def test_can_gain_subtractive():
audio = Audio.load_tone(20, 50, 'square', 50)
assert audio.data[0] == 1.0
audio2 = audio.gain(0.3, 'subtractive')
assert isinstance(audio, Audio)
assert audio2.data[0] == 0.7
def test_pitch_shift_plus_one():
''' Raise the pitch of the whole audio file, one tone '''
sample_rate = 250000
samples = sample_rate * 1
tone = Audio.load_tone(20, samples, 'square',
sample_rate=sample_rate).pitch_shift(1)
assert tone is not None, 'Pitch shift failed'
def test_can_gain_multiply():
audio = Audio.load_tone(20, 50, 'square', 50)
assert audio.data[0] == 1.0
audio2 = audio.gain(0.5, 'multiply')
assert isinstance(audio, Audio)
assert audio2.data[0] == 0.5
def test_can_load_tone_square():
freq = 2 # Hz
sample_rate = 50
samples = sample_rate
audio = Audio.load_tone(freq, samples, 'square', sample_rate)
assert isinstance(audio, Audio)
assert len(audio.data) == samples
assert audio.data[1] == 1.0
def test_time_stretch_half_time():
''' Causes the audio to play back twice as slow as its current speed '''
sample_rate = 250000
samples = sample_rate * 1
tone = Audio.load_tone(20, samples, 'square',
sample_rate=sample_rate).time_stretch(0.5)
assert tone is not None, 'Time stretch failed'
assert tone.data.shape[0] == samples / 0.5
def test_pitch_shift_minus_one():
''' Drop the pitch of the whole audio file, one tone '''
sample_rate = 250000
samples = sample_rate * 1
tone = Audio.load_tone(20, samples, 'square',
sample_rate=sample_rate).pitch_shift(-1)
assert tone is not None, 'Time stretch failed'
assert tone.data.shape[0] == samples
def test_can_load_tone_sawtooth():
freq = 2 # Hz
sample_rate = 50
samples = sample_rate
audio = Audio.load_tone(freq, samples, 'sawtooth', sample_rate)
assert isinstance(audio, Audio)
assert len(audio.data) == samples
assert audio.data[0] == -1.0
def test_spectrogram_256():
n_fft = 256
sample_rate = 250000
samples = sample_rate * 1
spectrogram = Audio.load_tone(
20, samples, 'sine', sample_rate).get_spectrogram_array(n_fft=n_fft)
spectrogram = to_uint8(spectrogram)
assert spectrogram.shape[0] == (n_fft / 2) + 1, 'spectrogram height'
assert spectrogram.shape[1] == int(
samples * 2 / n_fft) + 1, 'spectrogram width'
assert np.array([
all(0 <= y <= 255 for y in x) for x in spectrogram
]).all(), f'range check {spectrogram} failed. Expected all values 0-255'
def test_mel_spectrogram_256():
n_fft = 256
hop_length = 128
n_mels = 60
sample_rate = 384000
samples = sample_rate * 1
spectrogram = Audio.load_tone(20, samples, 'sine',
sample_rate).get_mel_spectrogram_array(
n_fft=n_fft,
n_mels=n_mels,
hop_length=hop_length)
spectrogram = to_uint8(spectrogram)
print(spectrogram.shape)
assert spectrogram.shape[0] == n_mels, 'spectrogram height'
assert spectrogram.shape[1] == int(
samples * 2 / n_fft) + 1, 'spectrogram width'
assert np.array([
all(0 <= y <= 255 for y in x) for x in spectrogram
]).all(), f'range check {spectrogram} failed. Expected all values 0-255'
