torchaudio.functional.compute_deltas

torchaudio.functional.compute_deltas(specgram: Tensor, win_length: int = 5, mode: str = 'replicate') → Tensor

Compute delta coefficients of a tensor, usually a spectrogram:

$$d_t = \frac{\sum_{n=1}^{\text{N}} n (c_{t+n} - c_{t-n})}{2 \sum_{n=1}^{\text{N}} n^2}$$

where $d_t$ is the deltas at time $t$, $c_t$ is the spectrogram coeffcients at time $t$, $N$ is (win_length-1)//2.

Parameters:

• specgram (Tensor) – Tensor of audio of dimension (…, freq, time)

• win_length (int, optional) – The window length used for computing delta (Default: 5)

• mode (str, optional) – Mode parameter passed to padding (Default: "replicate")

Returns:

Tensor of deltas of dimension (…, freq, time)

Return type:

Tensor

Example

>>> specgram = torch.randn(1, 40, 1000)
>>> delta = compute_deltas(specgram)
>>> delta2 = compute_deltas(delta)