def test_saved_spectrogram_keeps_metadata():
# Same issue as the test above
item0 = test_audio_tensor()
DBMelSpec = SpectrogramTransformer(mel=True, to_db=True)
a2s = DBMelSpec(f_max=20000, n_mels=137)
sg = a2s(item0)
with TemporaryFile("wb+") as f:
torch.save(sg, f)
f.seek(0, 0) # Go back to the begining of the file to read
new_sg = torch.load(f)
assert new_sg.sr == item0.sr
def test_spectrograms_right_side_up():
DBMelSpec = SpectrogramTransformer(mel=True, to_db=True)
a2s_5hz = DBMelSpec(
sample_rate=16000,
n_fft=1024,
win_length=1024,
hop_length=512,
f_min=0.0,
f_max=20000,
pad=0,
n_mels=137,
)
sine_5hz = 0.5 * torch.cos(2 * math.pi * 5 * torch.arange(0, 1.0, 1.0 / 16000))
at_5hz = AudioTensor(sine_5hz[None], 16000)
sg_5hz = a2s_5hz(at_5hz)
max_row = sg_5hz.max(dim=1).indices.mode().values.item()
assert max_row < 2
def test_crop_time_with_pipeline(ex_files):
"""
AudioToSpec->CropTime and ResizeSignal->AudioToSpec
will result in same size images
"""
oa = OpenAudio(ex_files)
crop_dur = random.randint(1000, 5000)
DBMelSpec = SpectrogramTransformer(mel=True, to_db=True)
pipe_cropsig = Pipeline(
[oa, DBMelSpec(hop_length=128),
CropTime(crop_dur)])
pipe_cropspec = Pipeline([
oa,
ResizeSignal(crop_dur),
DBMelSpec(hop_length=128),
])
for i in range(4):
_test_eq(pipe_cropsig(i).width, pipe_cropspec(i).width)
def test_load_audio():
item0 = test_audio_tensor()
DBMelSpec = SpectrogramTransformer(mel=True, to_db=True)
a2s = DBMelSpec(f_max=20000, n_mels=137)
sg = a2s(item0)
assert type(item0.data) == torch.Tensor
assert item0.sr == 16000
assert item0.nchannels == 1
assert item0.nsamples == 32000
assert item0.duration == 2
assert sg.f_max == 20000
assert sg.hop_length == 512
assert sg.sr == item0.sr
assert sg.mel
assert sg.to_db
assert sg.nchannels == 1
assert sg.height == 137
assert sg.n_mels == sg.height
assert sg.width == 63
defaults = {
k: v.default
for k, v in inspect.signature(MelSpectrogram).parameters.items()
}
hop_length = 345
a2s = DBMelSpec(f_max=20000, hop_length=hop_length)
sg = a2s(item0)
assert sg.n_mels == defaults["n_mels"]
assert sg.n_fft == 1024
assert sg.shape[1] == sg.n_mels
assert sg.hop_length == hop_length
# test the spectrogram and audio have same duration, both are computed
# on the fly as transforms can change their duration
_close(sg.duration, item0.duration, eps=0.1)