utils#
- pytsmod.utils._validate_audio(audio)#
validate the input audio and modify the order of channels.
- Parameters
- audionumpy.ndarray [shape=(channel, num_samples) or (num_samples) or (num_samples, channel)]
the input audio sequence to validate.
- Returns
- audionumpy.ndarray [shape=(channel, num_samples)]
the validataed output audio sequence.
- pytsmod.utils._validate_scale_factor(audio, s)#
Validate the scale factor s and convert the fixed scale factor to anchor points.
- Parameters
- audionumpy.ndarray [shape=(num_channels, num_samples) or (num_samples) or (num_samples, num_channels)]
the input audio sequence.
- snumber > 0 [scalar] or numpy.ndarray [shape=(2, num_points) or (num_points, 2)]
the time stretching factor. Either a constant value (alpha) or an (2 x n) (or (n x 2)) array of anchor points which contains the sample points of the input signal in the first row and the sample points of the output signal in the second row.
- Returns
- anc_pointsnumpy.ndarray [shape=(2, num_points)]
anchor points which contains the sample points of the input signal in the first row and the sample points of the output signal in the second row.
- pytsmod.utils.win(win_type='hann', win_size=4096, zero_pad=0)#
Generate diverse type of window function
- Parameters
- win_typestr
the type of window function. Currently, Hann and Sin are supported.
- win_sizeint > 0 [scalar]
the size of window function. It doesn’t contains the length of zero padding.
- zero_padint > 0 [scalar]
the total length of zero-pad. Zeros are equally distributed for both left and right of the window.
- Returns
- winnumpy.ndarray([shape=(win_size)])
the window function generated.
- pytsmod.utils.stft(x, ana_hop=2048, win_type='hann', win_size=4096, zero_pad=0, sr=44100, fft_shift=0, time_frequency_out=False)#
Short-Time Fourier Transform (STFT) for the audio signal. This function is used for phase vocoder.
- Parameters
- xnumpy.ndarray [shape=(num_samples)]
the input audio sequence. Should be a single channel.
- ana_hopint > 0 [scalar] or numpy.ndarray [shape=(num_frames)]
either a analysis hop size (scalar) or analyze window positions (array).
- win_typestr
type of the window function for the STFT. hann and sin are available.
- win_sizeint > 0 [scalar]
size of the window function.
- zero_padint > 0 [scalar]
the size of the zero pad in the window function.
- srint > 0 [scalar]
the sample rate of the audio sequence. Only used for time_frequency_out.
- fft_shiftbool
apply circular shift to STFT.
- time_frequency_outbool
returns time and frequency axis indices in (spec, t, f).
- Returns
- specnumpy.ndarray [shape=(win_size // 2 + 1, num_frames)]
the STFT result of the input audio sequence.
- tnumpy.ndarray [shape=num_frames]
timestamp of the output result.
- fnumpy.ndarray [shape=win_size // 2 + 1]
frequency value for each frequency bin of the output result.
- pytsmod.utils.istft(spec, syn_hop=2048, win_type='hann', win_size=4096, zero_pad=0, num_iter=1, original_length=- 1, fft_shift=False, restore_energy=False)#
Inverse Short-Time Fourier Transform to recover the audio signal from the spectrogram. This function is used for phase vocoder.
- Parameters
- Xnumpy.ndarray [shape=(num_bins, num_frames)]
the input audio complex spectrogram.
- syn_hopint > 0 [scalar]
the hop size of the synthesis window.
- win_typestr
type of the window function for the ISTFT. hann and sin are available.
- win_sizeint > 0 [scalar]
size of the window function.
- zero_padint > 0 [scalar]
the size of the zero pad in the window function.
- num_iterint > 0 [scalar]
the number of iterations the algorihm should perform to adapt the phase.
- original_lengthint > 0 [scalar]
original length of the audio signal.
- fft_shiftbool
apply circular shift to ISTFT.
- restore_energybool
tries to reserve potential energy loss.
- Returns
- ynumpy.ndarray [shape=(original_length)]
the output audio sequence.
- pytsmod.utils.lsee_mstft(X, syn_hop, win_type, win_size, zero_pad, fft_shift, restore_energy)#
Least Squares Error Estimation from the MSTFT (Modified STFT). Griffin-Lim procedure to estimate the audio signal from the modified STFT.
- Parameters
- Xnumpy.ndarray [shape=(num_bins, num_frames)]
the input audio complex spectrogram.
- syn_hopint > 0 [scalar]
the hop size of the synthesis window.
- win_typestr
type of the window function for the ISTFT. hann and sin are available.
- win_sizeint > 0 [scalar]
size of the window function.
- zero_padint > 0 [scalar]
the size of the zero pad in the window function.
- fft_shiftbool
apply circular shift to ISTFT.
- restore_energybool
tries to reserve potential energy loss.
- Returns
- xnumpy.ndarray [shape=num_samples]
the output audio sequence through LSEE_MSTFT
- pytsmod.utils._validate_f0(audio, f0)#
Validate the input f0 is suitable for input audio.
- Parameters
- audionumpy.ndarray [shape=(num_channels, num_samples) or (num_samples) or (num_samples, num_channels)]
the input audio sequence.
- f0numpy.ndarray [shape=(num_channels, num_pitches) or (num_pitches) or (num_pitches, num_channels)]
the f0 sequence that used for TD-PSOLA. If f0 is 1D array, the f0 of all audio channels are regarded as the same f0.
- Returns
- f0numpy.ndarray [shape=(num_channels, num_freqs)]
the f0 sequence that used for TD-PSOLA.