mask(sample_rate, tap_count, freq, dboct):
-    """Create a freq domain mask for a highpass filter"""
-    order = dboct / 6
-    max_freq = sample_rate / 2.0
-    f2s = max_freq / (tap_count / 2.0)
-    # Convert freq frequency to filter step unit
-    freq /= f2s
-    l = tap_count // 2
-    mask = []
-    for f in range(0, l + 1):
-        H = 1.0 / (1 + (freq / (f + 0.0001)) ** (2 * order)) ** 0.5
-        mask.append(H)
-    return mask
+	''' Create a freq domain mask for a highpass filter '''
+	order = dboct / 6
+	max_freq = sample_rate / 2.0
+	f2s = max_freq / (tap_count / 2.0)
+	# Convert freq frequency to filter step unit
+	freq /= f2s
+	l = tap_count // 2
+	mask = []
+	for f in range(0, l+1):
+		H = 1.0 / ( 1 + (freq / (f + 0.0001)) ** (2 * order) ) ** 0.5
+		mask.append(H)
+	return mask
 
 
 def combine_masks(mask1, mask2):
-    """Combine two filter masks"""
-    assert len(mask1) == len(mask2)
-    return [mask1[i] * mask2[i] for i in range(0, len(mask1))]
+	''' Combine two filter masks '''
+	assert len(mask1) == len(mask2)
+	return [ mask1[i] * mask2[i] for i in range(0, len(mask1)) ]
 
 
 def taps(sample_rate, freq, dboct, is_highpass):
-    cutoff_octaves = 60 / dboct
+	cutoff_octaves = 60 / dboct
 
-    if is_highpass:
-        cutoff = freq / 2**cutoff_octaves
-    else:
-        cutoff = freq * 2**cutoff_octaves
-        cutoff = min(cutoff, sample_rate / 2)
+	if is_highpass:
+		cutoff = freq / 2 ** cutoff_octaves
+	else:
+		cutoff = freq * 2 ** cutoff_octaves
+		cutoff = min(cutoff, sample_rate / 2)
 
-    transition_band = abs(freq - cutoff)
-    Bt = transition_band / sample_rate
-    taps = int(60 / (22 * Bt))
-    # print("Freq=%f,%f number of taps: %d" % (freq, cutoff, taps), file=sys.stderr)
-    return taps
+	transition_band = abs(freq - cutoff)
+	Bt = transition_band / sample_rate
+	taps = int(60 / (22 * Bt))
+	# print("Freq=%f,%f number of taps: %d" % (freq, cutoff, taps), file=sys.stderr)
+	return taps
 
 
 class filter:
-    def __init__(self, sample_rate, cutoff):
-        raise "Abstract"
+	def __init__(self, sample_rate, cutoff):
+		raise "Abstract"
 
-    def feed(self, original):
-        unfiltered = numpy.concatenate((self.buf, original))
-        self.buf = unfiltered[-len(self.coefs) :]
-        filtered = numpy.convolve(unfiltered, self.coefs, mode="valid")
-        assert len(filtered) == len(original) + 1
-        return filtered[1:]
+	def feed(self, original):
+		unfiltered = numpy.concatenate((self.buf, original))
+		self.buf = unfiltered[-len(self.coefs):]
+		filtered = numpy.convolve(unfiltered, self.coefs, mode='valid')
+		assert len(filtered) == len(original) + 1
+		return filtered[1:]
 
 
 class low_pass(filter):
-    def __init__(self, sample_rate, f, dbo):
-        tap_count = taps(sample_rate, f, dbo, False)
-        mask = lo_mask(sample_rate, tap_count, f, dbo)
-        self.coefs = impulse(mask)
-        self.buf = [0 for n in self.coefs]
+	def __init__(self, sample_rate, f, dbo):
+		tap_count = taps(sample_rate, f, dbo, False)
+		mask = lo_mask(sample_rate, tap_count, f, dbo)
+		self.coefs = impulse(mask)
+		self.buf = [ 0 for n in self.coefs ]
 
 
 class high_pass(filter):
-    def __init__(self, sample_rate, f, dbo):
-        tap_count = taps(sample_rate, f, dbo, True)
-        mask = hi_mask(sample_rate, tap_count, f, dbo)
-        self.coefs = impulse(mask)
-        self.buf = [0 for n in self.coefs]
+	def __init__(self, sample_rate, f, dbo):
+		tap_count = taps(sample_rate, f, dbo, True)
+		mask = hi_mask(sample_rate, tap_count, f, dbo)
+		self.coefs = impulse(mask)
+		self.buf = [ 0 for n in self.coefs ]
 
 
 class band_pass(filter):
-    def __init__(self, sample_rate, lo, hi, dbo):
-        tap_count = max(
-            taps(sample_rate, lo, dbo, True), taps(sample_rate, hi, dbo, False)
-        )
-        lomask = lo_mask(sample_rate, tap_count, hi, dbo)
-        himask = hi_mask(sample_rate, tap_count, lo, dbo)
-        mask = combine_masks(lomask, himask)
-        self.coefs = impulse(mask)
-        self.buf = [0 for n in self.coefs]
+	def __init__(self, sample_rate, lo, hi, dbo):
+		tap_count = max(taps(sample_rate, lo, dbo, True),
+				taps(sample_rate, hi, dbo, False))
+		lomask = lo_mask(sample_rate, tap_count, hi, dbo)
+		himask = hi_mask(sample_rate, tap_count, lo, dbo)
+		mask = combine_masks(lomask, himask)
+		self.coefs = impulse(mask)
+		self.buf = [ 0 for n in self.coefs ]
 
 
 class deemphasis(filter):
-    def __init__(self, sample_rate, us, hi, final_dbo):
-        # us = RC constant of the hypothetical deemphasis filter
-        us /= 1000000
-        # 0..lo is not deemphasized
-        lo = 1.0 / (2 * math.pi * us)
-        # attenuation from lo to hi should be 10dB
-        octaves = math.log(hi / lo) / math.log(2)
-        # slope in dB/octave of deemphasis filter
-        dedbo = 10 / octaves
+	def __init__(self, sample_rate, us, hi, final_dbo):
+		# us = RC constant of the hypothetical deemphasis filter
+		us /= 1000000
+		# 0..lo is not deemphasized
+		lo = 1.0 / (2 * math.pi * us)
+		# attenuation from lo to hi should be 10dB
+		octaves = math.log(hi / lo) / math.log(2)
+		# slope in dB/octave of deemphasis filter
+		dedbo = 10 / octaves
 
-        tap_count = max(
-            taps(sample_rate, lo, dedbo, False), taps(sample_rate, hi, final_dbo, False)
-        )
+		tap_count = max(taps(sample_rate, lo, dedbo, False),
+				taps(sample_rate, hi, final_dbo, False))
 
-        # Calculate deemphasis filter
-        demask = lo_mask(sample_rate, tap_count, lo, dedbo)
-        # Calculate low-pass filter after deemphasis
-        fmask = lo_mask(sample_rate, tap_count, hi, final_dbo)
+		# Calculate deemphasis filter
+		demask = lo_mask(sample_rate, tap_count, lo, dedbo)
+		# Calculate low-pass filter after deemphasis
+		fmask = lo_mask(sample_rate, tap_count, hi, final_dbo)
 
-        mask = combine_masks(demask, fmask)
-        self.coefs = impulse(mask)
-        self.buf = [0 for n in self.coefs]
+		mask = combine_masks(demask, fmask)
+		self.coefs = impulse(mask)
+		self.buf = [ 0 for n in self.coefs ]
 
 
 class decimator(filter):
-    def __init__(self, factor):
-        self.buf2 = []
-        self.factor = int(factor)
+	def __init__(self, factor):
+		self.buf2 = []
+		self.factor = int(factor)
 
-    def feed(self, original):
-        original = numpy.concatenate((self.buf2, original))
+	def feed(self, original):
+		original = numpy.concatenate((self.buf2, original))
 
-        # Gets the last n-th sample of every n (n = factor)
-        # If e.g. gets 12 samples, gets s[4] and s[9], and
-        # stoves s[10:] to the next round
-        """
+		# Gets the last n-th sample of every n (n = factor)
+		# If e.g. gets 12 samples, gets s[4] and s[9], and
+		# stoves s[10:] to the next round
+		'''
 		decimated = [ original[ self.factor * i + self.factor - 1 ] \
 			for i in range(0, len(original) // self.factor) ]
-		"""
-        decimated = original[(self.factor - 1) :: self.factor]
-        self.buf2 = original[: -len(original) % self.factor]
+		'''
+		decimated = original[(self.factor - 1)::self.factor]
+		self.buf2 = original[:-len(original) % self.factor]
 
-        return decimated
+		return decimated

fm_demod.py

@@ -19,24 +19,12 @@ from formats import FORMATS
 
 
 parser = argparse.ArgumentParser()
-parser.add_argument(
-    "-v", "--verbose", help="Print additional informational output", action="store_true"
-)
-parser.add_argument(
-    "-f",
-    "--format",
-    choices=list(FORMATS.keys()),
-    help="Input sample format",
-    required=True,
-)
-parser.add_argument(
-    "-s", "--sample-rate", metavar="rate", help="Source sample rate (Hz)", required=True
-)
-parser.add_argument(
-    "-d", "--demod-rate", metavar="rate", help="Output sample rate (Hz)", required=True
-)
+parser.add_argument('-v', '--verbose', help='Print additional informational output', action='store_true')
+parser.add_argument('-f', '--format', choices=list(FORMATS.keys()), help='Input sample format', required=True)
+parser.add_argument('-s', '--sample-rate', metavar='rate', help='Source sample rate (Hz)', required=True)
+parser.add_argument('-d', '--demod-rate', metavar='rate', help='Output sample rate (Hz)', required=True)
 # TODO JMT: Output to file
-# parser.add_argument('-o', metavar='file', help='Specify an output file for demodulated audio. Omit for stdout or use \'-\'.')
+#parser.add_argument('-o', metavar='file', help='Specify an output file for demodulated audio. Omit for stdout or use \'-\'.')
 args = parser.parse_args()
 
 INPUT_RATE = int(prefixed.Float(args.sample_rate))
@@ -44,19 +32,16 @@ OUTPUT_RATE = int(prefixed.Float(args.demod_rate))
 DECIMATION = INPUT_RATE / OUTPUT_RATE
 
 if DECIMATION != math.floor(DECIMATION):
-    print(
-        f"The output rate must be an integer divisor of the input rate: {INPUT_RATE}/{OUTPUT_RATE} = {DECIMATION}",
-        file=sys.stderr,
-    )
-    sys.exit(1)
+	print(f'The output rate must be an integer divisor of the input rate: {INPUT_RATE}/{OUTPUT_RATE} = {DECIMATION}', file=sys.stderr)
+	sys.exit(1)
 
 FORMAT = FORMATS[args.format].numpy
 DT = np.dtype(FORMAT)
 BYTES_PER_SAMPLE = 2 * DT.itemsize
 
-MAX_DEVIATION = 200000.0  # Hz
-FM_BANDWIDTH = 15000  # Hz
-STEREO_CARRIER = 38000  # Hz
+MAX_DEVIATION = 200000.0 # Hz
+FM_BANDWIDTH = 15000 # Hz
+STEREO_CARRIER = 38000 # Hz
 DEVIATION_X_SIGNAL = 0.999 / (math.pi * MAX_DEVIATION / (INPUT_RATE / 2))
 
 pll = math.pi - random.random() * 2 * math.pi
@@ -78,138 +63,137 @@ decimate2 = filters.decimator(DECIMATION)
 lo_r = filters.deemphasis(INPUT_RATE, 75, FM_BANDWIDTH, 120)
 
 # Band-pass filter for stereo (L-R) modulated audio
-hi = filters.band_pass(
-    INPUT_RATE, STEREO_CARRIER - FM_BANDWIDTH, STEREO_CARRIER + FM_BANDWIDTH, 120
-)
+hi = filters.band_pass(INPUT_RATE,
+	STEREO_CARRIER - FM_BANDWIDTH, STEREO_CARRIER + FM_BANDWIDTH, 120)
 
 # Filter to extract pilot signal
-pilot = filters.band_pass(
-    INPUT_RATE, STEREO_CARRIER / 2 - 100, STEREO_CARRIER / 2 + 100, 120
-)
+pilot = filters.band_pass(INPUT_RATE,
+	STEREO_CARRIER / 2 - 100, STEREO_CARRIER / 2 + 100, 120)
 
 last_angle = 0.0
-remaining_data = b""
+remaining_data = b''
 
 while True:
-    # Ingest 0.1s worth of data
-    data = sys.stdin.buffer.read((INPUT_RATE * BYTES_PER_SAMPLE) // 10)
-    if not data:
-        break
-    # TODO JMT: Something about this is broken for BYTES_PER_SAMPLE > 1
-    # data = remaining_data + data
+	# Ingest 0.1s worth of data
+	data = sys.stdin.buffer.read((INPUT_RATE * BYTES_PER_SAMPLE) // 10)
+	if not data:
+		break
+	# TODO JMT: Something about this is broken for BYTES_PER_SAMPLE > 1
+	#data = remaining_data + data
 
-    if len(data) < 2 * BYTES_PER_SAMPLE:
-        remaining_data = data
-        continue
+	if len(data) < 2 * BYTES_PER_SAMPLE:
+		remaining_data = data
+		continue
 
-    # Save one sample to next batch, and the odd byte if exists
-    if len(data) % 2 == 1:
-        print("Odd byte, that's odd", file=sys.stderr)
-        remaining_data = data[-3:]
-        data = data[:-1]
-    else:
-        remaining_data = data[-2:]
+	# Save one sample to next batch, and the odd byte if exists
+	if len(data) % 2 == 1:
+		print("Odd byte, that's odd", file=sys.stderr)
+		remaining_data = data[-3:]
+		data = data[:-1]
+	else:
+		remaining_data = data[-2:]
 
-    samples = len(data) // BYTES_PER_SAMPLE
+	samples = len(data) // BYTES_PER_SAMPLE
 
-    # Find angle (phase) of I/Q pairs
-    iqdata = np.frombuffer(data, dtype=FORMAT)
+	# Find angle (phase) of I/Q pairs
+	iqdata = np.frombuffer(data, dtype=FORMAT)
 
-    if args.verbose:
-        print(iqdata.dtype, iqdata.shape, iqdata, file=sys.stderr)
+	if args.verbose:
+		print(iqdata.dtype, iqdata.shape, iqdata, file=sys.stderr)
 
-    if np.issubdtype(FORMAT, np.integer):
-        iinfo = np.iinfo(FORMAT)
-        if np.issubdtype(FORMAT, np.unsignedinteger):
-            iqdata = iqdata - (iinfo.max / 2.0)
-            iqdata = iqdata / (iinfo.max / 2.0)
-        else:
-            iqdata = iqdata / np.float64(iinfo.max)
-    else:
-        iqdata = iqdata.astype(np.float64)
+	if np.issubdtype(FORMAT, np.integer):
+		iinfo = np.iinfo(FORMAT)
+		if np.issubdtype(FORMAT, np.unsignedinteger):
+			iqdata = iqdata - (iinfo.max / 2.0)
+			iqdata = iqdata / (iinfo.max / 2.0)
+		else:
+			iqdata = iqdata / np.float64(iinfo.max)
+	else:
+		iqdata = iqdata.astype(np.float64)
 
-    if args.verbose:
-        print(iqdata.dtype, iqdata.shape, iqdata, file=sys.stderr)
+	if args.verbose:
+		print(iqdata.dtype, iqdata.shape, iqdata, file=sys.stderr)
 
-    iqdata = iqdata.view(complex)
-    angles = np.angle(iqdata)
+	iqdata = iqdata.view(complex)
+	angles = np.angle(iqdata)
 
-    # Determine phase rotation between samples
-    rotations = np.ediff1d(angles)
+	# Determine phase rotation between samples
+	rotations = np.ediff1d(angles)
 
-    # Wrap rotations >= +/-180º
-    rotations = (rotations + np.pi) % (2 * np.pi) - np.pi
+	# Wrap rotations >= +/-180º
+	rotations = (rotations + np.pi) % (2 * np.pi) - np.pi
 
-    # Convert rotations to baseband signal
-    output_raw = np.multiply(rotations, DEVIATION_X_SIGNAL)
-    output_raw = np.clip(output_raw, -0.999, +0.999)
+	# Convert rotations to baseband signal
+	output_raw = np.multiply(rotations, DEVIATION_X_SIGNAL)
+	output_raw = np.clip(output_raw, -0.999, +0.999)
 
-    # At this point, output_raw contains two audio signals:
-    # L+R (mono-compatible) and L-R (joint-stereo) modulated in AM-SC,
-    # carrier 38kHz
+	# At this point, output_raw contains two audio signals:
+	# L+R (mono-compatible) and L-R (joint-stereo) modulated in AM-SC,
+	# carrier 38kHz
 
-    # Downsample and low-pass L+R (mono) signal
-    output_mono = lo.feed(output_raw)
-    output_mono = decimate1.feed(output_mono)
+	# Downsample and low-pass L+R (mono) signal
+	output_mono = lo.feed(output_raw)
+	output_mono = decimate1.feed(output_mono)
 
-    # Filter pilot tone
-    detected_pilot = pilot.feed(output_raw)
+	# Filter pilot tone
+	detected_pilot = pilot.feed(output_raw)
 
-    # Separate ultrasonic L-R signal by high-pass filtering
-    output_jstereo_mod = hi.feed(output_raw)
-    output_jstereo = []
+	# Separate ultrasonic L-R signal by high-pass filtering
+	output_jstereo_mod = hi.feed(output_raw)
+	output_jstereo = []
 
-    # Demodulate L-R, which is AM-SC with 53kHz carrier
-    for n in range(0, len(output_jstereo_mod)):
-        # Advance carrier
-        pll = (pll + tau * STEREO_CARRIER / INPUT_RATE) % tau
-        # Standard demodulation
-        output_jstereo.append(math.cos(pll) * output_jstereo_mod[n])
+	# Demodulate L-R, which is AM-SC with 53kHz carrier
+	for n in range(0, len(output_jstereo_mod)):
+		# Advance carrier
+		pll = (pll + tau * STEREO_CARRIER / INPUT_RATE) % tau
+		# Standard demodulation
+		output_jstereo.append(math.cos(pll) * output_jstereo_mod[n])
 
-        # Detect pilot zero-crossing
-        cur_pilot = detected_pilot[n]
-        zero_crossed = (cur_pilot * last_pilot) <= 0
-        last_pilot = cur_pilot
-        if not zero_crossed:
-            continue
+		# Detect pilot zero-crossing
+		cur_pilot = detected_pilot[n]
+		zero_crossed = (cur_pilot * last_pilot) <= 0
+		last_pilot = cur_pilot
+		if not zero_crossed:
+			continue
 
-        # When pilot is at 90º or 270º, carrier should be around 180º
-        ideal = math.pi
-        deviation = pll - ideal
-        if deviation > math.pi:
-            deviation -= tau
-        deviation_avg = 0.99 * deviation_avg + 0.01 * deviation
-        rotation = deviation_avg - last_deviation_avg
-        last_deviation_avg = deviation_avg
+		# When pilot is at 90º or 270º, carrier should be around 180º
+		ideal = math.pi
+		deviation = pll - ideal
+		if deviation > math.pi:
+			deviation -= tau
+		deviation_avg = 0.99 * deviation_avg + 0.01 * deviation
+		rotation = deviation_avg - last_deviation_avg
+		last_deviation_avg = deviation_avg
 
-        if abs(deviation_avg) > math.pi / 8:
-            # big phase deviation, reset PLL
-            pll = ideal
-            pll = (pll + tau * STEREO_CARRIER / INPUT_RATE) % tau
-            deviation_avg = 0.0
-            last_deviation_avg = 0.0
+		if abs(deviation_avg) > math.pi / 8:
+			# big phase deviation, reset PLL
+			pll = ideal
+			pll = (pll + tau * STEREO_CARRIER / INPUT_RATE) % tau
+			deviation_avg = 0.0
+			last_deviation_avg = 0.0
 
-        # Translate rotation to frequency deviation
-        STEREO_CARRIER /= 1 + (rotation * 1.05) / tau
+		# Translate rotation to frequency deviation
+		STEREO_CARRIER /= (1 + (rotation * 1.05) / tau)
 
-    # Downsample, Low-pass/deemphasis demodulated L-R
-    output_jstereo = lo_r.feed(output_jstereo)
-    output_jstereo = decimate2.feed(output_jstereo)
 
-    assert len(output_jstereo) == len(output_mono)
+	# Downsample, Low-pass/deemphasis demodulated L-R
+	output_jstereo = lo_r.feed(output_jstereo)
+	output_jstereo = decimate2.feed(output_jstereo)
 
-    # Scale to 16-bit and divide by 2 for channel sum
-    output_mono = np.multiply(output_mono, 32767 / 2.0)
-    output_jstereo = np.multiply(output_jstereo, 32767 / 2.0)
+	assert len(output_jstereo) == len(output_mono)
 
-    # Output stereo by adding or subtracting joint-stereo to mono
-    output_left = output_mono + output_jstereo
-    output_right = output_mono - output_jstereo
+	# Scale to 16-bit and divide by 2 for channel sum
+	output_mono = np.multiply(output_mono, 32767 / 2.0)
+	output_jstereo = np.multiply(output_jstereo, 32767 / 2.0)
 
-    # Interleave L and R samples using np trickery
-    output = np.empty(len(output_mono) * 2, dtype=output_mono.dtype)
-    output[0::2] = output_left
-    output[1::2] = output_right
-    output = output.astype(int)
+	# Output stereo by adding or subtracting joint-stereo to mono
+	output_left = output_mono + output_jstereo
+	output_right = output_mono - output_jstereo
 
-    sys.stdout.buffer.write(struct.pack("<%dh" % len(output), *output))
+	# Interleave L and R samples using np trickery
+	output = np.empty(len(output_mono) * 2, dtype=output_mono.dtype)
+	output[0::2] = output_left
+	output[1::2] = output_right
+	output = output.astype(int)
+
+	sys.stdout.buffer.write(struct.pack('<%dh' % len(output), *output))

formats.py

@@ -2,7 +2,6 @@ import numpy as np
 from SoapySDR import *
 from dataclasses import dataclass
 
-
 @dataclass
 class FormatSpec:
     name: str
@@ -10,10 +9,9 @@ class FormatSpec:
     numpy: np.dtype
     packing: str
 
-
 FORMATS = {
-    "CU8": FormatSpec("CU8", SOAPY_SDR_CU8, np.uint8, "=%dB"),
-    "CS8": FormatSpec("CS8", SOAPY_SDR_CS8, np.int8, "=%db"),
-    "CS16": FormatSpec("CS16", SOAPY_SDR_CS16, np.int16, "=%dh"),
-    "CF32": FormatSpec("CF32", SOAPY_SDR_CF32, np.float32, "=%df"),
-}
+    'CU8': FormatSpec('CU8', SOAPY_SDR_CU8, np.uint8, '=%dB'),
+    'CS8': FormatSpec('CS8', SOAPY_SDR_CS8, np.int8, '=%db'),
+    'CS16': FormatSpec('CS16', SOAPY_SDR_CS16, np.int16, '=%dh'),
+    'CF32': FormatSpec('CF32', SOAPY_SDR_CF32, np.float32, '=%df'),
+}

microservice.py

@@ -17,8 +17,7 @@ swag = Swagger(app)
 
 radios = {}
 
-
-@app.route("/report")
+@app.route('/report')
 def report():
     """Get streams report from the RTSP relay.
     ---
@@ -29,18 +28,19 @@ def report():
         description: JSON with error message.
     """
     try:
-        r = requests.get("http://localhost:9997/v1/paths/list")
-        j = r.json()
-        for item in j["items"]:
-            del j["items"][item]["conf"]
-            del j["items"][item]["confName"]
+      r = requests.get("http://localhost:9997/v1/paths/list")
+      j = r.json()
+      for item in j['items']:
+        del j['items'][item]['conf']
+        del j['items'][item]['confName']
 
-        return jsonify(j)
+
+      return jsonify(j)
     except Exception as e:
         return _error_message_json(e.message), 500
 
 
-@app.route("/radio/report")
+@app.route('/radio/report')
 def radio_report():
     """List radio devices available to the system.
     ---
@@ -52,8 +52,7 @@ def radio_report():
     devices = [dict(device) for device in soapy.Device.enumerate()]
     return jsonify(devices)
 
-
-@app.route("/radio/<radio>/connect")
+@app.route('/radio/<radio>/connect')
 def connect(radio):
     """Connect to a radio device, by driver name or serial number.
     ---
@@ -79,15 +78,15 @@ def connect(radio):
         if radio in device.values():
             try:
                 radios[radio] = Radio(radio, device)
-                return jsonify("message", "successfully connected radio"), 200
+                return jsonify("message","successfully connected radio"), 200
             except Exception as e:
                 radios.pop(radio)
                 return _error_message_json(e.message), 500
 
+
     return "Radio device not found", 400
 
-
-@app.route("/radio/<radio>/disconnect")
+@app.route('/radio/<radio>/disconnect')
 def disconnect(radio):
     """Disconnect from a radio device.
     ---
@@ -107,12 +106,11 @@ def disconnect(radio):
     """
     if radio in radios:
         radios.pop(radio)
-        return jsonify("message", "succesfully disconnected radio"), 200
+        return jsonify("message","succesfully disconnected radio"), 200
     else:
         return _error_message_json("Radio not connected"), 400
 
-
-@app.route("/radio/<radio>/configure/<frequency>")
+@app.route('/radio/<radio>/configure/<frequency>')
 def configure(radio, frequency):
     """Tune the radio to a frequency.
     You must connect to the radio before attempting to configure it.
@@ -140,8 +138,7 @@ def configure(radio, frequency):
     else:
         return _error_message_json("Radio not connected"), 400
 
-
-@app.route("/radio/<radio>/start")
+@app.route('/radio/<radio>/start')
 def start_stream(radio):
     """Start the radio stream.
     Once the stream has been started, connect to the stream at:
@@ -154,19 +151,18 @@ def start_stream(radio):
         type: string
         required: true
     responses:
-      200:
+      200: 
         description: JSON with message successful start of radio stream.
       400:
         description: JSON with error message.
     """
     try:
         radios[radio].start_stream()
-        return jsonify("message", "successfully started radio stream"), 200
+        return jsonify("message","successfully started radio stream"), 200
     except Exception as e:
         return _error_message_json(e.message), 400
 
-
-@app.route("/radio/<radio>/end")
+@app.route('/radio/<radio>/end')
 def end_stream(radio):
     """Terminate the radio stream.
     ---
@@ -184,13 +180,12 @@ def end_stream(radio):
     """
     try:
         radios[radio].end_stream()
-        return jsonify("message", "successfully ended radio stream"), 200
+        return jsonify("message","successfully ended radio stream"), 200
     except Exception as e:
         error_message = {"error_message": e.message}
         return _error_message_json(e.message), 400
 
-
-@app.route("/radio/<radio>/info")
+@app.route('/radio/<radio>/info')
 def radio_info(radio):
     """Get information about a radio.
     ---
@@ -214,8 +209,7 @@ def radio_info(radio):
 
 tubes = {}
 
-
-@app.route("/tuuube/<id>/start")
+@app.route('/tuuube/<id>/start')
 def start_tuuube_stream(id):
     """Start streaming from a youtube source.
     Once the stream has been started, connect to the stream at:
@@ -244,12 +238,11 @@ def start_tuuube_stream(id):
 
     try:
         tubes[id].start_stream()
-        return jsonify("message", "successfully started youtube stream"), 200
+        return jsonify("message","successfully started youtube stream"), 200
     except Exception as e:
         return _error_message_json(e.message), 400
 
-
-@app.route("/tuuube/<id>/end")
+@app.route('/tuuube/<id>/end')
 def end_tuuube_stream(id):
     """Terminate the youtube stream.
     ---
@@ -267,42 +260,47 @@ def end_tuuube_stream(id):
     """
     try:
         tubes[id].end_stream()
-        return jsonify("message", "succesfully ended youtube stream"), 200
+        return jsonify("message","succesfully ended youtube stream"), 200
     except Exception as e:
         return _error_message_json(e.message), 400
 
 
+
 """
     Helper function to return a JSON error message
     parameters: error_message - the error message to return
     returns: a JSON object with the error message
     """
-
-
-def _error_message_json(error_message: str):
+def _error_message_json(error_message:str):
     error_message = {"error_message": error_message}
     return jsonify(error_message)
 
-
-if __name__ == "__main__":
+if __name__ == '__main__':
     import subprocess
 
     rtsp_relay = subprocess.Popen(
-        ["./dependencies/mediamtx/mediamtx", "./mediamtx.yml"],
+        [
+            './dependencies/mediamtx/mediamtx',
+            './mediamtx.yml'
+        ],
         stdout=subprocess.DEVNULL,
-        stderr=subprocess.DEVNULL,
+        stderr=subprocess.DEVNULL
     )
 
-    for path, _, files in os.walk("./data/sampleaudio"):
+    for path, _, files in os.walk('./data/sampleaudio'):
         for file in files:
-            name, ext = os.path.splitext(file)
-            if ext == ".mp3":
-                tubes[name] = FileRadio(f"{path}/{file}")
-                tubes[name].start_stream()
+            name,ext = os.path.splitext(file)
+            if ext == '.mp3':
+              tubes[name] = FileRadio(f"{path}/{file}")
+              tubes[name].start_stream()
 
-    app.run(host="0.0.0.0", threaded=True, debug=False)
+    app.run(
+        host='0.0.0.0',
+        threaded=True,
+        debug=False
+    )
 
-    print("Stopping any currently streaming radios...")
+    print('Stopping any currently streaming radios...')
     for radio in radios:
         if radios[radio].is_streaming():
             radios[radio].end_stream()
@@ -313,6 +311,6 @@ if __name__ == "__main__":
             tubes[tube].end_stream()
     tubes = None
 
-    print("Killing RTSP relay...")
+    print('Killing RTSP relay...')
     rtsp_relay.kill()
-    rtsp_relay.wait()  # Necessary?
+    rtsp_relay.wait() # Necessary?

radio.py

@@ -11,8 +11,8 @@ from streamer import Streamer, is_alive
 
 
 class Radio(Streamer):
-    REST_PATH = "radio"
-    FORMAT = "CS16"
+    REST_PATH = 'radio'
+    FORMAT = 'CS16'
     SAMPLES = 8192
 
     def __init__(self, name, device_info):
@@ -33,7 +33,7 @@ class Radio(Streamer):
         frequency = int(prefixed.Float(frequency))
         bandwidth = 200000
 
-        sample_rates = preferred_sample_rates(self.capabilities["rx"]["sample-rates"])
+        sample_rates = preferred_sample_rates(self.capabilities['rx']['sample-rates'])
         if len(sample_rates) == 0:
             raise RuntimeError("No suitable sample rates are available")
         self.sample_rate, self.output_rate = sample_rates[0]
@@ -46,43 +46,41 @@ class Radio(Streamer):
         self.device.setGainMode(soapy.SOAPY_SDR_RX, 0, True)
 
         return {
-            "frequency": self.device.getFrequency(soapy.SOAPY_SDR_RX, 0),
-            "sample-rate": self.device.getSampleRate(soapy.SOAPY_SDR_RX, 0),
-            "bandwidth": self.device.getBandwidth(soapy.SOAPY_SDR_RX, 0),
-            "gain-mode": "auto"
-            if self.device.getGainMode(soapy.SOAPY_SDR_RX, 0)
-            else "manual",
+            'frequency': self.device.getFrequency(soapy.SOAPY_SDR_RX, 0),
+            'sample-rate': self.device.getSampleRate(soapy.SOAPY_SDR_RX, 0),
+            'bandwidth': self.device.getBandwidth(soapy.SOAPY_SDR_RX, 0),
+            'gain-mode': 'auto' if self.device.getGainMode(soapy.SOAPY_SDR_RX, 0) else 'manual',
         }
 
     def get_info(self):
         return {
-            "name": self.name,
-            "device": self.device_info,
-            "capabilities": self.capabilities,
-            "stream-path": self._stream_path(),
-            "streaming": self.is_streaming(),
+            'name': self.name,
+            'device': self.device_info,
+            'capabilities': self.capabilities,
+            'stream-path': self._stream_path(),
+            'streaming': self.is_streaming(),
         }
 
     def _get_capabilities(self):
         def get_direction_capabilities(direction):
             return {
-                "antennas": self.device.listAntennas(direction, 0),
-                "gains": self.device.listGains(direction, 0),
-                "frequencies": self.device.listFrequencies(direction, 0),
-                "sample-rates": self.device.listSampleRates(direction, 0),
-                "bandwidths": self.device.listBandwidths(direction, 0),
-                "sensors": self.device.listSensors(direction, 0),
-                "formats": self.device.getStreamFormats(direction, 0),
+                'antennas': self.device.listAntennas(direction, 0),
+                'gains': self.device.listGains(direction, 0),
+                'frequencies': self.device.listFrequencies(direction, 0),
+                'sample-rates': self.device.listSampleRates(direction, 0),
+                'bandwidths': self.device.listBandwidths(direction, 0),
+                'sensors': self.device.listSensors(direction, 0),
+                'formats': self.device.getStreamFormats(direction, 0),
             }
 
         return {
-            "rx": get_direction_capabilities(soapy.SOAPY_SDR_RX),
-            "tx": get_direction_capabilities(soapy.SOAPY_SDR_TX),
-            "clock-sources": self.device.listClockSources(),
-            "time-sources": self.device.listTimeSources(),
-            "register-interfaces": self.device.listRegisterInterfaces(),
-            "gpios": self.device.listGPIOBanks(),
-            "uarts": self.device.listUARTs(),
+            'rx': get_direction_capabilities(soapy.SOAPY_SDR_RX),
+            'tx': get_direction_capabilities(soapy.SOAPY_SDR_TX),
+            'clock-sources': self.device.listClockSources(),
+            'time-sources': self.device.listTimeSources(),
+            'register-interfaces': self.device.listRegisterInterfaces(),
+            'gpios': self.device.listGPIOBanks(),
+            'uarts': self.device.listUARTs(),
         }
 
     def _stream_thread(self):
@@ -91,7 +89,7 @@ class Radio(Streamer):
         while self.run:
             # Check that the child processes are still running
             if (not is_alive(self.demod)) or (not is_alive(self.playback)):
-                print("DSP chain failed, aborting stream.", file=sys.stderr)
+                print('DSP chain failed, aborting stream.', file=sys.stderr)
                 break
 
             result = self.device.readStream(self.stream, [self.buffer], Radio.SAMPLES)
@@ -101,18 +99,14 @@ class Radio(Streamer):
             elif result.ret < 0:
                 error = SoapyError(result.ret)
                 if error is not SoapyError.Timeout:
-                    print(
-                        "Stream read failed, aborting stream:", error, file=sys.stderr
-                    )
+                    print("Stream read failed, aborting stream:", error, file=sys.stderr)
                     break
                 continue
             else:
                 read_size = int(result.ret * 2)
                 self.demod.stdin.write(
-                    struct.pack(
-                        FORMATS[Radio.FORMAT].packing % read_size,
-                        *self.buffer[:read_size],
-                    )
+                    struct.pack(FORMATS[Radio.FORMAT].packing % read_size,
+                    *self.buffer[:read_size])
                 )
 
         self._cleanup_stream()
@@ -120,44 +114,32 @@ class Radio(Streamer):
     def _init_stream(self):
         self.playback = subprocess.Popen(
             [
-                "/usr/bin/ffmpeg",
-                "-f",
-                "s16le",
-                "-ar",
-                str(self.output_rate),
-                "-ac",
-                "2",
-                "-i",
-                "-",
-                "-f",
-                "rtsp",
-                self.stream_address(),
+                '/usr/bin/ffmpeg',
+                '-f', 's16le',
+                '-ar', str(self.output_rate),
+                '-ac', '2',
+                '-i', '-',
+                '-f', 'rtsp', self.stream_address()
             ],
             stdin=subprocess.PIPE,
             stdout=subprocess.DEVNULL,
-            stderr=subprocess.DEVNULL,
+            stderr=subprocess.DEVNULL
         )
 
         self.demod = subprocess.Popen(
             [
-                "/usr/bin/python3",
-                "fm_demod.py",
-                "-f",
-                "CS16",
-                "-s",
-                str(self.sample_rate),
-                "-d",
-                str(self.output_rate),
+                '/usr/bin/python3', 'fm_demod.py',
+                '-f', 'CS16',
+                '-s', str(self.sample_rate),
+                '-d', str(self.output_rate)
             ],
             stdin=subprocess.PIPE,
             stdout=self.playback.stdin,
-            stderr=subprocess.DEVNULL,
+            stderr=subprocess.DEVNULL
         )
 
         self.buffer = np.array([0] * Radio.SAMPLES * 2, FORMATS[Radio.FORMAT].numpy)
-        self.stream = self.device.setupStream(
-            soapy.SOAPY_SDR_RX, FORMATS[Radio.FORMAT].soapy
-        )
+        self.stream = self.device.setupStream(soapy.SOAPY_SDR_RX, FORMATS[Radio.FORMAT].soapy)
         result = self.device.activateStream(self.stream)
 
         if result != 0:
@@ -182,25 +164,26 @@ class Radio(Streamer):
         self.playback = None
 
 
+
 """
 Quick and dirty test of the Radio class.
 """
-if __name__ == "__main__":
+if __name__ == '__main__':
     import time
 
-    sdr = Radio("demo", {"driver": "sdrplay"})
+    sdr = Radio('demo', {'driver': 'sdrplay'})
 
-    print("Configuring...")
-    sdr.configure("105.5M")
-    print("Configured.")
+    print('Configuring...')
+    sdr.configure('105.5M')
+    print('Configured.')
 
-    print("Starting stream...")
+    print('Starting stream...')
     sdr.start_stream()
-    print("Stream started.")
+    print('Stream started.')
 
     # Let the stream play for a while
     time.sleep(15)
 
-    print("Ending stream...")
+    print('Ending stream...')
     sdr.end_stream()
-    print("Stream ended.")
+    print('Stream ended.')

samplerates.py

@@ -6,7 +6,7 @@ Sample rates stolen from:
     https://en.wikipedia.org/wiki/Sampling_(signal_processing)
 """
 supported_ouput_rates = [
-    8000,  # Telephone, P25 audio (sufficient for speech, some consonants unintelligble)
+    8000,   # Telephone, P25 audio (sufficient for speech, some consonants unintelligble)
     16000,  # Modern telephone/VoIP, good quality speech
     32000,  # FM radio
     44100,  # CD audio quality
@@ -14,10 +14,9 @@ supported_ouput_rates = [
     50000,  # Uncommon but supported
     88200,
     96000,  # DVD/Blu-ray audio
-    192000,  # Too much.
+    192000, # Too much.
 ]
 
-
 def score(pair, target_output=32000, target_ratio=10):
     """
     Heuristic for scoring input & output sample rates. The criteria are:
@@ -37,38 +36,29 @@ def score(pair, target_output=32000, target_ratio=10):
 
     ratio = pair[0] // pair[1]
 
-    return (
-        abs(pair[1] - target_output) / 2500
-        + max(0, target_output - pair[1]) / 2500
-        + abs(ratio - target_ratio) ** 0.8
-        + max(0, target_ratio - ratio) ** 2
-    )
-
+    return abs(pair[1] - target_output)/2500 \
+        + max(0, target_output - pair[1])/2500 \
+        + abs(ratio - target_ratio)**0.8 \
+        + max(0, target_ratio - ratio)**2
 
 def flatten(l):
     return [item for sublist in l for item in sublist]
 
-
 def flatten_dict(d):
-    return [(key, value) for key, rates in d.items() for value in rates]
-
+    return [(key,value) for key,rates in d.items() for value in rates]
 
 def get_pairs(input_rate):
     return [
-        (input_rate, rate) for rate in supported_ouput_rates if (input_rate % rate == 0)
+        (input_rate, rate)
+        for rate in supported_ouput_rates
+        if (input_rate % rate == 0)
     ]
 
-
 def supported_sample_rates(supported_input_rates):
     return {
-        in_rate: [
-            out_rate for out_rate in supported_ouput_rates if in_rate % out_rate == 0
-        ]
+        in_rate: [out_rate for out_rate in supported_ouput_rates if in_rate % out_rate == 0]
         for in_rate in supported_input_rates
     }
 
-
 def preferred_sample_rates(supported_input_rates):
-    return sorted(
-        flatten_dict(supported_sample_rates(supported_input_rates)), key=score
-    )
+    return sorted(flatten_dict(supported_sample_rates(supported_input_rates)), key=score)

soapyhelpers.py

@@ -1,7 +1,6 @@
 import SoapySDR as soapy
 from enum import IntEnum
 
-
 class SoapyError(IntEnum):
     Timeout = soapy.SOAPY_SDR_TIMEOUT
     StreamError = soapy.SOAPY_SDR_STREAM_ERROR
@@ -11,7 +10,6 @@ class SoapyError(IntEnum):
     TimeError = soapy.SOAPY_SDR_TIME_ERROR
     Underflow = soapy.SOAPY_SDR_UNDERFLOW
 
-
 class SoapyFlag(IntEnum):
     EndBurst = soapy.SOAPY_SDR_END_BURST
     HasTime = soapy.SOAPY_SDR_HAS_TIME

streamer.py

@@ -2,7 +2,7 @@ from threading import Thread
 import yaml
 
 
-with open("mediamtx.yml", "r") as config_file:
+with open('mediamtx.yml', 'r') as config_file:
     MEDIASERVER_CONFIG = yaml.safe_load(config_file)
 
 
@@ -11,8 +11,8 @@ def is_alive(subprocess):
 
 
 class Streamer:
-    PROTOCOL = "rtsp"
-    REST_PATH = "stream"
+    PROTOCOL = 'rtsp'
+    REST_PATH = 'stream'
 
     def __init__(self):
         self.run = False
@@ -30,7 +30,7 @@ class Streamer:
 
     def start_stream(self):
         if self.is_streaming():
-            raise RuntimeError("Stream thread is already running")
+            raise RuntimeError('Stream thread is already running')
 
         self.run = True
         self.thread = Thread(target=self._stream_thread, daemon=True, args=())
@@ -38,14 +38,14 @@ class Streamer:
 
     def end_stream(self):
         if self.thread is None:
-            raise RuntimeError("No stream thread to terminate")
+            raise RuntimeError('No stream thread to terminate')
 
         self.run = False
         self.thread.join()
         self.thread = None
 
 
-if __name__ == "__main__":
-    from pprint import pprint
 
-    pprint(MEDIASERVER_CONFIG)
+if __name__ == '__main__':
+    from pprint import pprint
+    pprint(MEDIASERVER_CONFIG)

tuuube.py

@@ -7,7 +7,7 @@ since their release, causing downloads to fail.
 Make sure you use the ./setup.sh script to obtain the latest github release of
 yt_dlp, as this version carries the latest fixes.
 """
-# import youtube_dl
+#import youtube_dl
 import yt_dlp as youtube_dl
 from streamer import Streamer, is_alive
 import subprocess
@@ -17,7 +17,7 @@ import os
 
 
 class Tuuube(Streamer):
-    REST_PATH = "tuuube"
+    REST_PATH = 'tuuube'
 
     def __init__(self, name):
         super().__init__()
@@ -28,51 +28,43 @@ class Tuuube(Streamer):
         return f"/tmp/{self.name}.mp3"
 
     def _stream_thread(self):
-        if not os.path.exists(self.source_path()) or not os.path.isfile(
-            self.source_path()
-        ):
+        if not os.path.exists(self.source_path()) or not os.path.isfile(self.source_path()):
             ydl_opts = {
-                "format": "bestaudio/best",
-                "outtmpl": f"/tmp/{self.name}.%(ext)s", # yt_dlp will append %(ext) if not specified,
-                "postprocessors": [                     # resulting in `/tmp/file.mp3.mp3` :/
-                    {  
-                        "key": "FFmpegExtractAudio",
-                        "preferredcodec": "mp3",
-                        "preferredquality": "192",
-                    }
-                ],
+                'format': 'bestaudio/best',
+                'outtmpl': f'/tmp/{self.name}.%(ext)s',   # yt_dlp will append %(ext) if not specified,
+                'postprocessors': [{                    # resulting in `/tmp/file.mp3.mp3` :/
+                    'key': 'FFmpegExtractAudio',
+                    'preferredcodec': 'mp3',
+                    'preferredquality': '192',
+                }],
             }
 
             try:
                 with youtube_dl.YoutubeDL(ydl_opts) as ydl:
-                    ydl.download([f"https://www.youtube.com/watch?v={self.name}"])
+                    ydl.download([f'https://www.youtube.com/watch?v={self.name}'])
             except Exception as e:
-                print(f"File sourcing failed, aborting stream. {e}", file=sys.stderr)
+                print(f'File sourcing failed, aborting stream. {e}', file=sys.stderr)
                 self.run = False
                 return
 
         self.playback = subprocess.Popen(
             [
-                "/usr/bin/ffmpeg",
-                "-re",
-                "-stream_loop",
-                "-1",
-                "-i",
-                self.source_path(),
-                "-c",
-                "copy",
-                "-f",
-                "rtsp",
-                self.stream_address("localhost"),
+                '/usr/bin/ffmpeg',
+                '-re',
+                '-stream_loop', '-1',
+                '-i', self.source_path(),
+                '-c', 'copy',
+                '-f', 'rtsp',
+                self.stream_address('localhost')
             ],
             stdin=subprocess.PIPE,
             stdout=subprocess.DEVNULL,
-            stderr=subprocess.DEVNULL,
+            stderr=subprocess.DEVNULL
         )
 
         while self.run:
             if not is_alive(self.playback):
-                print("Playback failed, aborting stream.", file=sys.stderr)
+                print('Playback failed, aborting stream.', file=sys.stderr)
                 break
             time.sleep(0.1)
 
@@ -83,10 +75,11 @@ class Tuuube(Streamer):
         self.playback = None
 
 
-if __name__ == "__main__":
-    tube = Tuuube("BaW_jenozKc")
+
+if __name__ == '__main__':
+    tube = Tuuube('BaW_jenozKc')
     tube.start_stream()
 
     while True:
         print(tube.is_streaming())
-        time.sleep(1)
+        time.sleep(1)